不同修剪模式对有机茶园节肢动物群落多样性的影响?

对夏季轻修剪、深修剪和不修剪的有机茶园中节肢动物群落进行了调查。结果表明，与不修剪相比，轻修剪1、2个月后对茶树害虫和天敌均产生了显著影响，深修剪的影响更大。修剪1个月后，轻修剪和深修剪茶树上假眼小绿叶蝉、茶尺蠖、茶橙瘿螨和蜘蛛的数量显著下降；修剪2个月后，轻修剪和深修剪茶树上假眼小绿叶蝉的数量显著增加，说明两种修剪方式均可推迟假眼小绿叶蝉虫口高峰出现的时间，深修剪还可有效避过茶橙瘿螨的危害。修剪3、4个月后，轻修剪、深修剪和不修剪茶树上节肢动物群落多样性指数和益害比差异不显著。轻修剪对有机茶园吸汁性害虫的持续控制效果可达1个月，深修剪的控制效果更好，但是需要统筹考虑防虫、养蓄天敌和后续茶叶的生产，要慎重选择。

Effects of Pruning on Biodiversity of Arthropod Communities at Organic Tea Plantations

Effect of plant pruning on the biodiversity of arthropod communities at organic tea plantations were investigated in the summer. Tea plants were subjected to light, deep or no pruning for observation in changes on the biodiversity at the plantations. The results indicated that one or two months after alight pruning, both pests and natural enemies were significantly affected. The effect was even greater when a deep pruning was applied. A month after a deep pruning, the number of arthropods including Empoasca vitis, Ectropis obliqua, Acaphyllatheaeand spiders were significantly reduced as compared with that without pruning. However, one month later, the Empoasca vitiscounts began to increase. Both light and deep pruning delayed the initial peak on the small green leafhopper count, and the deep pruning completely avoided the damage caused by the tea pink mites. In 3 or 4 months, no significant difference in arthropod community diversity index, nor the ratio of natural enemy/pest biomass, was observed among the treatments. Light pruning could put the leaf-sucker population in the plantations under control for as long as one month. Although deep pruning showed an even greater effect with respect topest reduction and natural enemy protection, the accumulated and subsequent tea production needed to be considered as well for a balanced benefit.