农业生态系统模式的形成演替及其空间分布格局探讨

农业生态系统模式是由生物要素与非生物环境之间相互作用而构成的一个物质实体 ,它会随时间的变化而发生状态的演替或“位移” ,在空间上也会呈现一定的分布格局 ,那么引起农业生态系统形成与演替的动因是什么 ?其运行的内在机制是什么 ?是农业生态学中值得探讨的一个重要问题 ,目前也是一个较为薄弱的研究领域。农业生态系统模式时空分布与演替规律的研究可对农业生态系统的设计与构建、区域模式群的景观生态规划与布局提供重要的理论依据与实践指导。1　农业生态系统模式形成与演替　　农业生态系统模式是区域自然环境与社会经济条件共同…

Discussion on the MainTypes of the Formation and Succession of Agricultural Ecosystems and Their SpatialDistribution.

The main mechanism and types of the formation and succession and spatial distribution pattern of agricultural ecosystem are discussed in this paper. It suggests that the formation and succession of agricultural ecosystem is co-influenced by the natural environmental conditions, natural resources, economic development level, market background, science and technology, policy systems,and social and cultural customs. But in different areas, the formation mechanism of the agroecosystem is also different. There are some main types such as the closed environment-induced, cultures and customs-induced, economy and technique-induced, resource-restricted, policy-induced types. Because of the interaction of above induced factors, agroecosystems often have following spatial distribution pattern, including gradient distribution, random inlaid distribution, island-like distribution and line or strip distribution.