内蒙古草原放牧恢复过程地衣生物量分布及其影响因素的研究

1　引　　言在干旱半干旱草原生态系统中,地衣是植物群落中的一个重要组成部分.地衣是真菌和具有光合功能的藻类的共生体,共生光合生物通过光合作用为自身和共生真菌提供碳水化合物,共生真菌为共生光合生物提供物理保护、水和矿物元素[9] .地衣芽枝可通过截获风蚀物质而增加土壤表面粗糙度,有利于积蓄降水和养分[1] ,地衣的共生真菌菌丝可以通过分泌粘质物而改善土壤团粒结构[3 ] .另外,地衣还可有效地分解矿物元素,同时还有较强的固氮功能[9,17] ,地衣不仅影响土壤的理化性状而且对维管植物也有潜在的影响.因此,地衣在草原生态系统中可促进…

Distribution of lichens biomass and its affecting factors during restoration process of Inner Mongolia steppe

An experiment was installed in the typical steppe area of Central Inner Mongolia to study the distribution characteristics of lichen biomass in the restoration process.The experimental areas were continuously grazed for ten years (1989 to 1998) under different stocking rate,and stopped grazing since 1999.Two years (2001 to 2002) monitoring on the distribution of lichen biomass and its affecting factors showed that no significant difference was found between different stocking rate treatments (P<0.05).There existed positive correlations between lichen biomass and plant species diversity and between soil water content and soil organic matter content (P<0.05),and negative correlations between lichen biomass and soil bulk density,and between Gramineae plant functional group and plant community coverage and biomass (P<0.05).