HACQUETIA 3/2 • 2004, 81–90 CRATAEGUS NIGRA WALDST. ET KIT. DOMINATED COMMUNITY IN THE FLOODED DANUBE RIVER AREA IN CROATIA Andraž ČARNI*, Josip FRANJIĆ** Željko ŠKVORC** Abstract The paper deals with a community dominated by Crataegus nigra and developed along the Danube River branches. The community has been classified into the association Euphorbio palustris-Crataegetum nigrae ass. nova (Alno-Quercion roboris, Populetalia albae, Querco-Fagetea). The community forms the edge of the pedunculate oak community Genisto elatae-Quercetum roboris and poplar trees community Populetum nigrae-albae. These sites are temporarily flooded, however, they are elevated above the normal water level so that organic material is swept away and deposited only to a limited extent. It is there where the processes of pedogenesis already start. Izvleček Delo obravnava združbo, v kateri dominira vrsta Crataegus nigra in je razširjena ob rokavih reke Donave. Združbo smo uvrstili v asociacijo Euphorbio palustris-Crataegetum nigrae ass. nova (Alno-Quercion roboris, Populetalia albae, Querco- Fagetea). Združba gradi rob gozdov doba Genisto elatae-Quercetum roboris in topolov Populetum nigrae-albae. Ta rastišča so sicer občasno poplavljena, vendar pa so že toliko dvignjena nad srednji vodostaj, da tu poplavna voda odnaša in odlaga organski material le v omejenem obsegu in se že začno procesi pedogeneze. Key words: flooded forests, mantle communities, Alno-Quercion roboris, Populetalia albae, vegetation, the Danube River, Croatia Ključne besede: poplavni gozdovi, zastorne združbe, Alno-Quercion roboris, Populetalia albae, vegetacija, Donava, Hrvaška 1. INTRODUCTION de Foucault 1991, being transitional between the alliance Berberidion Br.-Bl. 1950 and the class Fran- The research of forest edge vegetation began in guletea Doing ex Westhoff and Westhoff & Den the continental part of Croatia within the frame-Held 1969 (Čarni, Franjić & Škvorc 2002). work of the international project entitled “Vegeta-This research was carried out in a narrow belt of tion of forest edges and its significance for the for-land along the Danube River where the river inunest biodiversity”. In eastern Slavonia, the associa-dates every year and thus creates specific ecologic tion Crataego-Prunetum dasyphyllae Jurko 1964 was circumstances that facilitate the development of sampled. It can be found in warmer sites and it was specific plant species and plant communities. Declassified into a thermophilic alliance Prunion fruti-pending on the flood duration and quantities that cosae Tüxen 1952. Further, the association Viburno represent the basic gradient in the research area, opuli-Prunetum dasyphyllae Čarni, Franjić et Škvorc the following communities prosper in this area: 2002 was described anew. It develops in humid sites Salicetum albae s. lat. (Galio-Salicetum albae Rauš and was classified into the alliance Salici-Viburnion 1973), Salici-Populetum nigrae Tüxen 1931, Popule * Institute of Biology, Scientific Research Centre of the Slovenian Academy of Sciences and Arts, Novi trg 2, p. b. 306, SI-1001 Ljubljana ** Faculty of Forestry, University of Zagreb, Svetošimunska 25, p. b. 422, HR 10000 Zagreb, jozo.franjic@zg.htnet.hr, zeljko.skvorc@zg.htnet.hr 81 HACQUETIA 3/2 • 2004 tum albae-nigrae Slavnić 1952, as well as the Fraxino- Ulmetum laevis Slav. 1952 and the Genisto elatae-Quercetum roboris Ht 1938. The zonation is shown in Figure 1. The flooded forests build a narrow belt along the Danube River and are probably the best preserved flooded forests in Europe. Figure 1: Zonation of forest communities on the river bank. Height of the mean water level of the river Danube at Vukovar in the vegetation season in the period 1941–1970. Legend: VV – mean height of the high water level, SV – mean height of mean water level, MV – mean height of the low water level (Rauš 1976). Slika 1: Conacija gozdov na rečnem bregu. Višina srednjega vodostaja Donave pri Vukovarju v času vegetacijske dobe v obdobju 1941–1970. Legenda: VV – srednja višina visokega vodostaja, SV – srednja višina srednjega vodostaja, MV – srednja višina nizkega vodostaja (Rauš 1976). Mantle communities have not been studied along the forests where Salix alba dominates, and which consist of the Salicetum triandrae Malc. 1929 (Rauš et al. 1985), but higher on the river banks where the communities Populetum albo-nigrae, and particularly Genisto-Quercetum roboris, appear. The term mantle communities is a physionomic term and describes the communities appearing on forest edges and also separated from them. They are classified into various syntaxa. Moreover, the mantle communities in drier sites are classified into the class Rhamno-Prunetea (e.g. Čarni, Franjić & Škvorc 2002). The mantle communities of the white willow stands (Salicetum albae s. lat.), built by Salix triandra (Salicetum triandrae Malc 1929) are, however, classified into the class of riverine vegeta- The climate in this part of Croatia is the most continental in all Croatia (Ilijanić 1963). The average annual temperature in Vinkovci (Fig. 3) is 10 oC, the warmest month is July with a mean temperature of 21.4 oC and the coldest month is January, where the average monthly temperature is –2.1 oC. The absolute maximum has been 39.0 oC, and the absolute minimum –30.5 oC. The average precipitation is 660 mm, with a maximum in May and December. The quantity of precipitation falls towards the east of Croatia, thus the annual precipitation in Slavonski Brod is 798 mm, in Đakovo 733 and in Vinkovci only 622 mm (Rauš & Šegulja 1983). The water level is always high when snow melts in the mountains of Austria, Slovakia and Hungary, and this is usually in May. In addition, the water level may rise twice to three times a year depending on precipitation (Fig. 4) (Rauš 1976). tion Salicetea purpuraea Moor 1958 (Rauš 1976, Šilc 2003). The purpose of the research was to establish the floristic composition of mantle communities and their systematic classification. 2. DESCRIPTION OF THE RESEARCH AREA The area is located in the eastern part of Croatia along the Danube River on the border with Serbia and Montenegro (Fig. 2). Figure 2: Geographical position of the research area. Slika 2: Geografska lokacija raziskovanega območja. 82 ANDRAŽ ČARNI, JOSIP FRANJIĆ, ŽELJKO ŠKVORC: CRATAEGUS NIGRA WALDST. ET KIT. DOMINATED COMMUNITY IN THE FLOODED DANUBE RIVER AREA Figure 3: Climatic diagram for Vinkovci (Rauš & al. 1985). Slika 3: Klimatski diagram za Vinkovce (Rauš & al. 1985). Figure 4: Duration and frequency of flooding of the river Danube at Vukovar. (1) Frequency per year, (2) Duration of individual flood in days (Rauš 1976). Slika 4: Tranjanje in pogostnost poplav reke Donave pri Vu- kovarju. (1) Pogostnost poplav v letu, (2) trajanje posamez- ne poplave v dneh (Rauš 1976). Flooded forests that have been well preserved in the research area were often the subject of different vegetation research and have been relatively well studied (e.g. Slavnić 1952, Jovanović 1985, Rauš 1976, 1976a, Rauš & Šegulja 1983, Vukelić & Rauš 1998). Flooded forests are forests that could be found in flooded areas along rivers that are constantly periodically flooded by rivers. Therefore, these soils are developed depending on the flood duration and level. These are paraclimatic communities where the composition of the community depends heavily on the flood duration and level. The vegetation is divided into two groups of communities: forests of softwood trees appearing in more flooded sites, and forests of hardwood trees growing in sites flooded for a shorter time. The first group consists of the community Salicetum triandrae, Salicetum albae and Salici-Populetum. In addition to dominant species there are also Acer negundo, Fraxinus pensilvanica and Morus alba appearing in the tree layer and Galium palustre agg., Rubus caesius, Carex elata, Poa trivialis, Solanum dulcamara, and others appearing in the herb layer. In higher sites where the water level is lower, poplar trees with a few willows prosper in general since the poplar trees grow quicker than willows and, consequently, the willows are suffocated by poplar trees. In lower sites, where