林分光环境对格木生长及荔枝异形小卷蛾为害的调控机制

Shoot borers affect severely the quality and stability of the plantation, and their prevention and control are one of the important and difficult issues in forest management. Stand light environment influences significantly not only tree growth, but also life history and behaviour of shoot borers. However, comprehensive regulation by light environment for both tree growth and shoot borer damage has not been reported yet. In this project, Erythrophleum fordii, one of valuable timber tree species easily suffered from Cryptophlebia ombrodelta, a kind of shoot borer, is used to explore comprehensive regulation mechanism by light environment for tree growth, shoot borer attack. Control trials and stand plot survey are combined to assess effects of light on life history of C. ombrodelta, and its damage to E. fordii, to study changes of photosynthesis and nutrient use of E. fordii and thus release response of its growth to light environment. A case study is mainly conducted in a serial of forest gaps established with short-rotation and fast-growing species of Eucalyptus and long-rotation valuable tree species Erythrophleum fordii to investigate dynamics of light environment in gaps and tradeoff between tree growth and borer attack. The findings will provide evidences in reasonable cultivation and management techniques for tradeoff between tree growth and borer attack, and improve mixed model plan of E. fordii and facilitate healthy development of its plantation forestry. This is also an innovative attempt for theory and practice of mixed plantation.

钻蛀类害虫的发生与危害严重影响人工林质量和稳定性，是人工林经营的难点。光环境不仅影响林木生长，而且对害虫的生活史和行为特征等亦具有重要影响，以往研究多注重单方面研究，有关光环境对二者综合调控缺乏研究。本项目以格木 (Erythrophleum fordii) 以及严重为害其顶芽的荔枝异形小卷蛾 (Cryptophlebia ombrodelta)为研究对象，通过控制试验和典型样地调查，揭示光环境对荔枝异形小卷蛾生活史及其为害特征的影响和作用机理，探明系列光环境中格木光合生理和养分利用的变化从而揭示格木生长对光环境的响应机制，重点以应用桉树、格木营建的人工林窗为案例，研究林窗内光环境动态变化特征及其对格木生长、虫害的调控作用，从而为合理制定营林技术措施、协调格木生长与虫害之间矛盾提供理论依据，将有助于完善格木混交模式设计，促进其人工林的健康发展，亦是对混交林理论和实践的一种新尝试。