ACTA GEOGRAPHICA SLOVENICA GEOGRAFSKIZBORNIK 2024 64 2 0101661851779 ISSN 1581-6613 A C TA G E O G R A P H IC A S LO V E N IC A • G E O G R A FS K I Z B O R N IK • 64 -2 • 20 24ACTA GEOGRAPHICA SLOVENICA GEOGRAFSKI ZBORNIK 64-2 • 2024 Contents Matej Lipar, Sonja Lojen, Mateja Breg VaLjaVec, Maja andrič, andrej ŠMuc, Tom LeVanič, jure Tičar, Matija Zorn, Mateja Ferk Holocene climate variability in Slovenia: A review 7 HOLOCENE CLIMATE VARIABILITY IN SLOVENIA: A REVIEW GEOSCAPES 4 naslovnica 64-2_naslovnica 49-1.qxd 16.5.2024 13:12 Page 1 ACTA GEOGRAPHICA SLOVENICA GEOGRAFSKIZBORNIK 2024 64 2 0101661851779 ISSN 1581-6613 A C TA G E O G R A P H IC A S LO V E N IC A • G E O G R A FS K I Z B O R N IK • 64 -2 • 20 24ACTA GEOGRAPHICA SLOVENICA GEOGRAFSKI ZBORNIK 64-2 • 2024 Contents Matej Lipar, Sonja Lojen, Mateja Breg VaLjaVec, Maja andrič, andrej ŠMuc, Tom LeVanič, jure Tičar, Matija Zorn, Mateja Ferk Holocene climate variability in Slovenia: A review 7 HOLOCENE CLIMATE VARIABILITY IN SLOVENIA: A REVIEW GEOSCAPES 4 naslovnica 64-2_naslovnica 49-1.qxd 16.5.2024 13:12 Page 1 ACTA GEOGRAPHICA SLOVENICA 64-2 2024 ISSN: 1581-6613 UDC: 91 2024, ZRC SAZU, Geografski inštitut Antona Melika International editorial board/mednarodni uredniški odbor: Zoltán Bátori (Hungary), David Bole (Slovenia), Marco Bontje (the Netherlands), Mateja Breg Valjavec (Slovenia), Michael Bründl (Switzerland), Rok Ciglič (Slovenia), Špela Čonč (Slovenia), Lóránt Dénes Dávid (Hungary), Mateja Ferk (Slovenia), Matej Gabrovec (Slovenia), Matjaž Geršič (Slovenia), Maruša Goluža (Slovenia), Mauro Hrvatin (Slovenia), Ioan Ianos (Romania), Peter Jordan (Austria), Drago Kladnik (Slovenia), Blaž Komac (Slovenia), Jani Kozina (Slovenia), Matej Lipar (Slovenia), Dénes Lóczy (Hungary), Simon McCarthy (United Kingdom), Slobodan B. Marković (Serbia), Janez Nared (Slovenia), Cecilia Pasquinelli (Italy), Drago Perko (Slovenia), Florentina Popescu (Romania), Garri Raagmaa (Estonia), Ivan Radevski (North Macedonia), Marjan Ravbar (Slovenia), Aleš Smrekar (Slovenia), Vanya Stamenova (Bulgaria), Annett Steinführer (Germany), Mateja Šmid Hribar (Slovenia), Jure Tičar (Slovenia), Jernej Tiran (Slovenia), Radislav Tošić (Bosnia and Herzegovina), Mimi Urbanc (Slovenia), Matija Zorn (Slovenia), Zbigniew Zwolinski (Poland) Editors-in-Chief/glavna urednika: Rok Ciglič, Blaž Komac (ZRC SAZU, Slovenia) Executive editor/odgovorni urednik: Drago Perko (ZRC SAZU, Slovenia) Chief editors/področni urednik (ZRC SAZU, Slovenia): • physical geography/fizična geografija: Mateja Ferk, Matej Lipar, Matija Zorn • human geography/humana geografija: Jani Kozina, Mateja Šmid Hribar, Mimi Urbanc • regional geography/regionalna geografija: Matej Gabrovec, Matjaž Geršič, Mauro Hrvatin • regional planning/regionalno planiranje: David Bole, Janez Nared, Maruša Goluža • environmental protection/varstvo okolja: Mateja Breg Valjavec, Jernej Tiran, Aleš Smrekar Editorial assistants/uredniška pomočnika: Špela Čonč, Jernej Tiran (ZRC SAZU, Slovenia) Journal editorial system manager/upravnik uredniškega sistema revije: Jure Tičar (ZRC SAZU, Slovenia) Issued by/izdajatelj: Geografski inštitut Antona Melika ZRC SAZU Published by/založnik: Založba ZRC Co-published by/sozaložnik: Slovenska akademija znanosti in umetnosti Address/naslov: Geografski inštitut Antona Melika ZRC SAZU, Gosposka ulica 13, p. p. 306, SI – 1000 Ljubljana, Slovenija; ags@zrc-sazu.si The articles are available on-line/prispevki so dostopni na medmrežju: http://ags.zrc-sazu.si (ISSN: 1581–8314) This work is licensed under the/delo je dostopno pod pogoji: Creative Commons CC BY-NC-ND 4.0 Ordering/naročanje: Založba ZRC, Novi trg 2, p. p. 306, SI – 1001 Ljubljana, Slovenija; zalozba@zrc-sazu.si Annual subscription/letna naročnina: 20 € Single issue/cena posamezne številke: 12 € Cartography/kartografija: Geografski inštitut Antona Melika ZRC SAZU Translations/prevodi: DEKS, d. o. o., Živa Malovrh DTP/prelom: SYNCOMP, d. o. o. Printed by/tiskarna: Birografika Bori Print run/naklada: 250 copies/izvodov The journal is subsidized by the Slovenian Research and Innovation Agency (B6-7326) and is issued in the framework of the Geography of Slovenia core research programme (P6-0101)/Revija izhaja s podporo Javne agencije za znanstvenoraziskovalno in inovacijsko dejavnost Republike Slovenije (B6-7326) in nastaja v okviru raziskovalnega programa Geografija Slovenije (P6-0101). The journal is indexed also in/revija je vključena tudi v: Clarivate Web of Science (SCIE – Science Citation Index Expanded; JCR – Journal Citation Report/Science Edition), Scopus, ERIH PLUS, GEOBASE Journals, Current geographical publications, EBSCOhost, Georef, FRANCIS, SJR (SCImago Journal & Country Rank), OCLC WorldCat, Google Scholar, CrossRef, and DOAJ. Design by/Oblikovanje: Matjaž Vipotnik Front cover photography: Alpine landscapes contain many traces of past conditions, which are also recorded in tree rings (photograph: Matej Lipar). Fotografija na naslovnici: Alpske pokrajine hranijo številne sledi preteklih razmer, ki so zapisane tudi v letnicah dreves (fotografija: Matej Lipar). 64-2-uvod_uvod49-1.qxd 16.5.2024 13:11 Page 4 Acta geographica Slovenica, 64-2, 2024, 7–40 HOLOCENE CLIMATE VARIABILITY IN SLOVENIA: A REVIEW Matej Lipar, Sonja Lojen, Mateja Breg Valjavec, Maja Andrič, Andrej Šmuc, Tom Levanič, Jure Tičar, Matija Zorn, Mateja Ferk Forest vegetation changes are direct evidence of climatic variability. M AT E J LI PA R 64-2_acta49-1.qxd 16.5.2024 13:11 Page 7 Holocene climate variability in Slovenia: A review DOI: https://doi.org/10.3986/AGS.12798 UDC: 551.583.7(497.4)”628.64” Creative Commons CC BY-NC-ND 4.0 Matej Lipar1, Sonja Lojen2,3, Mateja Breg Valjavec1, Maja Andrič4, Andrej Šmuc5, Tom Levanič6, Jure Tičar1, Matija Zorn1, Mateja Ferk1 Holocene climate variability in Slovenia: A review ABSTRACT: The Slovenian climate has undergone significant fluctuations, and an understanding of the past climate is necessary to improve models and recognise long-term patterns. The cryosphere environment, such as ice core samples, provides valuable palaeoclimate data. Palynology and dendroclimatology are also effec- tive ways to study long-term changes in vegetation and reconstruct past climates using pollen and tree proxies. Sediment cores from various locations in Slovenia have been studied to understand past environmental changes. Borehole temperature profiles as well as historical records were also used to reconstruct past climate condi- tions. Studies have shown specific periods when climatic changes likely played a major role, but a complete timeline of the Slovenian climate throughout the Holocene has not yet been fully developed. KEYWORDS: palaeoclimate, climate proxy, glaciers, pollen, tree-rings, sediment, speleothems, historical data Holocenska podnebna spremenljivost v Sloveniji: pregled POVZETEK: Podnebje v Sloveniji je doživljalo velika nihanja in razumevanje preteklega podnebja je nujno za izboljšanje modelov in prepoznavanje dolgoročnih vzorcev. Kriosferno okolje, kot so vzorci ledenih jeder, zagotavlja dragocene paleopodnebne podatke. Tudi palinologija in dendroklimatologija sta učinkovita načina za preučevanje dolgoročnih sprememb rastja in rekonstrukcijo preteklega podnebja z uporabo analiz cvet- nega prahu in drevesnih branik. Sedimentna jedra z različnih lokacij v Sloveniji so bila preučena za razumevanje preteklih okoljskih sprememb. Za rekonstrukcijo preteklih podnebnih razmer so bili uporabljeni tudi temperature v vrtinah in zgodovinski viri. Študije so pokazale določena obdobja, v katerih so podnebne spremembe najverjetneje imele pomembno vlogo, vendar celotna časovnica sprememb slovenskega pod- nebja v holocenu še ni popolnoma izdelana. KLJUČNE BESEDE: paleopodnebje, podnebni podatki, ledenik, cvetni prah, branike, sediment, siga, zgodovinski podatki The article was submitted for publication on June 12th, 2023. Uredništvo je prejelo prispevek 12. junija 2023. 8 1 Research Centre of the Slovenian Academy of Sciences and Arts, Anton Melik Geographical Institute, Ljubljana, Slovenia matej.lipar@zrc-sazu.si (https://orcid.org/0000-0003-4414-0147), mateja.breg@zrc-sazu.si (https://orcid.org/0000-0002-7581-758X), jure.ticar@zrc-sazu.si (https://orcid.org/0000-0003-3567-8084), matija.zorn@zrc-sazu.si (https://orcid.org/0000-0002-5788-018X), mateja.ferk@zrc-sazu.si (https://orcid.org/0000-0003-0145-7590) 2 Jožef Stefan Institute, Department of Environmental Sciences, Ljubljana, Slovenia 3 University of Nova Gorica, School of Environmental Sciences, Nova Gorica, Slovenia sonja.lojen@ijs.si (https://orcid.org/0000-0001-8267-4372) 4 Research Centre of the Slovenian Academy of Sciences and Arts, Institute of Archaeology, Ljubljana, Slovenia maja.andric@zrc-sazu.si (https://orcid.org/0000-0003-1211-7081) 5 University of Ljubljana, Faculty of Natural Science and Engineering, Department of Geology, Ljubljana, Slovenia andrej.smuc@ntf.uni-lj.si (https://orcid.org/0000-0002-7883-4676) 6 Slovenian Forestry Institute, Ljubljana, Slovenia tom.levanic@gozdis.si (https://orcid.org/0000-0002-0986-8311) 64-2_acta49-1.qxd 16.5.2024 13:11 Page 8 1 Introduction The climate has constantly changed during Earth’s different geologic ages, and over the last two and a half million years of the Quaternary period (Gibbard and Head 2020) the climate has periodically oscillated between cold and warm episodes referred to as glacial and interglacial periods. We are currently experi- encing climate variabilities of the warm interglacial period, also termed the Holocene epoch. The modern climate is monitored by various agencies (e.g., the Global Observing System of the World Meteorological Organization, the International Telecommunication Union (ITU), and the European Earth Observation Programme as part of the Copernicus Programme), and climate variability and changes in Slovenia are monitored by the Slovenian Environment Agency. However, reliable data only span approx- imately 80 years, and to increase the reliability of models for major and minor climate variabilities, knowledge of climate variability in Slovenia in the past is needed. Holocene climate variabilities provide robustness of short-term climate events and are therefore essential for accurate predictions of future climate variabilities, including the environmental response to these changes. How the climate has evolved on a global scale dur- ing the Holocene is controversial due to large amounts of opposing palaeoclimate data from a variety of regions (e.g., Jiang et al. 2012; Marcott et al. 2013; Liu et al. 2014; Marsicek et al. 2018; Affolter et al. 2019); however, this also suggests that many palaeoclimate peculiarities and events occurred on a regional scale, and our understanding of recent climate variabilities should thus rely more on local evidence (Mayewski et al. 2004; Thornton et al. 2014; Wake 2015). There are four main types of climate in Slovenia: a temperate humid climate in the west; a temperate continental climate in the central and eastern part; a mountain climate in the mountain areas of north- western, northern, and part of southern Slovenia; and a sub-Mediterranean climate in the southwest (Komac, Pavšek and Topole 2020). This climate diversity would require climate reconstructions for different climate types to produce a reliable picture of the past climate of Slovenia. Nevertheless, since the reconstructions and interpretations of climate variabilities throughout the entire Holocene for the Slovenian territory are scarce, this article summarises all of them together. The Holocene data for Slovenia come from a variety of disciplines, spanning from cryosphere (Section 2.1) to geological analyses of clastic sediments (Section 2.2), palynology (Section 2.3), dendrochronology (Section 2.4), speleothems (Section 2.5), and historical sources (Section 2.7). This article reviews up-to- date interpretations of climate variability in Slovenia during the Holocene until the beginning of modern instrumental records based on studies of the Slovenian territory, collates climate data from various prox- ies, and subsequently highlights the gaps in the existing literature and promotes further research. To make the timeline and dates of events consistent, we report them in kiloyears (ka) before present (BP); very recent (and mostly historical) events in the last millennium are given in years Anno Domini (AD). 1.1 The Holocene The Holocene epoch (11.65 ka to present; the names comes from Greek ὅλος, holos ‘entirely’ + καινός, kain- os ‘new’ because preserved fossils from this epoch are of species not predating Homo sapiens; Gervais 1847), together with the preceding Pleistocene epoch (2.58 million years (Ma) to 11.65 ka BP; the name comes from Greek πλεĩστος, pleistos ‘mostly’ + καινός, kainos ‘new’; Lyell 1839), is part of the Quaternary (the name comes from Latin quaternarius ‘consisting of four parts’ because it is the fourth and final subdivi- sion of the previously proposed threefold subdivision of the geological record (Primary, Secondary and Tertiary; Desnoyers 1829; Walker et al. 2019; Head, Pillans and Zalasiewicz 2021). The Holocene was ini- tiated by the changes in insolation due to the eccentricity of Earth’s orbit, and obliquity and precession of Earth’s axis, termed Milankovitch cycles (Berger 1988; Hobart et al. 2023; Watanabe et al. 2023). The addi- tional variability of hydrological and temperature conditions during the Holocene is attributed to solar variability, volcanic aerosols, changes in air circulation, changes in the extent of continental ice, and green- house gas concentrations (Mayewski et al. 2004; Brayshaw, Hoskins and Black 2010; Brayshaw, Rambeau and Smith 2011). Sea surface warming started around 17–20 ka in Antarctica (Rahmstorf 2002), whilst the apparent warming in the Northern Hemisphere (Greenland) was detected 14.6 ka ago, with the delay most likely due to ocean currents (Gregoire et al. 2016). The initial warming was interrupted by the cold Younger Dryas event, which ended around 11.65 ka, marking the formal beginning of the Holocene (Walker et al. 2009; 2019). Acta geographica Slovenica, 64-2, 2024 9 64-2_acta49-1.qxd 16.5.2024 13:11 Page 9 Holocene climate variability in Slovenia: A review The currently adopted formal subdivision of the Holocene, ratified by the Executive Committee of the International Union of Geological Sciences (IUGS) on June 14th, 2018, is based on the universal use of geochronology constrained by a series of geochronometric methods (Walker et al. 2019; Head, Pillans and Zalasiewicz 2021). It starts with the oldest Greenlandian (Global Stratotype Section and Point (GSSP) in the North Greenland Ice Core Project ice core 2 (NGRIP2); corresponding to the Lower/Early Holocene) dated at 11.65ka. Climate records from the Greenland area show very rapid warming, even exceeding 10°C in a decade or two (Alley 2000). The second is the Northgrippian (GSSP in the Greenland ice core 1, NGRIP1; corre- sponding to the Middle Holocene), dated to 8.186 ka. The last is the Meghalayan (GSSP in a speleothem from the Mawmluh Cave, northeastern India; corresponding to the Upper/Late Holocene), with a date of 4.2 ka. Based on climate variability, the Holocene is also characterized by a variety of »periods« of global, hemi- spheric, or regional extent. For example, Mayewski et al. (2004) presented six global periods of significant Rapid Climate Change (RCC) during the Holocene, driven by Earth’s orbital variations, solar variability, and potentially to some extent by volcanic aerosol production, causing polar cooling, tropical aridity, and major atmospheric circulation changes during 9–8ka, 6–5ka, 4.2–3.8ka, 3.5–2.5ka, 1.2–1ka, and 0.6–0.15ka. »Cold« periods were also identified based on regional and/or individual data-dependent studies; for exam- ple, the Misox (8.4–7.3 ka), Frosnitz (7.2–6.8 ka), and Rotmoos (6.3–5.0 ka) oscillations identified by pollen data (Zoller 1960; Patzelt and Bortenschlager 1973; Ivy-Ochs et al. 2009). The most recent cool-climate ano- maly is the so-called Little Ice Age (LIA) between the Late Middle Ages and the mid-19th century (Grove 2004; Nussbaumer et al. 2011). The LIA can be subdivided into an early (AD 1260–1380), intermediate (AD 1380–1575), and main (AD 1575–1860) phase (Nicolussi et al. 2022). Shorter colder periods within the LIA are also known; for example, the Maunder Minimum of solar activity (AD 1645–1715; Eddy 1983). A number of »warm« periods have also been identified; for example, the Holocene Climatic Optimum (HCO), a period of high insolation and generally warmer-than-present climate between 11 and 5ka (Renssen et al. 2009; Solomina et al. 2015). Recent warmer periods are also the Minoan Warm Period with a peak around 3.3 ka, the Roman Warm Period around 2 ka, and the Medieval Warm Period about 1ka (Easterbrook 2016). According to the Intergovernmental Panel on Climate Change (IPCC), we are currently experienc- ing the first human-induced global warming (IPCC 2018). Following the Holocene subdivisions and periods, the Holocene has also been subject to short-term climatic changes, so-called »events«. The cooling 9.3 ka climatic event was probably caused by meltwater pulses to the Atlantic Ocean (Brynjólfsson et al. 2015). The 8.2 ka event briefly interrupted the trend of global warming with sudden strong cooling, attributed to the temporary weakening or disruption of the Gulf Stream caused by the spilling of huge amounts of melted ice into the North Atlantic (Thomas et al. 2007; Matero et al. 2017). The 4.2 ka event was characterised by dry and cool climatic conditions and has been accepted as the formal boundary of Northgrippian and Meghalayan, yet its exact origin remains con- troversial (Bini et al. 2019; Isola et al. 2019; Ran and Chen 2019). The latest 2.8 ka cold event is thought to have been driven by a grand solar minimum, with potential impacts on atmospheric dynamics and hydrol- ogy across the globe (Park et al. 2019; Harding et al. 2020). 