海南热带山地雨林森林循环不同阶段光、温环境的测定与分析

Measurement and analysis on light and temperature regimes in different patch types of forest cycle in a tropical mountain rain forest, Hainan Island.

以海南岛典型的热带山地雨林为对象 ,测定了森林循环不同阶段林分斑块内的光照、空气温度以及土壤不同层次内的温度因子 ,分析了其日变化规律 ,讨论了森林群落内环境因子异质性对群落内物种共存和多样性维持的意义 .海南岛热带山地雨林森林循环不同阶段斑块内光照与温度的日变化规律不同 .林隙阶段内光照的强度及其变动幅度都远大于其它 3个阶段 ,而且林隙内不同部位光照的日变化规律也存在着明显的差异 .森林循环各阶段斑块内光照强度及其变动幅度的大小顺序为林隙阶段 (G) >衰退阶段 (D) >建立阶段 (B)≥成熟阶段 (M) .不同斑块之间的气温基本上呈现出M >B >D >G的总趋势 .不同阶段斑块内土壤表面温差变动幅度的大小顺序为G >D >B >M .不同阶段斑块类型在土壤不同层次中温度的日变化不同 ,但各类型斑块在同一时刻同一土壤层次内的温度差异大都不超过 1℃ .森林循环不同阶段斑块内环境因子的时空差异 。

According to the theory of forest growth cycle, forest communities are dynamic mosaic systems composed of patches in different development stages. On the basis of measurement for light and temperature in a typical tropical mountain rain forest of Hainan Island,the daily changes in light and temperature regimes in different patch types of forest cycle were analyzed and the implications of environmental heterogeneity on species coexistence and maintenance of species diversity were discussed in this paper. The daily change patterns of light and temperature in different patch types in the forest cycle in the tropical mountain rain forest were different.The light intensity and its amplitude of changes in gap phase were much more greater than the other three phases in the forest cycle,and there were significant differences in variable parts of a gap.The light intensity and its amplitude of changes in different patch types followed the order of gap phase (G)>degenerate phase (D)>building phase (B)≥mature phase (M).The air temperature in different patch types followed the order of M>B>D>G.The amplitude of daily temperature changes in soil surface followed the order of G>D>B>M.Although the patterns of temperature changes in different layers of the soil under different patch types were different, the differences in temperature among different patch types in the same soil layer and at the same time were less than 1℃. The spatial and temperal heterogeneity of environmental factors in different patch types in the forest cycle lay the basis for the coexistence of species with different characteristics in forest communities.