鼎湖山3种演替群落凋落物及其水分特征及对比研究

对鼎湖山3种演替群落凋落物及其水分特征研究表明,凋落物现存量为针叶林＞混交林＞阔叶林,年凋落量阔叶林＞混交林＞针叶林,说明针叶林凋落物分解较阔叶林迟缓,针叶林凋落物中叶所占的比例最大,而阔叶林最小,枝和花果所占的比例以阔叶林最大,针叶林最小,与它们的林木分枝多少以及林冠幅度大小有关,凋落物的最大持水率为针叶林＞混交林＞阔叶林,但差异不明显,凋落物含水量以阔叶林最大,混交林次之,针叶林最小,与凋落物最大持水率恰恰相反,说明凋落物的含水量受林地环境条件的制约,凋落物饱和含水时相对自由水面蒸发率阔叶林为78．95％,混交林为82．45％,针叶林为91．22％,说明在相同的环境条件下,阔叶林凋落物水分损失较难,而针叶林凋落物水分损失较容易,这也是阔叶林具有较小的最大持水量而却有较大叶林凋落物态含水量的原因之一。

Characteristics of litter and its contained water in three succession communities in Dinghushan Mountain.

Studies on the characteristics of litter and its contained water in three succession communities in Dinghushan Mountain showed that the standing mass of litter was in the order of pine forest>mixed forest>broad-leaved forest,and the annual litterfall was broad-leaved forest>mixed forest>pine forest,indicating that the return rate of nutrients was lower in pine forest than in broad-leaved forest.The proportion of leaf litter decreased in the order of pine forest>mixed fo- rest>broad-leaved forest,and that of branch,flower,and fruit litter was on the contrary, because the broad-leaved fo- rest had the largest amount of branches and the biggest scope of canopy. The saturation water content of litter in pine forest, mixed forest and broad-leaved forest was 329.0%,313.0% and 295.0%,respectively,showing no significant difference,but the water content of litter in three communities differed significantly,followed the order of broad-leaved forest>mixed forest>pine forest.The evaporation ratio of litter water to free water in broad-leaved forest, mixed fo-rest and pine forest was 78.9%,82.45% and 91.22%,respectively.