2 Records of the Holocene climate in Slovenia Most palaeoclimate analyses rely on indirect methods based on analyses of a variety of media from geo- logical, chemical, biological, and historical archives (Hardy 2003; IPCC 2007; Ruddiman 2014). The following subsections are divided based on the media or environments characterised by particular types of media relevant to the Slovenian territory. 2.1 Cryosphere The cryosphere environment, including glaciers, ice sheets, sea and lake ice, and even seasonal snow cover, provides a number of possibilities to extract palaeoclimate data. Some of the most important ice cores on a global scale were drilled in the thick ice sheets of Antarctica and Greenland, where the 10 Figure 1: Relevant localities in Slovenia where palaeoclimate studies were done. p p. 11 64-2_acta49-1.qxd 16.5.2024 13:11 Page 10 A cta geographica Slovenica, 64-2, 2024 11 A u s t r i a C r o a t i a I t a l y H u n g a r y ± Cartography: Jure Tičar © ZRC SAZU Anton Melik Geographical Institute Historical evidence site Cave sediment site Dendrochronology site Palynology site Clastic sediment site Cryosphere site Legend 0 5 10 20 30 40 50 km © ZRC SAZU AnTon MELIk GEoGRAPhICAL InSTITUTE 6 4 -2 _ a c ta 4 9 -1 .q x d 1 6 .5 .2 0 2 4 1 3 :1 1 P a g e 1 1 Holocene climate variability in Slovenia: A review slow and continuous accumulation of ice over thousands or even millions of years provides an impor- tant interconnected palaeoclimate archive. The European Project for Ice Coring in Antarctica (EPICA), for example, has obtained a climate record for the past 740,000 years (Augustin et al. 2004), but stratigraphical sections spanning more than 2 Ma have also been found, and some are still being evaluated (Higgins et al. 2015; Kehrl et al. 2018). Reconstruction of the palaeoclimate can be based on the thickness of individual ice layers, seasonal stratigraphy and isotopic composition of ice, abundance and molecular composition of gas inclusions (CO2, CH4, and N2O) and dust particles (Hammer 2006; Jansen et al. 2007; Lemieux- Dudon et al. 2010). For dating the uppermost layers of ice, counting annual layers is usually used, whilst for deeper (recrystallised) ice, radiometric dating of mineral and/or organic dust combined with geochemical markers and/or cosmogenic isotopes, firn densification modeling, and wiggle matching of ice core records to insolation time series are used (Lemieux-Dudon et al. 2010). Palaeoclimate modelling based on ice cores has also been done on ice cores retrieved from Alpine glaciers (e.g., Schwikowski et al. 1999), small glacieretes (e.g., Grunewald and Scheithauer 2010), and ice accumulated in natural caves (e.g., May et al. 2011). Climate change also directly affects the extent of ice sheets and glaciers. Indirectly, their occurrence in individual time periods can be inferred from the dating of moraines and formerly glaciated areas (Stroeven et al. 2006). Whilst the Pleistocene glaciation played an important role in the transformation of the landscape in Slovenia (Gabrovec and Hrvatin 1998; Bavec and Verbič 2004; 2011; Ferk et al. 2015), only two remnants of glaciers persist in the present: the ice masses of the Triglav Glacier and the Skuta Glacier (Gabrovec et al. 2014; Zorn et al. 2020; 2020b; Figure 1). The Triglav Glacier is located below the peak of Mount Triglav (2,864 m) extending between 2,430 and 2,500 m in elevation and measuring around 0.7 hectares in size with a maximum thickness of around 5.5 m in 2002 (Gabrovec et al. 2013; 2014; Del Gobbo et al. 2016; Štok 2022). The Skuta Glacier is located below the peaks of Mount Skuta (2,532 m) and Mount Kranjska Rinka (2,453 m); it extends between 2,020 and 2,120 m in elevation and covers an area of about 1.5 hectares with a maximum thickness of around 7 m (Pavšek 2007; Triglav Čekada et al. 2020). Ice core data were obtained from the remaining ice masses of the Triglav and Skuta glaciers in 2022 to provide information about the Holocene palaeoclimate, but the investigation is still ongoing. Systematic monitoring of the ice masses began shortly after the Second World War, and since the mid-1950s (Gabrovec et al. 2014) they have taken place together with systematic meteorological measurements on Mount Kredarica (2,515 m) next to the Triglav Glacier. Both data sets reflect the recent trend of climate warming (Hrvatin and Zorn 2020), but direct climate measurements are undeniably more reliable than modelling from prox- ies. Nevertheless, monitoring of ice masses provides valuable data on the interaction between climate and ice in recent (monitored) climate variabilities. Archival imagery (Triglav Čekada, Zorn and Colucci 2014) of the Triglav Glacier shows its great extent and consequently indicate the presence of the LIA (i.e., colder climate conditions) in this area (Figure 2) at the end of the 19th century. Colucci and Žebre (2016) analysed the system of frontal moraine ridges of the Triglav Glacier identified by Šifrer (1963) and proposed that it was formed during the LIA; they con- sequently calculated the extent of the glacier to be about 44.2 hectares (compared to 0.7 hectares in 2022; Pavšek 2023) with a volume of 13.83 km³ (compared to 2.455 m³; i.e., 2.455 × 10−9 km³ in 2022; Pavšek 2023). The presence of the LIA glacier extent could be also expressed by the moraine ridges in the Upper Krnica Valley (Kozamernik et al. 2018), but this is also uncertain due to the absence of ages of moraine ridges. The radiocarbon (14C) analysis of the organic material sourced from a non-vegetated moraine located approx- imately 500 m below the present-day ice mass of the Triglav Glacier (as observed in 2022) produced an age range of 5.6 to 5.4 ka, indicating the extent of the glacier at that time similar to the LIA period and possibly suggesting another period of apparent colder climate (unpublished research conducted by Karsten Grunewald and associates; Lipar et al. 2021). Subglacial carbonate deposits collected downward from the current extent of the Triglav Glacier sug- gest the presence of ice mass in this area throughout the Holocene, but it is unclear whether the HCO was not so pronounced in this area that it would have caused melting of ice mass to the present extent, or whether there are other factors that were not present in the past that are accelerating melting (Lipar et al. 2021). 12 Figure 2: Vertical profile of the Triglav Glacier with approximate extent of the glacier around 5.6–5.4 ka, in the LIA, in 1950, and in 2022. p p. 13 64-2_acta49-1.qxd 16.5.2024 13:11 Page 12 A cta geographica Slovenica, 64-2, 2024 13 0 500 1,000 1,500 2,200 2,400 2,600 2,800 2,000 m m a .s. l. LIA5.6-5.4 ka 19502022 Mount Triglav (2864 m) Glava (2426 m) Triglav North Face 5.6-5.4 ka Triglav Sha! Upper Triassic massive limestone Upper Triassic limestone and dolostone Till © ZRC SAZU AnTon MELIk GEoGRAPhICAL InSTITUTE 6 4 -2 _ a c ta 4 9 -1 .q x d 1 6 .5 .2 0 2 4 1 3 :1 1 P a g e 1 3 Holocene climate variability in Slovenia: A review 14 In addition to terrestrial ice masses, there are more than 260 caves in Slovenia with permanent ice masses (Cave Register 2022), which are also subject to ice mass loss as the overall climate warms (Kranjc 2009; Colucci et al. 2016; Mihevc 2021; Blatnik et al. 2023). The studies of their ice mass balance fluctu- ation and glaciochemistry have revealed their potential to provide palaeoenvironmental records (Mihevc 2018; Carey et al. 2019; 2020; Smith et al. 2023), but preindustrial data with dating is currently only avail- able for the M-17 Cave located in the Tolmin Migovec massif of the Julian Alps (Racine et al. 2022). The ice mass balance of the M-17 Cave was assessed using radiocarbon dating of the organic remains embed- ded in ice. The developed chronostratigraphy suggests three primary phases of positive ice balance around 1.05–0.85 ka, 0.75–0.65 ka, and 0.25–0.15 ka, and a negative ice mass balance period around 0.65–0.55 ka (current ice mass loss has also been noted since its discovery in the 1980s). The overall positive ice mass balances are marked by cooler-than-average summers and wetter-than-average springs, whilst the nega- tive mass balance indicates warmer-than-average summers and dry springs. 2.2 Clastic lacustrine and marine sediments Marine, lake, and other continental sediments provide an important archive from which one can recon- struct past climate, biological, and geological changes and evaluate their impact on the environment. Sediment cores obtained from lake, marine, and continental unlithified sediments using a variety of coring meth- ods (gravity and piston corers) provide a unique opportunity to obtain undisturbed successions, where all primary sedimentary structures, textures, and compositions are preserved down to the level of indi- vidual laminae. By analysing sediment cores, it is possible to observe both gradual and rapid changes in sediments, which are the result of various changes in catchments: geomorphology, physicochemical changes in water bodies, bioproduction etc. In the Holocene successions, the main driver for these changes is relat- ed to climate changes. Sediment structure and texture are used to reconstruct sedimentary processes and to identify »normal« pelagic sedimentation and event beds. Sediment mineral and chemical composition are used for provenance analyses, which in some cases have also been associated with climate changes (Bradley 1999; Last and Smol 2001; Battarbee et al. 2002a; 2002b; Lauterbach et al. 2011). The most studied areas in Slovenia in relation to reliable ages of Holocene periods/events and palaeo- climatic interpretation are the Bay of Koper (Figure 1), where Holocene post-LGM warming marine transgression has been reconstructed, and lakes Bohinj and Bled, where the Holocene human and climate impacts on lake catchment have been investigated. The Slovenian coastal area, located in the northernmost part of the Adriatic Sea, is the southeastern part of the larger Bay of Trieste. In this area, a complete series of shallow (up to 3 m) and deeper (up to 45 m) cores from different parts of the bay have been analysed (Ogrinc et al. 2012; Novak et al. 2020). These include three short cores in the northern and central part of the Bay of Trieste (Covelli et al. 2006; Ogrinc et al. 2007), three long cores in the Bay of Koper (Ogorelec et al. 1997), one long core in the southern part of the bay near Sečovlje (Ogorelec et al. 1981), and four short cores near the Bay of Strunjan (Novak et al. 2020). Based on lithology (mainly carbonate content), geochemistry (δ13C, δ15N, and OC/TN ratio), biota, and radiocarbon dating of sediments, the Holocene transgression in the Bay of Trieste was reconstruct- ed (Ogorelec et al. 1981; 1997; Ogorelec, Mišič and Faganeli 2000; Covelli et al. 2006; Ogrinc et al. 2007; 2012; Mautner et al. 2018; Novak et al. 2020). The earliest evidence of the Holocene marine transgression is found in the cores from the Bay of Strunjan, dated to ~11.3 ka (Novak et al. 2020). Northward trans- gression progressed at a rate of between 1 and 3 km per century (Chiocci et al. 2017), and in a few hundred years most of the Bay of Trieste was already inundated by the advancing Adriatic Sea (Ogorelec et al. 1981; 1997; Ogorelec, Mišič and Faganeli 2000; Covelli et al. 2006; Ogrinc et al. 2007; 2012; Mautner et al. 2018; Novak et al. 2020). According to Ogrinc et al. (2012), this transgression pulse was followed by another pulse around 3 to 2 ka. The oldest reliable climate reconstruction based on the lake core successions supported by dates is from Lake Bled, elevation 475 m (Andrič et al. 2009; Figure 1) and is based on geochemical parameters (δ18O, δ13C), pollen, and biota. The conclusion was that in the Oldest Dryas the larger area around the lake was influenced by a cold and dry climate, with a trend towards wetter conditions. A period of climate warm- ing was observed at the beginning of the Late Glacial Interstadial at ca. 14.8 ka, followed by another period of warming at ca. 13.8 ka. After 12.8 ka (and throughout the Younger Dryas), the climate was colder and drier. A warmer climate marks the onset of the Late Glacial–Holocene transition. 64-2_acta49-1.qxd 16.5.2024 13:11 Page 14 In Lake Bohinj, elevation 526 m (Figures 1, 3), the sedimentary characteristics (provenance analysis) of the lake succession were used to reconstruct the Holocene wetter climate periods and associated increased flood activity (Andrič et al. 2020). These periods were marked by high terrigenous input at 6.1–6.0 ka, 5.7–5.55 ka, 5.0–4.6 ka, 3.9 ka, 3.7–3.55 ka, and 2.3–2.2 ka. These flood patterns match with periods of increased flooding in the wider Alpine region (Wirth et al. 2013), and the particular timing of 5.7–5.55 ka can also be correlated with the extreme floods in the Planina Cave based on the radiocarbon dating of a flow- stone layer on the flood sediments (Stepišnik et al. 2012). Small glacial Lake Planina pri Jezeru, located at an elevation of 1,430 m in the Eastern Julian Alps, has been the subject of ecological, geochemical, and palaeoenvironmental research in recent decades. Whilst geochemical studies have mainly focused on eutrophication (Muri et al. 2004; 2013; 2018; Muri, Wakeham and Rose 2006; Vreča and Muri 2006; 2010; Muri 2013) and its implications for the local ecosystems (Brancelj 2021 and references therein), the long-term changes in vegetation and sedimentary processes during the last 13,000 years were investigated using mineralogical, geochemical, and palynological methods by Caf et al. (2023). The radiocarbon method was used for dating the sediment core, and the climate change was reconstructed from sedimentological and vegetation parameters. Along with the pollen records (see Section 2.3), the warming at the beginning of the Holocene induced a transition from a wetland to a eutroph- ic lake surrounded by forest (Picea, Larix, Ulmus). Sedimentological characteristics and elemental records showed dry conditions after the Last Glacial Period with aeolian deposition of silty siliciclastic material. Between 12.45 and 12.2 ka, increased sedimentation of carbonate and decreased sedimentation of amor- phous material suggests the onset of a more humid and warmer climate. Between 11.7 and 10.2 ka, rapid accumulation of amorphous organic material occurred as a result of increasing algal biomass in the lake, leading to anoxic conditions in the sediment and formation of pyrite (FeS2). Between 10.2 and 4.5 ka, the area around the lake was heavily forested, as concluded from the high proportion of terrigenous detrital Acta geographica Slovenica, 64-2, 2024 15 Figure 3: Sediment core from Lake Bohinj, published in Andrič et al. (2020). A: The length of the sediment core was 12 m. B: optically visible lamina- tion of the core, indicating a change in lake hydrology as a consequence of climatic changes or events. A B © M A R k o Z A P LA TI L (A ), M A JA A n d R Ič (B ) 64-2_acta49-1.qxd 16.5.2024 13:11 Page 15 Holocene climate variability in Slovenia: A review organic matter with a high OC/TN ratio in the sediment. Periodical pulses of increased input of detrital dolomite point toward several consecutive periods with increased precipitation, alternating with periods of droughts. The 8.2 ka event and the cooling at 5.3–4.9 ka which were recorded in the pollen profile (see Section 2.3), remained unnoticed in sedimentological and mineralogical records. The subsequent fluc- tuations of geochemical parameters are attributed to changing land use rather than climate change (e.g., metallurgy since Roman times, and migrations in the Late Antiquity and the Early Middle Ages), when the settlements were located at lower elevations, whilst the pastures above the lake were used only during the summer (Caf et al. 2023). 