How to integrate the soundscape resource into landscape planning? A perspective from ecosystem services

In landscape planning and policy-making, environmental sounds have only negative impacts on human health. The natural sounds that promote healthy and supportive environments remain neglected. Although the soundscape concept and approach have considered natural sounds as a resource, the related knowledge has not been employed in landscape planning yet. The purpose of this study is to advance existing state of knowledge to synthesize common preferences for soundscape resources, and then to propose an assessment method for landscape planning. We introduce a planning-oriented soundscape resource evaluation framework to guide a PRISMA systematic literature review. The review includes an in-depth analysis of 74 peer-reviewed journal articles and a meta-analysis for 21 of them. We find that (1) current research has under-explored the soundscape with regard to spatiotemporal evolution, health benefits, and preferences and values; (2) in green spaces, people from different sociocultural contexts exhibit common preferences for soundscape resources. According to these, soundscape formal characters tend towards naturalness, diversity, and appropriateness; (3) exposure to natural sounds does have positive effects on human health and well-being, but the degree of the effects was varied. In addition to birdsongs and water sounds, wind-induced vegetation sounds also have high values. Based on these findings, we suggest basic natural sound scores and categorized indicators for evaluating NSES. It can be implemented in Geographic Information System to produce place-based and comparable results under uncertainty. The results can help landscape planners better consider the contribution of the acoustic environment to human health, well-being, and quality of life, protect the areas of high-quality soundscape resources without actual human uses, and reveal the differences between the actual provision of aesthetic values and demands for nature-based recreation.