Fitocenološke značajke šuma bijele johe (Alnus incana /L./ Moench) u Gorskome kotaru

The paper presents vegetation research of grey alder stands (Alnus incana /L./ Moench) along the beds of the rivers Kupa, Kupica, Čabranka and Belica in Gorski kotar. The standard Central European phytosociological method was used to record and analyze eight phytosociological relevés from 2010. Research results revealed that it was the association of grey alder with deadnettle, Lamio orvalae-Alnetum incanae, recently recorded in the west of Slovenia (DAKSKOBLER, 2007, 2010). Growing under similar ecological conditions and containing common diagnostic species as the Slovenian stands, the stands in Gorski kotar are characterized by the abundant presence of Helleborus dumetorum. For this reason, they have been classified as a new geographic variant of the above mentioned association.U radu su prikazana vegetacijska istraživanja sastojina bijele johe (Alnus incana /L./ Moench) uz korita rijeka Kupe, Kupice, Čabranke i Belice u Gorskome kotaru. Pri tome je korištena standardna srednjoeuropska fitocenološka metoda kojom je snimljeno i analizirano osam fitocenoloških snimki iz 2010. godine. Rezultati istraživanja pokazali su da se radi o asocijaciji bijele johe s mrtvom koprivom Lamio orvalae-Alnetum incanae, nedavno ustanovljenoj u zapadnoj Sloveniji (DAKSKOBLER, 2007, 2010). Uz slične ekološke uvjete i zajedničke dijagnostičke vrste, sastojine iz Gorskog kotara odlikuju se obilnom nazočnošću vrste Helleborus dumetorum, pa su izdvojene kao nova geografska varijanta spomenute asocijacije

Submontane-sub-pannonian beech forests of northern Croatia

Standardnom metodom srednjoeuropske fitocenološke škole (Braun-Blanquet 1964) istražena je i opisana nova asocijacija bukove šume s dugolisnom naglavicom – Cephalanthero longifoliae-Fagetum ass. nova, koja se rasprostire u kolinsko-submontanskom pojasu panonskoga gorja sjeverne Hrvatske, na visinama od 200 do 700 m, na lesnim i romboidnim naslagama povrh kojih se najčešće nalazi luvisol. Obilježava ju relativno siromašan i homogen florni sastav, izostanak brojnih vrsta ilirske sveze Aremonio-Fagion (Horvat 1938) Borhidi in Törek, Podani et Borhidi 1989, izrazita prevlast vrsta Festuca drymeia i Carex pilosa te stalnost vrsta srednjoeuropskih bukovih šuma. Svrstana je unutar srednjoeuropske sveze Fagion sylvaticae Laquet 1926. U odnosu na sastav ostalih bukovih šuma iste sinsistematske pripadnosti ističu se dijagnostičke vrste Festuca drymeia, Polystichum setiferum, Cephalanthera longifolia, Rubus hirtus, Tilia tomentosa, Potentilla micrantha i Ruscus hypoglossum. U radu je prikazano 15 novih i 137 već objavljenih fitocenoloških snimaka, na osnovi kojih je analizirana građa, sociološki i sintaksonomski karakter asocijacije Cephalanthero longifoliae-Fagetum te odnos prema srodnim asocijacijama na južnom i jugozapadnom rubu Panonske nizine i u susjednim područjima.A new association of beech forest with Sword-leaved Helleborine – Cephalanthero longifoliae-Fagetum ass. nova was described in the colline-submontane belt of northern Croatia, on the south-western edge of the Pannonian Plain. The method of the Central European Phytocoenological School (Braun-Blanquet 1964) was used in the research. Statistical comparison was performed by using programs TURBOVEG (Hennekens & Schaminée 2001) and PRIMER 6 (Clarke & Gorley 2001). MDA and UPGMA methods were made by use of Bray-Curtis similarity index. The association was presented on the basis of 15 new and 132 already published phytocoenological relevés (Table 1). In Table 2 and Figure 3 the association Cephalanthero longifoliae-Fagetum was compared with the related beech forests of the Illyrian floristic province (north-western Croatia, eastern Slovenia, northern Bosnia), then with the Central European association Galio odorati-Fagetum from the colline-submontane positions of Austria and southern Germany, and finally with beech forests of the Carpathian part of Romania. The association Cephalanthero longifoliae-Fagetum is distributed at altitudes from 200 to 700 m, with terrain inclinations usually ranging between 10 and 20 degrees. It grows in the temperate climate with average temperatures from 9.5 to 10.7 °C and average rainfall from 800 to 1,100 mm. The parent bedrock is made up of loess and rhomboid layers generally overlaid with luvisol in a humus-accumulative horizon of medium acidity (pH about 5). The association is characterized by a relatively poor and homogeneous floristic composition, the absence of numerous species of the Illyrian alliance Aremonio-Fagion (the associations Hacquetio-Fagetum, Lamio orvalae-Fagetum, Vicio oroboidi-Fagetum), the distinct prevalence of the species Festuca drymeia, Carex pilosa and Rubus hirtus, and the constancy of the species of Central European beech forests from the alliance Fagion sylvaticae and the order Fagetalia (Figure 2). Species of warmer and drier sites occur in moderate quantities. A synhorological analysis of the investigated association (according to Poldini 1992) gave the relatively expected results. Of the 206 species, 77 % belong to the widely distributed floral geoelement which does not characterize the southern edge of the Pannonian Plain in any particulars (cosmopolitan, circumboreal, Eurasian, Euro-Siberian, European, Mediterranean-Atlantic and others). In relation to beech forests of the Dinaric region, the studied stands completely lack the Illyrian