关键词: 蚂蚁')"> 蚂蚁, 紫胶虫')">紫胶虫, 植物多样性')">植物多样性, 上行效应')">上行效应, 互利关系')">互利关系, 下行效应')">下行效应, 营养级')">营养级

Abstract: 【Aim】 Mutualism between insects and plant diversity play an important role in the ecosystem. The purpose of this study is to investigate the top-down effects of the mutualism between ants and lac insects and the bottom-up effects of plant species diversity on various trophic levels of the arthropod community. 【Methods】 The experimental plots were located in a lac plantation in Yayi town, Mojiang county, Pu′er city, Yunnan province, southwestern China. In August and September, 2016, following a randomized split-plot experiment design, we collected all the arthropods on the host plants under three treatments of ant-lac insect mutualism (presence of mutualism, absence of mutualism, and natural control) and three levels of plant diversity (monoculture, bi-species plantation and tri-species plantation representing plant diversity 1, 2 and 3, respectively) in the experimental plots by using hand-collection, shake-down and sweeping methods, along with classification of all arthropods according to different trophic levels. 【Results】 Mutualism between ants and lac insects significantly reduced the consumer abundance［presence of mutualism (14.2±0.95)±1.13)±1.38)］(F=56.03, P<0.001), plant diversity increased the consumer abundance significantly ［plant diversity 1 (13.49±2.54)±2.50)±2.47)］ (F=4.290, P=0.017). Under the interaction effect of mutualism and plant diversity, consumer abundance in the treatment with the presence of mutualism was significantly lower than that in the treatment with absence of mutualism in all the three levels of plant species diversity (F=6.850, P<0.001). Mutualism had no significant effect on the predator abundance (F=1.277, P=0.284), plant diversity increased the predator abundance significantly ［plant diversity 1 (1.72±0.49)±0.54)±0.55)］ (F=10.976, P<0.001), and the interaction between plant diversity and mutualism had no significant effect on the predator abundance either (F=0.428, P=0.788). Mutualism and plant diversity significantly increased the ant abundance［natural control (44.08±8.94)±65.35)］ (F=48.9, P<0.001), ［plant diversity 1 (86.31±12.51)±18.80)±21.68)］ (F=137.85, P<0.001); and the interaction between them had a significant effect on the ant abundance(F=80.31, P<0.001). 【Conclusion】 Ant-lac insect mutualism significantly reduces the herbivorous pests on the plant, and has no significant effect on predators, but significantly increases the ant abundance. The plant diversity has a positive effect on various trophic levels of arthropods, and ant-lac insect mutualism and plant diversity have a certain combined effect, causing different effects on each trophic level.

Key words: Ants, lac insects, plant diversity, -up effect')">bottom-up effect, mutualism, -down effect')">top-down effect, trophic level