there is a higher water level, the poplar trees are not tolerant of floods and only willow trees remain. With regard to the syntaxonomic classification of the stands of soft deciduous trees, different points of view should be taken into consideration. A comprehensive synthetic work should be prepared, in which also the appurtenance to higher syntaxa should be established. The authors classify all stands of soft deciduous trees mostly into the alliance of Salicion albae Soó 1930 (class Salicetea purpureae Moor 1958) (Vukelić & Rauš 1998, Jovanović & al. 1985). A somehow intermediate place between the first and second group is taken by the community Populetum nigro-albae which is classified into the alliance of Salicion albae (Rauš & Vukelić 1998), or alliance Alno-Quecion roboris (Populetalia albae) (Parabućski & al. 1986). It also facilitates the classification of the community into the alliance of Populion albae Br.-Bl. 1931 (Populetalia albae) (Jovanović & al. 1986). The second group is composed of hardwood deciduous trees, the Fraxino-Ulmetum laevis Slav. 1952 and particularly the community Genisto elatae- Quercetum roboris Ht 1938. The well known “Slavo 83 HACQUETIA 3/2 • 2004 nian oak forests” that cover large continuous complexes are classified into this community. The sites of this community are located a few metres above the normal water level and are periodically flooded, however, they are flooded only for a shorter time or the sites are even not reached by floods, but in spite of that remain fresh. The tree layer is dominated by Quercus robur and, additionally, there are Fraxinus angustifolia, Ulmus laevis, Populus nigra in P. alba, etc. In the shrub layer, there are Genista elata, Crataegus monogyna, Prunus spinosa, Viburnum opulus, Frangula alnus, Rubus caesius, R. fruticosus, Rosa sp. div. etc. The community is ecologically similar to the community Querco-Ulmetum Oberdorfer 1953 that is found in Central Europe (Rauš & Vukelić 1998). The association is classified into the alliance Al- no-Quercion roboris Horvat 1950 (Vukelić & Rauš 1998). The name of the alliance is first mentioned by Horvat (1937), who believes that such forests are preserved by periodic floods. In 1938, he classified the association Genisto elatae-Quercetum roboris into the alliance Alnion incanae Pawł. 1928 (Horvat 1938). After that, Horvat described the alliance Al- no-Quercion roboris in 1950 (Horvat 1950). This is proposed by van der Maarel (1979). The nomeclature of plant species is according to Ehrendorfer (1973), except Fraxinus pensilvanica Kremer. 4. SYNTAXONOMIC SCHEME Querco-Fagetea Br.-Bl. et Vlieger ex Vlieger 1937 Populetalia albae Br.-Bl. ex Tschou 1948 Alno-Quercion roboris Horvat 1950 Euphorbio palustris-Crataegetum nigrae Čarni, Franjić et Škvorc 2004 5. COMMUNITY DESCRIPTION The community appears as an edge community of oak and poplar forests along the Danube River branches. (Fig. 5) The species Crataegus nigra appears sporadically also in closed forest stands although there it does not prosper well. It can be concluded that the ecological optimum of the species is on forest edges where it builds closed narrow forest edges preventing the effects of non-forest areas deeper in forests. accepted also in the contemporary literature (Rodwell & al. 2002). As to the syntaxonomic classification of individual species, the classification proposed by Brullo and Stampinato (1999) was taken into consideration. They also establish that hardwood deciduous trees like Quercus and Fraxinus dominate in these stands and that they differ essentially from the forests of softwood deciduous trees where the species from the genus Salix and Populus are dominant. Since the alliance shows certain similarities with the class Alnetea glutinosae, from which it differs ecologically and floristically, the alliance has to be classified into a specific order of the Populetalia albae (Brullo & Stampinato 1999). 