我国主要类型农业地区农田生态系统多样性的研究

Farmecosystem diversity in typical agricultural regions of China.

通过对我国 5个典型农业类型区农田生态系统多样性现状的调查 ,建立了农田生态系统多样性数据库 ,在分析了各典型调查地区的土地利用、作物接续、作物搭配、系统类型单元等多样性特征的基础上 ,计算出各农田生态系统多样性指标 .结果表明 ,我国主要类型农业地区的最大丰富度相差不大且普遍偏低 ;各地区间平均丰富度 ( Ta)差异明显 ,且总体上丘陵地区高于平原 ,平原地区自南向北递减 ;各地区间的均匀度 ( E)和优势度( D)无明显差异 ,丘陵地区的 E相对高于平原地区 ,而 D与 E相反 .据此提出了建设多样化的农田生态系统结构、改进当前农田生态系统多样性的建议 .

Through detailed investigation of farmecosystem diversity in five typical agricultural regions of China, the database of farmecosystem diversity is established. After analysing the characteristics of land use, crop sequence, crop arrangement and distribution of system′s units in these regions, the index of each region′s farmecosystem diversity is calculated. The results show that the maximum richness of these farmecosystems is quite low and their difference is not significant; the difference among the average richness (Ta) of each region is obvious, and in general, the Ta is higher in hilly areas than in plain areas, but that in plain areas has a trend to decline from south to north.Little difference of enenness (E) and dominance (D) can be found among these farmecosystems, but E is higher in hilly areas than in plain areas, and D is adverse to E. In accordance with the current situation, some suggestions for constructing diversified farmecosystem structure and for improving farmecosystem diversity are given.