Dissertation
Dissertation > Agricultural Sciences > Agriculture as the foundation of science > Soil > Soil chemistry, soil physical and chemical > Soil composition

Study on Soil Carbon Pool in Ebinur Lake Wetland Natural Reserve

Author ZhangXueNi
Tutor LvGuangHui;GongZuo
School Xinjiang University
Course Ecology
Keywords Ebinur Lake Soil organic carbon Soil inorganic carbon Density Kriging
CLC S153.6
Type Master's thesis
Year 2011
Downloads 215
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As the largest carbon pool of terrestrial ecosystem, soil carbon study is one of the priorities and hot spots in the terrestrial ecosystem carbon cycle and global change research. Soil carbon was storied in soil mainly in form of soil organic matter and carbonate, its status and change is closely related to the atmosphere carbon cycle. The Studies of arid area soil carbon pool is an important and indispensable component of terrestrial ecosystem carbon cycle, but the academy have not pay enough attention to it, and its storage and change process is still not clear. Therefore, it is necessary to conduct more soil carbon cycle in arid zone, so as to enrich and promote the terrestrial ecosystem soil carbon cycle research, and provide basis for scientific management of arid areas soil carbon. This thesis took Ebinur Lake wetland natural reserve as study area, the content, density, profile distribution and difference of soil organic and inorganic carbon was discussed under different soil and vegetation type respectively. Spatial distribution characteristics of soil organic and inorganic carbon density were analyzed, and soil carbon storage was estimated. At last, the relation between soil organic and inorganic carbon, and how soil physical and chemical properties affect soil carbon were studied. The main conclusions are as follow:1. Under different soil type, soil organic carbon content and density present decrease trend along with the increase of profile depth, but most of them rise at 50cm. The average soil organic carbon content and density of different soil type ranged between 0.93~3.19g/Kg and 0.13~0.41Kg/m~2 respectively. The overall ranking among these types is desert sand soil<gray-brown desert soil<hydromorphic soil<saline-alkali soil; There is significant differences between different layer’s soil organic carbon content of saline-alkali soil and desert sand soil, as for soil organic carbon density, only desert sand soil has significant differences between different layer. The soil organic carbon content and density significant differences of different type are not quite similar.2. Soil inorganic carbon content and density of different soil type vary greatly in soil profile, there is no clear trend. The average soil inorganic carbon content and density of different soil type ranged between 53.06~79.90g/Kg and 7.91~10.86Kg/m~2 respectively. The overall ranking among these types is desert sand soil<hydromorphic soil<saline-alkali soil<gray-brown desert soil; There are significant differences between different layer’s soil inorganic carbon content of gray-brown desert soil, and for soil inorganic carbon density, all types have significant differences between different layer, The soil inorganic carbon content and density significant differences of different type are not quite similar.3. Under different vegetation type, soil organic carbon content and density present decrease trend along with the increase of profile depth, but dwarf semi-shrub and halomorphic meadow rise near 50cm. The average soil organic carbon content and density of different vegetation type ranged between 1.61~3.99g/Kg and 0.21~0.49Kg/m~2 respectively, The overall ranking among these types is dwarf semi-shrub< semi-arbor<halomorphic meadow. There are significant differences between different layer’s soil organic carbon content of semi-arbor and halomorphic meadow, and for soil organic carbon density, halomorphic meadow have no significant differences between different layer, The soil organic carbon content and density significant differences of different type usually exist in layers below 70cm.4. Soil inorganic carbon content and density of different vegetation type present no clear trend, they vary greatly in layers up 50cm. The range of soil inorganic carbon content is 65.97~73.88g/Kg, the order of each type is dwarf semi-shrub<halomorphic meadow<semi-arbor. The range of soil inorganic carbon density of different vegetation type is 8.80~9.85Kg/m~2, The overall ranking among these types is halomorphic meadow<dwarf semi-shrub<semi-arbor; There have no significant differences between layer’s soil inorganic carbon content of all types, But soil inorganic carbon density is exactly the opposite, there are no significant differences among these types’soil inorganic carbon content and density.5. Soil organic carbon density has moderate spatial correlation,range of each layer varies greatly, Semivariogram is fit by exponential model, spatial interpolation use ordinary kriging method. The result shows that: soil organic carbon density of units depth decrease with increasing of profile depth, and its horizontal distribution character is that the northwest and southeast of study area have relatively high soil organic carbon density, high value in northwest area varies in each layer, while in southeast, high value mainly concentrate in Guertu. Besides, low value areas center in the southeast of lake, expand to north and south respectively, and extend to east and west along the lake. Total area of socd below the 0.34Kg/m account for more than half of the study area, the overall socd of study area is low.26. Soil inorganic carbon density has moderate spatial correlation,range of each layer varies greatly, Semivariogram is fit by Gaussian, Spherical and exponential model, spatial interpolation use ordinary kriging and universal method. Soil inorganic carbon density increase with increasing of profile depth, in horizontal distribution, low value in surface has the biggest area, area of SICD below 9.90Kg/m~2 reach to 92%, low area of layers after 10cm mainly in the vicinity of east lake, and expand to east and north lake on layer after 50cm. the average SICD of whole profile in the study area is 9.26Kg/m~2.7. Average soil carbon storage of study area is为2.44×1011Kg, soil organic and inorganic carbon storage are 7.36×109Kg and 2.37×1011Kg respectively, every method estimates Inorganic carbon storage are 30 times more of organic carbon. soil organic and inorganic carbon storage in 0~50cm account for 52.03% and 40.98% of 0~120cm respectively, the research area is short of soil organic carbon. 8. Correlation analysis between soil organic carbon and other factors showed that: totally, soil organic carbon was positively correlated with soil inorganic carbon, average correlation coefficient is 0.41, and the relation is weak. Soil organic carbon was positively correlated with soil total nitrogen, and their relation is strong. Soil organic carbon was positively correlated with soil water content in 0~10cm, and was negatively correlated with soil bulk and soil pH, but has weak relation with soil electrical conductivity. The regression analysis indicates that: the major factors which affect soil organic carbon are soil total nitrogen, soil water content, soil pH and soil inorganic carbon, but varies in different layer, these factors can explain most of the variation of soil organic carbon.9. Soil inorganic carbon was positively correlated with soil water content in layers below 20cm, and the relation become stronger with the increasing of profile depth. Soil inorganic carbon was positively correlated with soil total nitrogen on layers between 0~50cm, and was negatively correlated with soil bulk and soil pH, there has weak relation with soil electrical conductivity. The regression analysis indicates that the variation of soil inorganic carbon was affected by soil total nitrogen, soil water content, soil organic carbon and soil bulk, and the influence degree reduced in turn.

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