3. METHODS The research was carried out using the standard central European method (Braun-Blanquet 1964). Numerical analysis of the influence of ecological factors on the vegetation was made by programme package CANOCO 4.02, applying the Canonical correspondence analysis (ter Braak & Šmilauer 1989). The ecological factors were estimated using Ellenberg values (Ellenberg 1979). The coverage values were transformed into the ordinal scale as Figure 5: Euphorbio palustris-Crataegetum nigrae on forest edge. Slika 5: Euphorbio palustris-Crataegetum nigrae na gozdnem robu. Crataegus nigra (Fig. 6) is a shrub or low tree up to 7 m high. Ecologically, this hydrophilic species differs from the other species of the genus Crataegus in Europe. It crops up in flooded alluvial sites along large streams, in sites of poplar forests and ash-oak forests. At times, it forms small stands in the form of secondary hydrophilic shrub commu 84 ANDRAŽ ČARNI, JOSIP FRANJIĆ, ŽELJKO ŠKVORC: CRATAEGUS NIGRA WALDST. ET KIT. DOMINATED COMMUNITY IN THE FLOODED DANUBE RIVER AREA nities. The species is classified into the Pannonic and Balkan element and can be found in Hungary, Croatia, Serbia and Romania. It is frequently planted as a decorative species (Jovanović 1972). Figure 6: Dominant species Crataegus nigra. Slika 6: Dominantna vrsta Crataegus nigra. The stands were sampled in flooded areas, however in those areas, already distant from the river main streams, where no intensive sweeping away and depositing take place. Similar conclusions were also drawn by Antić & al. (1969), who established that there are interesting and frequent stands of species Crataegus nigra in the Danube section. Generally, they build mantle shrub communities on the edge of »relict oak« forests. A provisional name of Crataegetum nigrae was proposed. Jovanović & al. (1985) described the association Crataego nigrae-Salicetum albae within the area of Ada Huja. The stands are flooded 2 to 4 months. Parabućski (1972) described the community Crataego nigrae-Populetum albae Parabućski 1972 in the area of Koviljski rit. It can be ascertained that the community Euphorbio-Crataegetum crops up in sites flooded for a shorter time than the above stated communities. In this community, the dominant characteristic species build dense interweaving where other species can only seldom be found. Additionally, there are also species which are considerably well represented and are classified into the alliance Alno- Quercion roboris and Populetalia albae like Rubus caesius, Fraxinus pensilvanica, Rumex sanguineus, Leucojum aestivum, Galium elongatum, to enumerate only the most frequent ones. Besides, there are other species of the class Querco-Fagetea, like Symphytum officinale, Stachys palus tris and Cornus sanguinea. Among the species of high stalk and ruderal communities there are Urtica dioica, Solidago serotina, Calystegia sepium and Erigeron annuus, etc. Within the community, there are also Euphorbia palustris and Lysimachia vulgaris that are characteristic species of the alliance of forest edges in humid sites Filipendulion. With regard to the floristic composition, the community was classified into the alliance Alno-Quercion roboris, where also contact forests are classified. The nomenclature type of the community Euphorbio palustris-Crataegetum nigrae is the relevé number 7 in Table 1 (Holoptypus hoc loco: Tab. 1/7). 6. LOWER SYNTAXA According to the floristic composition and numerical analysis (Fig. 7) the association can be divided into three subassociations. The subassociation phalaridetosum arundinaceae subass. nova (Tab. 1/1–2, holotypus hoc loco: Tab. 1/1) can be found on the sunny, open sites. It is characterised by Phalaris arundinacea. The subassociation leucojetosum aestivi (Tab. 1/3–6, holotypus hoc loco: Tab. 1/3) is found in the most humid and nutrient rich sites. It is characterised by the presence of Leucojum aestivum and Galium elongatum. The third subassociation querceto- Figure 7: Results of the Canonical Correspondence Analy- sis. The species with minimum fit 30 are shown in the dia- gram. Slika 7: Rezultati kanonične skladnostne analize.V diagramu so prikazane vrste, ki ustrezajo najmanjši prilagoditvi 30. 