试论人工林下乡土树种定居限制问题

Recruitment limitations of native tree species under plantations:A preliminary review

人工林的生态系统服务功能比天然林差,多数人工林林下难以有乡土树种入侵并定居,如何改造并促进这些人工林向天然林或次生林演替并提高生态效益,已成为制约区域林业可持续发展的关键问题.在阐述定居限制原理的基础上,本文从种类特性、限制发生时间、影响定居的内外因素等方面概括了森林更新或恢复中的定居限制问题,认为人工林林下乡土树种的定居限制主要由种子的可到达性及环境条件所决定.基于恢复生态学中有关森林恢复的理论,提出应对不同时空尺度上植物更新过程中的种子和幼苗存活的影响因素进行整合.

The ecosystem service of plantation is inferior to that of native forest, but it is difficult for local and native species to colonize and establish under plantations. Therefore, how to improve the plantations to facilitate their succession to native or secondary forest is a bottleneck restricting the sustainability of forestry. Based on an introductory description of the principles of establishment limitation, this paper summarized the recruitment limitations in forest regeneration and restoration, with respects to the species characteristics, time of limitation occurrence, and other affecting factors. It was considered that the major determinants of local species colonization were the probability of seeds arrival and the environmental conditions. Based on the theories of forest restoration, it was suggested that the factors affecting the survival of seeds and seedlings in plant regeneration at different spatiotemporal scales should be integrated.