and south-eastern European species that are important for the alliance Aremonio-Fagion, such as Rhamnus alpinus ssp. fallax, Geranium nodosum, Stellaria nemorum ssp. glochidiosperma, Scopolia carniolica, Euphorbia carniolica, Calamintha grandiflora, Omphalodes verna, and Hacquetia epipacis. The species Cardamine trifolia, Cardamine enneaphyllos, Cardamine kitaibelii, Cardamine chelidonia, Lamium orvala, Vicia oroboides, Aposeris foetida, Aremonia agrimonoides, Epimedium alpinum and Helleborus odorus were recorded individually and sporadically only on the edges of the range and in the boundary region with the communities of the Illyrian character. Only Ruscus hypoglossum and Cyclamen purpurascens are more constant in the entire range of the studied association. A large number of earlier works, especially those taken from the overview composed by an international team of phytocoenologists (Marinček et al. 1993), allow for the conclusion that the community Cephalanthero longifoliae-Fagetum lacks the diagnostic species of the Illyrian alliance Aremonio-Fagion and its sub-alliances, on the basis of which it could be subordinated to them. According to these data and the analysis in Tables 1 and 2, these stands should be classified into the Central European alliance Fagion sylvaticae. The differentiating species towards the association Galio odorati-Fagetum and other Central European associations of the sub-alliance Galio odorati-Fagenion include Festuca drymeia, Polysichum setiferum, Cephalanthera longifolia, Ruscus hypoglossum, Rubus hirtus, Tilia tomentosa, Fraxinus ornus, and Potentilla micrantha. Investigations into the internal structure of these beech stands revealed the local dominance of the facieses of the species Carex pilosa and Festuca drymeia, but in over 60% of the cases they were recorded together. In addition to these two, another very important species in the diagnostic sense is Cephalanthera longifolia, which gave the association its name. This is a warmth-loving species of moderately acid to basic, predominantly dry sites, generally distributed in the colline and montane vegetation belt. Most phytocoenologists classify it into the sub-Mediterranean – Euro-Asian species. Sociologically, it belongs to the class Querco-Fagetea with a mild tendency towards the communities of the order Quercetalia pubescentis. The differentiating species Tilia tomentosa and Potentilla micrantha, with the centre of their distribution lying in the south-eastern part of Europe, are particularly important for the association. This stresses the transitional character of the association (see Figure 1). These investigations greatly contribute to the knowledge of the forest vegetation of Croatia and the boundary region of the Illyrian floristic province. The studied beech forests cover about forty thousand ha in Croatia. They have been described under the following names: Carici pilosae-Fagetum (Pelcer in: Cestar et al. 1983, Rauš et al. 1992, Trinajstić and Franjić 1999, Vukelić and Baričević 2002, 2003, Trinajstić 2007, Vukelić et al. 2007), partly under the name of Festuco drymeiae-Fagetum (Baričević 2002, Škvorc 2006, Škvorc et al. 2011, G. Horvat 2011, non Trinajstić and Cerovečki 2009), then as Polysticho setiferi-Fagetum (Baričević, Vukelić and Šapić 2009), while Marinček (1995) comprised them in the association Vicio oroboidi-Fagetum. The first three names were used earlier to describe the communities in other European areas (Germany, Romania, Slovakia, Italy), to which the stands from Croatia do not belong (compare Moriariu et al. 1968, Magic 1968, Ubaldi 1988, Coldea 1991, Oberdorfer 1992, Zupančič, Žagar and Surina 2000, and others), whereas the fourth community, Vicio oroboidi-Fagetum, differs from the former three by its composition and synsystematic affiliation. On the other hand, this confirms the assumption by Willner (2002) that a new, insufficiently investigated association which is related to the association Galio odorati-Fagetum in its lower positions begins southeast of the Alpine area and the range of the association Galio odorati-Fagetum. Analogously to the understanding of the scope of the association Galio odorati-Fagetum, the newly established association Cephalanthero longifoliae-Fagetum would be relatively widely distributed on the south-western and southern edge of the Pannonian Plain and the transition to the Dinaric and Central Balkan area. Naturally, this does not exclude the establishment of the association Galio odorati-Fagetum southeast of its clearly identified range in the southeast of Austria. In fact, according to the research currently under way, it can be assumed that its south-eastern boundary (which Willner considers unclear) lies precisely in the fresh sites well supplied with nutrients on dystric brown soils above moderately acid substrates of the submontane – montane belt of the Croatian Pannonian mountains (Papuk, Psunj, Krndija). The synsystematic affiliation of association is:             Querco-Fagetea Br.-Bl. et Vlieger 1937                         Fagetalia sylvaticae Pawl. 1928 in Pawl. et al. 1928                                     Fagion sylvaticae Laquet 1926                                                 Galio odorati-Fagenion (Tx. 1955) Th. Müller 1959                                                             Cephalanthero longifoliae-Fagetum Vukelić, Baričević et Šapić ass. nova. hoc.loco. Nomenclature type is relevé 6 in Table 1