85 HACQUETIA 3/2 • 2004 sum roboris (Tab. 1/7–10, holoptypus hoc loco: Tab. 1/9) is characterised by the presence of many woody species, indicating the development of the further succession stages of the association towards the forest. It is characterised by Quercus robur, Populus alba, Sambucus nigra and Frangula alnus. 7. CONCLUSIONS A new mantle community that builds a mantle of oak forests in the flooded area along the Danube River was described. Moreover, its optimal natural site as a mantle of flooded forests of hardwood deciduous trees was defined. The definition of its natural sites is also important, since it appears very often as a decorative species. 8. ACKNOWLEDGEMENT For the help offered in the elaboration of this article we would like to thank Barbara Šuštar who kindly prepared the table and drew up other graphical enclosures. We also thank to employees of Forest office Batina – Hrvatske šume d. o. o. for their help and suport during the field researches. The research was financed within the framework of the international project entitled “Vegetation of forest edges and its significance for the forest biodiversity”, co-financed by the Ministry of Education, Science and Sport of the Republic of Slovenia and the Ministry of Science and Technology of the Republic of Croatia. 9. LOCALITIES Croatia, Baranja, Monjoroš, branches of the river Danube: 1. lat. 45°46,516’, long. 18°51,096’; 2. 45°46,637’, 18°52,657’; 3. 45°46,246’, 18°51,143’; 4. 45°45,892’, 18°51,427’; 5. 45°46,069’, 18°51,376’; 6. 45°46,634’, 18°52,294’; 7. 45°46,076’, 18°51,415’; 8. 45°46,729’, 18°52,282’; 9. 45°46,255’, 18°50,857’; 10. 45°46,269’, 18°50,831’. 10. POVZETEK Združbavrste Crataegusnigra Waldst.etKit.vpoplavnem območju Donave na Hrvaškem Območje leži v vzhodnem delu Hrvaške ob reki Donavi na meji s Srbijo in Črno goro (slika 2). V tem delu je klima najbolj kontinentalna v celotni Hrvaški (Ilijanić 1963). V Vinkovcih (slika 3) je povprečna letna temperatura 10 oC, najtoplejši mesec je julij s srednjo temperaturo 21,4 oC in najhladnejši januar, ko je povprečna mesečna temperatura -2,1 oC. Absolutni maksimum je bil 39,0 oC, absolutni minimum pa –30,5 oC. Povprečna količina padavin je 660 mm, z maksimumoma v maju in decembru (Rauš 1976). Poplavni gozdovi so na območju, kjer reka redno in periodično poplavlja. Zato se tla intenzivno razvijajo in so odvisna od dolžine in višine poplav. To so paraklimaksne združbe. Njihov floristični inventar je odvisen od dolžine in višine poplav (slika 1, 4) Gozdno vegetacijo na rečnih bregovih lahko razdelimo v dve skupini združb: v gozdove mehkih listavcev, ki se pojavljajo na bolj poplavljenih rastiščih, in gozdove trdih listavcev, ki uspevajo na krajši čas poplavljenih rastiščih. V prvo skupino uvrščamo združbe Salicetum triandrae, Salicetum albae in Salici-Populetum. Poleg dominantnih vrst se v drevesni plasti pojavljajo Acer negundo, Fraxinus pensilvanica in Morus alba, v zeliščni pa Galium palustre agg., Rubus caesius, Carex elata, Poa trivialis, Solanum dulcamara in druge. V višjih predelih, kjer je vodostaj najnižji, navadno uspevajo topoli z majhno primesjo vrb, ker topoli rastejo hitreje od vrb in jih zadušijo. Na nižjih rastiščih, kjer je vodostaj višji, se topoli, ki ne prenesejo poplav, posušijo in ostanejo samo vrbe. Glede sintaksonomske uvrstitve sestojev mehkih listavcev so različni pogledi in bi bilo potrebno izdelati obsežno sintetsko delo, v katerem bi ugotovili tudi pripadnost višjim sintaksonom. Avtorji uvrščajo vse sestoje mehkih listavcev večinoma v zvezo Salicion albae (razred Salicetea purpureae) (Vukelić & Rauš 1998, Jovanović & al. 1985). Nekakšen vmesni položaj med prvo in drugo skupino ima združba Populetum nigro-albae, ki jo uvrščamo ali v zvezo Salicion albae (Rauš & Vukelić 1998) ali v zvezo Alno-Quercion roboris (Populetalia albae) (Parabućski & al. 1986); mogoča pa je tudi uvrstitev v zvezo Populion albae Br.