Vegetation change characteristic research of different evolution stages in Minqin Xishawo desert areas
Through eco-measurement and research at the Xishawo desert pasture in Minqin for 60 a,it was found that desert vegetation flora has experienced four main stages with ground water-table decline,they were the degraded meadow steppe and Tamarix flora,Tamarix and Nitraria flora,Nitrariaand degraded Tamarix flora,and Nitraria flora,the plant diversity and coverage dcreased in the processing,eco-degradation and desertification developed remarkably;with rain-fed area enlargement,desert herbal plants grew when precipitation was higher in the year,the plant diversity and coverage increased,and vice versa;some desert shrubs were relatively stable,its population growth and development improved when precipitation was over 140 mm,100-140 mm for basic growth,and<100 mm degraded gradually;most plant species of windbreak and sand-fixation afforestation degraded under drought conditions,Haloxylon ammodendron had strong eco-adaptability as an introduced species,it has developed into the biggest man-made windbreak and sand-fixation forest in Minqin desert areas,its big density and drought land were the main reasons for degradation,and sustainability could be increased under low density afforestation according to local plant carry capacity.Recently,with the integrated program implementation in the Shiyang River watershed area,eco-water has been increased,groundwater table has increased in some surroundings,some micro-wetlands have formed,original desert meadow steppe has reoccured,and their ecosystems are developing positively;however,ground water table still reduces slowly in most desert areas,and desertification has developed.
国家科技期刊平台
NSTL
万方数据
维普
