缀块性和缀块动态:Ⅲ.生态与进化效应

Patchiness and Patch Dynamics: Ⅲ. Ecological and Evolutionary Consequences.

自然界各种等级系统都普遍存在时间和空间的缀块性。它反映了系统内部或系统间的时空异质性,影响着生态学过程。不同缀块的大小、形状、边际性质以及缀块间的距离等空间分布特征构成缀块性的差异,并控制生态过程的速率。某一空间特有的缀块性也是生态过程的结果。

The authors suggest that pathiness can be represented on different hierarchical levels of ecological systems.It's considered that metapopulations result from patchiness and spatial distribution of resources is one of the strong factors shaping the population dynamics. There may be threshold effects of patchiness on energy balance and species survival. Disturbance results in patchiness and influences resource availability and distribution.In turn, patchiness may limit or prevail a disturbance.The interaction of patchiness and disturbance may result in a metastability. Human disturbance is considered as an event usually on a large spatial scale in a short time period. Ecological systems may not be able to keep up such rapid changes and vicious positive feedback may be invoked.In view of evolution,patchiness is a consequence of co-evolution of biotic and abiotic entities in nature,Biodiversity is, therefore,the fact and the result of patchiness.