ECOLOGICAL CHARACTERIZATION AND DIFFERENTIATION OF THE LOWLAND FOREST HABITATS IN THE RAVNI SREM (SERBIA)

摘要

In this paper the relevant ecological factors were researched on the basis of indicator values present floristic composition, as the base for ecological characterization and differentiation of the investigated forest habitats. According to the multiple regression CCA model, the ecological factors representing the bioindication gradients of moisture, temperature and light were shown to be the most important for structure of species variability and differentiation of researched lowland floodplain forests. Analysis of Similarity has shown the greatest degree of bioindication divergence between two oppositely distributed coenoecological groups of forest types (CEG) in CCA model: CEG Pedunculate Oak and Hornbeam (Carpinion betuli ilyrico rnoesiacum Horv.56, suballiance Quercion roboris planarum Raus.76, as the most xerophilous and the most thermophilous) and CEG Swamp forest of Black Alder (Alnion glutinosae Malc.29), asthe most hygrophilous and conditionally the most frigoriphilous, whereby it indicates a complete divergence of overall ecological conditions represented by indicator values of floristic composition. According to SIMPER procedure, alternation of hygro-thermal gradient is the main factor of existing vegetation variability and differentiation of lowland forests of both floodplain and out-of-floodplain areas of RavniSrem. Additionally, according to their overall bioindication character the studied forest habitats were mostly: mesophilous-submesophilous, mesothermic, semi-sciophilous, neutrophilous and mesotrophic. Special attention was given to discussion of the broader geographic context of bioindication studies of various habitats in both floodplain and out-of-floodplain forest areas, with special consideration of correlation patterns in bioindication gradients.