Analysis of Castanopsis sclerophylla Mixed Stand’s Natural Compose Index | 苦槠混交林自然构成指数分析

chinois. 提出自然构成指数的概念来描述森林的演替方向与进展演替的差异程度。通过参照树与相邻木生长优势和演替等级的对比,以了解不同演替等级的树种在林分中的优势程度,从而得到自然构成指数。以湖北省桂花林场的苦槠混交林为例,对4块样地进行自然构成指数的计算,给出林分结构调整的建议。结果表明：林分的平均自然构成指数为0.76,演替方向为进展演替,4块样地的自然构成指数分别为0.65,0.83,0.79,0.76。结合树种分析,以苦槠、杉木、马尾松为参照树的空间结构单元其平均自然构成指数均较高,说明总体演替方向为进展演替,只有少部分的演替方向为逆行演替;以枫香、小叶栎为参照树的空间结构单元其平均自然构成指数偏低,虽然总体演替方向仍为进展演替,但有相对较多的演替方向为逆行演替,应及时进行结构调整,使得该林分的演替方向更接近进展演替。

anglais. Forest succession direction was an important work for natural forest management. This paper presented a new index which named natural compose index and this parameter could be used to express the difference between forest succession and the progressive succession. After making a comparison between reference trees and neighbouring trees on advantage of growth and succession level, the advantage of trees in different succession level and natural compose index could be gotten. Castanopsis sclerophylla mixed stand in Guihua Forest Farm in Hubei has been taken as an example. The new index was used to calculate and adjust in mixed stand. The mean natural compose index of this stand was 0.76, and the succession trend of this stand was progressive succession, natural compose index of 4 sample plots were respectively 0.65, 0.83, 0.79, 0.76.Combined with the analysis of different tree species, we could know that the mean natural compose index of spatial structure units whose reference tree were Castanopsis sclerophylla, Cunninghamia lanceolata, Pinus massoniana were high, this one showed that the succession trend of these spatial structure units were progressive succession, and only small parts was regressive succession; the mean natural compose index of spatial structure units whose reference tree were Liquidambar formosana, Quercus chenii were low, although the succession trend of these spatial structure units were progressive succession, more spatial structure units’ succession trend were regressive succession. These spatial structure units should be timely structural adjustment, and made the forest succession direction closer to progressive succession.