摘要
围栏封育是一种常见的退化草地恢复措施,其改变了草地植物生长繁殖的小环境。在青藏高原东缘高寒草甸中,采用定点监测的方法研究了封育8年之后围栏内外植被与种子雨的差异。结果表明,围栏封育显著降低了植被中物种丰富度、Shannon-Wiener指数以及植株个体密度,但显著提高了种子雨中物种丰富度和种子雨密度,种子雨密度增加主要由禾本科植物种子数量增加所致;种子雨中物种多度等级分布模式在封育地中符合生态位优先占据模型,而在放牧地中符合对数正态模型。围栏封育对种子雨的季节动态没有明显影响,表现为放牧地与封育地的种子雨均为单峰模式。封育地中种子雨与植被相似性略高于放牧地,但封育地与放牧地中种子雨具有极高相似性。
Enclosure has been widely used in degraded grassland restoration as a brief and effective treat- ment, which changed micro-conditions of growth and production for plants. In the present study, the veg- etation and the seed rain were investigated in enclosed and grazed plots after 8-year enclosing on alpine meadow in the eastern Tibetan Plateau. The results showed that enclosure has significantly negative effects on species richness, Shannon index and individual density of vegetation, however, enclosure has significantly positive effects on richness and density of seed rain in enclosed plots compared with those in grazed plots. The changes of the numbers of Gramineae seeds played a key role in increasing of seed rain density. RAD （rank abundance distribution） displayed different patterns from enclosed plots to grazed ones. In enclosed and grazed plots, the pattern for seasonal dynamics of seed rain was unimodal. The Sorensen＇s similarity coefficient between seed rain and vegetation at fenced plots was higher than that at grazed plots, but the Sorensen＇s similarity coefficient between seed rain in enclosed plots and that in grazed plots was very high.
出处
《草业科学》
CAS
CSCD
北大核心
2012年第3期333-340,共8页
Pratacultural Science
基金
国家科技支撑项目(2009BAC53B01)
关键词
种子雨
封育
高寒草甸
青藏高原
seed rain
enclosure
alpine meadow
Tibetan Plateau
