海南铜鼓岭保护区2个不同演替阶段森林凋落叶的分解特性

Decomposition Characteristics of Leaf Litter of Forests at Two Different Succession Stages in Tongguling Nature Reserve,Hainan

以海南铜鼓岭保护区原生热带常绿季雨矮林和遭破坏后天然更新的山麓灌木林的共同凋落物优势种—贡甲(Maclurodendron oligophlebium)凋落叶、群落优势种—海南大风子(Hydnocarpus hainanensis)凋落叶以及2个演替阶段森林各自的混合凋落叶为研究对象,通过野外分解试验,探讨凋落叶分解速率与森林演替过程的关系和养分释放规律。经过1年的分解试验,结果表明:(1)凋落叶在季雨矮林中的分解速率明显高于灌木林;(2)凋落叶中N的释放规律为"富集-释放",其他元素整体表现为"直接释放";(3)在季雨矮林中,分解系数k与初始N质量分数呈显著正相关(P<0.05),与初始C/N值呈极显著负相关(P<0.01);在灌木林中,分解系数k与初始C质量分数及C/N值均呈显著负相关(P<0.05)。

A field experiment was conducted to decompose the leaf litters of Maclurodendron oligophlebium, a common leaf litter dominant species, and Hydnocarpus hainanensis, a community dominant species, and the mixed leaf litters of the aforesaid species and other tree species at 2 succession stages in the primary tropical evergreen monsoon rains elfin forest and the foothill shrubs regenerated naturally due to human disturbance in Hain- an Tongguling National Natural Reserve to observe the relationship between the leaf litter decomposition and the forest succession, and the nutrient release patterns. One year decomposition of the leaf litters showed the leaf lit- ter decomposition rate was significantly higher in the monsoon elfin forest than in the foothill shrubs. The N re- lease in the leaf litters followed the pattern of ＂enrichment-release＂, and the other elements such as C, K, Ca, P and Mg in the leaf litters were all directly released. In the monsoon elfin forest, the decomposition coefficient k had significantly positive correlation with the initial N mass fraction （ P 〈 0.05 ） , and highly significantly negative correlation with the initial C/N ratio （P 〈 0.01 ）. In the foothill shrubs, the decomposition coefficient k was significantly negatively correlated with the initial C mass fraction and C/N value （P 〈 0.05 ）.