海南岛霸王岭不同热带森林类型的种-个体关系

SPECIES RICHNESS-ABUNDANCE RELATIONSHIPS IN FOUR TROPICAL FORESTS ON ALTITUDINAL GRADIENT IN BAWANGLING NATURE RESERVE, HAINAN

比较分析了海南岛霸王岭自然保护区核心区热带低山雨林、山地雨林、云雾林、山地矮林等 4种热带森林类型中不同大小径级树木的物种 -个体关系。结果表明 :各种植被类型中物种数与个体数对数成线性关系是一种普遍现象 ,且不受调查树木的径木级影响。在相同个体数的条件下 ,累积物种数随海拔增高而逐渐减少 ,也即物种数由热带低山雨林、山地雨林、云雾林到热带山地矮林逐渐减少。对于各种植被类型的种 -多度关系 ,单个体、双个体的物种有相当高的比例 ,其后一般依个体数的增加 ,而逐渐降低物种的出现频率 ,呈典型的倒 J型曲线 。

Species richness abundance relationships in four types of tropical forest (tropical submontane rain forest, tropical montane rain forest, tropical cloud forest and tropical dwarf forest) were studied at Bawangling National Nature Reserve, Hainan. Four size classes of tree with diameter at breast height (DBH≥1, 5, 10, 30 cm respectively) were selected for comparison. The results indicate that the rate of species accumulation is related to the logarithm of number of individuals in each vegetation type, independent of diameter classes. Within samples containing the same number of individuals the rate of species accumulation decreased from the tropical submontane rain forest, through tropical montane rain forest and tropical cloud forest to the tropical dwarf forest. For each vegetation type, the proportion of rare species (singleton or doubleton: observed just one or two times respectively in samples) is very high. Their proportion is about 50% of the total species count in each DBH classes and increases with diameter class. On the other hand, the proportion of species with hundreds of individuals is very low, usually under 1%.