HACQUETIA 1/2 « 2002, 205-208
CONTRIBUTION TO THE KNOWLEDGE OF SEGETAL VEGETATION FROM CROATIA
Nada HULINA
Izvleček
Prispevek k poznavanju segetalne vegetacije na Hrvaškem
Prispevek obravnava plevelno vegetacijo posevkov v kontinentalnom delu Hrvaške. Ugotovljene so bile tri združbe, in sicer-. Kickxietum spuriae Krus et Vlieg. 1939, Papaveretum argemone (Libb. 32) Krus. et Vlieg. 1939 in Aphano-Matricarietum chamotnillaeTx 1937. em Pass. 57.
Abstract
The paper deals with the weed communities of cereals in the continental part of Croatia. Three associations were established. They are: Kicxietum (Linarietum) spuriae Krus et Vlieg. 1939, Papaveretum argemone (Libb. 32) Krus. et Vlieg. 1939., and Aphano-Matricarietum chamomillaeTx 1937. em Pass. 57.
Ključne besede: žitni pleveli, plevelne združbe žit, Secalietea, Secalietalia, Aperetalia spica-venti, Caucalion tappulae, Aperion spica-venti, Kickxietum spuriae, Papaveretum argemone, Aphano-Matricarietum chamomillae, Hrvaška
Key words: segetal weeds, weed associations of cereals, Secalielea, Secalietalia, Aperetalia spica-venti, Caucalion lappulae, Aperion spica-venti, Kickxietum spuriae, Papaveretum argemone, Aphano-Matricarietum chamomillae, Croatia
1. INTRODUCTION
Cereals (winter wheat, oat, barley, rye) are annual cultures with no cultivation after sowing. Weeds in cereals arc adapted to the germination conditions and to the season rhythm of the cereals species. Just these weeds are very sensitive on the intensified agriculture and they have become extinct in many parts of Europe (Holzner 1978). The weed stands on the stubble fields show often very distinctive block species. Moreover, the problem is to determine the weed association, because in the contemporary phytosociological weed communities system there arc different concepts to describe these communities and to fit them into the system.
It is possible, that these facts arc main reasons for the difficulties in the phytosociological classification and for relatively a few papers (Kovaeeviae 1962, 1969, 1971) subjected on the
weed communities of cereals, generally and in Croatia, too.
The aim of the present article is to give the contribution about the segetal vegetation in Croatia.
2. METHODS
A phytosociological analysis of the weed communities of the cereals was made using the method from Braun-Blanquet (1964). The field observations were carried out in the last twenty years. Syntaxa were named according to Oberdorfer (1983).
3. DESCRIPTION OF THE STUDY AREA
The investigated area is the continental part of Croatia between rivers Sava and Drava. This area
Agronomski fakultet, Sveučilište u Zagrebu, Svetošimunska 25, HR-10000 Zagreb.
Hacquf.tia 1/2 • 2002
belongs to the Pannonia Plain which is characterized by aluvial and diluvial valleys with different zonal and azonal soil types. The climate is a moderate continental (type) with moderately cold winters, warm summers and favorable annual distribution of precipitation. Due to orographic and soil properties and meteorological conditions this area is particularly favorable for agriculture.
There is about 3,300.000 ha of arable land in Croatia, but cereals cover an area of about 300.000-400.000 ha and it is predominantly in continental part of Croatia. In the current Croatian agriculture the private sector prevails with about 78% of cultivated land. It is characterized by the peasant small sized farms with conventional or extensive crop production.
4. RESULTS AND DISCUSSION
The species richness in weed communities of cereals in Croatia is rather high. It counts 122 plant species, from 6 to 29 species on the releve.
On the basis of the phytosociological releves it is established, that this weed vegetation belongs to the class Secalietea (syn. Stellarietea mediae, Ober-dorfer, 1983), and alliances Caucalidion lappulae within the Secalietalia order and Aperion spica-venti (suball. Aphanenion) within the Aperetalia spica-venti
order. Taking into consideration the floristic composition, the following associations may be distinguished: Kickxietum spuriaeKrus et Vlieg. 1939, Papaveretum argemone (Libb.32) Krus. el Vlieg. 1939 and Aphano-Matricarietum chamomillae Tx 1937. em Pass. 57.