Submontane-sub-pannonian beech forests of northern Croatia

Standardnom metodom srednjoeuropske fitocenološke škole (Braun-Blanquet 1964) istražena je i opisana nova asocijacija bukove šume s dugolisnom naglavicom – Cephalanthero longifoliae-Fagetum ass. nova, koja se rasprostire u kolinsko-submontanskom pojasu panonskoga gorja sjeverne Hrvatske, na visinama od 200 do 700 m, na lesnim i romboidnim naslagama povrh kojih se najčešće nalazi luvisol. Obilježava ju relativno siromašan i homogen florni sastav, izostanak brojnih vrsta ilirske sveze Aremonio-Fagion (Horvat 1938) Borhidi in Törek, Podani et Borhidi 1989, izrazita prevlast vrsta Festuca drymeia i Carex pilosa te stalnost vrsta srednjoeuropskih bukovih šuma. Svrstana je unutar srednjoeuropske sveze Fagion sylvaticae Laquet 1926. U odnosu na sastav ostalih bukovih šuma iste sinsistematske pripadnosti ističu se dijagnostičke vrste Festuca drymeia, Polystichum setiferum, Cephalanthera longifolia, Rubus hirtus, Tilia tomentosa, Potentilla micrantha i Ruscus hypoglossum. U radu je prikazano 15 novih i 137 već objavljenih fitocenoloških snimaka, na osnovi kojih je analizirana građa, sociološki i sintaksonomski karakter asocijacije Cephalanthero longifoliae-Fagetum te odnos prema srodnim asocijacijama na južnom i jugozapadnom rubu Panonske nizine i u susjednim područjima.A new association of beech forest with Sword-leaved Helleborine – Cephalanthero longifoliae-Fagetum ass. nova was described in the colline-submontane belt of northern Croatia, on the south-western edge of the Pannonian Plain. The method of the Central European Phytocoenological School (Braun-Blanquet 1964) was used in the research. Statistical comparison was performed by using programs TURBOVEG (Hennekens & Schaminée 2001) and PRIMER 6 (Clarke & Gorley 2001). MDA and UPGMA methods were made by use of Bray-Curtis similarity index. The association was presented on the basis of 15 new and 132 already published phytocoenological relevés (Table 1). In Table 2 and Figure 3 the association Cephalanthero longifoliae-Fagetum was compared with the related beech forests of the Illyrian floristic province (north-western Croatia, eastern Slovenia, northern Bosnia), then with the Central European association Galio odorati-Fagetum from the colline-submontane positions of Austria and southern Germany, and finally with beech forests of the Carpathian part of Romania. The association Cephalanthero longifoliae-Fagetum is distributed at altitudes from 200 to 700 m, with terrain inclinations usually ranging between 10 and 20 degrees. It grows in the temperate climate with average temperatures from 9.5 to 10.7 °C and average rainfall from 800 to 1,100 mm. The parent bedrock is made up of loess and rhomboid layers generally overlaid with luvisol in a humus-accumulative horizon of medium acidity (pH about 5). The association is characterized by a relatively poor and homogeneous floristic composition, the absence of numerous species of the Illyrian alliance Aremonio-Fagion (the associations Hacquetio-Fagetum, Lamio orvalae-Fagetum, Vicio oroboidi-Fagetum), the distinct prevalence of the species Festuca drymeia, Carex pilosa and Rubus hirtus, and the constancy of the species of Central European beech forests from the alliance Fagion sylvaticae and the order Fagetalia (Figure 2). Species of warmer and drier sites occur in moderate quantities. A synhorological analysis of the investigated association (according to Poldini 1992) gave the relatively expected results. Of the 206 species, 77 % belong to the widely distributed floral geoelement which does not characterize the southern edge of the Pannonian Plain in any particulars (cosmopolitan, circumboreal, Eurasian, Euro-Siberian, European, Mediterranean-Atlantic and others). In relation to beech forests of the Dinaric region, the studied stands completely lack the Illyrian and south-eastern European species that are important for the alliance Aremonio-Fagion, such as Rhamnus alpinus ssp. fallax, Geranium nodosum, Stellaria nemorum ssp. glochidiosperma, Scopolia carniolica, Euphorbia carniolica, Calamintha grandiflora, Omphalodes verna, and Hacquetia epipacis. The species Cardamine trifolia, Cardamine enneaphyllos, Cardamine kitaibelii, Cardamine chelidonia, Lamium orvala, Vicia oroboides, Aposeris foetida, Aremonia agrimonoides, Epimedium alpinum and Helleborus odorus were recorded individually and sporadically only on the edges of the range and in the boundary region with the communities of the Illyrian character. Only Ruscus hypoglossum and Cyclamen purpurascens are more constant in the entire range of the studied association. A large number of earlier works, especially those taken from the overview composed by an international team of phytocoenologists (Marinček et al. 1993), allow for the conclusion that the community Cephalanthero longifoliae-Fagetum lacks the diagnostic species of the Illyrian alliance Aremonio-Fagion and its sub-alliances, on the basis of which it could be subordinated to them. According to these data and the analysis in Tables 1 and 2, these stands should be classified into the Central European alliance Fagion sylvaticae. The differentiating species towards the association Galio odorati-Fagetum and other Central European associations of the sub-alliance Galio odorati-Fagenion include Festuca drymeia, Polysichum setiferum, Cephalanthera longifolia, Ruscus hypoglossum, Rubus hirtus, Tilia tomentosa, Fraxinus ornus, and Potentilla micrantha. Investigations into the internal structure of these beech stands revealed the local dominance of the facieses of the species Carex pilosa and Festuca drymeia, but in over 60% of the cases they were recorded together. In addition to these two, another very important species in the diagnostic sense is Cephalanthera longifolia, which gave the association its name. This is a warmth-loving species of moderately acid to basic, predominantly dry sites, generally distributed in the colline and montane vegetation belt. Most phytocoenologists classify it into the sub-Mediterranean – Euro-Asian species. Sociologically, it belongs to the class Querco-Fagetea with a mild tendency towards the communities of the order Quercetalia pubescentis. The differentiating species Tilia tomentosa and Potentilla micrantha, with the centre of their distribution lying in the south-eastern part of Europe, are particularly important for the association. This stresses the transitional character of the association (see Figure 1). These investigations greatly contribute to the knowledge of the forest vegetation of Croatia and the boundary region of the Illyrian floristic province. The studied beech forests cover about forty thousand ha in Croatia. They have been described under the following names: Carici pilosae-Fagetum (Pelcer in: Cestar et al. 1983, Rauš et al. 1992, Trinajstić and Franjić 1999, Vukelić and Baričević 2002, 2003, Trinajstić 2007, Vukelić et al. 2007), partly under the name of Festuco drymeiae-Fagetum (Baričević 2002, Škvorc 2006, Škvorc et al. 2011, G. Horvat 2011, non Trinajstić and Cerovečki 2009), then as Polysticho setiferi-Fagetum (Baričević, Vukelić and Šapić 2009), while Marinček (1995) comprised them in the association Vicio oroboidi-Fagetum. The first three names were used earlier to describe the communities in other European areas (Germany, Romania, Slovakia, Italy), to which the stands from Croatia do not belong (compare Moriariu et al. 1968, Magic 1968, Ubaldi 1988, Coldea 1991, Oberdorfer 1992, Zupančič, Žagar and Surina 2000, and others), whereas the fourth community, Vicio oroboidi-Fagetum, differs from the former three by its composition and synsystematic affiliation. On the other hand, this confirms the assumption by Willner (2002) that a new, insufficiently investigated association which is related to the association Galio odorati-Fagetum in its lower positions begins southeast of the Alpine area and the range of the association Galio odorati-Fagetum. Analogously to the understanding of the scope of the association Galio odorati-Fagetum, the newly established association Cephalanthero longifoliae-Fagetum would be relatively widely distributed on the south-western and southern edge of the Pannonian Plain and the transition to the Dinaric and Central Balkan area. Naturally, this does not exclude the establishment of the association Galio odorati-Fagetum southeast of its clearly identified range in the southeast of Austria. In fact, according to the research currently under way, it can be assumed that its south-eastern boundary (which Willner considers unclear) lies precisely in the fresh sites well supplied with nutrients on dystric brown soils above moderately acid substrates of the submontane – montane belt of the Croatian Pannonian mountains (Papuk, Psunj, Krndija). The synsystematic affiliation of association is:             Querco-Fagetea Br.-Bl. et Vlieger 1937                         Fagetalia sylvaticae Pawl. 1928 in Pawl. et al. 1928                                     Fagion sylvaticae Laquet 1926                                                 Galio odorati-Fagenion (Tx. 1955) Th. Müller 1959                                                             Cephalanthero longifoliae-Fagetum Vukelić, Baričević et Šapić ass. nova. hoc.loco. Nomenclature type is relevé 6 in Table 1