2.3 Palynology Palynology is an established approach to the study of fossil pollen produced by former plants and deposit- ed in lake/marsh sediments, where it can survive for thousands or even millions of years. By analysing pollen in sedimentary cores, long-term changes in vegetation can be reconstructed (Traverse 2007; Birks 2019; Chevalier et al. 2020). Plants respond to climate variability, internal vegetation dynamics (e.g., succession), and human impact on the environment. Since the vegetation has not been affected solely by climate fluc- tuations, pollen analyses cannot provide direct evidence of climate change. However, in combination with other palaeoclimate proxies (e.g., sedimentological, geochemical, and stable isotope characteristics of lake, ice, and marine cores, speleothems, and tree rings – see Sections 2.2, 2.4, 2.5), it is possible to better under- stand the impact of climate on the vegetation and reconstruct long-term climate variability. Major climate variabilities triggered significant changes in Pleistocene and early Holocene vegetation, whereas it is often difficult to distinguish between anthropogenic and climate impacts in the middle/late Holocene because the human impact on the environment was more pronounced (Birks 1981; Bennett and Willis 2001). Also important was the resilience of vegetation, which did not respond to minor changes in temperature or precipitation. Compared to northwestern Europe, where many palaeoclimate studies have been conducted (e.g., Dansgaard et al. 1993; O’Brien et al. 1995; Bond et al. 1997; Dahl-Jensen et al. 1998; Mayewski et al. 2004; Wanner et al. 2011), in Slovenia the vegetation changes associated with the cold- er/wetter climate may have been less pronounced due to the warmer climate and proximity to glacial tree refugia (e.g., Willis, Rudner and Sümegi 2000; Petit et al. 2003; Willis and Vanandel 2004; Magri et al. 2006). In Slovenia, palynological research in the 1960s focused on sediment cores from the Ljubljana Marsh, a tectonically active basin (Mencej 1990; Brenčič 2007; Bavec and Pohar 2009; Verbič and Horvat 2009), where Šercelj (1966) investigated pollen which had been deposited in colder and warmer periods of the Pleistocene and the Holocene. The results of palynological research on study sites in the Ljubljana Marsh (Šercelj 1966; Culiberg 1991; Andrič et al. 2008), Bela Krajina (Andrič 2011), the Julian Alps at Lake Bled (Andrič et al. 2009) and Lake Planina pri Jezeru (Caf et al. 2023; Figure 1) indicate that towards the end of the last Ice Age (Late Glacial ca. 15–11.7 ka), when the climate in Europe was cold and presumably dry (Peyron et al. 2005; Feurdean et al. 2008; Ivy-Ochs et al. 2008; Kerschner and Ivy-Ochs 2008), the landscape was covered by a steppe with few trees (e.g., Pinus, Betula, Larix, Picea), but during warmer periods, mesophilous deciduous trees (e.g., Quercus, Tilia, Corylus, Ulmus) spread. These climate variabilities and subsequent changes in vegeta- tion are evident in sedimentary cores of Lake Bled (Andrič et al. 2009), where colder and drier conditions have been suggested on the basis of multi-proxy data (sediment δ18O, pollen, microcharcoal, and cladocera and chironomid fauna) for the Oldest Dryas (ca. 18.5–14.8ka) and Younger Dryas (ca. 12.8–11.7ka). Climate warming occurred during the Late Glacial Interstadial (ca. 14.8–12.8 ka) and at the beginning of the Holocene (after ca. 11.7 ka). Similar fluctuations of Late Glacial climate and vegetation have also been detect- ed elsewhere (e.g., Vescovi et al. 2007; Feurdean et al. 2008 and references therein). During the Late Glacial Interstadial, for example, greater inter-seasonal variability and enhanced continental conditions (colder win- ters) compared to the present-day climate were detected in central and eastern Europe (Feurdean et al. 2014). At the transition to the Holocene the climate became markedly warmer. The seasonality of the early Holocene was driven by high summer insolation and therefore increased summer temperatures and drier conditions, leading to an increase in wildfire activity at 40°–50° N (Kutzbach and Guetter 1986; Feurdean et al. 2014). Temperate deciduous forests (Quercus, Ulmus, Tilia, Corylus, Fraxinus) were widespread in all phytogeographic regions of Slovenia. The increased microcharcoal concentration found at several study sites can be linked to the increase in natural forest fires, although the possible influence of local hunter- gatherer populations cannot be completely excluded (Andrič and Willis 2003; Andrič 2007). 16 64-2_acta49-1.qxd 16.5.2024 13:11 Page 16 The late successional shade-tolerant taxa Fagus and Abies are thought to have spread throughout Europe later in the Holocene, when the climate became less seasonal (i.e., less continental) and colder/wetter due to changes in solar insolation (Tinner and Lotter 2006). Both taxa are sensitive to drought, late frosts, and frequent disturbance such as forest fires in the early Holocene (Ellenberg 1988), and in most regions of Slovenia both taxa did not spread until after ca. 8.9–8.8 ka (Andrič and Willis 2003; Andrič 2007). In the Julian Alps at Lake Planina pri Jezeru, the 8.2 ka event is expressed as a short cold period with decreased drought stress, which is reflected in the pollen profile of the lacustrine sediment as expansion of Abies and Fagus, outcompeting the Corylus sp. (Caf et al. 2023). However, the differences in vegetation development between the different regions of Slovenia were sig- nificant. At the current level of research, it is difficult to estimate whether these differences were a result of different regional climates, human impact, bedrock, or a combination of all these factors. Therefore, independent palaeoclimate research is needed to better understand changes in vegetation and the envi- ronment. In the Ljubljana Marsh, for example, Fagus spread very early in the Holocene (ca. 11.4 ka), whilst Abies spread only after ca. 9.2 ka (Andrič et al. 2008). At the same time, the proportion of planktonic diatom taxa increased, indicating a deeper lake, which may be associated with a colder/wetter climate (9.3 and 8.2 ka events; Meese et al. 1994; Alley and Ágústsdóttir 2005). Between 6.75 and 6.0 ka, Abies, Fagus, and planktonic diatom taxa declined, which can possibly be related to a drier climate (Andrič et al. 2008). Palaeoclimate studies using other proxies need to be conducted in Slovenia to confirm these assumptions; however, a similar decline in lake levels has been noted at other study sites in Switzerland, Germany, and Croatia (Haas et al. 1998; Kalis, Merkt and Wunderlich 2003; Balbo et al. 2006). The diatom and geochemical record of the central Austrian alpine lakes suggests climate warming between 7.3 and 6.0 ka (Schmidt et al. 2006). Furthermore, the δ18O records at Lake Geneva (6.35–6.0 ka; Anadón et al. 2006) and at the Ernesto Cave (Grotta di Ernesto, 6.8–6.0 ka; McDermott et al. 1999) suggest a warmer and drier climate. Between 6.8 and 5.7 ka a major climate reversal has also been reconstructed in Scandinavia with more meridional flow patterns and anticyclonic summer conditions, and thus a drier climate and lower lake levels (pollen- based reconstructions of temperature and precipitation; Seppä and Birks 2001). Another change in vegetation in the Ljubljana Marsh occurred after 6.0 ka, when Fagus and later Abies began to increase again, and human impact on the vegetation (forest clearance and farming) was moderate. This change in forest composition can be associated with a cold and wet period (Haas et al. 1998; Mayewski et al. 2004), elevated lake levels (Magny 2004; Magny and Haas 2004), glacier advance after 5.8 ka (Denton and Karlén 1973; Seppä and Birks 2001), ice rafting (O’Brien et al. 1995; Bond et al. 1997), and peat formation between 5.1 and 4.4 ka (Seppä and Birks 2001). Late Holocene palaeoenvironmental changes in the Ljubljana Marsh are only part- ly investigated due to sedimentary hiatuses caused by water erosion (flood layers at 6–5 ka and at ca. 3.7 ka; Andrič 2020) and anthropogenic activities (peat cutting; Zorn and Šmid Hribar 2012). In the following millennia, human impact on the environment increased and »masked« potential palaeoclimate signals in the sense that it was more important for vegetation development than climate fluctuations. In Bela Krajina, Fagus appeared later in comparison to the Ljubljana Marsh, (ca. 8.9 ka), Abies was less abundant, and human impact (forest clearing and burning, which significantly affected forest composi- tion) was much stronger. Lower proportions of Fagus and Abies in Bela Krajina were possibly a consequence of a drier regional climate and the human impact of Neolithic farming communities (forest cutting and burning; Andrič 2007). The prevailing taxon after ca. 8.9 ka was Fagus. Here, an earlier decline and later recovery of Fagus (after ca. 7.5 and 5.7 ka, respectively) was observed compared to the Ljubljana Marsh, pos- sibly due to a drier climate and greater human impact. Abies did not spread until after 4.5 ka BP (4.5–2.0 ka), and a landscape similar to that of the present day formed after 1 ka when human activities had completely overridden potential palaeoclimate signals. In the late Holocene (after 4.5 ka), the global climate became wetter and presumably colder (Wanner et al. 2011). Due to minima in solar activity, lakes south of the Alps experienced high lake levels and high- er flood frequency between 4.2 and 2.4 ka (Vannière et al. 2013; Wirth et al. 2013; Sabatier et al. 2017; Rapuc et al. 2019). Some of these floods were also detected in the Ljubljana Marsh (Andrič 2020) and at Lake Bohinj (Andrič et al. 2020). At Lake Bohinj, Fagus-dominated forests spread after 3.3 ka, presumably due to the wetter climate, whereas Picea and Abies started to decline, together with increasing Bronze Age human impact on the environment (grazing). A major soil erosion event in the Iron Age (2.6 ka) was triggered by human impact (forest cutting, metallurgical activities, and grazing; Andrič et al. 2020), but it cannot be ruled Acta geographica Slovenica, 64-2, 2024 17 64-2_acta49-1.qxd 16.5.2024 13:11 Page 17 Holocene climate variability in Slovenia: A review out that it was further strengthened by the wet climate (ca. 2.8–2.3 ka; Haas et al. 1998; Bond et al. 2001; Magny 2004; Wanner et al. 2011; Magny et al. 2012; Rach et al. 2017). In at least the last 1–2 ka, intensive human impact on the vegetation has been the most important fac- tor shaping vegetation in all regions of Slovenia. Therefore, short-term (minor) fluctuations of the climate (e.g., the Medieval Warm Period and the LIA) are not clearly visible on pollen diagrams. Climate change was presumably not strong enough to cause significant changes in forest composition (at the low- land study sites), and human activities have altered forest composition more than climate. In addition, sampling resolution at many study sites was not detailed enough to detect these short-term changes; high–res- olution studies at high-elevation sites at the tree line might yield better results. 2.4 Dendrochronology Dendroclimatology, a subfield of dendrochronology, focuses on finding the relationship between climate and tree growth and on climate reconstruction, once the relationship between tree-ring proxy (a surro- gate for measured climate data) and climate is established (Martinelli 2004; Ruddiman 2014). Classical dendroclimatology is based on establishing the relationship between tree-ring widths and climate; how- ever, in recent times several other tree-ring proxies for climate reconstructions based on the wealth of information stored in tree-rings have been used. These new climate proxies include tree-ring density (max- imum ring density), stable isotope ratios (carbon, oxygen, and hydrogen), and various anatomical traits of tree rings and blue intensity (a surrogate for X-ray-based tree-ring density measurements), to name a few (Siegwolf et al. 2021). There are only a few long (ca. 2ka) tree ring–based climate reconstructions in the world with some poten- tial to go back to 6 ka (e.g., Wilson et al. 2011). However, there are several climate reconstructions of 1 ka or more based on tree-ring widths that cover the spatiotemporal variability of the climate in the last mil- lennia (Cook et al. 1991; 1999; 2010; 2015; 2016). Europe is relatively well covered in terms of tree ring-based climate reconstruction, with the Alpine region best represented in this respect (Büntgen et al. 2006; Nicolussi et al. 2009; Corona et al. 2010; Hafner et al. 2014). Currently in Slovenia, several tree-ring chronologies, which are an absolute basis for any climate recon- struction, have been developed: for the European larch (Larix decidua Mill.), a long-lived species at the upper tree line in the Alps; the pedunculate oak (Quercus robur L.), another long-lived species of the flood- plain forests in the Slovenian lowlands (as well as in the Pannonian lowland); and the European beech (Fagus sylvatica L.), Norway spruce (Picea abies Karst.), and silver fir (Abies alba Mill.), which are representatives of the vast forests below the tree line in the Alps and Dinaric Alps. Climate reconstructions in Slovenia have been done at the upper tree line using tree-ring proxies of European larch. The relationship between larch tree-ring widths and climate was studied at seven loca- tions in the Slovenian Alps. Analysis was performed for the period from 1900 to 2008. The response function analysis showed a significant positive response (wide tree ring) of larch to above-average temperatures in June and a significant negative response to above-average temperatures in March. A long tree-ring width chronology (Levanič 2005) with later updates (unpublished) was developed, covering the period from AD 914 to the present. However, this chronology has a gap between 1254 and 1414, and therefore only the part from the end of this gap (1415) to the present was used to reconstruct June temperatures for the last 559 years. Another climate reconstruction is based on stable carbon isotope ratios in European larch (Hafner et al. 2014). A 520-year stable carbon isotope chronology was tested against measured temperature and sunshine duration data. The stable isotope chronology correlates well with both studied parameters; how- ever, further tests showed that the relationship between sunshine duration and a stable carbon isotope ratio provides a more reliable reconstruction than average monthly temperature. Based on this, a 520-year recon- struction of sunshine duration for the period from June to August was developed for the southwestern European Alps, with three years standing out with particularly high predicted sunshine values (2006, 1911, and 1705) and two summers with particularly low predicted sunshine values (1840 and 1913). In the mid elevations, silver fir-beech forest thrives in Slovenia. Elevations between 700 and 1,300 m are optimal for the growth and development of silver fir-beech forest. In the context of the wider study, the climate growth relationship was analysed along a 1,000 km transect (Čater and Levanič 2019). For sites in Slovenia and neighbouring Croatia, it was confirmed that temperature in June (beech) and July (silver 18 64-2_acta49-1.qxd 16.5.2024 13:11 Page 18 fir) plays an important and positive role in the growth of beech and silver fir, but no further attempts have been made towards climate reconstruction. At least two long chronologies with tree-ring widths and thus climatic reconstructions have been devel- oped for low elevations in Slovenia. The first, a 349-year reconstruction, is based on the compilation of oak wood samples collected from old houses in the Dolenjska region and samples from old-growth for- est in the Krakovo Forest (Sršen 2019; Figure 1). Oak chronology was tested against several climate variables and various drought indices, and it provided statistically sound results. Based on the 349-year chronolo- gy, drought reconstruction (the Palmer Drought Severity Index, PDSI) was compiled for the region of Dolenjska. A similar reconstruction for the same region and slightly longer (506 years) was constructed for the De Martonne Aridity Index (AI; Čufar et al. 2008). This reconstruction identified both above-aver- age June precipitation and temperature as the most critical month for pedunculate oak growth in the region. Based on dendrochronological analyses, for example, precipitation and temperature conditions in June were reconstructed for the last half millennium for southeastern Slovenia (Čufar et al. 2008). The aver- age temperature of a very dry June was around 20°C, with average monthly rainfall around 40 mm, and the average temperature of a very wet June was around 16°C, with average monthly rainfall around 240 mm (Zwitter 2012). Dendrochronological analyses in the Slovenian Alps show two colder summer peri- ods, around 1770 and 1820 (Levanič 2005; Zwitter 2012). 