The diagnostical key for syntaxa of this class and their survey in Croatia were made and it presents on the Table 1.
A clear, distinctive block of species, which are characteristics for the class, order and alliances is good presented (Table 1). Some character species occur frequently and with high abundance. Such are: Fallopia convolvulus, Myosotis arvensis, Veronica agreslis, Bromus secalinus and Apera spica-venti. Some of them, such as Bromus secalinus and Apera spica-venti determine the floristic aspect of their stands. The species Agrostemma githago, Legousia speculum veneris, Ajuga chamaepytis, Consolida regain and Stachys annua were rarely noted.
The character species of associations are presented in different number, but clear indicate on the appointed associations (Table 1).
The diagnostic markers of Kickxietum spuriae are the species Kickxia spuria and K. elatine, Stachys annua and Chenorhinum minus. Locally, on stubble fields Stachys annua was predominant species.
Among the characteristic species of Papaveretum
Tablel. Diagnostical key for syntaxa of Secalietea and their survey in Croatia
Tabela 1. Diagnostični ključ za sintaksone razreda Secalielea in njihov pregled na Hrvaškem.
Secalietea Br.-BI. 52 (svn. Stellarietea mediae)
D. s.: Fallopia convolvolus, Myosotis arvensis. Viola arvensis, Veronica arvensis, Stellaria media, Anagallis arvensis, Rapistrum rugosurn, Lamiitm purpureum, Capsella bursa-pastoris, Tripleurospermum inodorum, Sonclius asper, Valerianella locusta and Agrostemma githago_
Secalietalia Br.-BI. 31 em. Br.-BI. 36_Aperetcdia spica-venti (Tx. 53) J. et R. Tx._
Caucalidion lappulae Tx. 50
D. s.: Papaver rhoeas. Ranunculus arvensis, Sinapis arvensis, Thlaspi arvense, Euphorbia helioscopio, Fumaria officinalis, Ajuga chamaepytis, Consolida regalis, Legousia speculum-veneris, Lathyrus tuberosus
Aperion spica-venti Tx. in Oberd. 49 D. s.: Bromus secalinus, Apera spica-venti Centaurea cyanus, Vicia tetrasperma, V. angustifolia, Verónica liederifolia, Vaccaria pyramidata, Vicia hirsuta, Eropliila venia
I .Ass. Kickxietum (Linarietum) spuriae Krus. et Vlieg. 39
1 .Ass. Papaveretum argemone (Libb.32) Krus. et Vlieg. 39
D.s.: Kickxia spuria, K. elatine, Cliaenorrhinum minus, D.s.: Papaver dubium, P.argemone, Veronica Lathyrus aphaca, Adonis aestivalis	triphyllos
2. Ass. Aphano-Matricarietum Meis. 67 _D.s.: Aphanes arvensis, Matricaria cliamomilla
The most frequent companions: Galium aparine, Cirsium arvense, Convolvulus arvensis, Ambrosia artemisiifolia, Conyza canadensis. Polygonum aviculare, Chenopodium album, Equisetum arvense.
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Nada HULINA: Con tribution to the knowledce ok secetal vegetation from Croatia
argemone (Tabic 1 ). Veronica triphyllosvias noted with high values for frequency and abundance.
From characteristic species of Aphano-Matricarietum chamomillae are found: Aphanes arvensis, Matricaria chamomilla, Tripleurospernium inodorum, Vicia tetrasperma and Vicia hirsuta. This association was the most widespread. It is distributed on less or more heavy soils with low pH but rich in nutrients in humid areas. It was occured by two variants which are characterized with the remarkble species group. They are: the Mentha arvensis-group ( M. arvensis, Stachys palustris, Equisetum arvense, Ranunculus repens) and Gnaphalium uliginosum-group ( G.uliginosum, Hypericum humifussum).
It is important to emphasize, that the archeophytes like Agrostemma gilhago, Adonis aestivalis, Lolium temulentum have disappeared under herbicide pressure and seed cleaning. These species are noted only on fields with extensive production. In chemically weeded cereals it was not rare to see infestations of Veronica hederifolia some weeks after sowing or of Galium aparine, Vicia spp., Fallopia convolvolus, Poa trivialis, Convolvulus arvensis and Calystegia sepiurn in spring. The extremely high abundance and cover of Ambrosia artemisiifolia or Conyza canadensis is often a characteristic of the stubble fields.