Raznolikost i strukturiranost hrvatskih kontinentalnih i alpsko-dinarskih populacija bijele johe (Alnus incana /L./ Moench subsp. incana); geografska i okolišna izolacija kao uzrok fenotipske divergencije

We studied the morphological variation and its correlation to the environment in a boreal tree species, Alnus incana (L.) Moench subsp. incana, across the Croatian continental and Alpine-Dinaric biogeographical regions. A total of seven grey alder populations from environmentally divergent habitats were included in the study. We combined descriptive and multivariate statistical methods by using morphological leaf traits and environmental features to examine the diversity and structure of grey alder populations. High phenotypic variation, and two distinct morphotypes were found: small-leaf in the Alpine-Dinaric region, and large-leaf in the continental region. We identified a biogeographical structuring of populations with a high level of among-tree variation within the populations. Multivariate phenotypic and environmental analysis confirmed the existence of small- and large-leaf ecotypes. Additionally, a lack of significant among-population variation within biogeographical regions was observed. Furthermore, we found that phenotypic divergence of the studied grey alder populations can be explained as a result of a significant level of isolation both by distance and by environment.Bijela, odnosno siva joha, Alnus incana (L.) Moench subsp. incana, listopadna je, jednodomna i anemofilna drvenasta vrsta iz porodice Betulaceae. Prirodno je rasprostranjena u sjevernoj, srednjoj i mjestimično južnoj Europi, zapadnom Sibiru i Turskoj, od nizinskoga pojasa do preko 1800 m nadmorske visine u alpskom području. Bijela joha je mezofilna do higrofilna vrsta koja dobro podnosi oštru planinsku i kontinentalnu klimu, a raste na karbonatnim, ali i silikatnim, pjeskovitim, šljunčanim, slabo humusnim tlima. Najčešća je u planinskim dolinama, uz potoke i rijeke gdje na vlažnim staništima s mnogim higrofilnim vrstama tvori guste, fragmentarne sastojine, često obnovljene iz panja. To su povremeno plavljeni lokaliteti uz vodotoke ili okolne padine kroz koje se postrano procjeđuje voda prema glavnom vodotoku.Prisutnost bijele johe u Hrvatskoj vezana je za dva oštro ograničena područja: sjeveroistočno, u nizinskom dijelu Hrvatske (110 do 190 m nadmorske visine) uz tok rijeke Drave; i sjeverozapadno, u alpsko-dinarskom području uz rijeku Kupu i njene pritoke (220 do 550 m nadmorske visine).U sjeveroistočnom području rasprostiru se sastojine definirane kao Equiseto hyemali-Alnetum incanae Moor 1958 (Trinajstić 1964; Franjić et al. 1999), u kojima se u odnosu na sastojine bijele johe u gorskome području kao razlikovne vrste izdvajaju: Ulmus laevis Pall., U. minor Mill., Prunus padus L., Equisetum hyemale L. i druge. Ove sastojine danas su rjeđe nego nekada, manje se koriste, a zbog nekadašnjeg načina sječe vrlo su često panjače. Nekadašnje šumske površine koje je Trinajstić istraživao (1964) danas više nisu pod šumom. Poplavne i vlažne šume u blizini urbanih središta isušuju se, a na njihovim su staništima izgrađena naselja i komunalna infrastruktura tako da su danas šume sive johe uz tok rijeke Drave u velikoj regresiji.U alpsko-dinarskom području istraživane sastojine svrstane su u šumsku zajednicu Lamio orvalae-Alnetum incanae Dakskobler 2010, a opisane su kao geografska varijanta Helleborus dumetorum (Vukelić et al. 2012, 2017). Ona se ističe mnogim vrstama iz dinarske vegetacijske zone, poput Fraxinus excelsior L., Ulmus glabra Huds., Fagus sylvatica L., Acer pseudoplatanus L., Lamium orvala L., Lunaria rediviva L., Scopolia carniolica Jacq., Helleborus dumetorum Waldst. et Kit., Knautia drymeia Heuff. subsp. drymeia i druge. Siva joha ovdje raste u kanjonu Kupe i na obalnim terasama koje su uglavnom antropogenizirane, a nekoć su bile korištene u poljoprivrednoj proizvodnji.Glavni ciljevi rada bili su utvrditi morfološku raznolikost i strukturiranost populacija bijele johe u Hrvatskoj te istražiti na koji način ekološki i geografski čimbenici utječu na varijabilnost populacija.Materijal za morfometrijsku analizu sakupljen je iz sedam prirodnih populacija – tri iz kontinentalne i četiri iz alpsko-dinarske regije (slika 1). Svaka populacija predstavljena je s 20 stabala, a svako stablo s 20 zdravih i neoštećenih listova s kratkih fertilnih izbojaka iz vanjskog, osvijetljenog dijela krošnje. Listovi su sakupljeni početkom srpnja 2016. godine, odnosno sredinom vegetacijskog razdoblja, kada su s obzirom na dimenzije i oblik u potpunosti razvijeni. Listovi su skenirani i izmjereni pomoću programa WinFolia. Ukupno je izmjereno devet lisnih značajki (slika 2).Deskriptivnim statističkim metodama utvrđena je visoka varijabilnost listova bijele johe, kao i jasan trend divergencije između kontinentalnih i alpsko-dinarskih populacija (slika 3). Najvarijabilnijim su se pokazale značajke: površina plojke, širina lista mjerena na 90 % dužine plojke i dužina peteljke. Za razliku od toga, najmanji stupanj varijabilnosti zabilježen je za varijable koje opisuju osnovu lisne plojke. Iako je trend variranja pojedinih značajki po populacijama bio sličan, u populacijama alpsko-dinarske regije zabilježena je nešto viša unutar-populacijska raznolikost. Kontinentalne populacije su imale veće vrijednosti svih mjerenih značajki lista u odnosu na populacije iz alpsko-dinarske regije.Analizom varijance, utvrđene su statistički značajne razlike između istraživanih regija te između stabla unutar populacija, dok su se populacije unutar regija razlikovale samo za četiri istraživane značajke (tablica 1). Unutarpopulacijska varijabilnost veća je od međupopulacijske varijabilnosti, što je odlika mnogih vrsta drveća. Multivarijatne analize potvrđuju postojanje jasne razlike između kontinentalnih i alpsko-dinarskih populacija bijele johe (slika 1, slika 4, tablica 3), što upućuje na mogućnost da istraživane populacije predstavljaju dva različita ekotipa.Morfološka udaljenost između populacija bila je korelirana s geografskom i ekološkom udaljenošću, što potvrđuje uzorak „isolation by distance“ i „isolation by environmental distance“. Drugim riječima, utvrđeno je da geografska udaljenost i ekološka divergencija imaju važan utjecaj na oblikovanje morfološke strukture populacija te da je ona posljedica njihove moguće lokalne prilagodbe na okolišne uvjete i njihove geografske udaljenosti (tablica 2).Dobivene spoznaje o varijabilnosti populacija mogu doprinijeti razvoju učinkovitijih planova očuvanja i gospodarenja sivom johom u Hrvatskoj. Kako bi se potvrdili dobiveni zaključci o varijabilnosti populacija sive johe dobiveni morfometrijskim metodama, istraživanja je svakako potrebno proširiti i na molekularno-biološke metode