2.5 Speleothems and other cave sediments Caves are a characteristic feature of karst landscapes and as such act as traps for clastic, chemical, and organ- ic sediments in the local environment (e.g., Osole 1968; Gospodarič 1988). Clastic sediments are generally allogenic and originate from the catchment, and therefore their facies reflect the water flow regime in both the cave and the catchment (Zupan Hajna et al. 2008a; 2008b; 2021; Stepišnik et al. 2012; Ferk 2016; Ferk et al. 2019). The most common authigenic chemical cave sediments generally consist of calcite, aragonite, and other carbonate precipitates in the form of speleothems or tufa. Because of the relatively stable climate conditions in caves, their growth rate and continuity are particularly important indicators for reconstructing past climate variabilities, along with their chemical and isotopic records (Ford and Williams 2007; Fairchild and Baker 2012). Despite the abundance of karst caves in Slovenia – the national database of caves (Cave Register, Speleological Association of Slovenia) currently has 14,695 recorded – only one analysed speleothem from Slovenia is listed in the SISAL (Speleothem Isotope Synthesis and Analysis) database of speleothems with published records (Genty et al. 1998; Comas-Bru et al. 2020). The first discrete isotope data on speleothems in several Slovenian caves (Škocjan Caves, Dimnica Cave, Divača Cave, Predjama Cave, Mačkovica Cave, and Kamnik Cave) were reported by Urbanc et al. (1985; 1987). In a stalagmite record from the Postojna Cave (Figure 1), the uppermost segment encompassing the period from about 1950 to 1995 was analysed for 14C history and growth rate, which was 0.13 to 0.20 mm/a for the samples analysed (Genty et al. 1998; Vokal 1999; Genty, Baker and Vokal 2001). To estab- lish the relationship between the stalagmite δ18O and δ13C values and the environmental parameters, local precipitation and drip water were analysed from 1996 to 1997; however, the sampled drip water was not associated with the stalagmite, so no direct correlation could be established (Vokal 1999; Mandić et al. 2013). The hydrogeological stable isotope study and 14C modelling provided important information on the C turnover rate in soils and the mean travel time of drip water feeding the speleothem (~11 years; Vokal 1999; Mandić et al. 2013), but the carbonate precipitation appeared to be in isotopic disequilibrium, making it unsuitable for palaeoclimate interpretation. Horvatinčić, Krajcar Bronić and Obelić (2003) also analysed the C and O isotope compositions in two 14C-dated stalagmites from the Postojna Cave, one recent and one roughly encompassing the last 14 ka. The fluctuations in δ13C values were attributed to the changing vegetation cover over the cave. The δ18O record did not reveal any anomalies that would indicate a sig- nificant change in ambient temperature; however, the temporal resolution of the isotope profile was too low to allow any plausible conclusions about the palaeoclimate. Black layers in speleothems in the Postojna Cave were studied by Šebela et al. (2015; 2017). Remains of charred carbon were found in dripstone in the Pisani Rov passage (8.24 ka), and in the Črna Jama Cave (8.39 ka), whilst the charcoal from soil above the cave at a depth of 1 m was dated to 8.21 ka (using the 14C method). These are the first findings from caves in Slovenia related to the 8.2 ka event, and they also explain Acta geographica Slovenica, 64-2, 2024 19 64-2_acta49-1.qxd 16.5.2024 13:11 Page 19 Holocene climate variability in Slovenia: A review the mechanism of transport of soot formed by forest fires into the cave by winter ventilation, where it was deposited as black aerosol deposits over older speleothems. Most probably, the recorded forest fire was a natural, lightning-caused fire, although an anthropogenic origin cannot be ruled out (Šebela et al. 2015). A palaeoclimate study has been in progress since 2009 in the Postojna Cave, in the terminal Pisani Rov passage (Domínguez-Villar et al. 2015; 2018; Lipar, Drysdale and Zhao 2019), but to date no detailed palaeoclimate interpretation of the stalagmite δ18O and geochemical profile has been retrieved. Only pre- liminary studies based on hydrochemical and isotopic analyses of drip water, stalagmite, and precipitation have been performed (Vreča et al. 2006; Vreča, Pavšek and Kocman 2022) and confirmed that (1) the cave temperature at the end of the passage at a depth of about 37 m reflects the temperature fluctuations at the surface related to global warming with a delay of 20 to 25 years; however, because of the transfer of sur- face atmosphere, thermal variability depends on the duration of the oscillations, so the thermal anomalies with periods of 7 to 15 years in duration have delay times < 10 years in the passage studied (Domínguez- Villar et al. 2015); (2) at the time of collection (2009), the stalagmite was in a state of dissolution and was not growing; (3) the upper 0.6 mm of the stalagmite grew from 1984 to 2003; and (4) the δ18O values of speleothem in that segment are synchronous with fluctuations of averaged δ18O values of drip water and local precipitation during the same period (Domínguez-Villar et al. 2018). 2.6 Borehole temperature profiles Studies of temperatures measured in boreholes can be used to reconstruct surface temperature. Due to the relatively low thermal diffusivity of rocks, temperature change at the surface propagates downwards and the way temperature changes along a borehole at the present time can indicate how the surface tem- perature has changed in the past (Cermak 1971; Bodri and Cermak 2007). In Slovenia, temperature profiles from boreholes come mostly from the northeastern part of the coun- try and span generally up to 300 years (Rajver, Šafanda and Shen 1998). Information about temperature changes beyond the past centuries are available from the Ljutomer borehole (drilled to a depth of 4,048 m and logged to almost 2,000 m) and the Šempeter borehole (drilled to 1,541 m and logged to 1,518 m), allow- ing reconstruction spanning the Holocene and the last glacial period (Rajver, Šafanda and Shen 1998; Šafanda and Rajver 2001). It shows the warming occurring after the last glacial period around 10 to 15 ka and reach- ing a maximum around 3 to 2 ka. The maximum could be related to the HCO–11 and 5 ka based on Renssen et al. (2009) and Solomina et al. (2015) since the amplitude and timing of the borehole values are quali- tative because of the diffusive nature of heat conduction and the assumptions about the parameters used in inversion routines that blur temperature changes in the distant past (Luterbacher et al. 2012). The shallower boreholes show a cold period around 1870–1890 (possibly related to the LIA), followed by a warming trend in the past 100 years. It is estimated that the ground surface temperature rose by 2° in the last 150 years (Rajver, Šafanda and Shen 1998; Šafanda et al. 2007). 2.7 Historical sources Written records of climate phenomena began with the advent of developed civilizations (Zorn and Komac 2007). Some of the observations were made individually or passed down through generations. Common observations included droughts and floods, freezing of water, and vegetation cycles. They were carefully recorded, especially in terms of their effects on society. Historical sources from before advances in weath- er instruments can therefore be considered only as secondary information regarding climate changes in recent centuries. Well-known examples of historical sources include El Niño and written evidence of rain- fall and weather-related disasters in China, etc. (Carey 2012; Ruddiman 2014). Studies dealing with climate in Slovenia in the pre-instrumental period are rare (Ogrin 2012), but for the 17th and 18th centuries they show that springs and summers with heavy rain were common between 1700 and 1720, and summers were warm in the mid-18th century. Winters were harsh between 1630 and 1650 and during the Maunder Minimum, 1680–1716. Sources suggest that the 17th century was »a rather varied period in terms of climate and weather« (Ogrin 2012, 96). In the first half of the 17th century and the first half of the 18th century, weather-related natural disasters were frequent, with their frequency com- parable to that of the late 20th century (Ogrin 2007b). 20 64-2_acta49-1.qxd 16.5.2024 13:11 Page 20 Slovenian historiography for the early Middle Ages, more precisely until AD 536, reports a severe famine that also affected the areas of present-day western Slovenia (Bratož 2019). Summer temperatures in Europe in AD 536 decreased by 1.6 to 2.5°C compared to the previous 30-year average due to a volcanic eruption in Iceland (Sigl et al. 2015; Gibbons 2018). Similarly, the eruption of the Mount Tambora volcano in Indonesia in April 1815 led to a drop in temperature of approximately 1.5°C in 1816 in what is now Slovenia, and this was accompanied by above-average rainfall (Čeč 2017); the estimated average surface temperature anom- alies of the northern hemisphere in the summers of 1816, 1817, and 1818 are −0.51, −0.44, and −0.29 K (Oppenheimer 2003). The year 1816 is also known as the »year without a summer« (Oppenheimer 2003), and the year 1817 as the »year of famine«. It was the 1816–1818 famine that contributed to the develop- ment of a new cultivar – the potato – in certain areas of present-day Slovenia (Čeč 2015; Studen 2018). More detailed historical studies of sources for weather and climate for the territory of present-day Slovenia are still lacking for the Middle Ages. These studies are more common for sources from the 16th century onward. For the beginning of the 17th century, the weather data collated by the bishop of Ljubljana and several annals have been preserved (Zwitter 2013). From these data, it is known that precipitation around the new year in central Slovenia was not only from snowfall and that the rise of temperatures above freez- ing was not uncommon. Sources for this period also confirm the occasional occurrence of very cold and wet summers in a single year or several years in a row (Zwitter 2013). The climate conditions in the second half of the 17th century and at the beginning of the 18th centu- ry (i.e., for the Maunder Minimum, when solar activity was at its lowest) can be inferred for Slovenian Istria or the coastal/southwestern part of Slovenia from sources on salt production. During this period, severe storms with hail and strong winds were statistically more frequent than in earlier or later periods (Paliska et al. 2015). Between the first half of the 17th century and the first half of the 18th century, salt production was at its lowest in the mid-17th century (Bonin 2001). An important climate indicator is frost damage to olive trees because olive trees in southwestern Slovenia grow at their northern climate limit. In the 20th century, the average recurrent period of frosts in the olive groves was 20 years, whilst in the 18th century it was shorter (10–15 years; Ogrin 2007a). For southwest- ern Slovenia, the occurrence of droughts was also reconstructed using historical sources. These were more common between 1540 and 1562, in the first half of the 18th century, and between 1820 and 1848. The droughts in the first half of the 18th century sometimes coincided with plagues of locusts (Ogrin 2003). Historical sources for the LIA in southwestern Slovenia indicate two periods with a higher frequen- cy of colder winters: (1) between 1300 and 1570 with peaks between 1400 and 1450, and between 1475 and 1570, and (2) between 1680 and 1865 with a peak in the first half of the 18th century (Ogrin 2005). Colder winters were also present between AD 800 and 865. Winter temperatures were 0.8°C lower at the end of the 15th century, and about 0.5°C lower in the first half of the 18th century than average temper- atures at the end of the 20th century (Ogrin 1994). The LIA is characterised by localized accusations of bad weather magic among the population. Witchcraft processes in Slovenia reached a high point during the second peak of the LIA at the end of the 17th and beginning of the 18th century (Rajšp 1988; Zwitter 2012). For northern Slovenia, more precisely in the Upper Savinja Valley, it is known from historical sources that several consecutive cold and rainy summers led to the short-term abandonment of some high-ele- vation farms in the last decade of the 17th century (Zwitter 2012). The highest located farms in the Slovenian Alps were probably established towards the end of the Medieval Warm Period (i.e., during the time of sec- ondary, high-elevation settlement), many of which were later abandoned (Ogrin 2012). Data on weather and climate conditions for the 16th and 17th centuries can be found in the urbari- um (or rent roll). Temperature and precipitation data are less frequently documented, but there are more data on harvests of various crops and meadows, and on the impact of weather on agricultural activities (Zwitter 2016). Based on court records from the first half of the 17th century, in the case of mountain graz- ing there was an awareness that in the second half of August the weather could already be cold, which influenced the earlier movement of livestock from higher to lower mountain pastures. This historical fact was still present in historical records in the mid-20th century, when August 10th was considered the last day of summer or the first day of autumn in many parts of Slovenia (Zwitter 2020). Poorer weather con- ditions may also have led to the introduction of new crops – in the mid-19th century, due to poor cereal harvests, the production of table potatoes became a necessity (Gestrin 1969; Zwitter 2012), along with a change in harvest time (Zwitter 2015). Acta geographica Slovenica, 64-2, 2024 21 64-2_acta49-1.qxd 16.5.2024 13:11 Page 21 Holocene climate variability in Slovenia: A review 22 The Glory of the Duchy of Carniola (Valvasor 1689) also provides weather and climate data for the 17th century, but care must be taken, as some of the statements may be exaggerated to a certain extent. Among other things, it is learned that high mountains could be covered with snow periodically, which means that the highest parts of the high mountains were not covered with permanent snow and ice during this peri- od of the LIA, even though summers were on average colder than today (Zwitter 2014). The harsh winters can be inferred from the ice on rivers, which the resulting floods were associated with during the melting period. In the 18th and 19th centuries, there were severe winters in northeastern Slovenia (Ptuj) in the first decade of the 18th century and in the second half of that century, as well as in the first half and at the end of the 19th century (Kolar 2020). 3 Synthesis The reconstruction of the Slovenian climate during the Holocene is still evolving, and it would be too speculative to present an overall timeline synthesis. In addition, Slovenia is climatically diverse, and the palaeoclimate cannot simply be inserted into an overall history but should be treated on a regional scale. Nevertheless, several valuable studies have already shown peculiar periods when climate variations most likely played a major role to which the environment responded, either in terms of changes of glacier extent, lake level and flood frequency, or the spread or growth discontinuity of particular plant species, or sim- ply through a historical remark in written records. In terms of the regional distribution of palaeoclimatic archives studied throughout Slovenia (Figure 4), the eastern and northeastern regions characterised by the most apparent continental climate have palaeo- climatic research based on historical sources such as winter weather events in the Ptuj area in the 18th to 20th century (Kolar 2020) and borehole temperature profiles (Rajver, Šafanda and Shen 1998; Šafanda and Rajver 2001). The studied regions with a temperate continental climate are southeastern and central Slovenia, which include palynological (Culiberg 1991; Andrič 2007; 2020; Andrič et al. 2008), dendrochronological (Čufar et al. 2008; Sršen 2019), borehole temperature (Šafanda et al. 2007), and hydrological studies (Andrič et al. 2008; Stepišnik et al. 2012). Mountain climates are well represented by cryosphere archives (Gabrovec et al. 2014; Colucci and Žebre 2016; Lipar et al. 2021; Racine et al. 2022), palynological and sedimento- logical studies (Andrič et al. 2009; 2020; Caf et al. 2023), dendrochronological research (Hafner et al. 2014), and historical sources (Zwitter 2015; 2020). Studies in regions with a sub-Mediterranean climate mostly focus on marine sediments and transgression (Ogrinc et al. 2012; Novak et al. 2020). As for the period from the beginning of the Holocene to the times of modern climate monitoring, the palaeoclimate data based on archives from the Slovenian territory exist for all three subdivisions – oldest to newest, these are Greenlandian, Northgrippian and Meghalayan. The palaeoclimate from Slovenian archives of each of these subdivisions is summarised, along with the major global climatic periods/events. The summary of events is shown in Figure 5. 3.1 Greenlandian (11.65–8.186 ka) The onset of the Holocene and the associated warmer climate on a global scale compared to the last glacia- tion period at the end of the Pleistocene also led to the retreat of major glaciers in Slovenia (Bavec and Figure 4: The present climate of Slovenia (Ogrin 2008) and the broad localities of major palaeoclimatic research. A: The Triglav Glacier (Gabrovec et al. 2014; Colucci and Žebre 2016; Hrvatin and Zorn 2020; Lipar et al. 2021), Lake Bohinj (Andrič et al. 2020), Lake Bled (Andrič et al. 2009), Lake Planina pri Jezeru (Caf et al. 2023), Vršič Pass (Hafner et al. 2014), the M-17 Ice Cave (Racine et al. 2022). B: The Skuta Glacier (Pavšek 2007; Triglav Čekada et al. 2020), the Dleskovec Plateau (Hafner et al. 2014), and the northeastern Slovenian Alps in general (Zwitter 2015; 2020). C: Ptuj (Kolar 2020) and the rest of north- eastern Slovenia (e.g., Ljutomer; Rajver, Šafanda and Shen 1998; Šafanda and Rajver 2001). D: The Ljubljana Marsh (Culiberg 1991; Andrič et al. 2008; Andrič 2020). E: The Planina Cave (Stepišnik et al. 2012) and the Postojna Cave System (Domínguez-Villar et al. 2015; Šebela et al. 2017; Domínguez-Villar et al. 2018; Lipar, Drysdale and Zhao 2019). F: Strunjan Bay (Ogrinc et al. 2012; Novak et al. 2020). G: Bela Krajina region (Andrič 2007; 2011). H: Krakovo Forest (Sršen 2019), the wider region between Novo Mesto and Krško (Šafanda et al. 2007), and southeastern Slovenia (Čufar et al. 2008). p p. 23 Figure 5: A summary of apparent palaeoclimatic data from the Slovenian territory, accompanied by the NGRIP curve (Andersen et al. 2007) and major climatic events (red arrows for major global periods/events – warm events; blue arrows for major global periods/events – cold events). © ZRC SAZU Anton Melik Geographical Institute p p. 24–25 64-2_acta49-1.qxd 16.5.2024 13:11 Page 22 A cta geographica Slovenica, 64-2, 2024 23 A B D C H G E F Mountain climate Climate of higher mountain area Climate of lower mountain area in western Slovenia Climate of lower mountain area in northern Slovenia Temperate continental climate of eastern Slovenia Temperate continental climate of southeastern Slovenia Temperate continental climate of western and southern Slovenia Temperate continental climate of central Slovenia Costal sub–Mediterranean climate Inland sub–Mediterranean climate © ZRC SAZU Anton Melik Geographical Institute 0 20 20 30 40 km Temperate continental climate Sub–Mediterranean climate 6 4 -2 _ a c ta 4 9 -1 .q x d 1 6 .5 .2 0 2 4 1 3 :1 1 P a g e 2 3 H olocene clim ate variability in Slovenia: A  review 24 NGRIP curve warmer–colder Variable sunshine duration for June-August for the last half