Abstract: Agroecosystems can provide many ecosystem services in addition to providing agricultural products for humans. It is a realistic and far-reaching impact on the sustainable development of farmland that to accurately evaluate the importance of ecosystem services provided by agroecosystem. In order to investigate the difference of different methods to evaluate the ecosystem service functions, this paper constructed the evaluation index system for agroecosystem service function and determined the weighted value of ecosystem service indicators of dryland and paddy field in Jiangsu province, using analytic hierarchy process and equivalent factor method based on agricultural statistic data and meteorological data from 1991 to 2020 by taking the agroecosystem in Jiangsu province as the research area. The results showed that the weighted values of paddy fields and dryland in the criterion layer B are in the following order: provisioning services, regulation and maintenance services, and cultural services by an analytical hierarchical process. In the index layer C, food production, gas regulation and raw material production showed higher weighted values for both paddy fields and dryland ecosystem. By the equivalent factor method, the weighted values of paddy fields in the criterion layer B are in the following order: regulation and maintenance services, provisioning services and cultural services. The weighted values of dryland are: regulation and maintenance services, provisioning services and cultural services. In the index layer C, the weighted values of hydrological regulation, food production and gas regulation of paddy fields were higher than other indicators, while the weighted values of food production, gas regulation and raw material production of dryland were higher than others. There are certain differences between the results of the two methods. The analytical hierarchical process relies on the experience of experts to some extent. In contrast, the equivalent factor method was influenced by the base equivalent factor table of ecosystem services. Therefore, to overcome the bias caused by single evaluation approach, different evaluation methods could be used for comprehensive analysis.

Key words: Agroecosystem service functions, Analytic hierarchy process, Equivalent factor method, Weight value