Distribution of woody vegetation on the slopes of regulated streams

Abstract

The paper presents the study material and analysis of the distribution of woody vegetation of regulated streams in southeast Lithuaiiia. The studies were carried out in 110 randomly selected slope strips of regulated streams in the Neris river basin in the Baltic Highland within the period of 2005 to 2006. During the studies 32 species of woody vegetation were foiind, from which 14 species of trees and 18 species of bushes- In regulated streams different species of willows are mdst common. However their distribution on channel slopes is different. For most species of woody vegetation the condftions are most favorable in the lower and middle part of slopes. Here their density is highest (0.34 ± 0-89 and 0.73 ± 0.139 units m~2 respectively), the frequency is 0.56 and 0-64 respectively. As it was determined, the frequency of woody vegetation on slope strips of regulated streams is na = 0.61. On the slope the fower overgrowth limit of woody vegetation is ra = 1-58 ± 0.16 m, the upper limit is rv — 4.13 ± 0.22 m. In southeast Lithuania, in discharge nctwork of drainage systems there are more possibilities for planning of eeological means, when trees and bushes are allowed to grow on slopes.