-Bl. 1931 (Populetalia albae) (Jovanović & al. 1986). V drugo skupino uvrščamo gozdove trdih listavcev, združbo Fraxino-Ulmetum Slav. 1952 in predvsem združbo Geniste elatae-Quercetum roboris Ht 1938. V to združbo uvrščamo znane slavonske hrastove gozdove, ki grade velike strnjene komplekse. Rastišča te združbe so nekaj metrov nad normalnim vodostajem in so periodično poplavljena, toda poplave trajajo le krajši čas ali pa so rastišča zunaj dosega poplav, vendar so kljub vsemu sveža. V dreves 86 ANDRAŽ ČARNI, JOSIP FRANJIĆ, ŽELJKO ŠKVORC: CRATAEGUS NIGRA WALDST. ET KIT. DOMINATED COMMUNITY IN THE FLOODED DANUBE RIVER AREA ni plasti prevladuje Quercus robur, poleg njega pa se pojavljajo Fraxinus angustifolia, Ulmus laevis, Populus nigra in P. alba itd. V grmovnem sloju pa se pojavljajo Genista elata, Crataegus monogyna, Prunus spinosa, Viburnum opulus, Frangula alnus, Rubus caesius, R. fruticosus, Rosa sp. div. itd. Združba je ekološko podobna združbi Querco-Ulmetum Oberdorfer 1953 v srednji Evropi (Rauš & Vukelić 1998). Asociacijo Genisto elatae-Quercetum roboris uvrščamo v zvezo Alno-Quercion Horvat 1950 (Vukelić & Rauš 1998). Ime zveze najprej omenja Horvat (1937), ki meni, da takšne gozdove ohranjajo periodične poplave. Leta 1938 uvršča asociacijo Genisto elatae-Quercetum roboris v zvezo Alnion incanae Pawł. 1928 (Horvat 1938). Horvat je zvezo veljavno opisal leta 1950, kar priznava tudi sodobna literatura (Rodwell & al. 2002). Pri sintaksonomski uvrstitvi posameznih vrst smo upoštevali razdelitev, ki jo predlagata Brullo & Stampinato (1999). Tudi onadva ugotavljata, da v teh sestojih prevladujejo trdi listavci, kot so Quercus in Fraxinus in se bistveno razlikujejo od gozdov mehkih listavcev, kjer prevladujejo vrste iz rodov Salix in Populus. Glede na to, da zveza nakazuje nekatere podobnosti z razredom Alnetea glutinosae, od katere se hkrati jasno ekološko in floristično razlikuje, jo moramo uvrstiti v poseben red Populetalia albae (Brullo & Stampinato 1999). Sintaksonomska uvrstitev Querco-Fagetea Br.-Bl. et Vlieger ex Vlieger 1937 Populetalia albae Br.-Bl. ex Tschou 1948 Alno-Quercion roboris Horvat 1950 Euphorbio palustris-Crataegetum nigrae Čarni, Franjić et Škvorc 2004 Opis združbe Združba se pojavlja kot robna združba hrastovih in topolovih gozdov ob rokavih Donave (slika 5). Crataegus nigra se sporadično pojavlja tudi v sklenjenih gozdnih sestojih, čeprav tam ne uspeva optimalno. Tako lahko sklepamo, da je ekološki optimum vrste na gozdnih robovih, kjer gradi sklenjene ozke gozdne robove, ki preprečujejo širjenje vplivov iz negozdnih površin globlje v gozd. Crataegus nigra (slika 6) je grm oz. nizko drevo do višine 7 m. Ekološko se ta hidrofilna vrsta razlikuje od ostalih vrst rodu Crataegus pri nas. Pojavlja se na naplavljenih aluvijalnih rastiščih ob velikih rekah, na rastiščih topolovih in jesenovo-dobovih gozdov. Občasno formira majhne sestoje v obliki sekundarnih hidrofilnih šibjakov. Vrsto uvrščamo med panonsko-balkanski florni element in jo najdemo na Madžarskem, Hrvaškem, v Srbiji in Romuniji. Pogosto jo sadijo kot dekorativno vrsto (Jovanović 1972). Sestoje smo popisovali v poplavnem območju, ki pa je že nekoliko oddaljeno od glavnega toka reke, kjer ni več tako intenzivnega odnašanja in odlaganja. Do podobnih zaključkov so prišli Antić in sodelavci (1969), ki so ugotovili, da se na donavskem sektorju pojavljajo zanimivi in pogosti sestoji vrste Crataegus nigra. Običajno grade zastorne grmiščne združbe na robu »reliktnih dobovih« gozdov. Predlagali so tudi provizorično ime Crataegetum nigrae. V tej združbi gradi dominantna značilna vrsta goste preplete, tako da v sestojih uspevajo le redke druge vrste, ki jih uvrščamo predvsem v zvezo Alno- Quercion in red Populetalia albae, kot so Rubus caesius, Fraxinus pensilvanica, Rumex sanguineus, Leucojum aestivum, Galium elongatum, če naštejemo le najpogostejše. Poleg njih so zastopane še vrste razreda Querco- Fagetea, kot so Symphytum officinale, Stachys palustris in Cornus sanguinea. Med vrstami visokih steblik in večletnih ruderalnih združb so Urtica dioica, Solidago setorina, Calystegia sepium in Erigeron annuus itd. V združbi sta tudi vrsti Euphorbia palustris in Lysimachia vulgaris, ki sta značilnici zveze gozdnih robov na vlažnih rastiščih. Združbo smo glede na floristično sestavo uvrstili v zvezo Alno-Quercion, kamor uvrščamo tudi kontaktne gozdove. Nižji sinaksoni Povezavo med popisi, vrstami in ekološkimi dejavniki prikazuje slika 7. Ločili smo subasociacijo phalaridetosum arundinaceae na osončenih rastiščih, subasociacijo leucojetosum aestivi na vlažnih in s hranili bogatih rastiščih ter subasociacijo quercetosum roboris, ki pa že predstavlja razvoj asociacije k višjemu sukcesijskemu stadiju. 