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Xinjiang University (2011)

Effect of River-flooding on Desert Riparian Plant Community and Soil

周斌;Zhou Bin

Titre : Effect of River-flooding on Desert Riparian Plant Community and Soil

Auteur : 周斌;Zhou Bin

Grade : Doctoral Dissertation 2011

Université : Xinjiang University

Résumé partiel
This paper relies on the projection of the water conveyance of the lower reaches of Tarim River, mainly researches the ecological variation after water conveyance through comparing with the vegetation characteristics under the different coming-water fashion, the causes of difference vegetation phenomena were analyze, the effect of flooding for vegetation restoration were discussed. We analyze the influence of the river flooding disturbance on soil physical-chemical properties, the characteristic of dissolve organic matter (DOM) and the vegetation. The influence of the river-flooding on the vegetation restoration was discussed.The species richness, individual density and cover degree of flooded sites are more than non-flooded sites. The comparison results of soil salinity on surface soil during fore-and-aft flooding in the lower reaches of the Tarim River were analyzed, and the effect of different flooding fashion on soil salinity were discussed, this research try to explain the reason of nature vegetation increased after Ecology Water Transferring. The results were showed as follows : (1) The total soil salt contents in the lower reaches of Tarim River are generally high, which affected the distribution and growth of nature vegetation. (2) The soil salinity of soil surface have changed obviously after flooding disturbance, the soil salinity decreased in different flooding area, for example, the total salt contents of Daxihai and Alagan flooding area are reduced 60%. (3) The results of ANOVA analysis about soil salinity of surface soil under different flooding fashion showed, the effect of more flooding frequency for the total soil salt contents are distinctive than less-flooding frequency and flooding scour, long-term submerge is disadvantage for soil desalination, so the effect of flooding fashion for soil salinity are significant. (4) The discussion about flooding fashion, the flooding frequency and standing time for soil salinity and species diversity index showed the moderate disturbance are beneficial for the ecology restoration in the lower Reaches of the Tarim River.The influence of the river-flooding on the vegetation restoration was discussed though the changes of soil physic-chemical properties and vegetation fore-and-aft river-flooding. The results show as follows : The contents of clay grain in river-flooding area is higher than non-flooding area, the contents of clay grain in less-flooding area is lower than in several times of river-flooding area in the same observed sites. With the times of flooding increasing, the contents of medium, fine and very fine sands decreased significantly, but the contents of medium and coarse silts increased, these phenomena may be aroused by water washing out and the deposits of soil sediment. Soil moisture contents and bulk density are increasing with the river-flooding, so the river-flooding made the soil compaction. The process of eluviation and sedimentation on soil nutrient are evident, which aroused the distribution of soil nutrient changed in the surface of soil-layer after flooding. From these changes of soil physical-chemical properties, it can be explained the obvious changes of vegetation coverage and species diversity in the river-flooding area.The results show that fluorescence characteristics of DOM from soil of different land using have the good correlation with dissolved organic carbon (DOC), the soil with different land using have the good correlation between the fluorescence intensity of DOM and DOC, so the change of fluorescence characteristics of DOM can reflect the changed DOC. The EEM spectra of DOM would drift when the soil in high temperature and UVB processing.

Mots clés : Flooding disturbance; vegetation restoration; Desert soil; DOM; soil salinity; Tarim River;

Présentation (CNKI)

Page publiée le 2 mai 2013, mise à jour le 14 mai 2018