赣南森林生态系统倒木特征研究

Study on Quantitative Features of the Fallen Trees in Southern Jiangxi Forest Ecosystems

对赣南地区常绿阔叶林、杉木林、毛竹林、马尾松林4种不同森林类型30个样地内不同分解等级倒木数量特征进行研究。结果表明，不同森林类型倒木生物量和材积分别为0.04～14.60 t／hm2、0.60～23.00 m3／hm2，常绿阔叶林倒木生物量和材积最大，且与其他森林类型差异显著；不同分解等级倒木比例差异较大，中度分解倒木所占比例最大，为60.7％，轻度、重度所占比例分别为22.1％、17.2％；赣南森林倒木材积分布以Ⅴ径级木（中央直径≥20 cm）为主，占36.4％，Ⅲ径级木（中央直径10～15 cm）次之，占25.8％，Ⅰ径级木（中央直径0～5 cm）最小，占0.3％。

The quantitative characteristics of the fallen trees with different decomposition classes in 30 sample plots of four forest types in south Jiangxi Province including the evergreen broad-leaved forest,Cunninghamia lanceolata plantation,Phyllostachys edulis plantation and Pinus massoniana forest were studied.The results showed that the biomass and volume of the fallen trees in the four different forest types were individually in the range of 0.04-14.6 t/hm2 and 0.60-23.00 m3/hm2 .Among the different forest types,both of the biomass and volume of the fallen trees in the evergreen broad-leaved forest were the maximum,and there were significant differences in the two indexes between the evergreen broad-leaved forest and the other forest types.There was a great difference in the proportion among decomposition classes of the fallen trees,the intermediately decomposed fallen trees accounted for the largest proportion by 60.7%,while the slightly and heavily decomposed fallen trees took 22.1%and 17.2%, respectively.The volume distribution of the fallen trees in south Jiangxi Province was dominated by class Ⅴdiameter trees （mid-diameter≥20cm）,which occupied 36.4% of the total,followed by class Ⅲ diameter trees （10-15 cm in mid-diameter）,which accounted for 25.8%,and the classⅠdiameter trees （0-5 cm in mid-di-ameter）,which accounted for only 0.3% of the total.