Study On Change Of Riparian Vegetation And Soil In Middle And Downstream Of Shiyang River

The study main application of common ecological methods and geostatistics methods for middle and downstream of Shiyang River typical reach vegetation characteristics and soil properties and their mutual relations in space and time of the survey,middle and downstream of Shiyang River banks of different sections based on differences in water status.Select the four river comparative analysis (drying section of the middle reaches,spring overflow section,wet section above reservoir and drying section following reservoir), designed by vegetation characteristics, soil characteristics and spatial variability of survey analysis,reveal the spatial variation of riparian vegetation and succession of soil characteristics and the corresponding changes,furthermore clarify the characteristics of the basin riparian vegetation and soil changes in the relationships between features,proposed middle and lower reaches of Shiyang river riparian vegetation restoration strategies and measures ,the major results as follows:(1)In the study area a total of 14 species of woody plants, 22 species of herbs. Dominant species have Artemisia desterorum ,Nitraria tangutorum ,Phragmites australis,Cacumen tamaricis,Artemisia ordosica ect.Less riparian plant communities,structure simple,most of the growth of aggregate,different area plant communities quite different.At daway from the river bank different distances of the different river reaches,shrub layer and herb layer of the important values and species richness of a certain distribution.Better soil and water conditions were better the higher species richness,herb layer of a certain importance;poor soil and water conditions werer the lower species richness,shrubs have a higher importance.(2)Typical riparian vegetation zones of the vertical variation of apparent.Riparian vegetation were arbor - shrub - herbal structure:the natural state of vegetation of small trees as Salix linearistipularis, shrub as Tamarix chinensis,herbal as Achnatherum splendens ect;Shrub-herbal structure: Artemisia ordosica semi-shrub and Leymus secalinus ect;Meadow structure:Leymus secalinus,Phragmites australis,Salsola collina ect;Shrub-herbal structure(typical desert vegetation):shrub have Nitraria tangutorum,Calligonum mongolicunl,herbal have Agriophyllum squarrosum,Astragalus membranaceus,Echinopsilon divaricatum ect. Such structural changes and community is closely related to changes in groundwater level.(3)Riparian vegetation leaf types main include Ring-shaped gate and the whole grid-type gate.Ring-shaped gate leaves had a high importance.Grass-type leaves of plants in soil moisture better the areat to the importance.At different distances from the different river reaches,leaf types of vegetation have to adapt to specific distribution of the external environment.(4)The development of riparian vegetation affect the development of regional soil,at the same time,soil formation also promote regional riparian vegetation type and spatial distribution and stability,different sections of riparian vegetation in the soil physical and chemicalproperties into both.(5)From riparian vegetation soil characteristics index change the results look,the growth of riparian vegetation not only closely related with the water content,but also vegetation succession on soil nutrient changes of significant differences.(6)According to riparian vegetation degradation and restoration theory,proposed vegetation protection and restoration strategies and measures.