Vertebrate species distribution in selected wetlands of the Danube river basin

Riverine wetlands are key territories for the conservation of biodiversity on a river basin scale. The analysis of available data can offer valuable information underlining the importance of recent investigations for the researches in the field of wetlands biodiversity. Data collected for five vertebrate groups (fish, amphibians, reptiles, birds and mammals) in eight chosen riverine wetlands distributed in five countries of the Upper, Middle and Lower Danube were submitted to comparative analyses. The main components and cluster analyses of the data calculated for basic environmental parameters and the species composition of fish, reptile and birds fauna, presents visible differences between functioning floodplain wetlands well connected with the river and those with lacking connection to the river. The calculated mean values of similarity between the wetlands present for some vertebrate groups - with exception of fish and reptiles - significant differences. From all the environmental factors considered the connectivity with the main river is the key factor, correlated statistically significant with the variability of species number of two vertebrate groups, fish and reptiles (Pisces, Reptilia).