Details

Autor(en) / Beteiligte

• Krawczyk, Rafał

Titel

Species richness and vegetation structure in different morphogenetic types of river lakes in the San River valley

Ist Teil von

• Annales Universitatis Mariae Curie-Skłodowska. Sectio C. Biologia, 2010-01, Vol.65 (1), p.29

Ort / Verlag

Lublin: Maria Curie-Skłodowska University

Erscheinungsjahr

2010

Quelle

EZB Free E-Journals

Beschreibungen/Notizen

• Species richness and vegetation structure in different morphogenetic types of river lakes in the San River valley The aim of the conducted research was to check in what way the genetic diversity of the old river beds of the San River influences species richness as well as the structure of aquatic and rush vegetation in those water basins. The investigation was carried out during the period of 2003-2007 in the San River valley from Ulanów to the river's mouth. Three main types of old river beds were distinguished: two at the meadow ([rendzind]) terrace (meander river lakes, irregular river lakes) and one on the floodplain (braided river lakes). The flora of 28 river lakes in the San valley was analyzed by statistical methods. The study shows some differences in species richness and vegetation structure (species composition and abundance) connected with the morphogenetic variability of lakes in the study area. Essential relationships were observed in the case of some of the species richness indices. The irregular river lakes of the meadow terrace turned out to be the richest group of all; 72 species, i.e. 86.8% of the flora of all the explored old river beds, have been found there. The average number of species for this group amounted to 44.5, whereas for the meander and braided ones the value of this index was 30.9 and 25.9, respectively. The differences between the two main groups of the old river beds, connected with the two main terraces (active floodplain and meadow terrace outside the embankments) can be marked on the level of the average number of all considered species and the average number of helophytes and floating-leaved macrophytes per river lake. However, small richness of floodplain lakes resulted mainly from their small size. The differences become statistically irrelevant after levelling the influence of the surface area of the lakes. The interpretation of the results of PCA analysis indicates that the location of old river beds in the valley and their connectivity to the river, as well as the stage of terrestralization can be regarded as the main drivers behind the vegetation structure.