Diversity of Forest Vegetation in the Hilly Požega Region

U radu su prikazani rezultati sinekološko-fitocenoloških istraživanja šumske vegetacije Požeške i Babje gore. Istraživano područje kao južni dio slavonskoga gorja izuzetno je vrijedan objekt u vegetacijskoj slici Republike Hrvatske. Šumske sastojine, nažalost, do sada nisu dostatno istražene i opisane te vrednovane. Pri terenskim istraživanjima korištene su klasične fitocenološke metode. Ukupno je istraženo dvjestotinjak lokaliteta u svim oblicima šumske vegetacije te su provedene multivarijatne statističke analize podataka pomoću kompjutorskih programa SinTax2000 i Juice 6.3. One su pokazale međusobno vrlo slične rezultate i iste opće zakonitosti. Kao rezultat toga jasno su definirane sve šumske zajednice na istraživanome području te sinekološki čimbenici presudni za pridolazak i rasprostranjenost pojedine zajednice. U okviru opisanih šumskih zajednica ukupno je evidentirano 240 vrsta, od kojih su neke i na crvenom popisu ugroženih biljaka Republike Hrvatske u skupini rizično ugroženih i u skupini nisko rizično ugroženih. Spektar flornih geoelemenata potvrđuje uvodne pretpostavke i stajališta da se istraživano područje nalazi na raskrižju vrlo raznolikih utjecaja. To jasno pokazuje iznimno velik broj vrlo različitih flornih geoelemenata i njihovih kombinacija. Općenito gledano, na relativno maloj površini s vrlo sličnim općim ekološkim uvjetima imamo vrlo raznolike mikroklimatske i mikroreljefne uvjete, što se vidi na velikim razlikama u vrstama i broju biljaka koje pridolaze u pojedinoj zajednici. Kada bismo generalno opisali cjelokupno istraživano područje kroz ekoindikatorske vrijednosti biljnih vrsta koje pridolaze u šumskoj vegetaciji, mogli bismo zaključiti da su ekološki uvjeti iznimno povoljni za razvitak vegetacije. To se izvrsno reflektira kroz veliku biološku raznolikost i bogatstvo šumske vegetacije Požeškoga gorja.The paper addresses the results of synecological-phytocoenological research into the forest vegetation of Požeška and Babja Gora. The investigated area, a part of southern Slavonian Mountains, represents an exceptionally valuable site in the vegetation picture of Croatia. So far, regrettably, the forest stands have not been properly investigated, described and evaluated. Field research was conducted using classical phytocoenological methods. In addition to investigating some two hundred localities with diverse forms of forest vegetation, multivariate statistical data analyses were also performed by means of SinTax2000 and Juice 4 software. These analyses provided mutually very similar results and revealed identical general patterns. This resulted in a clear definition of all the forest communities in the study area, as well as the synecological factors crucial for the occurrence and distribution of particular communities. A total of 240 species were identified within the described forest communities, of which some are on the red list of threatened plants in the Republic of Croatia, belonging to both the high and low threat category. The range of floral geoelements confirms the introductory hypotheses and views that the studied area is situated at the crossroads of highly diverse impacts. This is evidenced by a high number of very different floral geoelements and their combinations. In general, the relatively small area with very similar ecological conditions enjoys highly diverse micro-climatic and micro-relief conditions, as manifested by significant species diversity and a high number of plants occurring in a particular community. Broadly speaking, if we described the entire study area in terms of eco-indicator values of plant species occurring in the forest vegetation, we could conclude that the ecological conditions here are exceptionally conducive to the development of vegetation. This is very well reflected in high biological diversity and the abundance of forest vegetation in the hills of Požega

