Primena metoda multivarijantne analize u proučavanju korovske vegetacije na primeru severozapadnog Balkana

Studies of weed vegetation by using Braun-Blanquet's method have been traditional in the north-western Balkans but only studies based on synoptic tables of weed vegetation have so far been conducted in the area of the former Yugoslavia (Kojić, 1975). Over the past two years, all available relevés of weed vegetation (4258) in the area have been collected in a database, which we have analysed using the latest methods of multivariate analysis in different statistical softwares, such as JUICE, CANOCO, PC-ORD, etc. The results of classification, indirect and direct ordination and application of indicator values (Pignatti, Raunkier forms) in the analysis of weed vegetation are shown on examples from the former Yugoslavia, and will be compared to results acquired under the conventional approach of Braun-Blanquet's scool. It will show the advantages of the new approach in studies and interpretation of weed or any other type of vegetation.Korovska vegetacija u Evropi je najviše proučena klasičnim florističko-fitocenološkim metodama i to uglavnom na regionalnom nivou. Međutim, poslednjih desetak godina sve više se upotrebljavaju veći setovi podataka (velika područja), koji su donekle uticali na drugačiji pristup tumačenju faktora koji utiču na floristički sastav i diferenciranost korovske vegetacije. U vezi s tim, analiza i interpretacija korovske vegetacije primenom multivarijacionih metoda je postala pravi trend u ovakvoj vrsti istraživanja. Proučavanje korovske vegetacije Braun-Blanquetovom metodom ima bogatu tradiciju na tlu severozapadnog Balkana, ali do sada su uglavnom rađene samo studije iz pojedinih područja kao sinoptičke tablice pregleda korovske vegetacije za područje bivše Jugoslavije (Kojić, 1975). U zadnje dve godine u bazi podataka sakupljeni su svi dostupni vegetacijski snimci (4258 sastojina) korovske vegetacije sa tog području, koje smo analizirali koristeći najsavremenije metode multivarijantne analize u različitim statističkim programima kao što su JUICE, CANOCO, PC-ORD itd. Na praktičnim primerima u radu će biti prikazani rezultati klasifikacije, indirektne i direktne ordinacije i primene indikacionih vrednosti (Pignatti, Raunkierovi oblici) u analizi korovske vegetacije razvijene na prostorima bivše Jugoslavije i kao takvi biće upoređeni sa rezultatima pregleda korovske vegetacije rađene klasičnim principima Braun-Blanquetove škole. Dakle, dobiće se uvid u prednosti novog pristupa u proučavanju i interpretaciji korovske, odnosno bilo koje druge vegetacije. Multivarijantne metode omogućavaju dobijanje informacija iz više-dimenzionalnog sveta, kao što je priroda, a naročito dinamična korovska vegetacija, a koje nisu direktno vidljive. Klasifikacija korovskih/ biljnih zajednica ovim sistemom omogućava objektivnije grupisanje velikog broja podataka, za razliku od starih principa Braun-Blanquetove škole gde je to rađeno intuitivno, tj. na osnovu iskustava istraživača. Ordinacionim tehnikama mogu se koristiti i merljivi parametri kao što su tip useva, godina, sezona, nadmorska visina itd., a primenom parcijalnih ordinacija uticaj pojedinih varijabli i nivo njihove statističke značajnosti u razvoju određenog tipa vegetacije

Alien plant species and factors of invasiveness of anthropogenic vegetation in the Northwestern Balkans - a phytosociological approach

We studied the anthropogenic vegetation of the Northwest Balkans in order to determine its susceptibility to invasion by alien plant species. We compiled a dataset of 3089 vegetation plots sampled between 1939 and 2009, recording a set of variables for each sample plot in order to determine which factors have the most effect on a habitat's vulnerability to invaders. We calculated the proportion of native species, archaeophytes and neophytes for each plot. We used regression tree models to determine the site conditions of the most invaded anthropogenic habitats. The sample plots contained an average of 12.7% alien plant species, with a low proportion of archaeophytes (4.3%) and 8.4% neophytes. Local habitat conditions proved to have the largest effect, rather than climatic variables or propagule pressure. The proportion of archaeophytes follows a different pattern than that seen in central and northern Europe, indicating that macroecological factors are more important. Neophytes show a similar distribution to other European locations

