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根据1973—2008年7次全国森林资源清查的资料,对我国天然林的现状、结构变化以及需抚育的面积进行了分析。结果表明:1973—1988年,天然林面积和蓄积明显减少,15年间面积减少10%,蓄积减少11%;1989—2008年,天然林面积和蓄积稳步增长,20年间面积和蓄积分别比1973年增加25%和34%。同时,林种结构变化明显,成过熟林面积和蓄积比例大幅降低,中幼龄林面积剧增,需抚育的面积巨大,全国约3 780万hm2。
Based on the data of seven national forest inventories from 1973 to 2008, the status quo of natural forests, the structural changes and the areas to be nurtured were analyzed. The results showed that from 1973 to 1988, the area and accumulation of natural forests decreased significantly, with a decrease of 10% in area and a decrease of 11% in volume in 15 years. From 1989 to 2008, the area and accumulation of natural forest increased steadily. Increase by 25% and 34%. At the same time, the structure of forest species changed obviously. The proportion of mature forest area and storage area decreased sharply. The area of medium-aged and young forest increased sharply and the area needing tending was huge, accounting for 37.8 million hm2 nationwide.