Correlations Of The Damaged Desert Riparian Vegetation With Changes In Water And Soil In The Middle And Lower Reaches Of Shiyang River Basin

The study area is located at middle and lower reaches of Shiyang River in the arid desert area.With the destruction of riparian vegetation, biological diversity decline, regional ecosystem andecological process are affected seriously. It divided the study area into wet reaches, seasonal wetreaches and dry reaches three types in this paper. A traditional ecological method combined withgeostatistics method was applied to the investigation of desert riparian vegetation characteristics,soil and hydrology factors at middle and lower reaches of Shiyang River. Aspect of hydrologicalprocess integrity losing, take spatial change instead of time process, analyzed vegetation variation,hydrology, soil properties change at different tamp-spatial scales. The relationship betweenhydrology, soil feature variation and riparian vegetation damage was clarified. This paper offersbasic theory, advices for desert riparian vegetation reestablish and ecosystem restoration. Theprimary conclusions were as follows:(1)The desert riparian vegetation was seriously influenced by human being at middle andlower reaches of Shiyang river. And vegetation type variation has distinctly gradient at differenttemp-spatial scales. There are15species of woody plants and45species of herbs in study area.The dominant species are deserta at middle and lower reaches of Shiyang River. The dominantspecies with more frequency are Artemisia areanaria, Tamarix spp., Peganum harmala, NitrariaSpp.,etc. With disappearing of the runoff, the vegetation coverness declined and the groupstructure tend to become simple.(2)The evolution of hydrology process at study area was conducted by human being inmodern times. The geomorphology, geology, steam replenishment and human inference have bigdiversity impacts on underground water level at different reaches. The underground water and soilmoisture has different extent othernss among different reaches. With the disappearing of steamrunoff, the underground water fall, soil moisture decreased. And the desert riparian vegetation took adapted evolution: meadow changed into saline meadow, desert riparian forest change intobush(shrub and small shrub) desert and then to annual vegetation.(3)The soil qualities showed a degeneration trend, soil moisture and nutrient condition gotworsen with the runoff disappear at middle and lower reaches of Shiyang River. However, thedegraded soil in dry reaches has been improved. The vegetation coverness, richness, diversityrelevant with variation of water and soil factors were stay the same generally. The water factordecided the vegetation condition, affected the soil compose to some extent,the vegetation and soilhas a relationship of feedback and restriction to each other, controlled the ecological environmentdegeneration and restoration process together.(4)The abundant ecological function of desert riparian vegetation has significant meaning toregional ecosystem restoration. The vegetation has a role on improving soil condition, that’s a goodstart for restoring damaged vegetation and ecological environment. Aiming at the cause of riparianvegetation damage, summarized the experience in ecology protection construction, advices forecology restoration were given as follows: first, increase the education investment to improvingthe awareness of ecology protection; Second, regulate the exploitation of underground water,enhance the watershed management, distribute the water resource of whole reasonably, and addthe share for ecological use in all. Last but not the least, do not take sacrifice of ecologyenvironment to achieve development of economy. Put the artificial assisted enclosure into effect,reduce the human disturb at the process of natural vegetation restoration and recover further, tohave the damaged desert riparian ecosystem restored gradually.