BİTKİ SOSYOLOJİSİ ÇALIŞMALARINDA KULLANILAN SAYISAL METOTLAR VE BAZI BİLGİSAYAR PROGRAMLARI

Türkiye’deki bitki sosyolojisi çalışmaları, bitki toplumlarını belirleme üzerine yoğunlaşmıştır. Bitki toplumlarının ekolojik, biyolojik ve yapısal özellikleri konularında ise pek çalışma bulunmamaktadır. Bu kapsamda, geliştirilmiş olan sayısal metotlar (ordinasyon-sınıflandırma) ve bu metotların kullanımını olanaklı kılan bilgisayar programları önemli yardımcı araçlardır. Bu metotlar ve programlar sayesinde, bitki toplumlarının sınıflandırılması ve onların ekolojik, biyolojik ve yapısal özelliklerinin ortaya konması çok kolaylaşmıştır. Bu çalışmada, tüm dünyada ve özellikle Avrupa’daki bitki sosyolojisi ve vejetasyon ekolojisi araştırmalarında yoğun olarak kullanılan ordinasyon ve sınıflandırma teknikleriyle, kapsamlı bir veri yönetim sistemi olan TURBOVEG ve bitki sosyolojisi verilerini analiz etmek ve düzenlemek amacıyla kullanılan JUICE programları tanıtılarak, uygulamaları konusunda bilgi verilmeye çalışılmıştır. Anahtar Kelimeler: Bitki sosyolojisi, Juice, Ordinasyon, Sınıflandırma, Turboveg

Grassland communities of Stol mountain (eastern Serbia ): Vegetation and environment al relationships

The systematic survey of grassland communities was performed on Mt. Stol (eastern Serbia). The main aims of the research were to: (1) determine grassland vegetation types of the researched area; (2) correlate the impacts of the soil and environmental conditions on the occurrence of certain plant communities, and (3) comment on the conservational value of the grasslands in the researched area. The data set included 60 phytosociological relevés of grasslands recorded between 2001 and 2004. The main environmental gradients of species composition were analyzed by Detrended Correspondence Analysis (DCA). For the ecological interpretation of ordination axes, ecological indicator values were used. Three associations were distinguished: Danthonietum calycinae, Asperulo-Agrostietum vulgaris and Ranunculo bulbosi- Arrhenatheretum elatioris belonging to two alliances and two classes: Chrysopogono-Danthonion - Festuco-Brometea and Arrhenatherion - Molinio-Arrhenatheretea. The results of the DCA support our assumption that the main environmental gradient in the species composition of the grasslands is related to nutrients and moisture. The conservational value of grasslands in the researched area is discussed

Formalized classification of semi-dry grasslands in central and eastern Europe

European semi-dry grasslands are among the most species-rich vegetation types in the northern hemisphere and form an important part of the habitat mosaics in the forest-steppe zone. However. there is no comprehensive evaluation of the variation in their composition and the phytosocio-logical classification of these grasslands. For the syntaxonomic revision, we used a dataset of 34,173 vegetation plot records (releves) from central and eastern Europe. which were assigned to the class Fesiuco-Bromeiea using the diagnostic species listed in the EuroVegChecklist. To determine the diagnostic species of the orders, we used a TWINSPAN classification of the whole dataset. Of the total dataset, 15,449 releves were assigned to the order Brachypodietalia pinnati. which corresponds to semi-dry grasslands. This subset was again classified using TWINSPAN. Formal definitions of the following alliances were established: Mesobromion erecti, Cirsio-Brachypodion pinnati (incl. Fragario-Trifolion montani. Agrosiio-Avenulion schellianae, Scabioso ochroleucae-Poion angustifoliae and Adonido vernalis-Stipion iirsae), Scorzonerion villosae and Chrysopogono-Danshonion. Another alliance, Armerion elongatae (=Koelerio-Phleion phleoidis p.p.). is transitional towards the class Koelerio-Corynephoreiea and its status needs further evaluation. We also established formal definitions of all of the associations of Mesobromion and Cirsio-Brachypodion within the area studied. Associations were identified using (i) a TWINSPAN classification of the whole order, (ii) TWINSPAN classifications of regionally restricted data sets (usually all Brachypodietalia plots in one country) and (iii) existing national classification schemes. All formal definitions were written in the expert system language of the JUICE program. To obtain a more complete picture of the floristic similarities and gradients. we performed a DCA ordination of the associations. Our results revealed that meadow steppes in the forest-steppe zone in eastern Europe are very similar to semi-dry grasslands in central Europe

Weeds shift from generalist to specialist: narrowing of ecological niches along a north-south gradient

There are changes in the realized niches of species along environmental gradients, especially at the edge of their distribution where they become more specialized. A classical case is weeds of the Caucalidion alliance that spread with agriculture from the Fertile Crescent and thrive in a wide range of climates that differ from that prevailing in their native area. We used large data sets of vegetation collected in central Europe (3383 plots) and north-western Balkans (4505 plots) and used a co-occurrence species algorithm to calculate the specialist/generalist status of weed species. The change in the width of the ecological niches was tested using target species. Our assumptions were confirmed as the same characteristic species of Caucalidion weed vegetation in the north-western Balkans are more specialized in central Europe, where they occupy more basic habitats that vary less in terms of soil reaction. Testing niche theory using real data is especially important for nature conservation because specialists are more prone to decline in abundance or to go extinct

