Mapping and assessing supply–demand matching of recreational ecosystem services in Shandong province, China

Globally, natural landscapes and their recreational ecosystem services (RES) are both under threat from anthropogenic activities and environmental changes. But the demand for RES increases with the development of human living standards. Therefore, mapping and assessing the supply–demand relationships of RES is crucial for landscape planning, management, and human well-being. This study aimed to study the relationships between supply and demand of RES in Shandong province, China, quantify the supply, demand, and supporting capacity of RES, analyze the degree of matching and coupling between the supply and demand of RES, and explore the effect of terrain gradient to RES. The results indicated that the average value of coupling coordination (CCD) between supply–demand of RES in Shandong province was 0.45, which is a mild balance. According to the supply–demand matching types, areas with low supply-high demand accounted for 6.62%, indicating a serious shortage matching of supply and demand. Using hotel quantity and roads as indicators of the supporting capacity of RES, the overall coordination between landscape aesthetic quality (LAQ) and regional hotel quantity shows a mild imbalance (0.38), while that with the regional road density shows a good balance (0.60). Furthermore, the scenery spots density, RES supply, RES supply–demand CCD and support capacity CCD shows an upward trend with the increase of elevation and slope, an "increased-decreased-increased" trend with the increase of terrain niche index. This study provides spatial matching of RES supply and demand in Shandong province. Optimizing land-use structures and improving natural resource allocation were proposed to boost coordination of RES supply and demand.