Abstract: The core area of Hebei Weichang Hongsongwa Natural Reserve had been enclosed for more than ten years.As all disturbing activities from human and livestock were forbidden,more and more litter was accumulated and had a significant effect on the plant reviving and seedling establishment.In order to provide the theoretical basis for the scientific management of the nature reserve,a single-factorial field random experiment with three litter layer levels(complete litter removal,5cm stubble height,no litter removal as CK) was carried out to investigate the effect and its mechanism of litter layer on perennial plant community of mountain meadow using quadrat survey method in July of 2007 and 2008 in the core area.The results indicate that litter layer significantly affected the number of species,coverage,and aboveground biomass of plant communities and peak values showed under 5 cm stubble height treatment.But there was no significant effect on height of plant community.Results of plant community component analysis show that removal of litter layer increased the plant percentage of Leguminosae,Gramineae,and Compositae and decreased the proportion of other herbs.The percentage of Cyperaceae and other herbs showed a peak value under CK treatment.The Shannon-Wiener index and Simpson index of mountain meadow plant community together indicate that 5cm stubble height treatment would be beneficial to the maintenance of biological diversity.

Key words: Litter, Mountain meadow, Biomass, Plant diversity, Community composition

摘要： 针对围场红松洼国家级自然保护区核心区枯死物大量积累的现状,按枯死物的自然存在状况设置了1因素(枯死物因素)3水平(完全去除枯死物,留茬5 cm,自然状态CK)的随机实验,并分别于2007、2008年7月进行样方调查,就枯死物对以多年生植物为主的山地草甸植物群落的影响及其作用机制进行研究,以期为保护区的科学管理提供理论基础。结果表明:在实验期内,自然状态下枯死物的存在对红松洼山地草甸植物群落的物种数、盖度以及地上生物量影响显著(P<0.05),在留茬5 cm时达到最大值,而对植物群落高度没有显著影响;植物群落组成分析表明,去除枯死物提高了植物群落中豆科(Leguminosae)、禾本科(Gramineae)和菊科(Compositae)植物的比重,降低了杂类草植物所占比重;而自然状态下,莎草科(Cyperaceae)和杂类草植物的重要值达到峰值;草甸植物群落的Shannon-Wiener多样性指数和Simpson优势度指数同时表明留茬5cm有利于植物多样性的维持。

关键词: 枯死物, 山地草甸, 生物量, 植物多样性, 群落组成