全球气候变暖对“植物-害虫-天敌”互作系统的影响

Impacts of global warming on the interaction between host plants,insect pests and their natural enemies

全球气候变化是近来人类关注的焦点问题,其最显著的特征是气候变暖。因为昆虫具有生活周期短、繁殖率高等特点,所以,气候变暖对昆虫的发育、繁殖和存活会产生强烈的直接影响。气候变暖促使一些昆虫提前春天的物候现象,向高纬度或高海拔地区迁移。然而,昆虫在自然界并非孤立地存在,它们与寄主植物和自然天敌相互联系、相互作用,并在长期的进化过程中逐渐适应特定区域的气候条件。因此,全球气候变暖对"植物-害虫-天敌"的种间关系必然产生直接或间接的影响,导致不同昆虫之间以及昆虫与其相关营养层的物种之间的相互关系在气候变化下呈现出时间上的异步性和空间上的错位,从而影响植物的适应性和抗虫性、害虫的发生规律和危害程度以及天敌的种群消长和控害效能。昆虫除了可以通过休眠或滞育的方式在时间上避开高温的影响外,还可以通过迁飞或移动的方式在空间上避开高温的影响,在这种迁移和扩散不同步的情况下可能使害虫食性和取食植物的害虫及其天敌的种类发生变化,从而改变生物群落的组成与结构,影响生态系统的服务和功能。

Global change, especially global warming, has become a global problem and challenge. Because insects have a short generation time and high reproductive rate they are likely to manifest effects of global warming in their development, reproduction and survival. Global warming can potentially affect insects in several ways, such as phonological changes, and latitudinal and altitudinal shifts in distribution. Insects are living in an interactive system with many species of plants and predators, all of which are affected directly or indirectly by changes in temperature. Such influences can lead to large variation in relative growth rates and phenological synchrony of host plants, insect pests and their natural enemies, and such species-specific responses to global warming can change the interactive system of interspecific （food-chain） components. Insects may escape unsuitable temperatures either temporally or spatially. Temporal escape is achieved by dormancy and diapauses whereas spatial escape is achieved by migration and dispersal. Variation in temporal or spatial synchrony can lead to changes in the species composition of communities and resultant changes in ecosystem services and function.