Environmental drivers of ground-floor bryophytes diversity in temperate forests.

Bryophytes play important role in forest ecosystem functioning and their distribution and diversity are driven by numerous environmental factors. The aim of the present study was to bring new insights in deeper understanding of terrestrial bryophytes diversity in temperate forests, as well as to determine the environmental factors which have predominant influence on ground-floor bryophytes. The survey was conducted in Fruska Gora Mountain (Serbia) across seven forest sites where ground-bryophytes were sampled. Soil moisture, temperature, and pH were measured as soil characteristics, while herbaceous cover, litter cover, stream distance, number of trees and shrubs were used as characteristics of stand structure. Species richness, Shannon diversity index, and evenness index were used as diversity measures. Generalised linear model and canonical correspondence analysis (CCA) were used to test the influence of environmental variables on bryophyte diversity. Litter cover was the most important explanatory variable, followed by soil moisture, stream distance and tree number, respectively. Overall, the stand structure was found to have a greater impact on ground-floor bryophyte diversity compared to soil characteristics. Identification of the most significant ecological factors affecting the diversity and distribution of bryophytes in forest ecosystems is of great importance in forest ecology with the aim of defining adequate management methods to preserve the biodiversity of forests, with particular emphasis on endangered and rare bryophyte species.

Combined effects of physical environmental conditions and anthropogenic alterations are associated with macrophyte habitat fragmentation in rivers - Study of the Danube in Serbia.

We hypothesize that the physical features of river habitats and anthropogenic hydromorphological alterations influence macrophyte communities and lead to habitat fragmentation. Sampling included 1081 contiguous survey units positioned in the main channel and side arms along 588km of the Danube River, along its middle course. To identify habitat fragments, Multivariate Regression Tree analysis (MRT) was applied on macrophyte and environmental data. Indicator species analyses were combined with MRT. To identify habitat fragments on a scale larger than final MRT groups, we set thresholds for an MRT complexity parameter. We identified 20 fine, 7 medium, and 3 large scale habitat fragments. Damming was the main fragmentation agent. Macrophyte communities show continuous variation at all scales of habitat fragmentation. High species diversity indicates major anthropogenic alteration of the river's hydrology and decline of the natural riparian zone. Future studies of the macrophyte communities, and their habitat fragmentation must include more factors (e.g. nutrient status, physicochemical quality of the water, etc.), as well as assessment of the importance of tributaries.