杉木人工林衰退机理探讨

杉木是我国特有的速生丰产树种，在商品木材的生产中占有重要的地位，而杉木连栽导致生产力下降和地力衰退一直是阻碍我国林业生产的重要问题，这引起了许多学者和林业工作者的兴趣和注意．本文对杉木人工林连栽后出现的生产力下降的现象进行了描述，并对导致杉木人工林连栽生产力下降的原因进行了总结和概括，对杉木人工林衰退机理做了分析．概括起来，杉木连栽导致生产力下降、地力衰退主要表现在：杉木人工林生产力下降和林地土壤物理和化学性质的恶化．而导致出现此现象的原因不外乎两个方面的原因，一是营林措施不合理，这是外因；其次是杉木自身的生物学特性，这是内因．内外因的结合导致杉木人工林连栽后出现生产力下降和地力衰退的现象．

Degradation mechanism of Chinese fir plantation

Chinese fir (Cunninghamia lanceolata) is a fast-growing species native to China,and has a very important status in production of commercial timber.In response to the growing need for timber,pure Chinese fir plantations have been extensively replanted on the same site in successive rotations,which has resulted in serious problems of soil fertility degradation and productivity decline,and these problems have caused considerable attention from foresters,microbiologists,soil scientists and ecologists.They have also done a lot of work on these problems and studied the mechanism of productivity decline of replanted Chinese fir plantation.In this article,the author described the characteristics of productivity decline and soil degradation,and summed up the factors caused lower productivity,and analyzed the degradation mechanism of replanted Chinese fir plantation.In sum,productivity decline and soil physical and chemical characteristics deterioration were the main properties of replanted Chinese fir plantation.The factors summarized primarily as two kinds of reasons.One was the unreasonable management that was the edogenic factor,and another was the biotic self-characteristics of Chinese fir that was the intrinsic factor of poor establishment of replanted Chinese fir plantation.The combination of the edogenic and intrinsic factors reduced the productivity decline and soil degradation of the replanted Chinese fir plantation.