摘要
以阿拉善极度退化的草原化荒漠区为研究对象,对放牧与围封条件下退化群落的物种多样性、生产力和群落演替及其生态机制进行了初步研究,结果表明:1)荒漠植物群落物种多样性指数在时间尺度上的变化表现为随着自由放牧时间的延长逐渐降低,随着围封时间的延续逐渐增加,而生态优势度变化趋势则相反。2)围封导致荒漠群落物种多样性指数增加的主导因子是物种丰富度的增加;围封使荒漠群落恢复的生态机制在于消除牧压后不同种群繁殖对策的实现,拓殖能力的增强和剩余资源的充分利用。3)围封第3年草原化荒漠群落优势种发生变化,短花针茅大量生长,群落发生恢复演替的结果使群落生产力得到大幅度提高。
An overgrazinginduced steppe desert community dominated by Zygophyllum xanthoxylum and Stipa glareosa in Alashan area has been researched on the following items:species diversity, palatable forage productivity and the succession under either continual grazing or enclosure. The results are as follows: 1)The species diversity index of the steppe desert community decreased with the extended time of free grazing, and increased with enclosure; but the change of the ecological dominance was opposite. 2)The increase in abundance in species is the main factor that caused the increase in the species diversity index of the steppe desert community by means of enclocure. The mechanism of ecological restoration of the steppe desert community by enclosing is the increase of reproductivity ability of several communities of the steppe desert community. Also the full utility of surplus resources. 3) The dominant species S.breviflora grew rapidly by the third year of enclosure, which caused the increase of reproductivity of the steppe desert community.
出处
《草业学报》
CSCD
2003年第1期34-40,共7页
Acta Prataculturae Sinica
基金
国家自然科学基金重点项目(39730100)
国家重点基础研究发展规划项目(G2000048705)
国家基金西部重大项目(90102011)资助。
