杂草生防作用物对本土生物群落的影响

传统生物防治是治理外来入侵杂草危害切实可行的有效策略和途径,近来对传统生物防治的批评主要集注于,引进的生防作用物攻击威胁本土非靶标生物。引进的生防作用物可能对本土非靶标生物产生直接和间接影响,这类影响通过不同营养级生物之间的取食关系,以及通过同一营养级内生物间的竞争关系,而影响本土非靶标生物群落。列举若干杂草生物防治案例对以上影响方式及其发生途径进行了评述。就防范杂草生防作用物对非靶标生物的负面影响,提出了以下对策:(i)把引进天敌防治外来入侵生物作为最后的有效手段;(ii)适当增加对非靶标生物潜在影响的生态学评估;(iii)选择寄主专一性强而且能有效控制靶标杂草的天敌;(iv)加强对杂草传统生物防治的生态学研究。

Non-target impacts of weed biological control agents on native community and safeguard approaches

The classical biological control is a viable,effective approach to the management of alien invasive weeds.Recent criticisms of weed biological control have mainly centered on non-target impacts,the negative effects of biological control agents on species other than the targeted weed.These non-target impacts include both direct and indirect effects on native organisms due to changes in competition within trophic levels and changes in exploitation relationship between trophic levels in food webs.In this paper,we examined a wide range of weed biological control cases and discussed in detail the possible pathways to non-target impacts of biological control agents.In order to increase the ecological safety of weed biological control practices,we proposed to:(i)use imported natural enemies only as a last resort in fight against some of the most damaging exotic pests;(ii)consider only highly host-specific and highly effective biological control agents;(iii)conduct careful risk assessment of biological control agents before release,being particularly alert to their potential ecological impacts on non-target native organisms;and(iv)highly prioritize the need for taking ecology to the heart in biological control of weeds both in research and in application.