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群落异质性对于揭示破碎化生境上的生态格局具有十分重要的参考价值。本文以黄土高原子午岭林区的油松林为研究对象,通过群落中的物种组成异质性度量群落异质性,分析了其林下植被的群落异质性大小及其成分(物种内嵌成分和物种更替成分)对总体群落异质性的相对贡献,揭示了生境异质性对群落异质性的影响。结果表明:(1)油松林林下植被呈现了较高的群落异质性,并随粒度的增加(即随着取样单元数的增加)而逐渐增大,最终趋于稳定状态。(2)油松林的群落异质性由物种内嵌和物种更替两种过程共同完成,二者的相对贡献依赖于空间粒度,但以物种更替为主。(3)生境异质性与群落异质性及物种更替成分均呈显著正相关,解释了二者变异的71%~84%;生境异质性与物种内嵌成分呈显著负相关,解释了其变异的25%~44%。从物种多样性保护的角度考虑,人工油松林的所有样地都具有恢复其林下物种多样性的保护价值,而营造较高的生境异质性可能是促进物种多样性恢复的重要保证。
Community heterogeneity is very important for revealing the ecological pattern of the fragmented habitat. In this paper, the Pinus tabulaeformis forest in the Ziwuling area of the Loess Plateau was used as the research object. Community heterogeneity was measured by the species composition heterogeneity in the community. The heterogeneity of community size and its components And species replacement components) on the overall community heterogeneity revealed the impact of habitat heterogeneity on community heterogeneity. The results showed that: (1) The understory vegetation of Pinus tabulaeformis forest showed high community heterogeneity, and gradually increased with the increase of grain size (ie, with the increase of sampling unit number) and finally stabilized. (2) The community heterogeneity of Pinus tabulaeformis forest is accomplished by both the process of species inbreeding and the process of species replacement. The relative contribution of the two depend on the spatial grain size, but mainly the species replacement. (3) Habitat heterogeneity was significantly and positively correlated with community heterogeneity and species replacement components, which explained 71% ~ 84% of the variation between the two. There was a significant negative correlation between habitat heterogeneity and species internals, which explained that The variation of 25% to 44%. From the perspective of the conservation of species diversity, all plots of Pinus tabulaeformis forest have the protection value of restoring their species diversity under the forest, and creating high habitat heterogeneity may be an important guarantee to promote the recovery of species diversity.