围封对元江稀树灌草丛林下植被物种组成及生物量分配的影响  

Effects of exclosure on species diversity and biomass allocation of understory vegetation of Savanna ecosystem in Yuanjiang dry-hot valley,Yunnan,Southwest China

作　　者：金艳强 李敬[1,3] 刘运通[1] 张一平[1] 费学海[1,3] 李培广[2] 张树斌[2] 

机构地区：[1]中国科学院西双版纳热带植物园,热带森林生态学重点实验室,云南勐仑666303 [2]中国科学院西双版纳热带植物园,元江干热河谷生态站,云南元江653300 [3]中国科学院大学,北京100049

出　　处：《生态学杂志》2017年第2期343-348,共6页Chinese Journal of Ecology

基　　金：国家自然科学基金与云南省联合项目(U1202234);国家自然科学基金青年项目(41405143);国家自然科学基金重大项目(31290221);云南省基金面上项目(2015FB186)资助

摘　　要：以元江干热河谷稀树灌草丛植被为对象,通过设置围封与自由放牧两种处理,对稀树灌草丛林下植被物种组成、多样性指数及生物量进行了研究,以探明两种处理下稀树灌草丛林下植被群落结构的变化趋势及林下植被生物量的分配特点。结果表明:围封显著增加了林下灌木和草本的高度、盖度和生物量(P<0.05);但降低了物种多样性指数。相比放牧样地,围封对灌木地下/地上生物量之比的影响不明显(P>0.05),但围封显著提高了灌木的枝叶生物量比(P<0.05);同时,围封还降低草本的地下/地上生物量比(P<0.05),这是植物通过改变自身的资源分配,以应对干扰等不利环境对自身发育的影响,是一种适应性机制。总之,围封对植被的恢复是有效的,但适当的干扰对维持生态系统稳定和群落演替是有利的。Effects of exclosures on species diversity and biomass allocation were studied in a savanna ecosystem in Yuanjiang dryhot valley, Yunnan, Southwest China over two years. The response of understory vegetation to exclosure was compared with the free grazing area. We found that the average height, percentage cover and biomass of understory and its components increased significantly with exclosure compared to free grazing area. Herbaceous species diversity was significantly declined with exclosure. Compared to free grazing, the belowground/aboveground biomass ratio （B∶A ratio） of shrubs under exclosure varied insignificantly, while the branch/leaf biomass ratio for shrubs increased. However, the B∶A ratio of herbs was significantly decreased under exclosure treatments. This could be attributed to adaptation strategies in which plant changes in resource allocation pattern in response to adverse environmental conditions. In general, the exclosure was an effective approach of vegetation restoration and subsequent biomass accumulation. However, appropriate competition and intermediate disturbance （e.g., grazing） can buffer species richness, which is helpful for maintaining the ecosystem stability and functions per se.

关 键 词：物种多样性 生物量 干热河谷 植被恢复 

分 类 号：Q948[生物学—植物学]