Vegetation Structure and Species Diversity of Riparian Zone and its Adjacent Upland of Wenyuhe Watershed Upstream

Aims Riparian forests contribute to the diversity and function of both terrestrial and aquatic ecosystems,but we do not understand the disciplines of plant species diversity and vegetation distribution patterns between riparian vegetation and its adjacent upland.To reveal these disciplines,we compared plant species diversity and vegetation distribution patterns on temporary plots of upland forests and riparian zones in three representing reaches of Wenyuhe Watershed upstream of Shanxi province,China.Methods We chosen the three most representative reaches of the upstream of Wenyuhe Watershed: ① Spruce Reach: It had spruce forest climax community and less disturbed;② Birch reach: It represents birch forest or scrubland community,and had been disturbed by humans cutting and Livestock feeding;③ crop and pasture reach,riparian zones had been cleared for farmland,only had some remnant riparian meadow between farmland and river.We set up tree riparian zone plots(10m*10m) and four high plots(10m*10m) in each reach.Based on the data of community investigation,we used the Detrended Correspondence Analysis(DCA) and Margalef species richness index analyzed the riparian zone and its adjacent upland plots.Important findings ① a longitudinal pattern from upstream to downstream related to the changes of climate and soil with the gradient change altitude and a lateral pattern from river to adjacent upland related to relative distance to river,relatively high to river,soil moisture and nutrient were exist;and ② DCA ordering is not only suitable to analyses the differences of habitats in large scales,but also suitable to analyses it in a very small scales,ordination axes can be explained by altitude,relative location and relative distance to river,and other factors;and ③ species richness of upland communities were higher than it of riparian plant communities in the tree layer and herb layer,were lower than it in shrub layer.In specific circumstances of each river there were differences,so we can not determine the species richness of riparian communities were higher than upland communities;and ④ appropriate interference can improve species richness of community in some level and excessive interference would reduce species richness of community in some layer.