Abstract: Farmland ecosystem service has a real and far-reaching effect on the sustainable development of human society,and its study is one of the hotspots in ecology.This paper introduced the connotations of farmland ecosystem service and its valuation methodology,and summarized the present status in researching the formation mechanism of farmland ecosystem service from the aspects of the characteristics of abiotic environment,biota,ecosystem process,and human activity.It’s considered that besides its importance in supplying human society a great number of products,farmland ecosystem is of significance in providing environmental service and maintaining regional ecological safety.Abiotic environment,biota,ecosystem process,and their interactions are the bases of the formation of farmland ecosystem service,and human activity is the primary driving force.It’s imperative to build up an indices system to valuate farmland ecosystem service,and to strengthen the research of the effects of human activity on the farmland ecosystem service formation.

Key words: Forest ecosystem, Vegetation carbon storage, Vegetation carbon density