Tourists' valuation of nature in protected areas: A systematic review.

In the face of biodiversity loss, it is crucial to broaden the arguments for conservation of protected areas by acknowledging diverse values of nature. We systematically reviewed empirical studies to investigate tourists' values of nature in protected areas over time and across regions. To do so, we explored (1) the main ecological and social characteristics of the case studies; (2) methodological approaches; and (3) value types. Based on the review of 152 articles, we found that economic valuation has received the most scientific attention, while socio-cultural valuation approaches have recently increased. Values were primarily elicited and analyzed quantitatively and in monetary metrics, although valuation methods and frameworks have diversified over the past two decades. However, considering the role of valuation methods and frameworks as value-articulating institutions, we suggest that future research on nature valuation also applies qualitative and non-monetary methods, elicits diverse values, and conducts plural valuation.