某些观察材料证明,一些树种的分泌物可能对专门危害另一些树种的昆虫或微生物有害。因此,某些树种可以保护另一些树种不受病虫害感染。但是,由于乔木树种间的相互关系很复杂,并且目前对此问题研究得还很不够,混交林设计中往往单纯凭经验选择树种,引起不良后果。此外,由于外来树种的大量引种,某些新创造的林分是自然界中未曾有过的。因此有必要研究造林树种选择和搭配的理论基础。本文目 Some observational materials demonstrate that the secretions of some species may be detrimental to insects or microorganisms that specifically harm other species. Therefore, some species can protect other species from pests and diseases. However, the interrelationship between tree species is very complicated, and the current research on this issue is still not enough. In the mixed forest design, tree species are often selected by experience based on experience alone, causing undesirable consequences. In addition, some newly created stands have not been found in nature due to the large introduction of exotic species. Therefore, it is necessary to study the theoretical basis of tree species selection and collocation. This article