millenium in the Alps and Dolenjska ( ufar et al. 2008; Hafner et al. 2014; Sršen 2019) Č Positive ice balance in the M–17 ice cave around 1.05–0.85 ka, 0.75–0.65 ka, and 0.25–0.15 ka; negative ice balance around 0.65–0.55 ka (Racine et al. 2022) Major floods in Lake Bohinj at 3.9 ka, 3.7–3.55 ka, and 2.3–2.2 ka (Andri et al. 2020)č 3–2 ka transgression pulse (Ogrinc et al. 2012) and maximum warming based on borehole temperature profile (Rajver, Šafanda and Shen 1998) Beginning or middle of the 19th century: potatoe cultivation due to poor cereal harvest (Zwitter 2012, 2015) 1700–1720: springs and summers with heavy rain; 1630–1650 and 1680–1716: harsh winters (Ogrin 2012) AD 536 severe famine (Bratož 2019) Archival pictures and monitoring since 1984 show retreating trend of the Triglav and Skuta ice masses (Gabrovec et al. 2014) Reduced temperature in 1816 and above–average rainfall ( e 2017)Č č Large extent of the Triglav Glacier during the LIA based on archival pictures and morainic ridges (Colucci and Žebre 2016) Cooling at 5.3–4.9 ka Lake Planina ri Jezeru (Caf et al. 202 ) p 3 Major floods in the Tiha Jama Cave and Planina Cave around 5.7 ka (Stepišnik et al. 2012) Moraine ridge dated to 5.6–5.4 ka indicating similar size of the Triglav Glacier as during LIA (Lipar et al. 2021) Floods of the Ljubljana Marsh and Lake Bohinj between 4.2 and 2.4 ka (Andrič 2020; Andrič et al. 2020) Major global periods/events Rapid climate change periods (Mayevski et al. 2004) N O R T H G R IP P IA N N O R T H G R IP P IA N M E G H A L A Y A N H O L O C E N E First half of the 17th century: short summers (Zwitter 2020) Harsh winters in NE SLO in the 18th and 19th century (in parts, not all the time) (Kolar 2020) Minimum temperatures 1870 1890, then warming based on borehole temperature p (Rajver, Šafanda and Shen 1998; Šafanda et al. 2007) – rofile 0 4.2 ka event Roman Period Medieval Warm Period AD 536 eruption 6 ka 4 ka 2 ka R o tm o o s o sc. Minoan Warm Period 2.8 ka event L IA M 6 4 -2 _ a c ta 4 9 -1 .q x d 1 6 .5 .2 0 2 4 1 3 :1 1 P a g e 2 4 A cta geographica Slovenica, 64-2, 2024 25 Drier climate due to decline of shade–tolerant taxa in the Ljubljana Marsh between 6.75–6.0 ka (and between 7.5–5.7 ka in Bela rajina), then increase after 6 ka again (Andrič 2007; Andrič et al. 2008) k Major floods in Lake Bohinj at 6.1–6.0 ka, 5.7–5.55 ka, and 5.0–4.6 ka (Andrič et al. 2020) Expansion of shade–tolerant taxa around 8.2 ka evident in Lake Planina pri Jezeru indicating short cold period and decreased drought stress (Caf et al. 2023) In 8.9–8.8 ka change to less continental and colder/wetter climate based on shade–tolerant taxa (Andrič 2007; Andrič and Willis 2003) 15–10 ka the onset of warming after the last glacial period based on borehole temperature pr (Rajver, Šafanda and Shen 1998; Šafanda and Rajver 2001) ofile 11.3 ka marine transgression in Strunjan Bay (Novak et al. 2020) Colder/wetter climate at 9.3 or 8.2 ka indicated by increased proportion of planktonic diatom taxa in the Ljubljana Marsh (Andrič et al. 2008). The Triglav and Skuta ice masses probably present at all times (Lipar et al. 2021) Lake Bled sedimentary core shows the spread of mesophilous deciduous trees–warming of the climate after the Pleistocene (Andrič 2009) PLEISTOCENE δ 18 O of Greenland ice (NGRIP data, Andersen et al. 2007) VSMOW G R E E N L A N D IA N N N O R T H G R IP P IA N M 8 ka 10 ka 12 ka 8.2 ka event F ro sn itz o sc. R 9.3 ka event M iso x o sc. Y o u n ger D ryas –35 ‰ –40 ‰ 6 4 -2 _ a c ta 4 9 -1 .q x d 1 6 .5 .2 0 2 4 1 3 :1 1 P a g e 2 5 Holocene climate variability in Slovenia: A review Verbič 2011), although some ice masses (e.g., the Triglav and Skuta glaciers) were still present (Lipar et al. 2021). The borehole temperature profile from Ljutomer also clearly shows a warming trend at the end of the last glacial period and the beginning of the Greenlandian. The earliest evidence of marine transgres- sion, dated to 11.3 ka, comes from Strunjan Bay (Novak et al. 2020), and the onset of a warmer – and also more humid climate compared to the late Pleistocene is also supported by increased sedimentation of car- bonate and decreased sedimentation of amorphous material in Lake Planina pri Jezeru (Caf et al. 2023) and the spread of mesophilous deciduous trees evident in the sediment core of Lake Bled (Andrič et al. 2009). The high insolation at the beginning of the Greenlandian also aided seasonality with drier conditions and higher temperatures in summer, possibly reflected in increased microcharcoal concentrations (Andrič and Willis 2003; Andrič 2007). Toward the end of Greenlandian, the shade-tolerant taxa, which general- ly spread after ca. 8.9–8.8 ka (Andrič and Willis 2003; Tinner and Lotter 2006; Andrič 2007), may indicate a decline in solar insolation and consequently a less seasonal and colder/wetter climate. Notable region- al differences (e.g., the spread of shade-tolerant taxa earlier in the Ljubljana Marsh than in Bela krajina) allow rare opportunities to compare the palaeoclimate on a regional scale and could indicate a drier region- al climate in the temperate continental climate of southeastern Slovenia, compared to the temperate continental climate in central Slovenia. The end of the Greenlandian and the beginning of Northgrippian are marked by the 8.2 ka event, and the very prominent expansion of shade-tolerant taxa in the Lake Planina pri Jezeru core (Caf et al. 2023) could be associated with this event, which can be characterised as a short cold period with lower drought stress. The increased proportion of planktonic diatom taxa, indicating a deeper lake possibly associated with a colder/wetter climate, was also observed in the Ljubljana Marsh (Andrič et al. 2008), although this may also be associated with the 9.3 ka event. On the contrary, the extensive black-layered speleothems in the Črna Jama Cave are thought to be the result of massive forest fires around 8.2 ka (Šebela et al. 2017), which could indicate a drier climate at that time. This could indicate either minor regional palaeoclimatic differences in Slovenia, similar to the wider European region where this event was characterised by wet conditions in some parts and dry conditions in others (Gałka et al. 2016 and references therein), or an unclear sequence of relatively rapidly changing climatic events; for example, higher-than-average air temperatures before and after 8.2 ka in Europe (Gałka et al. 2016; Andersen et al. 2017) could also contribute to more frequent forest fires. 3.2 Northgrippian (8.186–4.2 ka) The first apparent palaeoclimatic change after the 8.2 ka event is evident in the decline of shade-tolerant taxa recorded in the Ljubljana Marsh between 6.75 and 6.0 ka, which may be related to a drier climate; after 6 ka, the shade-tolerant taxa increased again, possibly indicating a cold and wet period (Andrič et al. 2008). In Bela Krajina, a decline in shade-tolerant taxa was recorded over a longer time interval, between 7.5 and 5.7 ka (Andrič 2007), possibly indicating a drier climate in southeastern Slovenia compared to cen- tral Slovenia, but a stronger human influence cannot be excluded. These longer periods of drier climate coexist with the HCO, which, in fact, spans from 11 to 5 ka, but, due to the variation of climatic events on a shorter timescale, the HCO period seems to be very generalised. Furthermore, temperature data from the boreholes, reaching a maximum between 3 to 2 ka, have also been considered related to the HCO (Rajver, Šafanda and Shen 1998), but the estimates of the ages do not overlap. Nevertheless, the enhanced flood activity at 6.1–6.0 ka, 5.7–5.55 ka, and 5.0–4.6 ka indicated by terrige- nous input to Lake Bohinj (Andrič et al. 2020) may be the result of decreasing insolation and the end of the HCO at around 6ka. This could furthermore be strengthened by the advances of the Triglav Glacier (5.6–5.4ka; Lipar et al. 2021), possibly related to the two-phased Rotmoos Oscillation between around 6.3 and 5.0 ka, when advances of small glaciers were reported in the Alps (Patzelt and Bortenschlager 1973; Ivy-Ochs et al. 2009). Cooling was also noted at 5.3 to 4.9 ka in pollen records of the Lake Planina pri Jezeru (Caf et al. 2023). 3.3 Meghalayan (4.2 ka–present) The Meghalayan begins with the 4.2 ka event, which is almost coincident in most of the archives discussed (Sevink et al. 2011; Wanner et al. 2011), but it has not been clearly detected in proxies from the Slovenian region. Detected flooding in the Ljubljana Marsh (Andrič 2020) and Lake Bohinj (Andrič et al. 2020) may 26 64-2_acta49-1.qxd 16.5.2024 13:11 Page 26 indicate a wetter and presumably colder climate in the early Meghalayan due to minima of solar activity. At Lake Bohinj, the spread of Fagus after 3.3 ka also suggests a wetter climate, and increased flood activ- ity was recorded at 3.9, 3.7–3.55, and 2.3–2.2 ka, whilst a major soil erosion event between 2.8–2.3 ka could also be related to human impact (otherwise also a wetter climate; Andrič et al. 2020). The apparent cooling was detected during the LIA, as indicated by morainic ridges of the Triglav Glacier (Colucci and Žebre 2016). It is also possible that the very low salt production on the Slovenian coast and particularly the witchcraft trials at the end of the 17th and beginning of the 18th centuries indicate the climate of the LIA. Dendrochronological data show the variability of summer insolation in the eastern Alps during the LIA until today (Hafner et al. 2014); they show that summer insolation was variable with par- ticularly hot summers around 1705. Based on dendrochronological data from Dolenjska region, no extreme summers (featuring either extreme dryness or wetness) were observed (Sršen 2019), but relatively wet sum- mers were observed in the early 18th century and similarly after 1797. Summers became slightly less wet in the last decade of the 18th century. Based on historical imagery since the end of the 19th century, the melting of the two remaining ice masses in Slovenia, the Triglav and Skuta glaciers, and borehole tem- perature profiles indicate the onset of a warmer period after the LIA (Rajver, Šafanda and Shen 1998; Šafanda et al. 2007; Triglav Čekada et al. 2014). 4 Conclusion Studies based on climatic indicators from the Slovenian territory have revealed a number of particular peri- ods when climate variations played a major role, whether in the form of changes in glacier extent, lake levels and frequency of floods, or the spread or discontinuity of growth of certain plant species, or simply through historical remarks in written records. Slovenia is climatically diverse, and consequently the data show that palaeoclimate cannot simply be inserted into an overall territory but should be treated on a region- al scale with correlations to transboundary palaeoclimate data from broader yet similar regional features (e.g., the southeastern Alps, the Dinaric Alps, the Pannonian Basin, and the Mediterranean region). The following list of climatic events, nevertheless, summarises all reported changes in the Slovenian territory: • Before the Holocene: the landscape was dominated by steppes with few trees due to a colder and dry climate. Variability in climate was observed, with warmer periods allowing the spread of mesophilous deciduous trees. A warmer global climate led to major glacial retreats. A trend towards wetter condi- tions was noted before the climatic warming observed at around 14.8 ka. • 14.8 ka (Lake Bled): phase of warming. Another phase of warming occurred at around 13.8 ka. The climate became colder and drier after 12.8 ka. • 15–10 ka: approximate time gap when the borehole temperature profile data from Ljutomer and Šempeter start showing a warming trend occurring after the last glacial period, reaching a maximum temperature around 3 to 2 ka. This maximum could be associated with the HCO. • The onset of the Holocene: the climate became warmer, leading to widespread temperate deciduous forests in Slovenia. There were increased summer temperatures and drier conditions, leading to increased forest fires. • 11.4–8.8 ka: varieties of trees such as Fagus and Abies began to spread, and the climate became less sea- sonal but colder and wetter. Different regions in Slovenia showed variability in vegetation development due to multiple factors, including regional climates and human impacts. • 11.3 ka (Bay of Trieste): the earliest evidence of Holocene marine transgression in the cores from the Bay of Strunjan. Most of the Bay of Trieste was inundated by the Adriatic Sea within a few hundred years, marking significant marine transgressions. • 10.2–4.5 ka (Lake Planina pri Jezeru): the area around the lake was heavily forested, marking a period of lush vegetation. Intermittent periods of increased precipitation and drought were recorded. • 8.8–6.0 ka: there were fluctuations in vegetation and climate, with indications of drier and warmer periods. These changes were influenced by various factors, including human activities such as forest clearing and farming. • 8.2 ka: black layers found in speleothems in the Postojna Cave and Črna Jama Cave were analysed, reveal- ing charred carbon remains. These layers suggest that soot from forest fires was transported into the caves, marking an important climatic event. Acta geographica Slovenica, 64-2, 2024 27 64-2_acta49-1.qxd 16.5.2024 13:11 Page 27 Holocene climate variability in Slovenia: A review • 6.1–2.2 ka (Lake Bohinj): several episodes of increased flood activity were noted, associated with wetter climatic conditions. Specific episodes were identified at 6.1–6.0, 5.7–5.55, 5.0–4.6, 3.9, 3.7–3.55, and 2.3–2.2 ka, reflecting patterns of increased terrigenous input due to flooding. • 5.6–5.4ka (Triglav Glacier): radiocarbon analysis of organic material from a moraine near the Triglav Glacier indicates that the glacier extent was similar to the LIA, suggesting a colder climate during this period. • 4.5 ka onward: there was a more significant human impact on vegetation, and the climate became gen- erally colder and wetter. The dominance of human activities, such as forest cutting and metallurgical activities, made it challenging to clearly distinguish the impact of climate variations based on pollen studies. • 3 to 2 ka (Bay of Trieste): another significant marine transgression pulse was identified during this peri- od, following the earlier Holocene transgressions. • 1.05–0.85, 0.75–0.65, and 0.25–0.15 ka (M-17 Cave): ice in the M-17 Cave shows periods of positive ice mass balances, implying cooler and wetter conditions during these times. There was also a period of negative ice balance around 0.65–0.55 ka, indicative of warmer and drier conditions. • AD 536: severe famine due to a volcanic eruption in Iceland that caused summer temperatures in Europe to decrease by 1.6 to 2.5°C compared to the previous 30-year average. • AD 914 onward: a study focused on European larch in Slovenia, with a notable gap from 1254 to 1414. Climate reconstruction has been mainly utilized from 1415 onward, focusing on June temperatures. Based on oak wood samples, the De Martonne Aridity Index and the Palmer Drought Severity Index were devel- oped for the last ~500 and 350 years, respectively. • 1300–1570, 1680–1865: historical sources from southwestern Slovenia of periods with colder winters, notably between 1300–1570 and 1680–1865, with winter temperatures being lower than the average tem- peratures at the end of the 20th century. • The LIA (Triglav Glacier): the Triglav Glacier had a more significant extent during the LIA compared to its present state, indicating colder climate conditions at that time. • 1540–1562, first half of the 18th century, 1820–1848: southwestern Slovenia experienced more common occurrences of droughts during these periods, sometimes coinciding with locust plagues. • 1630–1650, 1680–1716: harsh winters were recorded in these years, corresponding with the Maunder Minimum, a period of low solar activity. • Late 17th century to early 18th century: weather-related natural disasters were frequent, and, in the sec- ond half of the 17th century, climate conditions affected agricultural practices, such as the timing of moving livestock and introducing new crops. • 1700–1720: heavy rainfall during springs and summers was common. • 1705, 1911, and 2006: exceptional sunshine values were noted in the southwestern European Alps, based on stable carbon isotope ratios in European larch. However, in 1770 and 1820 colder summer periods were identified in the Slovenian Alps, marking distinct climatic phases. • 18th–19th centuries: harsh winters were recorded in northeastern Slovenia, notably in the first decade of the 18th century, the second half of the 18th century, and the beginning and end of the 19th centu- ry, influencing agricultural practices and social behaviours. • 1815: the eruption of the Mount Tambora volcano caused temperatures in Slovenia to drop by about 1.5°C, resulting in the »year without a summer« in 1816 and the »year of famine« in 1817. • 1870–1890: borehole temperature profiles indicate a colder period within these years, possibly relating to the LIA. Then, over the past century and a half, a warming trend has been observed, with the ground surface temperature estimated to have risen by 2°C, as indicated by more recent temperature profiles from boreholes in northeastern Slovenia. • 1950s to present (Triglav and Skuta glaciers): the Triglav and Skuta glaciers’ size and volume have sig- nificantly decreased, with current sizes much smaller compared to historical extents, reflecting recent global warming trends. ACKNOWLEDGMENTS: This work was supported by the Slovenian Research and Innovation Agency projects J1-2478, J4-8216, J6-3141, J6-3142, J6-50213, J6-50214, and J7-1817 and by the Slovenian Research and Innovation Agency research core funding programs »Geography of Slovenia« (P6-0101), »Forest Biology, Ecology, and Technology« (P4-0107), »Archaeological Research« (P6-0064), »Geoenvironments and Geomaterials (P1-0195)«, »Cycling of Substances in the Environment, Mass Balances, Modelling of Environmental Processes, and Risk Assessment« (P1-0143), and »Infrastructure Programme« (I0-0031). 