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贺兰山封山育林育草项目实施 5年来 ,经封育区 75块标准样地、对照区 1 2块对照样地几年监测表明 :项目区植被的总覆盖度从 1 995年的 35 .0 %提高到 2 0 0 0年的 44.2 % ,项目区的总覆盖度在逐年增高 ;而对照区植被的总覆盖度总的趋势却在降低。
In the past five years since the implementation of the project of closing hillsides for afforestation in Helan Mountains, monitoring of 75 standard plots in the enclosed area and 12 control plots in the control area showed that the total coverage of vegetation in the project area increased from 35.0% in 1995 to 44.2% in 2000, the total coverage of the project area is increasing year by year; while the overall trend of the total coverage of vegetation in the control area is decreasing.