Journal of Rangeland

Stream morphometric characteristics affect the distribution of plant species. Vegetation characteristics affect the hydrological and erosion processes in watershed basins. This study aimed to evaluate the correlation of vegetation characteristics with some morphometric characteristics including valley width, valley depth, channel width, channel depth, channel slope, valley width / valley depth, channel width / channel depth, valley width/channel width, valley depth/channel depth, (valley width / valley depth) / (channel width /channel depth) in a relatively homogeneous streams derived from Hydro-geomorphic classification. According to the results, the correlation between vegetation cover percentage and valley width, channel width, valley depth/channel depth, channel width/channel depth, valley width variables were 0.62, 0.60, 0.60, 0.50, 0.44 respectively (p ˂ 0.01). The correlation between the (valley width/valley depth)/(channel width/channel depth) variable and vegetation cover percentage was negatively significant (p ˂ 0.01). The vegetation cover percentage had also a negative significant correlation with stream channel gradient (p ˂ 0.05). Medium and large sizes streams had more vegetation cover compared to small streams and their vegetation cover percentage varied significantly (p ˂ 0.05). According to the Principal Component Analysis (PCA), the correlation between the valley width and channel width factors with first ordination axis were 0.48 and 0.44 respectively. The correlations between valley width/valley depth and valley width/channel width variables with second PCA axis were 0.51 and 0.51 respectively. Also the CCA test showed that the correlation coefficient between first species axis with channel depth and channel width factors were 0.63 and 0.41 respectively. The correlations of these two variables with first environmental axis of CCA were 0.81 and 0.53 respectively. This study highlights the effects of piedmont stream geomorphic characteristics on vegetation cover percentage and presence or absence of plant species in the study area.