28 64-2_acta49-1.qxd 16.5.2024 13:11 Page 28 5 References Affolter, S., Häuselmann, A., Fleitmann, D., Edwards, R. L., Cheng, H., Leuenberger, M. 2019: Central Europe temperature constrained by speleothem fluid inclusion water isotopes over the past 14,000 years. Science Advances 5-6. DOI: https://doi.org/10.1126/sciadv.aav3809 Alley, R. B. 2000: The Younger Dryas cold interval as viewed from central Greenland. Quaternary Science Reviews 19-1,5. DOI: https://doi.org/10.1016/s0277-3791(99)00062-1 Alley, R., Ágústsdóttir, A. 2005: The 8k event: Cause and consequences of a major Holocene abrupt climate change. Quaternary Science Reviews 24-10,11. DOI: https://doi.org/10.1016/j.quascirev.2004.12.004 Anadón, P., Moscariello, A., Rodríguez-Lázaro, J., Filippi, M. L. 2006: Holocene evironmental changes of Lake Geneva (Lac Léman) from stable isotopes (δ13C, δ18O) and trace element records of Ostracod and Gastropod carbonates. Journal of Paleolimnology 35-3. DOI: https://doi.org/10.1007/s10933-005-4009-5 Andersen, K. K., Bigler, M., Buchardt, S. L., Clausen, H. B., Dahl-Jensen, D., Davies, S. M., Fischer, et al. 2007: Greenland Ice Core Chronology 2005 (GICC05) and 20 year means of oxygen isotope data from ice core NGRIP. PANGAEA. DOI: https://doi.org/10.1594/PANGAEA.586838 Andersen, N., Lauterbach, S., Erlenkeuser, H., Danielopol, D. L., Namiotko, T., Hüls, M., Belmecheri, S. et al. 2017: Evidence for higher-than-average air temperatures after the 8.2ka event provided by a Central European δ18O record. Quaternary Science Reviews 172. DOI: https://doi.org/10.1016/j.quascirev.2017.08.001 Andrič, M. 2007: Holocene vegetation development in Bela krajina (Slovenia) and the impact of first farmers on the landscape. The Holocene 17-6. DOI: https://doi.org/10.1177/0959683607080516 Andrič, M. 2011: Poznoglacialna vegetacija v okolici Blejskega jezera in Gribelj (Bela krajina): primerjava v zadnjem stadialu poledenele in nepoledenele pokrajine. Drobci ledenodobnega okolja, Zbornik ob življenjskem jubileju Ivana Turka. Ljubljana. Andrič, M. 2020: Maharski prekop, Stare gmajne and Blatna Brezovica settlements and the vegetation of Ljubljansko barje (Slovenia) in the 4th millennium cal BC. Documenta Praehistorica 47. DOI: https://doi.org/ 10.4312/dp.47.24 Andrič, M., Kroflič, B., Toman, M. J., Ogrinc, N., Dolenec, T., Dobnikar, M., Čermelj, B. 2008: Late Quaternary vegetation and hydrological change at Ljubljansko barje (Slovenia). Palaeogeography, Palaeoclimatology, Palaeoecology 270-1,2. DOI: https://doi.org/10.1016/j.palaeo.2008.09.008 Andrič, M., Massaferro, J., Eicher, U., Ammann, B., Leuenberger, M. C., Martinčič, A., Marinova, E. et al. 2009: A multi-proxy Late-glacial palaeoenvironmental record from Lake Bled, Slovenia. Hydrobiologia 631. DOI: https://doi.org/10.1007/s10750-009-9806-9 Andrič, M., Sabatier, P., Rapuc, W., Ogrinc, N., Dolenec, M., Arnaud, F., von Grafenstein, U. et al. 2020: 6600 years of human and climate impacts on lake-catchment and vegetation in the Julian Alps (Lake Bohinj, Slovenia). Quaternary Science Reviews 227. DOI: https://doi.org/10.1016/j.quascirev.2019.106043 Andrič, M., Willis, K. J. 2003: The phytogeographical regions of Slovenia: A consequence of natural envi- ronmental variation or prehistoric human activity? Journal of Ecology 91-5. DOI: https://doi.org/10.1046/ j.1365-2745.2003.00808.x Augustin, L., Barbante, C., Barnes, P. R., Barnola, J. M., Bigler, M., Castellano, E., Cattani, O. et al. 2004: Eight glacial cycles from an Antarctic ice core. Nature 429. DOI: https://doi.org/10.1038/nature02599 Balbo, A. L., Andrič, M., Rubinić, J., Moscariello, A., Miracle, P. T. 2006: Palaeoenvironmental and archaeological implications of a sediment core from Polje Čepić, Istria, Croatia. Geologica Croatica 59-2. DOI: https://doi.org/10.4154/GC.2006.08 Battarbee, R. W., Grytnes, J. A., Thompson, R., Appleby, P. G., Catalan, J., Korhola, A., Birks, H. J. et al. 2002a: Comparing palaeolimnological and instrumental evidence of climate change for remote mountain lakes over the last 200 years. Journal of Paleolimnology 28-1. DOI: https://doi.org/10.1023/a:1020384204940 Battarbee, R. W., Thompson, R., Catalan, J., Grytnes, J. A., Birks, H. J. B. 2002b: Climate variability and ecosystem dynamics of remote alpine and artic lakes: the MOLAR project. Journal of Paleolimnology 28. DOI: https://doi.org/10.1023/a:1020342316326 Bavec, M., Pohar, V. 2009: Kvartar. Geologija Slovenije. Ljubljana. Bavec, M., Verbič, T. 2004: The extent of Quaternary glaciations in Slovenia. Developments in Quaternary Sciences 2-1. DOI: https://doi.org/10.1016/S1571-0866(04)80088-5 Bavec, M., Verbič, T. 2011: Glacial history of Slovenia. Developments in Quaternary Sciences 15. DOI: https://doi.org/10.1016/b978-0-444-53447-7.00029-5 Acta geographica Slovenica, 64-2, 2024 29 64-2_acta49-1.qxd 16.5.2024 13:11 Page 29 Holocene climate variability in Slovenia: A review Bennett, K. D., Willis, K. J. 2001: Pollen. Tracking environmental change using lake sediments 3: Terrestrial, algal, and siliceous indicators. Dordrecht. DOI: https://doi.org/10.1007/0-306-47668-1_2 Berger, A. 1988: Milankovitch theory and climate. Reviews of Geophysics 26-4. DOI: https://doi.org/10.1029/ RG026i004p00624 Bini, M., Zanchetta, G., Perşoiu, A., Cartier, R., Català, A., Cacho, I., Dean, J. R. et al. 2019: The 4.2 ka BP Event in the Mediterranean region: An overview. Climate of the Past 15-2. DOI: https://doi.org/10.5194/ cp-15-555-2019 Birks, H. J. B. 1981: The use of pollen analysis in the reconstruction of past climates: a review. Climate and History. Studies in Past Climates and their Impact on Man. Cambridge. Birks, H. J. B. 2019: Contributions of Quaternary botany to modern ecology and biogeography. Plant Ecology & Diversity 12-3,4. DOI: https://doi.org/10.1080/17550874.2019.1646831 Blatnik, M., Obu, J., Košutnik, J., Gabrovšek, F. 2023: Use of terrestrial LiDAR scanner for monitoring of ice thickness in ice caves; Examples from Slovenia. EuroKarst 2022, Advances in Karst Science. Cham. DOI: https://doi.org/10.1007/978-3-031-16879-6_27 Bodri, L., Cermak, V. 2007: Borehole climatology: A new method on how to construct climate. Amsterdam. Bond, G., Kromer, B., Beer, J., Muscheler, R., Evans, M. N., Showers, W., Hoffmann, S. et al. 2001: Persistent solar influence on North Atlantic climate during the Holocene. Science 294-5549. DOI: https://doi.org/ 10.1126/science.1065680 Bond, G., Showers, W., Cheseby, M., Lotti, R., Almasi, P., deMenocal, P., Priore, P. et al. 1997: A perva- sive millennial-scale cycle in North Atlantic Holocene and glacial climates. Science 278-5341. DOI: https://doi.org/10.1126/science.278.5341.1257 Bonin, F. 2001: Proizvodnja soli v Piranskih solinah od 16. do druge polovice 18. stoletja. Annales, Series Historia et Sociologia 11-1. Bradley, R. S. 1999: Paleoclimatology: Reconstructing climates of Quaternary. San Diego. Brancelj, A. 2021: Shifts in zooplankton communities in high-mountain lakes induced by singular events (fish stocking, earthquakes): Evidence from a 20-year survey in Slovenia (Central Europe). Aquatic Ecology 55-4. DOI: https://doi.org/10.1007/s10452-021-09858-1 Bratož, R. 2019: Pridelava in poraba hrane v provinci Venetia et Histria v vzhodnogotski dobi. Marušičev zbornik. Ljubljana. Brayshaw, D. J., Hoskins, B., Black, E. 2010: Some physical drivers of changes in the winter storm tracks over the North Atlantic and Mediterranean during the Holocene. Philosophical Transactions of the Royal Society, Mathematical, Physical and Engineering Science 368-1931. DOI: https://doi.org/10.1098/ rsta.2010.0180 Brayshaw, D. J., Rambeau, C. M. C., Smith, S. J. 2011: Changes in Mediterranean climate during the Holocene: Insights from global and regional climate modelling. The Holocene 21-1. DOI: https://doi.org/10.1177/ 0959683610377528 Brenčič, M. 2007: Subsidence rate of Ljubljansko barje in Holocene. Geologija 50-2. DOI: https://doi.org/ 10.5474/geologija.2007.031 Brynjólfsson, S., Schomacker, A., Ingólfsson, Ó., Keiding, J. K. 2015: Cosmogenic 36Cl exposure ages reveal a 9.3 ka BP glacier advance and the Late Weichselian-Early Holocene glacial history of the Drangajökull region, northwest Iceland. Quaternary Science Reviews 126. DOI: https://doi.org/10.1016/j.quascirev. 2015.09.001 Büntgen, U., Frank, D. C., Nievergelt, D., Esper, J. 2006: Summer temperature variations in the European Alps, A.D. 755–2004. Journal of Climate 19-21. DOI: https://doi.org/10.1175/jcli3917.1 Caf, N., Sabatier, P., Šmuc, A., Ogrinc, N., Dolenec, M., Rapuc, W., Potočnik, D. et al. 2023: Multi‐proxy reconstruction of the Holocene vegetation and land use dynamics in the Julian Alps, north‐west Slovenia. Journal of Quaternary Science 38-1. DOI: https://doi.org/10.1002/jqs.3461 Carey, A. E., Smith, D. F., Welch, S. A., Zorn, M., Tičar, J., Lipar, M., Komac, B. et al. 2020: The geochemistry of ice in the Triglav Area, Slovenia. Acta geographica Slovenica 60-2. DOI: https://doi.org/10.3986/ AGS.7420 Carey, A., Zorn, M., Tičar, J., Lipar, M., Komac, B., Welch, S., Smith, D. et al. 2019: Glaciochemistry of cave ice: Paradana and Snežna caves, Slovenia. Geosciences 9-2. DOI: https://doi.org/10.3390/ geosciences9020094 30 64-2_acta49-1.qxd 16.5.2024 13:11 Page 30 Carey, M. 2012: Climate and history: A critical review of historical climatology and climate change histori- ography. WIREs Climate Change 3-3. DOI: https://doi.org/10.1002/wcc.171 Cave Register: Speleological Association of Slovenia. Ljubljana, 2024. Cermak, V. 1971: Underground temperature and inferred climatic temperature of the past millennium. Palaeogeography, Palaeoclimatology, Palaeoecology 10-1. DOI: https://doi.org/10.1016/0031-0182(71) 90043-5 Chevalier, M., Davis, B. A. S., Heiri, O., Seppä, H., Chase, B. M., Gajewski, K., Lacourse, T. et al. 2020: Pollen- based climate reconstruction techniques for late Quaternary studies. Earth-Science Reviews 210. DOI: https://doi.org/10.1016/j.earscirev.2020.103384 Chiocci, F. L., Casalbore, D., Marra, F., Antonioli, F., Romagnoli, C. 2017: Relative sea level rise, palaeoto- pography and transgression velocity on the continental shelf. Under the Sea: Archaeology and Palaeolandscapes of the Continental Shelf. Cham. DOI: https://doi.org/10.1007/978-3-319-53160-1_3 Colucci, R. R., Fontana, D., Forte, E., Potleca, M., Guglielmin, M. 2016: Response of ice caves to weather extremes in the southeastern Alps, Europe. Geomorphology 261. DOI: https://doi.org/10.1016/ j.geomorph.2016.02.017 Colucci, R. R., Žebre, M. 2016: Late Holocene evolution of glaciers in the southeastern Alps. Journal of Maps 12-sup1. DOI: https://doi.org/10.1080/17445647.2016.1203216 Comas-Bru, L., Atsawawaranunt, K., Harrison, S. et al. 2020. SISAL (Speleothem Isotopes Synthesis and AnaLysis Working Group) database version 2.0. University of Reading Research Data Archive. DOI: https://doi.org/10.17864/1947.256 Cook, B. I., Anchukaitis, K. J., Touchan, R., Meko, D. M., Cook, E. R. 2016: Spatiotemporal drought vari- ability in the Mediterranean over the last 900 years. Journal of Geophysical Research: Atmospheres 121-5. DOI: https://doi.org/10.1002/2015jd023929 Cook, E. R., Anchukaitis, K. J., Buckley, B., D’Arrigo, R., Jacoby, G., Wright, W. E. 2010: Asian monsoon failure and megadrought during the last millennium. Science 328-5977. DOI: https://doi.org/10.1126/ science.1185188 Cook, E. R., Meko, D., Stahle, D. W., Cleaveland, M. K. 1999: Drought reconstructions for the continental United States. Journal of Climate 12-4. DOI: https://doi.org/10.1175/1520-0442(1999)012<1145: DRFTCU>2.0.CO;2 Cook, E. R., Seager, R., Kushnir, Y., Briffa, K. R., Büntgen, U., Frank, D., Krusic, P. J. et al. 2015: Old World megadroughts and pluvials during the Common Era. Science Advances 1-10. DOI: https://doi.org/ 10.1126/sciadv.1500561 Cook, E., Bird, T., Peterson, M., Barbetti, M., Buckley, B., D’Arrigo, R., Francey, R., Tans, P. 1991: Climatic change in Tasmania inferred from a 1089-year tree-ring chronology of Huon pine. Science 253-5025. DOI: https://doi.org/10.1126/science.253.5025.1266 Corona, C., Guiot, J., Edouard, J. L., Chalié, F., Büntgen, U., Nola, P., Urbinati, C. 2010: Millennium-long summer temperature variations in the European Alps as reconstructed from tree rings. Climate of the Past 6-3. DOI: https://doi.org/10.5194/cp-6-379-2010 Covelli, S., Fontolan, G., Faganeli, J., Ogrinc, N. 2006: Anthropogenic markers in the Holocene stratigraphic sequence of the Gulf of Trieste (northern Adriatic Sea). Marine Geology 230-1,2. DOI: https://doi.org/ 10.1016/j.margeo.2006.03.013 Culiberg, M. 1991: Late glacial vegetation in Slovenia. Ljubljana. Čater, M., Levanič, T. 2019: Beech and silver fir’s response along the Balkan’s latitudinal gradient. Scientific Reports 9-1. DOI: https://doi.org/10.1038/s41598-019-52670-z Čeč, D. 2015: Družbena percepcija in pravna obravnava zločinov iz stiske: primer eksistenčne krize 1816–1818 na Slovenskem. Upor, nasilje in preživetje: slovenski in evropski primeri iz srednjega in novega veka. Koper. Čeč, D. 2017: Gospodarska in družbena kriza zaradi izbruha vulkana Tambora v Indoneziji aprila 1815. Zgodovina v šoli 25-1. Čufar, K., De Luis, M., Eckstein, D., Kajfež-Bogataj, L. 2008: Reconstructing dry and wet summers in SE Slovenia from oak tree-ring series. International Journal of Biometeorology 52-7. DOI: https://doi.org/ 10.1007/s00484-008-0153-8 Acta geographica Slovenica, 64-2, 2024 31 64-2_acta49-1.qxd 16.5.2024 13:11 Page 31 Holocene climate variability in Slovenia: A review Dahl-Jensen, D., Mosegaard, K., Gundestrup, N., Clow, G. D., Johnsen, S. J., Hansen, A. W., Balling, N. 1998: Past temperatures directly from the Greenland ice sheet. Science 282-5387. DOI: https://doi.org/ 10.1126/science.282.5387.268 Dansgaard, W., Johnsen, S. J., Clausen, H. B., Dahl-Jensen, D., Gundestrup, N. S., Hammer, C. U., Hvidberg, C. S. et al. 1993: Evidence for general instability of past climate from a 250-kyr ice-core record. Nature 364-6434. DOI: https://doi.org/10.1038/364218a0 Del Gobbo, C., Colucci, R. R., Forte, E., Triglav Čekada, M., Zorn, M. 2016: The Triglav Glacier (South- Eastern Alps, Slovenia): Volume estimation, internal characterization and 2000–2013 temporal evolution by means of ground penetrating radar measurements. Pure and Applied Geophysics 173-8. DOI: https://doi.org/10.1007/s00024-016-1348-2 Denton, G. H., Karlén, W. 1973: Holocene climatic variations – Their pattern and possible cause. Quaternary Research 3-2. DOI: https://doi.org/10.1016/0033-5894(73)90040-9 Desnoyers, J. 1829: Observations sur un ensemble de dépôts marins plus récents que les terrains tertiaires du bassin de la Seine, et pouvant constituer une formation géologique distincte. Annales des sciences naturelles 16. Domínguez-Villar, D., Lojen, S., Krklec, K., Baker, A., Fairchild, I. J. 2015: Is global warming affecting cave temperatures? Experimental and model data from a paradigmatic case study. Climate Dynamics 45-3,4. DOI: https://doi.org/10.1007/s00382-014-2226-1 Domínguez-Villar, D., Lojen, S., Krklec, K., Kozdon, R., Edwards, R. L., Cheng, H. 2018: Ion microprobe δ18O analyses to calibrate slow growth rate speleothem records with regional δ18O records of precip- itation. Earth and Planetary Science Letters 482. DOI: https://doi.org/10.1016/j.epsl.2017.11.012 Easterbrook, D. J. 2016: Temperature fluctuations in Greenland and the Arctic. Evidence-Based Climate Science. Amsterdam. DOI: https://doi.org/10.1016/b978-0-12-804588-6.00008-2 Eddy, J. A. 1983: The Maunder Minimum: A reappraisal. Solar Physics 89-1. DOI: https://doi.org/10.1007/ bf00211962 Ellenberg, H. 1988: Vegetation ecology of Central Europe. Cambridge. Fairchild, I. J., Baker, A. 2012: Speleothem science: From process to past environments. Oxford. DOI: https://doi.org/10.1002/9781444361094 Ferk, M. 2016: Paleopoplave v porečju kraške Ljubljanice. Geografija Slovenije 33. Ljubljana. DOI: https://doi.org/ 10.3986/9789612548452 Ferk, M., Gabrovec, M., Komac, B., Zorn, M., Stepišnik, U. 2015: Pleistocene glaciation in Mediterranean Ferk, M., Lipar, M., Šmuc, A., Drysdale, R. N., Zhao, J. 2019: Chronology of heterogeneous deposits in the side entrance of Postojna Cave, Slovenia. Acta geographica Slovenica 59-1. DOI: https://doi.org/10.3986/ AGS.7059 Feurdean, A., Klotz, S., Brewer, S., Mosbrugger, V., Tămaş, T., Wohlfarth, B. 2008: Lateglacial climate devel- opment in NW Romania – Comparative results from three quantitative pollen-based methods. Palaeogeography, Palaeoclimatology, Palaeoecology 265-1,2. DOI: https://doi.org/10.1016/j.palaeo.2008.04.024 Feurdean, A., Perşoiu, A., Tanţău, I., Stevens, T., Magyari, E. K., Onac, B. P., Marković, S. et al. 2014: Climate variability and associated vegetation response throughout Central and Eastern Europe (CEE) between 60 and 8 ka. Quaternary Science Reviews 106. DOI: https://doi.org/10.1016/j.quascirev.2014.06.003 Ford, D., Williams, P. 2007: Karst hydrogeology and geomorphology. Chichester. DOI: https://doi.org/10.1002/ 9781118684986 Gabrovec, M., Hrvatin, M. 1998: Površje. Geografski atlas