%0 Journal Article
%T Effects of desertification on C and N storages in grassland ecosystem on Horqin sandy land<br>沙漠化对科尔沁沙质草地生态系统碳氮储量的影响
%A ZHAO Ha-lin
%A LI Yu-qiang
%A ZHOU Rui-lian
%A <br>赵哈林
%A 李玉强
%A 周瑞莲
%J 应用生态学报
%D 2007
%I 
%X Sandy grassland is widespread in northern China,where desertification is very common because of overgrazing and estrepement.However,little is known about the effects of desertification on grassland C and N storages in this region.A field survey was conducted on Horqin sandy grassland,and desertification gradients were established to evaluate the effects of desertification on C and N storages in soil,plant,and litter.The results showed that desertification had deep effects on the contents and storages of grassland C and N.The C and N contents and storages in the grassland decreased significantly with increasing desertification degree.Comparing with those in un-desertified grassland,the C and N contents in lightly,moderately,heavily,and severely desertified grasslands decreased by 56.06% and 48.72%,78.43% and 74.36%,88.95% and 84.62%,and 91.64% and 84.62% in 0-100 cm soil layer,and by 8.61% and 6.43%,0.05% and 25.71%,2.58% and 27.14%,and 8.61% and 27.86% in plant components,respectively.Relevantly,the C and N storages decreased by 50.95% and 43.38%,75.19% and 71.04%,86.76% and 81.48%,and 91.17% and 83.17% in plant underground components in 0-100 cm soil layer,and by 25.08% and 27.62%,30.90% and 46.55%,73.84% and 80.62%,and 90.89% and 87.31% in plant aboveground components,respectively.In 2000,the total area of desertified grassland in Horqin sandy land was 30152.7 km2,and the C and N loss via desertification reached up to 107.53 and 9.97 Mt,respectively.Correlation analysis indicated that the decrease of soil C and N contents was mainly come from the decreased soil fine particles caused by wind erosion in the process of desertification,and the degradation of soil texture-and nutrient status led finally to the rapid decrease of C and N storages in plant biomass and litter.
%K arid and semiarid area
%K sandy grassland
%K desertification
%K C and N storages
%K loss amount<br>干旱半干旱区
%K 沙质草地
%K 沙漠化
%K 碳氮储量
%K 损失量
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=42FEDDFE54F8BCD9D5FD1926ABDD7722&aid=DB0102F3D87A1711A243C1AC1D727F0F&yid=A732AF04DDA03BB3&vid=13553B2D12F347E8&iid=708DD6B15D2464E8&sid=FB474E05BEE5C0B6&eid=0DA35393715E494A&journal_id=1001-9332&journal_name=应用生态学报&referenced_num=0&reference_num=26