森林生态系统中草层植物的生态功能

综述了过去20年国内外有关森林生态系统中草层植物的生态功能研究。森林生态系统中的草层植物是指活的草本类植物及在一定高度（通常40cm)以下的乔灌木幼苗的总和，它和枯落物以及林下土壤共同构成森林生态系统中的林下层亚生态系统。森林生态系统中的草层植物具有明显增加生物多样性，防止水土流失，改良土壤结构，保持和提高土壤肥力，促进林木生长，改善林地小气候，加速生态恢复等方面的功效。其功能是相当强大且多种多样的，我国南亚热带森林生态系统中的草层植物研究应在以下方面进一步加强：1）草层植物与枯落物各自的生态功能与生态效益；2）人工林下的草层植物发生与演替规律；3）林下幼苗的更新演替规律；4）草层植物在复合农林业生态系统中的生态功能及其机理；5）加强草层植物的良种的选育和应用研究等。

Ecological Functions of Herbaceous Layer in Forest Ecosystem

Study on ecological functions of the herbaceous layer in forest ecos ys tem conducted in the last two decades is reviewed. The concept of herbaceous lay er in forest ecosystem is defined as living grasses and forbs, and tree see dling s usually lower than 40 cm. Herbaceous layer, together with litter, and am bient soil constitutes an understory sub-ecosystem. Herbaceous layer has been r eported to have a lot of ecological functions, such asincreasing ecosystem diversity, preventing water and soil loss, enhancing soil n utrition, amending soil structure, improving seedling growth, improving microcl i mate, and accelerating ecological restoration. However, there areseveral aspects that should be paid more attention in the study on herb layer in the low subtropical forest ecosystem, e. g. 1) ecological functions and benefi t s of herbaceous layer or litter; 2) the colonization and succession of herbaceous layer in understory of artificial forests; 3) mechanism of seedling r enovation in the forest; 4) the eco-functions and mechanisms of herbaceous laye r in agroforestry ecosystem; 5) screening for more excellent herbaceous species .