Diversity of Forest Vegetation in the Hilly Požega Region

U radu su prikazani rezultati sinekološko-fitocenoloških istraživanja šumske vegetacije Požeške i Babje gore. Istraživano područje kao južni dio slavonskoga gorja izuzetno je vrijedan objekt u vegetacijskoj slici Republike Hrvatske. Šumske sastojine, nažalost, do sada nisu dostatno istražene i opisane te vrednovane. Pri terenskim istraživanjima korištene su klasične fitocenološke metode. Ukupno je istraženo dvjestotinjak lokaliteta u svim oblicima šumske vegetacije te su provedene multivarijatne statističke analize podataka pomoću kompjutorskih programa SinTax2000 i Juice 6.3. One su pokazale međusobno vrlo slične rezultate i iste opće zakonitosti. Kao rezultat toga jasno su definirane sve šumske zajednice na istraživanome području te sinekološki čimbenici presudni za pridolazak i rasprostranjenost pojedine zajednice. U okviru opisanih šumskih zajednica ukupno je evidentirano 240 vrsta, od kojih su neke i na crvenom popisu ugroženih biljaka Republike Hrvatske u skupini rizično ugroženih i u skupini nisko rizično ugroženih. Spektar flornih geoelemenata potvrđuje uvodne pretpostavke i stajališta da se istraživano područje nalazi na raskrižju vrlo raznolikih utjecaja. To jasno pokazuje iznimno velik broj vrlo različitih flornih geoelemenata i njihovih kombinacija. Općenito gledano, na relativno maloj površini s vrlo sličnim općim ekološkim uvjetima imamo vrlo raznolike mikroklimatske i mikroreljefne uvjete, što se vidi na velikim razlikama u vrstama i broju biljaka koje pridolaze u pojedinoj zajednici. Kada bismo generalno opisali cjelokupno istraživano područje kroz ekoindikatorske vrijednosti biljnih vrsta koje pridolaze u šumskoj vegetaciji, mogli bismo zaključiti da su ekološki uvjeti iznimno povoljni za razvitak vegetacije. To se izvrsno reflektira kroz veliku biološku raznolikost i bogatstvo šumske vegetacije Požeškoga gorja.The paper addresses the results of synecological-phytocoenological research into the forest vegetation of Požeška and Babja Gora. The investigated area, a part of southern Slavonian Mountains, represents an exceptionally valuable site in the vegetation picture of Croatia. So far, regrettably, the forest stands have not been properly investigated, described and evaluated. Field research was conducted using classical phytocoenological methods. In addition to investigating some two hundred localities with diverse forms of forest vegetation, multivariate statistical data analyses were also performed by means of SinTax2000 and Juice 4 software. These analyses provided mutually very similar results and revealed identical general patterns. This resulted in a clear definition of all the forest communities in the study area, as well as the synecological factors crucial for the occurrence and distribution of particular communities. A total of 240 species were identified within the described forest communities, of which some are on the red list of threatened plants in the Republic of Croatia, belonging to both the high and low threat category. The range of floral geoelements confirms the introductory hypotheses and views that the studied area is situated at the crossroads of highly diverse impacts. This is evidenced by a high number of very different floral geoelements and their combinations. In general, the relatively small area with very similar ecological conditions enjoys highly diverse micro-climatic and micro-relief conditions, as manifested by significant species diversity and a high number of plants occurring in a particular community. Broadly speaking, if we described the entire study area in terms of eco-indicator values of plant species occurring in the forest vegetation, we could conclude that the ecological conditions here are exceptionally conducive to the development of vegetation. This is very well reflected in high biological diversity and the abundance of forest vegetation in the hills of Požega

Forest Vegetation of Hardwood Tree Species along the Mirna River in Istria (Croatia)

Background and Purpose: The paper presents the forest vegetation of periodically flooded and wet forests of hardwood tree species along the Mirna River (Istria, Croatia). The main objective was to study the older and less influential stands, and to compare them among themselves and with related syntaxa of the Mediterranean and continental area. Materials and Methods: The research was conducted on the basis of 33 new phytocoenological relevés and 12 from previous studies, according to the principles of the standard Central European Phytocoenological School. Results and Conclusions: Based on 45 phytocoenological relevés two main vegetation types were found. In the lowest and periodically flooded habitats grow forests dominated by Fraxinus angustifolia and numerous hygrophilous species. In somewhat higher and drier localities, but with a high level of ground waters, grow mixed forests of Quercus robur, Fraxinus angustifolia, Ulmus minor and Carpinus betulus, with a greater presence of mesophilous species. The paper analyzes their mutual relationship, phytocoenological affiliation, as well as their position with regard to the related syntaxa of the Mediterranean and continental area. The results suggest isolation and a transitional character of the studied forests, which is a consequence of the biogeographical position in the north Mediterranean, of the ecological conditions, and to a lesser extent of anthropogenic influence

Identification and mapping of Natura 2000 forest habitat types in Croatia (I) – 91E0*alluvial forest with black alder Alnus glutinosa and common ash Fraxinus excelsior (Alno-Padion, Alnion incanae, Salicion albae)

U radu je opisano 16 šumskih stanišnih tipova iz Nacionalne klasifikacije staništa Republike Hrvatske koji su obuhvaćeni stanišnim tipom 91E0* Natura 2000. On je prioritetni europski stanišni tip, a odnosi se na močvarne, povremeno poplavne i vlažne šumske zajednice. Od drveća prevladavaju – ovisno o tipu – uskolisne vrbe, bijela i crna topola, bijela i crna joha, poljski i obični jasen. U prizemnom su sloju glavne higrofilne vrste uz veći ili manji udjel biljaka iz okolnih šuma viših položaja. U članku je europski stanišni tip 91E0* detaljnije prikazan, a svaki stanišni tip iz nacionalne klasifikacije predstavljen je kratkim opisom s arealom i dijagnostičkim pokazateljima. Također su navedeni i njegovi povezani tipovi, odgovarajući kôd prema EUNIS-ovoj klasifikaciji i literatura u kojoj je podrobnije opisan. Članak ima praktičnu važnost jer pomaže u prepoznavanju i kartiranju šumskih stanišnih tipova, a ti se zadaci upravo provode u hrvatskom šumarstvu.Habitat type 91E0 in Croatia extends to approximately 80,000 ha. It contains 16 types according to the National habitat classification of Croatia (NHC). They are based on phytosociological principles and are aligned with the level of association. They are:E.1. Riparian alluvial willow forests (Salicion albae Soó 1930), poplar (Populion albae Br.-Bl. 1931) and white alder forests (Alnion incanae Pawl. in Pawl. et al. 1928)                 Riparian alluvial willow and poplar forests (Salicion albae, Populion albae)                E.1.1.1. – Salicetum albae-fragilis Soó (1930) 1958                E.1.1.2. – Salicetum albae Isller 1926                E.1.1.3. – Salici-Populetum nigrae (R. Tx. 1931) Meyer Drees 1936                E.1.2.1. – Populetum albae (Br.-Bl.) Tchou 1947                 E.1.2.2. – Populetum nigro-albae Slavnić 1952                Alluvial white alder forests (Alnion incanae)                E.1.3.1. – Equiseto hyemali-Alnetum incanae M. Moor 1958                 E.1.3.2. – Lamio orvalae-Alnetum incanae Dakskobler 2010E.2. Floodplain forests of pedunculate oak, black alder and narrow-leaved ash (Alnion glutinosae Malcuit 1929, Alnion incanae)                Swamp and floodplain forests of black alder narrow-leaved ash (Alnion glutinosae)                E.2.1.4. – Frangulo-Alnetum glutinosae Rauš (1971) 1973                E.2.1.6. – Carici elongatae-Alnetum glutinosae W. Koch 1926 ex Tx. 1931                E.2.1.7. – Leucojo-Fraxinetum angustifoliae Glavač 1959                 E.2.1.9. – Carici acutiformis-Alnetum glutinosae Scamoni 1935                Alluvial and wetland forests of black alder, elms, narrow-leaved and common ash (Alnion incanae)                 E.2.1.1. – Fraxino angustifoliae-Ulmetum laevis Slavnić 1952                 E.2.1.2. – Carici remotae-Fraxinetum excelsioris W. Koch 1926 ex Faber 1936                E.2.1.3. – Carici brizoidis-Alnetum glutinosae Horvat 1938                E.2.1.5. – Pruno-Fraxinetum angustifoliae Glavač 1960                E.2.1.8. – Stellario nemorum-Alnetum glutinosae Lohmayer 1957             The article contains a description, area of distribution in Croatia, and diagnostic indicators for each type. For each type related types are listed, the corresponding code according to EUNIS-classification, and literature in which is described in more detail. This article has practical importance because it helps in the identification and mapping of forest habitat types, and these tasks are currently being implemented in the Croatian forestry