5. CONCLUSIONS
Research results show:
1.	The species richness in weed communities of cereals in Croatia was rather high. The total number of species was 122, and from 6 to 29 species in the single relevé.
2.	The weed vegetation belongs to the class Secalietea
(syn. Stellarietea mediae, Oberdorfer, 1983), and alliances Caucalion lappulaewithin the Secalietalia order and Aperion spica-venti (suball. Aphanion) within the Aperetalia spica -venti order.
3.	Three weed associations in cereals on the fields
in the continental part of Croatia were distinguished: Kickxietum (Linarietum) spuriaeKrus et Vlieg. 1939, Papaveretum argemone (Libb.32) Krus. et Vlieg. 1939., and Aphano-Matricarietum chamomillae Tx 1937. em Pass. 57.
4.	The archeophytes like Agrostemma githago, Adonis
aestivalis, Lolium temulentum have disappeared under herbicide pressure and seed cleaning. These species are noted only on fields with extensive production.
5.	In chemically weeded cereals it was not rare to
see infestations of Veronica hederifolia some weeks after sowing or of Galium aparine, Vicia spp., Fallopia convolvolus, Poa trivialis, Convolvulus arvensis and Calystegia sepium in spring. 6. The extremely high abundance and cover of Ambrosia artemisiifolia or Conyza canadensis is often a characteristic of the stubble fields.
6. POVZETEK
Prispevek k poznavanju segetalne vegetacije na Hrvaškem
Po standardni srednjeevropski metodi (Braun-Blanquet 1964) smo proučili plevelno vegetacijo žit (pšenice, oves, ječmen, rž) in njihovih strnišč v kontinentalnem delu Hrvaške. Terenske raziskave so potekle zadnjih dvajset let. Ugotovili smo, da plevelno vegetacijo uvrščamo v zvezi Caucalidion lappulae (red Secalietalia) in Aperion spica-venti (red Aperetalia spica venti) znotraj razreda Secalietea. Razlikujemo naslednje asociacije: Kickxietum (Linarietum)spuriaeKrus et Vlieg. 1939, Papaveretum argemone (Libb. 32) Krus. et Vlieg. 1939. in Aphano-Matricarietum chamomillae Tx 1937. em Pass. 57.
Najbolj razširjena je asociacija Aphano-Matricarietum chamomillae. Ločimo lahko nekaj variant, kijih označujejo pomembne skupine vrst, kot na primer Mentha «rveniiVskupina in Gnaphalium u liginos um-sku p i na.
Na intenzivno obdelanih njivah se pojavljajo plevelne združbe v osiromašenih oblikah s trajnicami in vrstami, ki so odporne na herbicide. Posebej občutljive na uporabo herbicidov so vrste, značilne za zvezo Caucalidion. Na strnišču se pogosto pojavita vrsti: Ambrosia artemisiifolia in Conyza canadensis.
Zaključimo lahko, da so plevelne združbe žit izredno nestabilne in da se njihova floristična sestava zaradi antropogenega vpliva bistveno in hitro spreminja.
7. LITERATURE
Braun-Blanquet, J. (1964): Pflanzensoziologie. Grudziige der Vegetationskunde. 3. Aufl. -Springer Verlag, Wien-New York, 865 pp. Holzner, W. (1978): Weed species and weed
communities. Vegetatio 38, 1: 13-20. Kovačevič, J. (1962): Korovske cenoze Hrvatsko-slavonskog meduriječja. - II. kongres biologa Jugoslavije, pp. 149-150. Kovačevič, J. (1969): Fitocenoze žitarica. Dokumen-
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tacija za tehnologiju i tehniku u poljoprivredi
3: 27.
Kovačevič.J. (1971): Korovskc zajednice u Posavini. Savjetovanje o Posavini. III. pp. 341-349.
Oberdorfer, E. (1983): SuddeutschePflanzen-gesellschaften, III, Wirtschaftwiesen und Unkrautgesellschaften, Gustav Fischer Verlag, Jena, 455 pp.
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