Study on Farmland Ecosystem Stability Evaluation Based on Dynamic Factors

Farmland ecological stability is the foundation of regional farmland ecological security and sustainable development.Based on analysis of differences between the natural ecosystem and farmland ecosystem,and combined with existing studies on the ecological stability in and out of China,the concept of farmland ecosystem stability was developed that keeping a relatively high output and dynamic fluctuation are the basic and typical characteristic,respectively,of the stability of the farmland ecosystem.The farmland ecosystem pattern was analyzed in order to construct an assessment index system,which included regional eco-environmental quality,artificial and natural input process,yield formation process and economy-society process and 19 concrete indices.Dongguan municipality was taken as a case study and its ecological stability situation of farmland from 1990 to 2004 was assessed quantitatively with the assessment indexes.The result showed that farmland ecosystem in Dongguan was at a stable status and indicated the correctness of the evaluation model.