11. REFERENCES Antić, M., Jovanović, B., Jović, N., Munkačević, V. & Nikolandić S. (1969): Fitocenološko-pedološka istraživanja u plavnom području Baranje. Jelen 8: 99–119. Braak ter, C. J. F. & Šmilauer, P. (1998): CANOCO reference manual and user’s guide. Center for biometry, Wageningen, 351 pp. 87 HACQUETIA 3/2 • 2004 Braun-Blanquet, J. (1964): Pflanzensoziologie. Grundzüge der Vegetationskunde. 3. Auflage, Springer Verlag, Wien, 865 pp. Brullo, S. & Stampinato, G. (1999): Syntaxonomy of hygrophilous woods of the Alno-Quercion roboris. Annali di Botanica 57: 133–146. Čarni, A., Franjić, J. & Škvorc, Ž. (2002): Vegetacija grmastih šumskih rubova u Slavoniji (Hrvatska). Šumarski list 126(9–10): 459–468. Ehrendorfer, F. (1973): Liste der Gefässpflanzen Mitteleuropas. Gustav Fischer Verlag, Stuttgart, 318 pp. Ellenberg H. (1979): Zeigerwerte der Gefässpflanzen Mitteleuropas. Scripta Geobotanica 9, Göttingen, 121 pp. Horvat, I. (1937): Pregled šumske vegetacije u Hrvatskoj. Šumarski list 61: 337–344. Horvat, I. (1938): Biljnosociološka istraživanja šuma u Hrvatskoj. Glasnik za šumske pokuse 6: 127–279. Horvat, I. (1950): Šumske zajednice Jugoslavije. Institut za šumarska istraživanja. Zagreb, 73 pp. Ilijanić, L. (1963): Typologisch-geographische Gliederung der Niederungswiesen Nordkroatiens im klimatischen Zusammenhang. Acta Botanica Croatica 22: 119–132. Jovanović, B. (1965): Biljni svet – osnovne karakteristike autohtone flore i vegetacije Beljskog lovno-šumskog područja. Jelen 3: 61–81. Jovanović, B. (1972): Fam. Malvaceae Lois.-Deslongch. pp. 127–178. In: Josifović, M. (ed.) Flora SR Srbije, Srpska akademija nauka i umetnosti, Beograd. Jovanović, B., Vukićević, E. & Radulović, S. (1985): Vegetacija i vegetacijska karta Ade Huje kod Beograda. Glasnik Šumarskog fakulteta 64: 289– 317. Jovanović, B., Lakušić, R., Rizovski, R., Trinajstić, I. & Zupančič, M. (1986): Prodromus phytocoensum Jugoslaviae ad mappam vegetationis m 1: 200.000. Naučno veće vegetacijske karte Jugoslavije, Bribir-Ilok, 46 p. Maarel van der, E. (1979): Transforming of cover- abundance values in phytosociology and its effect on community similarity. Vegetatio 39: 97–114. Parabućski, S. (1972): Šumska vegetacija Koviljskog rita. Zbornik za prirodne nauke Matica srpska 42: 5–88. Parabućski, S., Stojanović, S., Butorac, B. & Pekanović, V. (1986): Prodromus vegetacije Vojvodine. Zbornik matice srpske za prirodne nauke 71: 5–40. Rauš, Đ. (1975): Vegetacijski i sinekološki odnosi šuma u bazenu Spačve. Glasnik za šumske pokuse 18: 225–344. Rauš, Đ. (1976): Vegetacija ritskih šuma dijela Podunavlja od Aljmaša do Iloka. Glasnik za šumske pokuse 19: 5–75. Rauš, Đ. (1976a): Šumska vegetacija Đakovštine. Jugoslavenska akademija znanosti i umjetnosti, Centar za znanstveni rad – Vinkovci, Posebna izdanja 3: 115–146, Zagreb Rauš, Đ. & Šegulja, N. (1983): Flora Slavonije i Baranje. Glasnik za šumske pokuse 21: 179–211. Rauš, Đ., Šegulja, N. & Topić, J. (1985): Vegetacija sjeveroistočne Hrvatske. Glasnik za šumske pokuse 23: 223–355. Rodwell, J. S., Schaminée, J. H. J., Mucina, L., Pignatti, S., Dring, J., Moss, D. (2002): The diversity of European vegetation. An overview of phytosociological alliances and their relationship to EUNIS habitats. National reference centre for Agriculture, Nature and Fisheries, Wageningen, 168 pp. Slavnić, Ž. (1952): Nizinske šume Vojvodine. Zbornik matice srpske, serija prirodnih nauka 42: 17–38. Šilc, U. (2003): Vegetation of the class Salicetea purpureae in Dolenjska (SE Slovenia). Fitosociologia 40(2): 3–27. Vukelić, J. & Rauš, Đ. (1998): Šumarska fitocenologija i šumske zajednice u Hrvatskoj. Sveučilište u Zagrebu, Zagreb 310 pp. Weber, H. E., Moravec, J. & Theurillat, J. P. (2000): International code of the phytosociological nomenclature. J. Veg. Sci. 11: 739–768. Received 7. 