Phytocoenological analysis of grey alder (Alnus incana /L./ Moench supsp. incana) forest in Croatia

U članku su prikazani rezultati fitocenoloških istraživanja i analize šumskih sastojina bijele johe (Alnus incana /L./ Moench subsp. incana) u Hrvatskoj. Na temelju 11 novih i 37 fitocenoloških snimaka iz prijašnjih istraživanja analizirane su sastojine iz Gorskoga kotara uz rijeku Kupu i njezine pritoke opisane u okviru asocijacije Lamio orvalae-Alnetum incanae Dakskobler 2010 te sastojine iz sjeverozapadne Hrvatske uz rijeku Dravu definirane kao Equiseto hyemali-Alnetum incanae Moor 1958. U radu se analizira njihov međusobni odnos, a opširnije florni sastav i dinamika promjena u sastojini bijele johe sa zimskom preslicom u sjeverozapadnoj Hrvatskoj.This paper provides a comprehensive survey of the results of phytocoenological research of Alnus incana (L.) Moench subsp. incana stands in Croatia. Here, the grey alder appears in two biogeographic regions with contrasting climates (Figure 1): the continental region, along the course of the Drava river; and the mountainous Alpine-Dinaric region in Gorski kotar, along the course of the Kupa river and its tributaries. In the continental region of Croatia, the grey alder occurs mainly in riparian and floodplain forests along the main watercourse of the river Drava, where it forms smaller and isolated stands. These stands are included within the association Equiseto hyemali-Alnetum incanae Moor 1958 (Figure 3). Stands from the north-western Dinarides are defined within the association Lamio orvalae-Alnetum incanae Dakskobler 2010 var geogr. Helleborus dumetorum Vukelić et al. 2012 (Figure 4, Figure 5).Our main objectives were: (1) to present the results of recent studies of the association Equiseto hyemali-Alnetum incanae; (2) to compare them with the results of the studies from early second half of the 20th century (Trinajstić 1964, 1973); and (3) to compare them with the phytocoenological characteristics of grey alder forests from the Dinaric area of Croatia.The research was conducted on the basis of 11 new phytocoenological relevés and 37 from previous studies, according to the principles of the standard Central European Phytocoenological School (Braun-Blanquet 1964). Plant nomenclature was coordinated with the Flora Croatica Database (Nikolić 2015), and the mosses with Atherton et al. (2010). A part of the syntaxa was described in accordance with ICPN (Weber et al. 2000), and another part follows a multidimensional classification of vegetational units (Matuszkiewicz and Matuszkiewicz 1981). The sociological species affiliation was determined according to Vukelić (2012). The analysis of the floral composition of the association Equiseto hyemali-Alnetum incanae (=Alnetum incanae Lüdi 1921) from north-western Croatia demonstrates a high degree of floral similarity with colline stands of the same association presented in the forest vegetation of Austria (Willner and Grabherr 2007). As grey alder stands in Podravina grow on lower altitudes, they lack or have considerably less of the following species: Fraxinus excelsior, Lonicera xylosteum, Cardus perssonata, Picea abies, Anemone ranunculoides, Salvia glutinosa and others. On the other hand, some species in them have certain differential significance, namely: Ulmus laevis, U. minor, Quercus robur, Fraxinus angustifolia, Populus alba, Valeriana dioica and others. Table 1 shows 11 new relevés of grey alder-scouring rush stands. Due to major anthropogenic interventions, grey alder-scouring rush forests have seen considerable regressive changes in the distribution and floral composition, hence just like the species Equisetum hyemale, they should be considered an endangered type of habitat. A large part of the original forests and shrubbery has been cleared over the last 50 years due to the construction of two accumulation lakes and other melioration and infrastructural needs. Meliorations have greatly impacted the hydrological regime of the entire area, which resulted in alterations in the habitat, and eventually in the disappearance of areas that used to be covered by grey alder forests. In order to determine the changes in the floral composition of grey alder-scouring rush stands, we compared our phytocoenological relevés with those from 1964 (Trinajstić 1964). Table 2 specifies 35 species that indicate changes in the habitat and composition of the association. The table clearly demonstrates that the number of hygrophytes has been reduced, and the share of mesophilic species and species from less wet habitats considerably increased (column 2, table 2), especially from the order Fagetalia and class Querco-Fagetea Br.-Bl. et Vlieger 1937.The association Equiseto hyemali-Alnetum incanae has been compared with the stands from Gorski kotar, i.e. with the association Lamio orvalae-Alnetum incanae, where it was found that they differ significantly both from the ecological and from the floral point of view (Figure 2). Floral differences of the said forest communities result primarily from the climate and orographic factors of biogeographic regions, and the share of species from zonal forests in whose belts they grow. Table 3 specifies 76 differentiating species: seven for the association Equiseto hyemali-Alnetum incanae and 69 for the association Lamio orvalae-Alnetum incanae. The criterion employed to single them out was that they grow in only one association with at least 20% of relevés, or that the difference between the level of representation in associations is in excess of 35%. The largest number of differentiating species are mesophytes from the alliances Aremonio-Fagion /Ht. 1938/ Borhidi in Törek et al. 1989, Tilio-Acerion Klika 1955, Erythronio-Carpinion (Ht. 1938) Marinček in Wallnöfer et al. 1993 and the order Fagetalia (33 species in total). The large number and frequency of those differentiating species is the reason for clear independence and identity of the association Lamio orvalae-Alnetum incanae compared to other European grey alder forests (Vukelić et al. 2017). The most important differentiating species of the association Equiseto hyemali-Alnetum incanae is Prunus padus. With regard to syntaxonomy, the analyzed associations Equiseto hyemali-Alnetum incanae and Lamio orvalae-Alnetum incanae belong to the suballiance Alnenion glutinoso-incanae Oberd. 1953, alliance Alnion incanae Pawl. in Pawl. et al. 1928, of the order Fagetalia sylvaticae Pawl. in Pawl. et al. 1928 and class Querco-Fagetea Br.-Bl. et Vlieger 1937