Phytosociological alliances in the vegetation of arable fields in the northwestern Balkan Peninsula

A stratified dataset of 2426 releves of weed vegetation of arable fields of the Balkan Peninsula was analysed by cluster analysis. The major division in species composition was associated with the type of crop. This accords with the syntaxonomical and ecological pattern already detected for southeast Europe and is in conflict with the Central European classification that has appeared in recent years. Clusters resulting from numerical classification reproduced the majority of traditionally recognized phytosociological alliances (Oxalidion, Panico-Setarion and Eragrostion are associated with root crops, while Scleranthion, Caucalidion and Galeopsion with cereals). Galeopsion was grouped with some Caucalidion releves, which is not surprising since both consist of weed communities from cereals. Vernal communities form a separate cluster and indicate a special community type, which has been treated in some classification systems as a phenological aspect

Weed vegetation in the north-western Balkans: diversity and species composition

P>Surveys of weed vegetation of the western Balkan peninsula (1939-2006) were used to study changes in species composition. A large data set of arable weed vegetation was compiled and analysed with direct and indirect ordination, regression and beta (beta) diversity analysis. Five environmental variables (altitude, season, year, crop, phytogeographical region) were used to determine broad-scale changes in weed species composition. The most important parameter was phytogeography and the second was crop. Altitude and season were found to be less important, although significant, which contrasts with results from Central and Northern Europe. beta-diversity was higher in cereals and in summer, while decline along the altitudinal gradient previously demonstrated in Central Europe, was not observed. In southern parts of the studied area, thermophilous species have shifted to higher altitudes. The results and ranking of importance of environmental and spatial variables are discussed in relation to similar studies in Northern and Central Europe

Typificati on and correction of syntaxa from the class Molinio- Arrhenatheretea TX. 1937 in Serbia

A list of corrected and typified grassland communities of the class Molinio-Arrhenatheretea Tx. 1937 occurring in Serbia was provided. The nomenclature rules of the International Code of Phytosociological Nomenclature were strictly followed. Syntaxonomic affiliation of communities to higher syntaxa was assessed according to the existing syntaxonomical schemes for Serbia, i.e. according to the position determined by the original source. Higher syntaxa followed the synsystem of the so-called "EuroVegChecklist". Since syntaxonomic disagreements concerning a certain plant association's position within the whole classification system have not been discussed, such a list should serve as the starting point for a further revision of the status of grassland communities in Serbia. So far, a total of 87 plant communities of the class Molinio-Arrhenatheretea were described for Serbia. The list provided here will enable more precise and more accurate mapping of vegetation in Serbia, as well as classification of these communities into the Habitat Directive which will enable the establishment of the Red list of Habitats for Serbia

Classification, ecology and biodiversity of Central Balkan dry grasslands

Dry grasslands are highly diverse vegetation types of great importance for livestock production in rural Balkan areas. We analysed a large data set of phytosociological releves of dry grasslands (Festuco-Brometea and Festucetea vaginatae classes) in Serbia to produce the first overview of its classification, distribution, environmental conditions and biodiversity patterns. Phytocoenological releves from relevant literature sources and our own investigations were stored in the Vegetation Database of Serbia (EU-RS-002) and the Balkan Dry Grassland Database (EU-00-013). After heterogeneity-constrained random resampling, the final dataset contained 1,897 releves and 1,323 species. Species composition was classified hierarchically by the beta flexible method. We used species ecological indicator values for the estimation of the ecological conditions. Floristic and vegetation diversity and the conservation relevance of various dry grassland types, based on an assessment of endemic and protected species, were analysed. We identified 11 clusters, which were well characterised by their species composition and ecology. The first three clusters included loess and sand steppe grasslands mostly found in the Pannonian part of Serbia (Festucion rupicolae and Festucion vaginatae). The next three clusters consisted of Balkan ultramafic rocky grasslands of the order Halacsyetalia sendtneri, Balkan submediterranean mountain steppe grasslands on calcareous substrates, belonging to the order Astragalo-Potentilletalia and grasslands of the Balkan alliance Saturejion montanae on limestone. The third group of releves comprised Balkan alliances of dry grasslands on deep soils, the Chrysopogono-Danthonion and sub-continental steppes of the alliance Festucion valesiacae in hilly areas of Serbia, mostly in the thermophilous oak zone. According to ordination analysis (DCA), the main floristic gradient was largely determined by temperature and moisture. The Festuco-Brometea class exhibited high floristic diversity (1,323 plant species) and very high conservation relevance in view of the large number of Balkan endemic species (204). A total of 233 species and subspecies protected by national legislation within the studied vegetation were recorded