The Study On The Geochemical Characteristics Of Phosphorus In Four Typical Lakes Of Inner Mongolia Plateau

Inner Mongolia Plateau lakes are rich in wetland resource and occupy an important position in the study of lakes and wetlands. In many lakes in Inner Mongolia, Wuliangsuhai Lake (WLSH),Daihai Lake (DH), Dalinuoer Lake (DLNE) and Hulunhu Lake (HLH) which are important fishery production base in Inner Mongolia, play an important role in the national economy of Inner Mongolia, and eutrophication and salinity difference of four lakes which are most obvious, are to explore the different areas of environmental factors on the forms of phosphorus mechanisms of the lake. Phosphorus of the overlying water in the lake sediment can be fixed, by clay minerals, iron and aluminum hydrate, and apatite or organic, these different forms of phosphorus have particular ecological significance. So it is important to research the content of phosphorus in lake sediments, chemical speciation and distribution of lake sediments, also has important implications for the nature of the scientific management of the lake and lake pollution control and reveal eutrophication problem and provide a reliable scientific basis.This paper is on the basis of the geochemical characteristics of forms of phosphorus, systematically compare phosphorus contents and form distribution in four typical Inner Mongolia plateau lakes. In order to provide basic data for the study of the mechanisms of different types of lake eutrophication. Main achievements are obtained in this study as follow:1. The mechanism of diversity on geochemical characteristics of phosphorus was first explained in sediments of four typical Inner Mongolia plateau lakes. The order of total phosphorus content on four lakes in overlying water is:DLNE>HLH>DH> WLSH. Plankton of DLNE is less than other lakes except DH. WLSH has a large number of plants and algae, and the growth and reproduction of algae and other aquatic plants assimilated a lot of phosphorus, this is also the reason of the highest total phosphorus content of the overlying water of lake DLNE and lowest of lake WLSH.2. The order of speciations of Phosphorus content in the WLSH is as follows: De-P> ACa-P> Or-P> ACa-P> Oc-P> Ex-P. The order of speciations of Phosphorus content in the DH is as follows:De-P> Or-P> ACa-P> Oc-P> Ex-P. The order of speciations of Phosphorus content in the DLNE is as follows:ACa-P> De-P> Or-P> Ex-P> Oc-P. The order of speciations of Phosphorus content in the HLH is as follows: De-P>ACa-P> Or-P> Ex-P> Oc-P. In inorganic phosphorus of surface sediments of the four lakes De-P is its main chemical speciation, DH>WLSH>HLH>DLNE.3. Four lakes are alkaline environment which is not conducive recycling of De-P. The basin weathering crust and soil rich in calcium is one of the reasons of high De-P content.4. Inorganic Phosphorus in four lakes surface sediments ACa-P is relatively high, The order of ACa-P content in the four lakes are as follows:DLNE>WLSH> HLH>DH.5. Ex-P and Or-P in the four lakes showed a significant positive correlation at the0.01level, it reveals the Ex-P content in arid and semiarid regions of Inner Mongolia plateau lake surface sediments are mainly affected by degradation of Or-P mineralization.