Characteristics Of Herbaceous Plant Community And Benefitsof Soil And Water Conservation In Riparian Zone Of Baiyangdian River Basin

Riparian vegetation is an important part of riparian ecosystem and plays an important role in riparian function.As one of the main types of riparian vegetation,herbaceous plants are more sensitive to environmental changes and human activities.Hence,it has become one of the hot spots in the study of riparian vegetation.In this study,the herbaceous plant communities of four representative rivers entering Baiyangdian Lake(Xiaoyi,Bao,Fu,and Baigouyin River)were selected as the research objects,and the herbaceous species in the riparian zone entering Baiyangdian Lake were systematically investigated by using the typical sample plot method.Shannon-wiener diversity index(H'),Pielou evenness index(J)and Patrick richness index(R)were used to analyze the composition and species diversity of herbaceous plant communities,and redundancy analysis(RDA)was used.The relationship between species diversity and distribution pattern of herbaceous plant community and soil environmental factors in riparian zone of four rivers was discussed.On this basis,the effects of 11 planted configurations on soil and water conservation in typical riparian area of Fuhe River were tested by using runoff plot method and natural rainfall method,in order to put forward the optimal vegetation configuration mode suitable for ecological restoration of the river basin.The results showed that:(1)A total of 83 species of herbaceous plants belonging to 66 genera and 27 families were investigated in the riparian zone entering Baiyangdian Lake.Most of the herbaceous plants,including Poaceae,Asteraceae and Chenopodiaceae,were weeds or associated plants.The riparian vegetation was greatly affected by human disturbance.(2)Among the four riparian zone vegetation,The Shannon-wiener(H')diversity index,Pielou evenness index(J)and Patrick richness index(R)of Xiaoyi river,Baigou river and Fu river were better,however,the Bao river is the worst.Bao river has a single species type and a fragile ecosystem.(3)Physical and chemical properties of shallow soil(0-20cm)were one of the most important factors affecting the distribution of herbaceous plants in the study area.The vegetation coverage and species diversity of herbaceous community in riparian zone were positively correlated with soil organic matter and water content,but negatively correlated with soil p H,TN and TP.(4)Under different rainfall conditions,rainfall intensity is positively correlated with runoff and sediment yield,that is,the greater the rainfall,the greater the runoff and sediment yield,and vice versa;Under the same rainfall condition,the cumulative runoff and sediment yield of each runoff plot were positively correlated,and the runoff and sediment reduction benefits of Poa annua plot were the best,followed by the mixed graee plot,and the Ophiopogon japonicus plot were the worst.The analysis shows that the core area of riparian zone(50 m)of baiyangdian river can reduce the disturbance of human activities,increase soil moisture and reduce pollutant discharge.Meanwhile,the vegetation composition can be adjusted appropriately in the area seriously damaged by vegetation,which is more conducive to vegetation restoration and biodiversity stability.