农牧交错带土壤及表生植被某些特性变异与荒漠化的相关性——以冀北康保县为例

Relation Between Some Variations of Soil and Surface Vegetation and Desertization in Agriculture-pasture Interlacing Zone --An Example From Kangbao County,North Hebei

农牧交错带因特有的自然条件 ,体系稳定性差 ,自调能力弱 ,平衡易破坏 ,生境十分脆弱。虽然近 2 0年大风与沙尘暴平均次数有所减少 ,主要气候要素趋向良性 ,但因人畜增长 ,人为过度垦、牧、樵等负面活动强化 ,导致该区表层土壤颗粒粗化 ,有机质含量降低 ,植被覆盖度下降 ,植物群落结构变异、退化 ,土地荒漠化加重。由此表明

The studied agriculture pasture interlacing zone has its specific natural conditions, at which the natural systems are unstable, their self regulation capability is low, the equilibrium is easily broken, and hence the habitat is fairly vulnerable.During the last 20 years,the increasing population and livestock ,over reclamation,over pasturing,over deforesting,and other intensified negative human activities in the zone resulted in coarsening of surface soil,decrease of organic matter content in soil,reduction of vegetation coverage,variation and degradation of flora structure,and hence in desertization of the land.This has proved that it is very relative to some variations of soil and surface vegetation and desertization.