Slovenije. Ljubljana. Gabrovec, M., Hrvatin, M., Komac, B., Ortar, J., Pavšek, M., Topole, M., Triglav Čekada, M., Zorn. M. 2014: Triglavski ledenik. Geografija Slovenije 30. Ljubljana. DOI: https://doi.org/10.3986/9789610503644 Gabrovec, M., Ortar, J., Pavšek, M., Zorn, M., Triglav Čekada, M. 2013: The Triglav glacier between the years 1999 and 2012. Acta geographica Slovenica 53-2. DOI: https://doi.org/10.3986/AGS53202 Gałka, M., Tanţău, I., Ersek, V., Feurdean, A. 2016: A 9000 year record of cyclic vegetation changes iden- tified in a montane peatland deposit located in the Eastern Carpathians (Central-Eastern Europe): Autogenic succession or regional climatic influences? Palaeogeography, Palaeoclimatology, Palaeoecology 449. DOI: https://doi.org/10.1016/j.palaeo.2016.02.007 Genty, D., Baker, A., Vokal, B. 2001: Intra- and inter-annual growth rate of modern stalagmites. Chemical Geology 176-1,4. DOI: https://doi.org/10.1016/s0009-2541(00)00399-5 32 64-2_acta49-1.qxd 16.5.2024 13:11 Page 32 Genty, D., Vokal, B., Obelic, B., Massault, M. 1998: Bomb 14C time history recorded in two modern sta- lagmites – importance for soil organic matter dynamics and bomb 14C distribution over continents. Earth and Planetary Science Letters 160-3,4. DOI: https://doi.org/10.1016/s0012-821x(98)00128-9 Gervais, P. 1847: Mémoires de la Section des sciences 1. Montpellier. Gestrin, F. 1969: Oris gospodarstva na Slovenskem v obdobju agrarne revolucije in prevlade manufakturne proizvodnje. Kronika 17-2. Gibbard, P. L., Head, M., J. 2020: The Quaternary Period. Geologic Time Scale 2020. Amsterdam. DOI: https://doi.org/10.1016/B978-0-12-824360-2.00030-9 Gibbons, A. 2018: Why 536 was ‘the worst year to be alive’. Science. DOI: https://doi.org/10.1126/ science.aaw0632 Gospodarič, R. 1988: Paleoclimatic record of cave sediments from Postojna Karst. Annales de la Société géologique de Belgique 111. Gregoire, L. J., Otto-Bliesner, B., Valdes, P. J., Ivanovic, R. 2016: Abrupt Bølling warming and ice saddle collapse contributions to the Meltwater Pulse 1a rapid sea level rise. Geophysical Research Letters 43-17. DOI: https://doi.org/10.1002/2016GL070356 Grove, J. M. 2004: Little ice ages: Ancient and modern. London. DOI: https://doi.org/10.4324/9780203770269 Grunewald, K., Scheithauer, J. 2010: Europe’s southernmost glaciers: response and adaptation to climate change. Journal of Glaciology 56-195. DOI: https://doi.org/10.3189/002214310791190947 Haas, J. N., Richoz, I., Tinner, W., Wick, L. 1998: Synchronous Holocene climatic oscillations recorded on the Swiss Plateau and at timberline in the Alps. The Holocene 8-3. DOI: https://doi.org/10.1191/ 095968398675491173 Hafner, P., McCarroll, D., Robertson, I., Loader, N., Gagen, M., Young, G., Bale, R. et al. 2014: A 520 year record of summer sunshine for the eastern European Alps based on stable carbon isotopes in larch tree rings. Climate Dynamics 43-3. DOI: https://doi.org/10.1007/s00382-013-1864-z Hammer, C. U. 2006: Ice-core chronology. Glacier Science and Environmental Change. Oxford. DOI: https://doi.org/10.1002/9780470750636.ch78 Harding, P., Langdon, C., Walsh, A., Biddulph, G. E., Blockley, S. P. E., Milner, A. M., Langdon, P. et al. 2020: The 2.8 BP Event: A high-resolution multiproxy perspective from Diss Mere, Norfolk, UK. EGU General Assembly. DOI: https://doi.org/10.5194/egusphere-egu2020-11311 Hardy, J. T. 2003: Climate change: Causes, effects, and solutions. Chichester. Head, M. J., Pillans, B., Zalasiewicz, J. A. 2021: Formal ratification of subseries for the Pleistocene series of the Quaternary System. Episodes 44-3. DOI: https://doi.org/10.18814/epiiugs/2020/020084 Higgins, J. A., Kurbatov, A. V., Spaulding, N. E., Brook, E., Introne, D. S., Chimiak, L. M., Yan, Y. et al. 2015: Atmospheric composition 1 million years ago from blue ice in the Allan Hills, Antarctica. PNAS, Earth, Atmospheric, and Planetary Sciences 112-22. DOI: https://doi.org/10.1073/pnas.1420232112 Hobart, B., Lisiecki, L. E., Rand, D., Lee, T., Lawrence, C. E. 2023: Late Pleistocene 100-kyr glacial cycles paced by precession forcing of summer insolation. Nature Geoscience 16. DOI: https://doi.org/10.1038/ s41561-023-01235-x Horvatinčić, N., Krajcar Bronić, I., Obelić, B. 2003: Differences in the 14C age, δ13C and δ18O of Holocene tufa and speleothem in the Dinaric Karst. Palaeogeography, Palaeoclimatology, Palaeoecology 193. DOI: https://doi.org/10.1016/S0031-0182(03)00224-4 Hrvatin, M., Zorn, M. 2020: Climate and hydrological changes in Slovenia’s mountain regions between 1961 and 2018. Ekonomska i ekohistorija 16. IPCC 2007. Climate Change 2007: Synthesis report. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Intergovernmental Panel on Climate Change. Geneva. IPCC 2018. Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty. Intergovernmental Panel on Climate Change. Geneva. Isola, I., Zanchetta, G., Drysdale, R. N., Regattieri, E., Bini, M., Bajo, P., Hellstrom, J. C. et al. 2019: The 4.2 ka event in the central Mediterranean: New data from a Corchia speleothem (Apuan Alps, central Italy). Climate of the Past 15-1. DOI: https://doi.org/10.5194/cp-15-135-2019 Acta geographica Slovenica, 64-2, 2024 33 64-2_acta49-1.qxd 16.5.2024 13:11 Page 33 Holocene climate variability in Slovenia: A review Ivy-Ochs, S., Kerschner, H., Maisch, M., Christl, M., Kubik, P. W., Schlüchter, C. 2009: Latest Pleistocene and Holocene glacier variations in the European Alps. Quaternary Science Reviews 28-21,22. DOI: https://doi.org/10.1016/j.quascirev.2009.03.009 Ivy-Ochs, S., Kerschner, H., Reuther, A., Preusser, F., Heine, K., Maisch, M., Kubik, P. W. et al. 2008: Chronology of the last glacial cycle in the European Alps. Journal of Quaternary Science 23-6,7. DOI: https://doi.org/10.1002/jqs.1202 Jansen, E., Overpeck, J., Briffa, K. R., Duplessy, J. C., Joos, F., Masson-Delmotte, V., Olago, D. et al. 2007: Palaeoclimate. The physical science basis. Climate Change 2007. Cambridge. Jiang, D., Lang, X., Tian, Z., Wang, T. 2012: Considerable model–data mismatch in temperature over China during the Mid-Holocene: Results of PMIP simulations. Journal of Climate 25-12. DOI: https://doi.org/ 10.1175/jcli-d-11-00231.1 Kalis, A. J., Merkt, J., Wunderlich, J. 2003: Environmental changes during the Holocene climatic optimum in central Europe – human impact and natural causes. Quaternary Science Reviews 22-1. DOI: https://doi.org/ 10.1016/s0277-3791(02)00181-6 Kehrl, L., Conway, H., Holschuh, N., Campbell, S., Kurbatov, A. V., Spaulding, N. E. 2018: Evaluating the duration and continuity of potential climate records from the Allan Hills Blue Ice area, East Antarctica. Geophysical Research Letters 45-9. DOI: https://doi.org/10.1029/2018gl077511 Kerschner, H., Ivy-Ochs, S. 2008: Palaeoclimate from glaciers: Examples from the Eastern Alps during the Alpine Lateglacial and early Holocene. Global and Planetary Change 60-1,2. DOI: https://doi.org/ 10.1016/j.gloplacha.2006.07.034 Kolar, N. 2020: Extraordinary winter weather events in the area of Ptuj from 1700 to 1941. Ekonomska i ekohistorija 16. Komac, B., Pavšek, M., Topole, M. 2020: Climate and weather of Slovenia. The geography of Slovenia: Small but diverse. World Regional Geography Book Series. Cham. DOI: https://doi.org/10.1007/978-3-030- 14066-3_5 Kozamernik, E., Colucci, R. R., Stepišnik, U., Forte, E., Žebre, M. 2018: Spatial and climatic characterization of three glacial stages in the Upper Krnica Valley, SE European Alps. Quaternary International 470-A. DOI: https://doi.org/10.1016/j.quaint.2017.05.047 Kranjc, A. 2009: Ice change in the caves of Slovenia shown by the old literature. Data of Glaciological Studies Publication 107, 14th Glaciological Symposium. Irkutsk. Kutzbach, J. E., Guetter, P. J. 1986: The influence of changing orbital parameters and surface boundary con- ditions on climate simulations for the past 18 000 years. Journal of the Atmospheric Sciences 43-16. DOI: https://doi.org/10.1175/1520-0469(1986)043<1726:Tiocop>2.0.Co;2 Last, W., Smol, J. P. 2001: Tracking environmental change using lake sediments. Volume 2: Physical and gochemical methods. Dordrecht. DOI: https://doi.org/10.1007/0-306-47670-3 Lauterbach, S., Brauer, A., Andersen, N., Danielopol, D. L., Dulski, P., Hüls, M., Milecka, K. et al. 2011: Environmental responses to Lateglacial climatic fluctuations recorded in the sediments of pre-Alpine Lake Mondsee (northeastern Alps). Journal of Quaternary Science 26-3. DOI: https://doi.org/10.1002/ jqs.1448 Lemieux-Dudon, B., Blayo, E., Petit, J.-R., Waelbroeck, C., Svensson, A., Ritz, C., Barnola, J.-M. et al. 2010: Consistent dating for Antarctic and Greenland ice cores. Quaternary Science Reviews 29. DOI: https://doi.org/10.1016/j.quascirev.2009.11.010 Levanič, T. 2005: Vpliv klime na debelinsko rast macesna (Larix decidua Mill.) na zgornji gozdni meji v JV Alpah. Zbornik gozdarstva in lesarstva 78. Lipar, M., Drysdale, R., Zhao, J. X. 2019: The preliminary results of the Holocene stalagmite palaeoenvi- ronmental record from Postojna Cave, Slovenia. INQUA 2019. Dublin. Lipar, M., Martín-Pérez, A., Tičar, J., Pavšek, M., Gabrovec, M., Hrvatin, M., Komac, B. et al. 2021: Subglacial carbonate deposits as a  potential proxy for a  glacier’s former presence. Cryosphere 15-1. DOI: https://doi.org/10.5194/tc-15-17-2021 Liu, Z., Zhu, J., Rosenthal, Y., Zhang, X., Otto-Bliesner, B. L., Timmermann, A., Smith, R. S. et al. 2014: The Holocene temperature conundrum. PNAS Environmental Sciences 111-34. DOI: https://doi.org/ 10.1073/pnas.1407229111 34 64-2_acta49-1.qxd 16.5.2024 13:11 Page 34 Luterbacher, J., García-Herrera, R., Acker-On, S., Allan, R., Alvarez-Castro, M.-C., Benito, G., Booth, J. et al. 2012: A review of 2000 years of paleoclimatic evidence in the Mediterranean. The Climate of the Mediterranean Region. Amsterdam. DOI: https://doi.org/10.1016/B978-0-12-416042-2.00002-1 Lyell, C. 1839: Éléments de géologie. Paris. Magny, M. 2004: Holocene climate variability as reflected by mid-European lake-level fluctuations and its probable impact on prehistoric human settlements. Quaternary International 113-1. DOI: https://doi.org/ 10.1016/s1040-6182(03)00080-6 Magny, M., Haas, J. N. 2004: A major widespread climatic change around 5300 cal. yr BP at the time of the Alpine Iceman. Journal of Quaternary Science 19-5. DOI: https://doi.org/10.1002/jqs.850 Magny, M., Joannin, S., Galop, D., Vannière, B., Haas, J. N., Bassetti, M., Bellintani, P. et al. 2012: Holocene palaeohydrological changes in the northern Mediterranean borderlands as reflected by the lake-level record of Lake Ledro, northeastern Italy. Quaternary Research 77-3. DOI: https://doi.org/ 10.1016/j.yqres.2012.01.005 Magri, D., Vendramin, G. G., Comps, B., Dupanloup, I., Geburek, T., Gomory, D., Latałowa, M. et al. 2006: A new scenario for the Quaternary history of European beech populations: Palaeobotanical evidence and genetic consequences. New Phytologist 171-1. DOI: https://doi.org/10.1111/j.1469-8137.2006.01740.x Mandić, M., Mihevc, A., Leis, A., Lojen, S., Krajcar Bronić, I. 2013: Mean residence time of drip water in Postojna Cave, Slovenia. 3rd International Conference Waters in Sensitive and Protected Areas. Zagreb. Marcott, S. A., Shakun, J. D., Clark, P. U., Mix, A. C. 2013: A reconstruction of regional and global temperature for the past 11,300 years. Science 339-6124. DOI: https://doi.org/10.1126/science.1228026 Marsicek, J., Shuman, B. N., Bartlein, P. J., Shafer, S. L., Brewer, S. 2018: Reconciling divergent trends and millennial variations in Holocene temperatures. Nature 554-7690. DOI: https://doi.org/10.1038/ nature25464 Martinelli, N. 2004: Climate from dendrochronology: Latest developments and results. Global and Planetary Change 40-1,2. DOI: https://doi.org/10.1016/s0921-8181(03)00103-6 Matero, I. S. O., Gregoire, L. J., Ivanovic, R. F., Tindall, J. C., Haywood, A. M. 2017: The 8.2 ka cooling event caused by Laurentide ice saddle collapse. Earth and Planetary Science Letters 473. DOI: https://doi.org/ 10.1016/j.epsl.2017.06.011 Mautner, A.-K., Gallmetzer, I., Haselmair, A., Schnedl, S.-M., Tomašových, A., Zuschin, M. 2018: Holocene ecosystem shifts and human-induced loss of Arca and Ostrea shell beds in the north-eastern Adriatic Sea. Marine Pollution Bulletin 126. DOI: https://doi.org/10.1016/j.marpolbul.2017.10.084 May, B., Spötl, C., Wagenbach, D., Dublyansky, Y., Liebl, J. 2011: First investigations of an ice core from Eisriesenwelt cave (Austria). The Cryosphere 5-1. DOI: https://doi.org/10.5194/tc-5-81-2011 Mayewski, P. A., Rohling, E. E., Stager, J. C., Karlén, W., Maasch, K. A., Meeker, L. D., Meyerson, E. A. et al. 2004: Holocene climate variability. Quaternary Research 62-3. DOI: https://doi.org/10.1016/ j.yqres.2004.07.001 McDermott, F., Frisia, S., Huang, Y., Longinelli, A., Spiro, B., Heaton, T. H. E., Hawkesworth, C. J. et al. 1999: Holocene climate variability in Europe: Evidence from δ18O, textural and extension-rate varia- tions in three speleothems. Quaternary Science Reviews 18-8,9. DOI: https://doi.org/10.1016/ s0277-3791(98)00107-3 Meese, D. A., Gow, A. J., Grootes, P., Stuiver, M., Mayewski, P. A., Zielinski, G. A., Ram, M. et al. 1994: The accumulation record from the GISP2 core as an indicator of climate change throughout the Holocene. Science 266-5191. DOI: https://doi.org/10.1126/science.266.5191.1680 Mencej, Z. 1990: Prodni zasipi pod jezerskimi sedimenti Ljubljanskega barja. Geologija 31-32. Mihevc, A. 2018: Ice caves in Slovenia. Ice caves. Amsterdam. DOI: https://doi.org/10.1016/b978-0-12-811739- 2.00030-9 Mihevc, A. 2021: Ice in caves and its effect on thermal inversion and permafrost in the case of the Velika ledena jama v Paradani, Smrekova draga and neighbouring dolines. Acta Carsologica 50-2,3. DOI: https://doi.org/10.3986/ac.v50i2-3.10495 Muri, G. 2013: Atmospheric deposition chemistry in a subalpine area of the Julian Alps, North-West Slovenia. Journal of Limnology 72-2. DOI: https://doi.org/10.4081/jlimnol.2013.e23 Muri, G., Čermelj, B., Jaćimović, R., Ravnikar, T., Šmuc, A., Turšič, J., Vreča, P. 2018: Factors that contributed to recent eutrophication of two Slovenian mountain lakes. Journal of Paleolimnology 59. DOI: https://doi.org/10.1007/s10933-017-9996-5 Acta geographica Slovenica, 64-2, 2024 35 64-2_acta49-1.qxd 16.5.2024 13:11 Page 35 Holocene climate variability in Slovenia: A review Muri, G., Čermelj, B., Jaćimović, R., Skaberne, D., Šmuc, A., Burnik Šturm, M., Turšič, J., Vreča, P. 2013: Consequences of anthropogenic activity for two remote alpine lakes in NW Slovenia as tracked by sed- iment geochemistry. Journal of Paleolimnology 50-4. DOI: https://doi.org/10.1007/s10933-013-9738-2 Muri, G., Wakeham, S. G., Pease, T. K., Faganeli, J. 2004: Evaluation of lipid biomarkers as indicators of changes in organic matter delivery to sediments from Lake Planina, a remote mountain lake in NW Slovenia. Organic Geochemistry 35-10. DOI: https://doi.org/10.1016/j.orggeochem.2004.06.004 Muri, G., Wakeham, S. G., Rose, N. L. 2006: Records of atmospheric delivery of pyrolysis-derived pollu- tants in recent mountain lake sediments of the Julian Alps (NW Slovenia). Environmental Pollution 139-3. DOI: https://doi.org/10.1016/j.envpol.2005.06.002 Nicolussi, K., Kaufmann, M., Melvin, T. M., van der Plicht, J., Schießling, P., Thurner, A. 2009: A 9111 year long conifer tree-ring chronology for the European Alps: A base for environmental and climatic inves- tigations. The Holocene 19-6. DOI: https://doi.org/10.1177/0959683609336565 Nicolussi, K., Le Roy, M., Schlüchter, C., Stoffel, M., Wacker, L. 2022: The glacier advance at the onset of the Little Ice Age in the Alps: New evidence from Mont Miné and Morteratsch glaciers. The Holocene 32-7. DOI: https://doi.org/10.1177/09596836221088247 Novak, A., Šmuc, A., Poglajen, S., Vrabec, M. 2020: Linking the high-resolution acoustic and sedimentary facies of a transgressed Late Quaternary alluvial plain (Gulf of Trieste, northern Adriatic). Marine Geology 419. DOI: https://doi.org/10.1016/j.margeo.2019.106061 Nussbaumer, S. U., Steinhilber, F., Trachsel, M., Breitenmoser, P., Beer, J., Blass, A., Grosjean, M. et al. 2011: Alpine climate during the Holocene: A comparison between records of glaciers, lake sediments and solar activity. Journal of Quaternary Science 26-7. DOI: https://doi.org/10.1002/jqs.1495 O’Brien, S. R., Mayewski, P. A., Meeker, L. D., Meese, D. A., Twickler, M. S., Whitlow, S. I. 1995: Complexity of Holocene climate as reconstructed from a Greenland ice core. Science 270-5244. DOI: https://doi.org/ 10.1126/science.270.5244.1962 Ogorelec, B., Faganeli, J., Mišič, M., Čermelj, B. 1997: Reconstruction of paleoenvironment in the Bay of Koper (Gulf of Trieste, northern Adriatic). Annales, Series Historia Naturalis 7-1. Ogorelec, B., Mišič, M., Faganeli, J. 2000: Sečoveljske soline – geološki laboratorij v naravi. Annales, Series Historia Naturalis 10-2. Ogorelec, B., Mišič, M., Šercelj, A., Cimerman, F., Faganeli, J., Stegnar, P. 1981: Sediment sečoveljske soline. Geologija 24-2. Ogrin, D. 1994: Modern age climatic fluctuation in the area of the Gulf of Trieste. Geografski zbornik 34. Ogrin, D. 2003: Suha in mokra leta v submediteranski Sloveniji od 14. do srede 19. stoletja. Annales, Series Historia Naturalis 13-1. Ogrin, D. 2005: Spreminjanje podnebja v holocenu. Geografski vestnik 77-1. Ogrin, D. 2007a: Olive growing in Slovenian Istria and climatic limitations to its development. Moravian Geographical Reports 15-3. Ogrin, D. 2007b: Severe storms and their effects in sub-Mediterranean Slovenia from the 14th to the mid- 19th century. Acta geographica Slovenica 47-1. DOI: https://doi.org/10.3986/ags47101 Ogrin, D. 2008: Climate, Scale: 1 : 1,000,000. Slovenia in focus. Ljubljana. Ogrin, D. 2012: Climate research on Slovenian territory in pre-instrumental period: Weather and climate in the 17th century. Geografski vestnik 84-1. Ogrinc, N., Covelli, S., Ogorelec, B., Faganeli, J., Budja, M. 2012: Rekonstrukcija paleookolja Tržaškega zaliva v holocenu z uporabo geokemijskih metod. Dolgoročne spremembe okolja. Ljubljana. DOI: https://doi.org/10.3986/9789612545925 Ogrinc, N., Faganeli, J., Ogorelec, B., Čermelj, B. 2007: The origin of organic matter in Holocene sediments in the Bay of Koper (Gulf of Trieste, northern Adriatic Sea). Geologija 50-1. DOI: https://doi.org/10.5474/ geologija.2007.014 Oppenheimer, C. 2003: Climatic, environmental and human consequences of the largest known historic eruption: Tambora volcano (Indonesia) 1815. Progress in Physical Geography: Earth and Environment 27-2. DOI: https://doi.org/10.1191/0309133303pp379ra Osole, F. 1968: Jamski sediment Notranjsko-Primorskega krasa kot posledica pleistocenskih klimatskih nihanj. Prvi kolokvij o geologiji Dinaridov. Ljubljana. 