短花针茅草原群落种间联结研究

Interspecific associations in Stipa breviflora desert steppe community

种间联结能够反映群落中物种之间的交互作用,在群落结构功能研究中占有重要位置。在1m×1m样方尺度上研究了短花针茅荒漠草原群落中出现频率较高的13个物种之间的交互联结性。结果表明,短花针茅群落多种间负相关,多物种之间存在对资源的竞争;11个种对联结显著,其中5个种对联结极显著;显著联结的11个种对中,4对为正联结,7对为负联结;其余种之间相对独立,互为中性联结或联结性不显著。关键种与其它物种之间呈中性联结或联结性不显著,在群落中表现出很强的独立性,分布不受其它物种的影响或所受影响很小,在群落中能够稳定存在并占据优势生态位。伴生种或杂类草与其它物种之间联结显著,正向或负向,在群落中表现出很强的依赖性,分布易受其它物种的影响,在群落中不能稳定存在且只占据劣势生态位。

Interspecific associations can reflect interspecific competitive interactions in communities, and have been playing a central role in the functioning of all ecosystems since the early history of life. Interspecific associations of 55 specific pairs from 13 frequent species in a Stipa breviflora desert steppe community by 1 m×1 m size quadrates were studied. The results showed that there were negative multi-interspecific associations and interspecific competitions in the S. breviflora desert community. The interspecific associations of 11 specific pairs were significant including 5 specific pairs being greatly significant. Among the 11 specific pairs, there were 4 specific pairs with positive associations and 7 specific pairs with negative associations. Others were neutral interspecific associations. Interspecific associations of keystone species with others were neutral or not significant. Keystone species showed great independent and occupied prior ecological niche in the community, which distributions were not susceptible to other species. This partly accounted for the persistency of keystone species in the community. Interspecific associations of accompanying species or weeds with others were significant, negative or positive, which both indicated the great dependency of accompanying species or weeds on other species. Distributions of accompanying species or weeds were susceptible to other species and only occupied inferior ecological niche in the community, which resulted in their transition or unstability in the ecosystem development.