Comparison of ecosystem service value of freeway and agriculture—A case study of Southwest Zhengzhou City freeway

In accordance with the characteristics of freeway ecosystem and the connotation of ecosystem service，soil and water conservation,CO₂ fixation,O₂ release,dust absorption,deleterious gas (SO₂) absorption and nutrient elements cycling were selected as indexes to evaluate ecosystem service at different periods of the southwest suburban freeway of Zhengzhou City by a combination of matter and value quantities based on market value method,shallow engineering method,production cost method and opportunity cost method.Results show total annual service values of agro-ecosystem in the research area to be 4.242 million Yuan, that of freeway ecosystem before and after ecological protection are 1.975 and 4.846 million Yuan respectively.Ecological service values are remarkably different among ecosystems in different freeway service periods.