不同林分类型毛竹林节肢动物群落的多样性与稳定性

Diversity and stability of the arthropod communities in different forest types of the bamboo Phyllostachys heterocycla cv. pubescens

通过2001年9月到2002年7月对毛竹Phyllostachysheterocyclacv.pubescens与杉木Cunninghamialanceolata、毛竹与马尾松Pinusmassoniana、毛竹与阔叶树种混交林和毛竹纯林中节肢动物群落的定位与跟踪调查,分析和比较了上述4种不同类型林分中节肢动物群落的多样性与稳定性。结果表明:竹阔混交林中节肢动物群落的丰富度显著高于其他2种混交林和毛竹纯林,主要体现为林下层中同翅目、半翅目、鞘翅目和双翅目及竹冠层中蜱螨目、同翅目、半翅目和鞘翅目等植食性或捕食性物种明显较多;但各类林分中节肢动物群落之间的物种多样性、均匀度和优势集中性无显著差异。总体上混交林竹冠层和林下层中植食性和捕食性功能群的共有种较多,两个层次间的相似性均高于毛竹纯林。不同林分类型中节肢动物群落的稳定性具有显著差异,竹阔混交林和毛竹纯林竹冠层节肢动物类群的稳定性低,天敌对害虫的控制作用小,毛竹叶部植食性螨类和蠕须盾蚧Kuwanaspisvermiformis危害较重。因此认为在两种(类)害虫常发区,可考虑将林分改造为竹杉混交林或竹松混交林。

Through systematic location and surveys in four representative field sites in Sanming City, Fujian Province from 2001 to 2002, the diversity and stability of the arthropod communities in the pure and three different mixed types of the bamboo Phyllostachys heterocycla cv. pubescens forests were compared and analyzed, aiming to explore the relationships between types of the bamboo forests and outbreaks of the major leaf pests such as phytophagous mites, Pantana phyllostachysae and Kuwanaspis vermiformis which heavily infested the bamboo in South China in recent years. The results showed that the arthropod richness in the bamboo forest mixed with broadleaf trees was higher than in the pure bamboo forest and in the bamboo forests mixed with Cunninghamia lanceolata or Pinus massoniana. Significantly more predatory and phytophagous arthropod species were found in the bamboo forest mixed with broadleaf trees, which mainly belong to the arthropod orders of Homoptera, Hemiptera, Coleoptera and Diptera in the lower layer of the forest and Acarina, Homoptera, Hemiptera and Coleoptera in the canopy of the forest. However, overall the species diversity, evenness and dominant concentration of the communities in the four forest types of the bamboo showed no significant differences. The common species in the predatory and phytophagous guilds between in the lower layers and the canopies of the three types of mixed forests were all more than those in the pure forest, which resulted in higher similarity of species composition between the two layers of the mixed forests. The measurements of the community stability in the four forest types showed significant differences. The stability of the canopy both in the bamboo forest mixed with broadleaf and in the pure bamboo forest was lower than in the other two mixed forests; the control effects of the natural enemies to the pests in the former two forest types were also lower, and the numbers of individuals of phytophagous mites and Kuwanaspis vermiformis on the bamboo leaves were also higher. We so suggested that in the bamboo forests hurt seriously by the two pests above, such measures as rebuilding of the bamboo forests mixed with Cunninghamia lanceolata or Pinus massoniana should be considered.