POPULATION VARIABILITY OF GREY (Alnus incana /L./ Moench) AND BLACK ALDER (A. glutinosa /L./ Gaertn.) IN THE MURA AND DRAVA REGION ACCORDING TO THE LEAF MORPHOLOGY

Morfološka varijabilnost listova bijele (Alnus incana /L./ Moench) i crne johe (A. glutinosa /L./ Gaertn.) istražena je u pet prirodnih populacija na području Podravine i Međimurja, uz rijeke Dravu i Muru. Unutarpopulacijska i međupopulacijska varijabilnost utvrđena je na osnovi deset morfoloških značajki listova i četiri izvedena omjera, pri čemu su korištene deskriptivne i multivarijatne statističke metode. Provedenim istraživanjem utvrđena je visoka varijabilnost istraživanih populacija. Unutarpopulacijska varijabilnost veća je od međupopulacijske varijabilnosti kod obje vrste. Stabla unutar populacija signifikantno se razlikuju za sva analizirana svojstva. Klasterskom i kanoničkom diskriminantnom analizom dobiveno je jasno razdvajanje populacija bijele i crne johe, a na području Podravine utvrđena je prisutnost jedinki s prijelaznim značajkama koje odgovaraju hibridima među tim vrstama. U odnosu na roditeljske vrste, hibridi pokazuju intermedijarna svojstva za većinu istraživanih značajki. Populacije crne johe međusobno se signifikantno razlikuju u četiri istraživane značajke, dok se populacije bijele johe signifikantno ne razlikuju.White and black alder are our indigenous noble broad-leaved species. In Croatian forestry, black alder has an important place, while the white alder does not have economic importance and it is becoming increasingly neglected. White alder appears on shingle, active material in mainstream, on river banks and terraces which are periodically or at least sporadically flooded. It very rarely occurs on its own on drifts and it does not appear in swamp habitats which are characteristics of black alder. The farther the area is from the mainstream watercourse, the higher is the probability of black alder supervention. Finally, in swampy, peaty areas, black alder forms its stands.Stands of white and black alder are relatively clearly distinguished in the researched area, although somewhere is common their joint supervention on the same stands. In the areas where white and black alder habitats are overlapped, their spontaneous hybridisation is possible. White and black alder crosses have been so far noticed only in NW Croatia.Variability of a species is one of the most important preconditions for its adaptive potential in variable environment conditions, and in a long term, for survival of the species. That is, variability insures adaptability of populations towards environment changes through generations. The optimal variability of white and black alder in the area of riparian forest ecosystems is disturbed by negative anthropogenic activities.This paper researches the intra-population and inter-population variability of white and black alder in five natural populations along rivers Drava and Mura on the basis of morphological leaf traits.Material for the morphometric analysis was collected in five natural populations in the areas of Podravina and Međimurje, along rivers Drava and Mura (Figure 1). Three populations of white alder and two populations of black alder were included in the research. Each population was represented by 20 trees and each tree by 20 healthy and undamaged leaves, collected from short fertile shoots of the outer, light-exposed part of tree top. The leaves were scanned and measured by the WinFolia programme. Ten foliar traits were defined and measured altogether (Figure 2). From the measured traits, the following ratios were derived: MPW/BL, PW1/BL, PMPW/BL, PL/BL.The measured morphological traits were shown through descriptive statistical parameters. For determining the intra-population and inter-population variability, the univariate analysis of variance was used. For determining similarities or differences of analyzed populations on the basis of measured morphological leaf traits, multivariate statistical methods were used – cluster and discriminant analysis. These statistical analyses were conducted using the statistical programme STATISTICA 8.0.The results of the descriptive statistical analysis are presented in Table 1, by population. For both species, the trees within populations differ significantly on all analysed traits (Tables 2 and 3). Populations of white alder do not differ significantly between themselves on any trait, while the differentiation of populations of black alder is at significant level 0,01 inherent for variables BL, PMPW, LA1 and LA2. For each species individually, smaller variability among populations has been determined, while the remaining component regarding variability of the leaves within the tree takes up the largest proportion of the total variance (Tables 4 and 5).It can be seen from the dendrogram that the inter-population variability of black alder is greater than the inter-population variability of white alder (Figure 3).In order to determine which traits best discriminate researched populations and to additionally clarify the trend of their differentiation, discriminant analysis was conducted (Tables 6 and 7, Figure 4). For the populations of white alder, it was determined that canonical projections of trees within populations are weakly connected, in the sense that the populations are almost completely overlapping. The weak differentiation between populations and great variability within populations can be explained by similar ecological conditions of their supervention and by intensive flow of genes between populations. Although the canonical value projections for individual trees are partly overlapping, the trend of differentiation between populations of black alder is clearly perceived. Considering that the researched species belong to different river and forest systems, we can assume that the obtained differences in variability are caused by hydrological and ecological influences.Although the trees of white and black alder clearly differ between themselves, it can be seen that individual trees from white alder population Varaždinsko jezero cross to the right side of the diagram (Figure 4). Considering that the mentioned trees are intermediary in relation to researched species, we can conclude that it is the case of hybrid individuals. Through subsequent analysis, intermediary traits on most researched variables were identified for the crosses (Table 8).Genetic diversity is one of the basic preconditions for adaptability of a certain species to particular habitat conditions. Through this research, the knowledge of the intra-population and inter-population variability of white and black alder on Podravina – Međimurje area was gained. This knowledge represents the basis for further research that needs to be conducted in order to obtain guidelines for improvement and preservation of genetic resources of the alder species in Croatia