Cold/hot spots identification and tradeoff/synergy analysis of ecosystem services in Taihang Mountain area

Mountains provide people with water conservation, soil conservation, climate regulation, biodiversity maintenance, product supply, and other ecosystem services. These ecosystem services are irreplaceable. Research on the characteristics of cold/hot spots of ecosystem services is of great significance for the protection and promotion of ecosystem services. Therefore, taking Taihang Mountain area as a research area, the cold/hot spots of ecosystem services were identified, and the tradeoff/synergies among ecosystem services were analyzed to provide theoretical support for the protection and promotion of ecosystem services in the Taihang Mountain. Cold/hot spots of were identified based on Getis-Ord Gi* statistical index. On this basis, the correlation coefficient method was used to analyze the tradeoff/synergy between the four ecosystem services in the cold/hot spots regions. The results are as follow: 1) On the grid scale, the total value of ecosystem services ranged from 0 Yuan to 185.06 million Yuan. The ecosystem service values were divided into five grades. The area and spatial distribution of the total value of ecosystem services on the grid scale remained unchanged from 1990 to 2015. The main distribution grades were 3.68−11.56 million Yuan and 11.56−33.85 million Yuan, and the two sections account for approximately 80% of the total area of Taihang Mountain area. The high-value area of 62.18−185.06 million Yuan has the least distribution area, accounting for only 1% of Taihang Mountain area. 2) In 2015, the total ecosystem service hot spots were distributed throughout the mountain area. The distribution area was the largest in the sub-alpine region (9558 km²), followed by the mid-mountainous region (5238 km²), and the smallest was in the hilly region (3969 km²). The cold spots area was mainly distributed in the eastern and western edges of the mountain area, whose distribution area in the low hills accounted for approximately 70% of the total area. 3) There were no cold spots in forests, water areas, or wetlands. There were no hot spots in the desert ecosystem. The hot spots in the water area, forest, and wetland were large in proportion; water areas had the largest proportion of hot spots (up to 65%), followed by forests and wetlands. The cold spots area in deserts, construction lands, and farmlands were large in proportion, and desert had the largest proportion of cold spots (up to 69%), followed by construction lands and farmlands. 4) In the cold/hot spots areas of the total ecosystem services in 2015, there was only a synergistic relationship among the ecosystem services. The conclusions drawn from the above results are as follows: 1) Based on the spatial distribution characteristics, the priority area for ecosystem services protection should be the subalpine area. 2) Based on land use, the priority protected areas for ecosystem services should include forests, water areas, and wetlands. 3) Based on the tradeoff and synergy between the four categories of ecosystem services in the cold/hot spots area of the Taihang Mountain, the cold/hot spots area can be used as the priority area for improving the protection of ecosystem services from the perspective of conservation efficiency.