Relation between some variations of soil and surface vegetation and desertization in agriculture-pas

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The studied agriculture-pasture interlacing zone has itsspecific natural conditions, at which the natural systems areunstable, their self-regulation capability is low and theequilibrium is easily broken, and hence the habitat is fairlyvulnerable. During last 20 years the increasing population andlivestock, over-reclamation, over-pasturing, over-deforesting, andother intensified negative human activities in the zone resulted incoarsening of surface soil, decrease of organic mater content insoil, reduction of vegetation coverage, variation and degradationof flora structure, and hence in desertization of the land,although average of gales and sandstorms some decreased and theclimate tended to be better in the region. However, the frequentsandstorms occurring in the springs of last and present years hasattracted much attention. Investigations confirmed that the maincause for the phenomena is the unreasonable human activities ratherthan the natural factors.
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