11. 2003 Revision received 2. 2. 2004 Accepted 3. 3. 2004 88 ANDRAŽ ČARNI, JOSIP FRANJIĆ, ŽELJKO ŠKVORC: CRATAEGUS NIGRA WALDST. ET KIT. DOMINATED COMMUNITY IN THE FLOODED DANUBE RIVER AREA Table 1 (Tabela 1): Ass. Euphorbio palustris-Crataegetum nigrae Čarni, Franjić et Škvorc 2004 Relevé number 12345678910 Altitude (m) 80 73 100 100 100 70 100 80 100 100 Surface (m2) 100 80 100 50 50 80 50 100 100 50 Coverage of layers B 100 100 100 100 100 100 100 100 100 100 C 30 20 20 30 30 20 30 20 20 20 Inclination 0 0 0 0 0 0 0 0 0 0 Const. classPresence Number of species Ass. char. species layer 17 17 23 23 22 29 24 24 31 29 Crataegus nigra B 5 5 4 3 4 3 3 3 4 3 10 V Crataegus nigra C . + + + + + + . + . 7 IV AQ ALNO-QUERCION ROBORIS, POPULETALIA ALBAE Rubus caesius C + + 1 1 + 1 2 1 1 + 10 V Rubus caesius B . + + + + + 1 + + 1 9 V Fraxinus pensilvanica + + + + + + + + . . 8 IV Rumex sanguineus C + + + + + + + + . . 8 IV d2 Leucojum aestivum . . 1 1 + + . . + . 5 III d2 Galium elongatum . . + + + + . + . . 5 III Carex otrubae + . + . + . + . . . 4 II Ulmus laevis B . + + . . + + . . . 4 II Solanum dulcamara C . . . . + + . + + . 4 II Salix purpurea B . . . . . + . + + 2 4 II d3 Populus alba . . . . . . 1 + + + 4 II Viburnum opulus . . . 2 . . 1 + . . 3 II d3 Quercus robur . . . . . . . + + + 3 II d3 Sambucus nigra . . . . . . . . + + 2 I d3 Frangula alnus . . . . . . . . + + 2 I Acer negundo . + . . . . . . . . 1 I Carex remota C . . . . . + . . . . 1 I Amorpha fruticosa . . . . . . + . . . 1 I Salix cinerea B . . . . . . . . + . 1 I QF QUERCO-FAGETEA & RHAMNO-PRUNETEA Symphytum officinale C . + + + + + + . + . 7 IV Stachys palustris . + + + + + . . + + 7 IV Cornus sanguinea B . . . + 2 3 4 3 2 2 7 IV Rhamnus catharcticus C . . . . + . . . . + 2 I Equisetum telmateia . . . . . . + . . + 2 I Circaea lutetiana . . . . . + . . . . 1 I Crataegus monogyna B . . . . . . . . . 1 1 I Crataegus monogyna C . . . . . . . . . + 1 I Prunus avium B . . . . . . . . . + 1 I Brachypodium sylvaticum C . . . . . . . . . + 1 I A ARTEMISIETEA & GALIO-URTICETEA Urtica dioica C 1 1 1 + 1 1 1 + + + 10 V Solidago serotina + 1 . + + + + + + + 9 V 89 HACQUETIA 3/2 • 2004 Relevé number 1 2 3 4 5 6 7 8 9 10 Calystegia sepium + . + + + + + . + + 8 IV Erigeron annuus . . . + + + . + + + 6 III Galeopsis pubescens + . . . . . . . + + 3 II Glechoma hederacea . . . + . . . . + + 3 II Agropyron repens + . . . . . + . . . 2 I Galium aparine . . . . . . + . . + 2 I Torylis japonica . . . . . . . . . + 1 I Lapsana communis . . . . . . . . . + 1 I Silene alba . . . . . . . . + . 1 I PH PHRAGMITETEA Iris pseudacorus C + . + + + . . . + . 5 III Carex elata . . + + + . . . + . 4 II d1 Phalaris arundinacea + + . . . . . . . . 2 I Poa palustris . . + + . . . . . . 2 I Scutellaria galericulata . . . . . + . + . . 2 I Lycopus europaeus . . . . . + . . . . 1 I F FILIPENDULION Euphorbia palustris C + + + + + + + + + + 10 V Lysimachia vulgaris + + + + + . + + + . 8 IV Lythrum salicaria . + + . + . + . . . 4 II Myosotis scorpiodes . . + . . . . . . . 1 I Cirsium oleraceum . . . . + . . . . . 1 I MA MOLINIO-ARRTHENATHERETEA Poa trivialis C + + + . . + 1 + . . 6 III Ranunculus repens . . + + . + . + . 5 III Lysimachia nummularia . . + + . . . + + . 4 II Prunella vulgaris . + . . . . + . . + 3 II Deschampsia cespitosa . . . + . + . + . . 3 II Carex hirta + . . . . . . . + . 2 I Dactylis glomerata . . . . . . . . . + 1 I Pastinaca sativa . . . . . . . . . + 1 I Other species Oxalis fontana . . . . . + + + + . 4 II Carex echinata + + . . . . + . . . 3 II Polygonum hidropiper . . + . . + . . . 3 II Morus alba B . . . . . + . + . . 2 I Bidens tripartita C . . . . . + . + . . 2 I Arabis hirsuta . . . . . . . . + + 2 I Erysimum cheiranthoides . . . . . + . . . . 1 I Viola hirta . . . . . . . . + . 1 I Veronica chamaedrys . . . . . . . . . + 1 I d1, d2,d3 - differential species of the subassociations/ razlikovalnice subasociacij 90