农业生态系统协调度测度理论与实证研究

依据数理统计理论与方法构建了农业生态系统协调度测度理论和模型,包括功效函数、协调函数和协调度的变化范围和协调度等级,建立了农业生态系统系统评价指标体系,以湖南省益阳市资阳区为例进行了农业生态系统自协调发展实证研究。结果表明:该地区农业生态系统1990—2002年系统协调度呈现上升趋势、1990—1998年呈弱度失调在5级以下、1999—2002年呈弱度协调在6级以上;系统协调度的变化主要受子系统影响,1990年的系统协调度低主要是因经济和社会子系统的协调度太低,1998年系统协调度低的主要原因是生态子系统的协调度太低;从研究时段看,影响农业生态系统系统协调度主要随经济子系统和生态子系统的协调度变化而改变,通常表现为经济子系统是提升协调度、生态子系统是降低协调度,揭示出经济与生态的协调是农业生态系统协调发展的关键。

Harmony coefficient theory and case study on agricultural ecosystem

Harmony coefficient(HC) theory was constructed by mathematical statistics principle and method to agricultural ecosystem in the paper,which consists of efficacy function,harmony coefficient function,range of harmony coefficient value and rank of harmony coefficient(RHC),and the appraised index on agricultural ecosystem was established.Finally,Ziyang county,Yiyang city of Hunan province(ZYH) was case studied with harmony coefficient theory.The result made know that ZYH of agricultural ecosystem is ascending trend from 1990 to 2002.RHC is 5 and HC is feeble maladjustment from 1990 to 1998;RHC is 6 and HC is feeble harmony from 1999 to 2002.HC of agricultural ecosystem is influenced by sub-system.In 1990,HC of agricultural ecosystem is low because of low HC of economic subsystem and social sub-system.HC of agricultural ecosystem is low because of low HC of ecological sub-system in 1998.HC of agricultural ecosystem is impacted mainly by economic sub-system and ecological sub-system as a whole,and economic sub-system is positive,and ecological sub-system is negative.The relationship between economic benefit and ecological benefit is one of central contradictions to agricultural ecosystem development.