森林凋落物对种子萌发与幼苗生长的影响

Effects of forest litter on seed germination and seedling growth:A review

森林更新是森林生态系统维持自身稳定的重要环节,其早期阶段(种子萌发与幼苗生长)对气候变化十分敏感,同时显著地受到森林凋落物的影响。对这种影响机制的深入研究,有助于进一步认识和了解森林更新动态和群落演替方向。本文简要概述了近年来国内外森林凋落物研究动态,从森林凋落物影响种子萌发与幼苗生长的物理作用机制(凋落物对种子与幼苗产生的物理障碍与机械损伤,微环境的温度、湿度以及光照条件的变化等)、生物化学作用机制(产生化感物质、降解释放营养物质)以及通过改变土壤理化性质间接对其产生影响等3个方面进行了系统综述,并且就气候变化与森林凋落物的协同作用通过多种方式直接或间接地对树木种子萌发与幼苗生长产生影响的机理进行了初步探讨。在此基础上提出了这一领域未来研究趋势和需要加以重视的问题。

Forest regeneration is the premise of maintaining forest ecosystem stability,and its early phase （seed germination and seedling growth） is very sensitive to climate change and markedly affected by forest litter. To deep understand the related affecting mechanisms can help us to further know the dynamics of forest regeneration and the direction of community succession. This paper summarized the research progress on forest litter,and discussed the physical mechanisms the forest litter affects seed germination and seedling growth （mechanical hinders of forest litter to seed and seedling emergence,changes in temperature,moisture,and light conditions of microenvironment,and so on）,biochemical mechanisms （allelochemicals and nutrients release）,indirect effects induced by the alternation of soil physical and chemical properties,and direct or indirect effects induced by the synergistic action of climate change and forest litter. The future directions in this research field were also discussed.