Background Trade-off relationship among forest ecosystem services is one of the important factors causing regionally and globally ecological and environmental problems. Scientifically understanding trade-off relationships of forest ecosystem is significant to enhance human well-beings and achieve win-win situation of ecological protection and social and economic development.

Methods On the basis of comprehending domestic and foreign research literatures, we expounded the connotation of forest ecosystem service trade-off, and clarified the basic characteristics and main steps of trade-off analysis of forest ecosystem services. Then we sorted the principles, techniques and main functions of trade-off analysis methods, as well as their scope of application, and analyzed the driving roles of natural and human factors in trade-off of forest ecosystem services.

Results 1) Human choice preferences lead to trade-offs among forest ecosystem services. The trade-offs among forest ecosystem services are characterized by universality, reversibility, time-space scale, uncertainty and externality. Universality refers to the general existence of trade-offs between various forest ecosystem services, and reversibility indicates the resilience of damaged forest ecosystem services. Time-space scale shows the spatial and temporal scale characteristics of trade-off relationship, and uncertainty means that the trade-off relationship is not constant. Externality reveals the impact of trade-off management on ecosystem services in non-target areas. 2) The main research procedure of forest ecosystem trade-off includes evaluation index selection, data acquisition quantitative and evaluation trade-off analysis. The research methods mainly include eco-economic integration model method, statistical method, mapping of ecosystem services, scenario analysis and service liquidity analysis. The eco-economic integration model is suitable for analyzing trade-off relationship between the supply services and regulation services convenient for marketization, the statistical method for analyzing correlation relationship between various forest ecosystem services, and mapping of ecosystem services for revealing trade-off spatial heterogeneity. Scenario analysis holds for scenario analysis and finding the best optimization scheme, and service liquidity analysis method for analyzing trade-off occurrence mechanism and ecological process. 3) The driving factors for trade-offs among forest ecosystem services can be divided into natural factors and human factors. Natural factors containing ecological factors and environmental factors are the basis of trade-offs among forest ecosystem services, while human factors include human choice preference, human activity mode and human activity behavior are main ones for trade-offs among forest ecosystem services.

Conclusions The trade-offs among forest ecosystem services are generated by co-driving or direct interaction of driving factors. The trade-offs among forest ecosystem services are insufficient in temporal scales terms of uncertainty of evaluation results, driving factors and spatial and temporal scaling effects of mechanisms. Forest ecosystem trade-offs assessment methods, quantitative models, spatiotemporal scaling effect of driving factors and their mechanisms will be the focus of future research in forest ecosystem services trade-offs.