砂仁种植对热带雨林植物多样性的影响探讨

通过对各种不同状况的林下种植砂仁的热带雨林片断与同样类型的原始热带雨林的比较研究 ,探讨了砂仁种植对热带雨林植物多样性各个方面的影响。砂仁种植必须大量清除小树、林下幼树、灌木层植物 ,致使种植了砂仁的热带雨林片断的乔木下层及几乎整个的幼树、灌木层遭严重破坏 ,物种和个体大量流失 ,群落结构变得非常不稳定。由于热带雨林的更新主要依赖于其林下层的幼苗库 ,林下层的幼树、苗库被清除或破坏 ,热带雨林就难以自我更新 ,故林下种植砂仁的更大的潜在危害是使得热带雨林不能自我更新。种植了砂仁的热带雨林片断 ,物种和个体数的减少或流失 ,主要是直接的人为清除的结果 ,清除强度大 ,种类和个体减少就多。热带雨林下砂仁种植后 ,那些在原乔木层中占多数的只有 1～ 2个个体的脆弱种类 (种群 )将首先消失

A discussion on the loss of biodiversity of tro- pical rain forest by Amomum planting underneath in south Yunnan

Based on comparison between primary tropical rain forest and rain forests with Amomum villosum plantation in different disturbance intensity,influences of Amomum planting on species composition,individual abundance,community structure,physiognomy and forest dynamics etc. of tropical rain forest were studied. Because of the essential cleaning to mainly young trees, saplings,seedlings and shrubs by Amomum planters,the rain forest,especially the lower tree layer and sapling-shrub layer was seriously destroyed. Besides the direct cleaning to plants,a potential threat was the destruction of sapling-seedling bank of rain forest made the forest lose its regeneration capability because rain forest regenerated mainly from its sapling-seedling bank. The quantity loss of species and individuals of rain forest was manipulated mainly by the cleaning intensity to plants at planters' intention. So the quantitative evaluation of the losses of species and individuals of rain forest with Amomum plantation was hardly obtained. It was also revealed that the tree species at the largest loss were those which contribute the most of tree species composition but with only one or two individuals in tree layers of tropical rain forest.