We designed three studies to explore the effect of materialistic values on pro-environmental behavior among youth and the mediated role of nature connectedness between materialistic values and pro-environmental behavior. Through a self-report questionnaire survey (Study 1) and an experimental manipulation of materialistic values (Study 2), we found that materialistic values negatively predicted pro-environmental behavior, and that nature connectedness played a mediating role. Further, we used natural contact strategies to control the level of nature connectedness, and found that the negative impact of high materialistic values on pro-environment behavior decreased with the increase of nature connectedness, further supporting the mediating role of nature connectedness (Study 3). These results may contribute to the design of strategies that effectively mitigate the negative effects of materialistic values on pro-environmental behavior.

While many studies suggest evidence for the health benefits of nature, there is currently no standardized method to measure time spent in nature or nature contact, nor agreement on how best to define nature contact in research. The purpose of this review is to summarize how nature contact has been measured in recent health research and provide insight into current metrics of exposure to nature at individual and population scales. The most common methods include surrounding greenness, questionnaires, and global positioning systems (GPS) tracking. Several national-level surveys exist, though these are limited by their cross-sectional design, often measuring only a single component of time spent in nature, and poor links to measures of health. In future research, exposure assessment combining the quantifying (e.g., time spent in nature and frequency of visits to nature) and qualifying (e.g., greenness by the normalized difference of vegetation index (NDVI) and ratings on perception by individuals) aspects of current methods and leveraging innovative methods (e.g., experience sampling methods, ecological momentary assessment) will provide a more comprehensive understanding of the health effects of nature exposure and inform health policy and urban planning.