沙漠化对土地生产力的影响——以通辽市为例

内蒙古通辽市科尔沁沙地沙漠化程度越来越严重,在强烈的风蚀作用下,土壤颗粒逐渐变粗,土壤化学性质发生变化,地表裸露,土壤失去肥力,土地生产力下降。研究表明,沙漠化过程中植被减少,生物量损失严重,主要体现在生态系统的退化中。科尔沁沙地不同的植被特征其频率曲线有很大差异,其中高度、盖度、地上生物量和均匀度均为比较陡峭的单峰曲线,密度为C型曲线,这主要是由不同类型的沙漠化决定的。不同程度的沙漠化对土地生产力的影响有很大差别,轻度和中度沙漠化土地土壤层还没有完全破坏,土地生产力水平下降41.1%~50.6%,严重沙漠化土地几乎丧失生产力,土壤层破坏,生产力已是非沙漠化时的3.3%~10.4%。

Impact of the Desetrification on the Land Productivity of Tongliao Tegion

Tongliao City is located in the Horqin Sandy Land and administrated by Inner Mongolia.For the strong wind erosion,the desertification in this area was increasingly serious,which caused soil particles gradually thicker,soil chemical properties change,the ground become bare,soil fertility loss,and land productivity decline gradually.The research result showed that the process of desertification reduced vegetation and biomass,which mainly reflected in the ecosystem degradation.The frequency curves of different vegetation characteristics were very various in Horqin Sandy Land,in which the vegetation height,coverage,aboveground biomass and evenness were the steep single-peak curve,with a density of the C-type curves.This was due largely to the different types of desertification decision.The land productivity had a huge difference between mild desertified land.The soil layer of slight and moderate desertification land was not completely destroyed,and land productivity level dropped 41.1%～50.6%.Very serious desertification land had not almost lost productivity,the soil layer was destroyed and the land productivity levels dropped to 3.3%～10.4%.