Within our several projects, we are engaged in an integrated assessment of the interrelationships between human society and natural systems. Sudden and gradual changes in ecosystems have different implications for human society and various components of the quality of human well-being. Because society and nature are associated vessels, we call this issue as a study of socio-ecological systems. The approaches we use to analyze complex links between society and nature include ecosystem services, vulnerability and risk assessment, participatory approaches, scenario development, and integrated approaches and models. Part of the issue is to link our knowledge of the state of ecosystems and their predicted development with community-based decision-making and management, including preventing potential reversals following catastrophic changes in ecosystems and overshooting of ecosystems use, with implications for sustainability of ecosystem services.