36 64-2_acta49-1.qxd 16.5.2024 13:11 Page 36 Paliska, D., Kerma, S., Čop, R., Bonin, F. 2015: An attempt to demonstrate the influence of Maunder min- imum climate on salt production and its price in the Slovenian Istria (Sečovlje salt-pans). Annales, Series Historia Naturalis 25-2. Park, J., Park, J., Yi, S., Cheul Kim, J., Lee, E., Choi, J. 2019: Abrupt Holocene climate shifts in coastal East Asia, including the 8.2 ka, 4.2 ka, and 2.8 ka BP events, and societal responses on the Korean peninsula. Scientific Reports 9-1. DOI: https://doi.org/10.1038/s41598-019-47264-8 Patzelt, G., Bortenschlager, S. 1973: Die postglazialen Gletscher- und Klimaschwankungen in der Venedigergruppe (Hohe Tauern, Ostalpen). Zeitschrift für Geomorphologie 16. Pavšek, M. 2007: Ledenik pod Skuto kot pokazatelj podnebnih sprememb v slovenskem delu Alp. Dela 28. DOI: https://doi.org/10.4312/dela.28.207-219 Pavšek, M. 2023: Triglavski ledenik. DEDI – digitalna enciklopedija naravne in kulturne dediščine na Slovenskem. Internet: http://dedi.si/dediscina/449-triglavski-ledenik (6. 2. 2024). Petit, R., Aguinagalde, I., de Beaulieu, J. L., Bittkau, C., Brewer, S., Cheddadi, R., Ennos, R. et al. 2003: Glacial refugia: Hotspots but not melting pots of genetic diversity. Science 300-5625. DOI: https://doi.org/ 10.1126/science.1083264 Peyron, O., Bégeot, C., Brewer, S., Heiri, O., Magny, M., Millet, L., Ruffaldi, P. et al. 2005: Late-Glacial cli- matic changes in Eastern France (Lake Lautrey) from pollen, lake-levels, and chironomids. Quaternary Research 64-2. DOI: https://doi.org/10.1016/j.yqres.2005.01.006 Rach, O., Engels, S., Kahmen, A., Brauer, A., Martín-Puertas, C., van Geel, B., Sachse, D. 2017: Hydrological and ecological changes in western Europe between 3200 and 2000 years BP derived from lipid biomarker δD values in lake Meerfelder Maar sediments. Quaternary Science Reviews 172. DOI: https://doi.org/ 10.1016/j.quascirev.2017.07.019 Racine, T. M. F., Spötl, C., Reimer, P. J., Čarga, J. 2022: Radiocarbon constraints on periods of positive cave ice mass balance during the last Millennium, Julian Alps (NW Slovenia). Radiocarbon 64-2. DOI: https://doi.org/10.1017/rdc.2022.26 Rahmstorf, S. 2002: Ocean circulation and climate during the past 120,000 years. Nature 419-6903. DOI: https://doi.org/10.1038/nature01090 Rajšp, V. 1988: Čarovniški procesi na Slovenskem. Zgodovinski časopis 42-3. Rajver, D., Šafanda, J., Shen, P. Y. 1998: The climate record inverted from borehole temperatures in Slovenia. Tectonophysics 291. DOI: https://doi.org/10.1016/S0040-1951(98)00045-6 Ran, M., Chen, L. 2019: The 4.2 ka BP climatic event and its cultural responses. Quaternary International 521. DOI: https://doi.org/10.1016/j.quaint.2019.05.030 Rapuc, W., Sabatier, P., Arnaud, F., Palumbo, A., Develle, A.-L., Reyss, J.-L., Augustin, L. et al. 2019: Holocene- long record of flood frequency in the Southern Alps (Lake Iseo, Italy) under human and climate forcing. Global and Planetary Change 175. DOI: https://doi.org/10.1016/j.gloplacha.2019.02.010 Renssen, H., Seppä, H., Heiri, O., Roche, D. M., Goosse, H., Fichefet, T. 2009: The spatial and temporal complexity of the Holocene thermal maximum. Nature Geoscience 2-6. DOI: https://doi.org/10.1038/ ngeo513 Ruddiman, W., 2014: Earth’s climate: Past and future. New York. Sabatier, P., Wilhelm, B., Ficetola, G. F., Moiroux, F., Poulenard, J., Develle, A.-L., Bichet, A. et al. 2017: 6-kyr record of flood frequency and intensity in the western Mediterranean Alps – Interplay of solar and temperature forcing. Quaternary Science Reviews 170. DOI: https://doi.org/10.1016/j.quascirev. 2017.06.019 Schmidt, R., Kamenik, C., Tessadri, R., Koinig, K. A. 2006: Climatic changes from 12,000 to 4,000 years ago in the Austrian Central Alps tracked by sedimentological and biological proxies of a lake sediment core. Journal of Paleolimnology 35-3. DOI: https://doi.org/10.1007/s10933-005-2351-2 Schwikowski, M., Brütsch, S., Gäggeler, H. W., Schotterer, U. 1999: A high-resolution air chemistry record from an Alpine ice core: Fiescherhorn glacier, Swiss Alps. Journal of Geophysical Research: Atmospheres 104-D11. DOI: https://doi.org/10.1029/1998jd100112 Seppä, H., Birks, H. J. B. 2001: July mean temperature and annual precipitation trends during the Holocene in the Fennoscandian tree-line area: Pollen-based climate reconstructions. The Holocene 11-5. DOI: https://doi.org/10.1191/095968301680223486 Acta geographica Slovenica, 64-2, 2024 37 64-2_acta49-1.qxd 16.5.2024 13:11 Page 37 Holocene climate variability in Slovenia: A review Sevink, J., van Bergen, M. J., van der Plicht, J., Feiken, H., Anastasia, C., Huizinga, A. 2011: Robust date for the Bronze Age Avellino eruption (Somma-Vesuvius): 3945±10 calBP (1995±10 calBC). Quaternary Science Reviews 30-9,10. DOI: https://doi.org/10.1016/j.quascirev.2011.02.001 Siegwolf, R. T. W., Brooks, J. R., Roden, J., Saurer, M. (eds.) 2021: Stable isotopes in tree rings: Inferring physiological, climatic and environmental responses. Cham. DOI: https://doi.org/10.1007/978-3-030- 92698-4 Sigl, M., Winstrup, M., McConnell, J. R., Welten, K. C., Plunkett, G., Ludlow, F., Buntgen, U. et al. 2015: Timing and climate forcing of volcanic eruptions for the past 2,500 years. Nature 523-7562. DOI: https://doi.org/10.1038/nature14565 Smith, D. F., Lyons, W. B., Welch, S. A., Zorn, M., Tičar, J., Lipar, M., Carey, A. E. 2023: The chemistry of cave ice: Two examples from Slovenia. Environmental and Engineering Geoscience 29-4. DOI: https://doi.org/10.21663/EEG-D-23-00001 Solomina, O. N., Bradley, R. S., Hodgson, D. A., Ivy-Ochs, S., Jomelli, V., Mackintosh, A. N., Nesje, A. et al. 2015: Holocene glacier fluctuations. Quaternary Science Reviews 111. DOI: https://doi.org/10.1016/ j.quascirev.2014.11.018 Sršen, S. 2019. Dolga rekonstrukcija klime s pomočjo drevesnih branik hrasta (Quercus species) na zahodnem delu Panonske nižine. Master thesis, Univerza v Ljubljani. Ljubljana. Stepišnik, U., Ferk, M., Gostinčar, P., Černuta, L. 2012: Holocene high floods on the Planina Polje, Classical Dinaric Karst, Slovenia. Acta Carsologica 41-1. DOI: https://doi.org/10.3986/ac.v41i1.44 Stroeven, A. P., Harbor, J., Fabel, D., Kleman, J., Hättestrand, C., Elmore, D., Fink, D. 2006: Characteristic cosmogenic nuclide concentrations in relict surfaces of formerly glaciated regions. Glacier Science and Environmental Change. Oxford. DOI: https://doi.org/10.1002/9780470750636.ch90 Studen, A. 2018: Lakota na Notranjskem 1865: primer okraja Lož. Lakote in pomanjkanje: slovenski primer. Ljubljana. Šafanda, J., Rajver, D. 2001: Signature of the last ice age in the present subsurface temperatures in the Czech Republic and Slovenia. Global and Planetary Change 29-3,4. DOI: https://doi.org/10.1016/S0921- 8181(01)00093-5 Šafanda, J., Rajver, D., Correia, A., Dĕdeček, P. 2007: Repeated temperature logs from Czech, Slovenian and Portuguese borehole climate observatories. Climate of the Past 3. DOI: https://doi.org/10.5194/ cp-3-453-2007 Šebela, S., Miler, M., Skobe, S., Torkar, S., Zupančič, N. 2015: Characterization of black deposits in karst caves, examples from Slovenia. Facies 61-6. DOI: https://doi.org/10.1007/s10347-015-0430-z Šebela, S., Zupančič, N., Miler, M., Grčman, H., Jarc S. 2017: Evidence of Holocene surface and near-sur- face palaeofires in karst caves and soils. Palaeogeography, Palaeoclimatology, Palaeoecology 485. DOI: https://doi.org/10.1016/j.palaeo.2017.06.015 Šercelj, A. 1966: Pelodne analize pleistocenskih in holocenskih sedimentov Ljubljanskega barja. Ljubljana. Šifrer, M. 1963: Nova geomorfološka dognanja na Triglavu. Geografski zbornik 8. Štok, K. 2022: Preliminarno poročilo meritev z georadarsko metodo na Triglavskem ledeniku. Poročilo, Konstat biro. Ljubljana. Thomas, E. R., Wolff, E. W., Mulvaney, R., Steffensen, J. P., Johnsen, S. J., Arrowsmith, C., White, J. W. C. et al. 2007: The 8.2ka event from Greenland ice cores. Quaternary Science Reviews 26-1,2. DOI: https://doi.org/10.1016/j.quascirev.2006.07.017 Thornton, P. K., Ericksen, P. J., Herrero, M., Challinor, A. J. 2014: Climate variability and vulnerability to climate change: A review. Global Change Biology 20-11. DOI: https://doi.org/10.1111/gcb.12581 Tinner, W., Lotter, A. 2006: Holocene expansions of Fagus silvatica and Abies alba in Central Europe: Where are we after eight decades of debate? Quaternary Science Reviews 25-5,6. DOI: https://doi.org/10.1016/ j.quascirev.2005.03.017 Traverse, A. 2007: Paleopalynology. Dordrecht. DOI: https://doi.org/10.1007/978-1-4020-5610-9 Triglav Čekada, M., Barbo, P., Pavšek, M., Zorn, M. 2020: Changes in the Skuta Glacier (southeastern Alps) assessed using non-metric images. Acta geographica Slovenica 60-2. DOI: https://doi.org/10.3986/ ags.7674 Triglav Čekada, M., Zorn, M., Colucci, R. R. 2014: Changes in the area of the Canin (Italy) and Triglav Glaciers (Slovenia) since 1893 based on archive images and aerial laser scanning. Geodetski vestnik 58-2. DOI: https://doi.org/10.15292/geodetski-vestnik.2014.02.274-313 38 64-2_acta49-1.qxd 16.5.2024 13:11 Page 38 Urbanc, J., Pezdič, J., Dolenec, T., Perko, S. 1985: O izotopih kisika in ogljika v jamskih vodah in sigah Slovenije. Acta Carsologica 8. Urbanc, J., Pezdič, J., Krajcar Bronić, I., Srdoč, D. 1987: Comparison of isotopic composition of different forms of calcite precipitated from fresh water. Isotope Techniques in Water Resources Development, Proceedings of International Symposium on the Use of Isotope Techniques in Water Resources Development. Vienna. Valvasor, J. W. 1689: Die Ehre dess Hertzogthums Crain. Ljubljana. Vannière, B., Magny, M., Joannin, S., Simonneau, A., Wirth, S. B., Hamann, Y., Chapron, E. et al. 2013: Orbital changes, variation in solar activity and increased anthropogenic activities: Controls on the Holocene flood frequency in the Lake Ledro area, Northern Italy. Climate of the Past 9-3. DOI: https://doi.org/ 10.5194/cp-9-1193-2013 Verbič, T., Horvat A. 2009: Geologija Ljubljanskega barja. Ljubljanica – kulturna dediščina reke. Ljubljana. Vescovi, E., Ravazzi, C., Arpenti, E., Finsinger, W., Pini, R., Valsecchi, V., Wick, L. et al. 2007: Interactions between climate and vegetation during the Lateglacial period as recorded by lake and mire sediment archives in Northern Italy and Southern Switzerland. Quaternary Science Reviews 26-11,12. DOI: https://doi.org/10.1016/j.quascirev.2007.03.005 Vokal, B. 1999. The carbon transfer in karst areas – An application to the study of environmental changes and paleoclimatic reconstruction. Ph.D. thesis, Nova Gorica Polytechnic. Nova Gorica. Vreča, P., Krajcar Bronić, I., Horvatinčić, N., Barešić, J. 2006: Isotopic characteristics of precipitation in Slovenia and Croatia: Comparison of continental and maritime stations. Journal of Hydrology 330-3,4. DOI: https://doi.org/10.1016/j.jhydrol.2006.04.005 Vreča, P., Muri, G. 2006: Changes in accumulation of organic matter and stable carbon and nitrogen isotopes in sediments of two Slovenian mountain lakes (Lake Ledvica and Lake Planina), induced by eutrophication changes. Limnology and Oceanography 51-1,2. DOI: https://doi.org/10.4319/lo.2006.51.1_part_2.0781 Vreča, P., Muri, G. 2010: Sediment organic matter in mountain lakes of north-western Slovenia and its stable isotopic signatures: records of natural and anthropogenic impacts. Hydrobiologia 648. DOI: https://doi.org/ 10.1007/s10750-010-0148-4 Vreča, P., Pavšek, A., Kocman, D. 2022: SLONIP – A Slovenian Web-Based Interactive Research Platform on water isotopes in precipitation. Water 14-13. DOI: https://doi.org/10.3390/w14132127 Wake, B. 2015: Global versus local. Nature Climate Change 5-11. DOI: https://doi.org/10.1038/nclimate2858 Walker, M., Gibbard, P., Head, M. J., Berkelhammer, M., Björck, S., Cheng, H., Cwynar, L. C. et al. 2019: Formal subdivision of the Holocene series/epoch: A summary. Journal of the Geological Society of India 93-2. DOI: https://doi.org/10.1007/s12594-019-1141-9 Walker, M., Johnsen, S., Rasmussen, S. O., Popp, T., Steffensen, J.-P., Gibbard, P., Hoek, W. et al. 2009: Formal definition and dating of the GSSP (Global Stratotype Section and Point) for the base of the Holocene using the Greenland NGRIP ice core, and selected auxiliary records. Journal of Quaternary Science 24-1. DOI: https://doi.org/10.1002/jqs.1227 Wanner, H., Solomina, O., Grosjean, M., Ritz, S. P., Jetel, M. 2011: Structure and origin of Holocene cold events. Quaternary Science Reviews 30-21,22. DOI: https://doi.org/10.1016/j.quascirev.2011.07.010 Watanabe, Y., Abe-Ouchi, A., Saito, F., Kino, K., O’ishi, R., Ito, T., Kawamura, K., Chan, W.-L. 2023: Astronomical forcing shaped the timing of early Pleistocene glacial cycles. Communications Earth and Environment 4. DOI: https://doi.org/10.1038/s43247-023-00765-x Willis, K. J., Rudner, E., Sümegi, P. 2000: The full-glacial forests of Central and Southeastern Europe. Quaternary Research 53-2. DOI: https://doi.org/10.1006/qres.1999.2119 Willis, K., van Andel, T. 2004: Trees or no trees? The environments of central and eastern Europe during the Last Glaciation. Quaternary Science Reviews 23-23,24. DOI: https://doi.org/10.1016/j.quascirev.2004.06.002 Wilson, R., Loader, N. J., Rydval, M., Patton, H., Frith, A., Mills, C. M., Crone, A. et al. 2011: Reconstructing Holocene climate from tree rings: The potential for a long chronology from the Scottish Highlands. The Holocene 22-1. DOI: https://doi.org/10.1177/0959683611405237 Wirth, S. B., Glur, L., Gilli, A., Anselmetti, F. S. 2013: Holocene flood frequency across the Central Alps – solar forcing and evidence for variations in North Atlantic atmospheric circulation. Quaternary Science Reviews 80. DOI: https://doi.org/10.1016/j.quascirev.2013.09.002 Zoller, H. 1960: Pollenanalytische Untersuchungen zur Vegetationsgeschichte der insubrischen Schweiz. Denkschriften Schweiz Naturforschenden Gesellschaft 83. Acta geographica Slovenica, 64-2, 2024 39 64-2_acta49-1.qxd 16.5.2024 13:11 Page 39 Holocene climate variability in Slovenia: A review Zorn, M., Ferk, M., Lipar, M., Komac, B., Tičar, J., Hrvatin, M. 2020a: Landforms of Slovenia. The geography of Slovenia: Small but diverse. Cham. DOI: https://doi.org/10.1007/978-3-030-14066-3_3 Zorn, M., Komac, B. 2007: Naravni procesi v svetih knjigah. Geografski vestnik 79-2. Zorn, M., Komac, B., Carey, A., Hrvatin, M., Ciglič, R., Lyons, B. 2020b: The disappearing cryosphere in the southeastern Alps: Introduction to special issue. Acta geographica Slovenica 60-2. DOI: https://doi.org/10.3986/AGS.9396 Zorn, M., Šmid Hribar, M. 2012: A landscape altered by man as a protected area: A case study of the Ljubljana Marsh (Ljubljansko Barje). Ekonomska i ekohistorija 8. Zupan Hajna, N., Mihevc, A., Bosák, P., Pruner, P., Hercman, H., Horáček, I., Wagner, J. et al. 2021: Pliocene to Holocene chronostratigraphy and palaeoenvironmental records from cave sediments: Račiška pečina secion (SW Slovenia). Quaternary International 605-606. DOI: https://doi.org/10.1016/j.quaint.2021.02.035 Zupan Hajna, N., Mihevc, A., Pruner, P., Bosák, P. 2008a: Palaeomagnetism and Magnetostratigraphy of Karst Sediments in Slovenia. Carsologica 8. Ljubljana. Zupan Hajna, N., Pruner, P., Mihevc, A., Schnabl, P., Bosák, P. 2008b: Cave sediments from the Postojnska- Planinska cave system (Slovenia): Evidence of multi-phase evolution in epiphreatic zone. Acta Carsologica 37-1. DOI: https://doi.org/10.3986/ac.v37i1.160 Zwitter, Ž. 2012: Podnebne spremembe na Slovenskem v zadnjem tisočletju. Geografija v šoli 21-1,2. Zwitter, Ž. 2013: Vremenska in klimatska zgodovina v koledarjih in podložniških dnevnikih ljubljanskega škofa Tomaža Hrena (1597–1630). Zgodovinski časopis 67-3,4. Zwitter, Ž. 2014: Okolje na Kranjskem v 17. stoletju po Slavi vojvodine Kranjske. Studia Valvasoriana: zbornik spremnih študij ob prvem integralnem prevodu Die Ehre Deß Hertzogthums Crain v slovenski jezik. Ljubljana. Zwitter, Ž. 2015: Subsistence, prosperity and abandonment of Alpine isolated farms in the dynamic 17th century environment: Case study from the Upper Savinja Valley with special emphasis on tenants’ inven- tories. Ekonomska i ekohistorija 11. Zwitter, Ž. 2016: Urbarji iz 16. in 17. stoletja kot vir za okoljsko zgodovino. Urbarji na Slovenskem skozi stoletja. Ljubljana. Zwitter, Ž. 2020: Eine Wissensgeschichte der Wiesen und Weiden im Südosten der Alpen im 16. und im frühen 17. Jahrhundert. Mitteilungen des Instituts für Österreichische Geschichtsforschung 128-1. DOI: https://doi.org/10.7767/miog.2020.128.1.49 40 64-2_acta49-1.qxd 16.5.2024 13:11 Page 40