The Ecological Evolution Analysis of Heritage Sites Based on The Remote Sensing Ecological Index—A Case Study of Kalajun–Kuerdening World Natural Heritage Site

As very fragile natural ecological areas, the spatiotemporal ecological environment (EE) analysis of World Natural Heritage Sites (WNHSs) is particularly important for their conservation and sustainable development. Timely, objective and quantitative evaluation of the spatiotemporal EE change characteristics of WNHSs is of great significance for ecological, environmental protection and government policy formulation. This study quantitatively evaluates the spatiotemporal distribution characteristics of the EE of the Kalajun–Kuerdening WNHS by selecting the Remote Sensing Ecological Environment Index (RSEI) for 2006, 2011, 2016 and 2021. We studied the spatiotemporal differences of the EE in buffer zones and nominated sites in the heritage sites and their change patterns and trends. The EE changes and land use changes from 2006–2011, 2011–2016 and 2016–2021 were overlaid and analyzed to explore the relationship between EE evolution and land use changes in the heritage site. The results show that (1) the heritage site was in a state of ecological change equilibrium from 2006 to 2011, and a form of slight decline in EE quality from 2011 to 2016 under the influence of natural factors, but it maintained a stable state with a small degree of fluctuation, and a state of ecological change recovery from 2016 to 2021. The areas with better EE grades were located in the northwest region (Kalajun) and northeast region (Kuerdening) of the heritage site. (2) The EE grade change in the heritage site shows the characteristics of neighborhood change without a large number of leap changes. (3) From 2006 to 2021, the EE quality in the nominated site was better than that of the buffer zone, but from 2016 onward, the difference between the two gradually decreased until 2021. The average EE quality was basically the same until 2021, but, spatially, the EE quality of most areas in the buffer zone was better than that in the nominated area. (4) The types of land use transformation that caused EE enhancement in the heritage sites were barren–grassland, snow/ice–barren and barren–snow/ice, while the types of land use transformation that caused EE quality reduction were grassland–barren and barren–snow/ice. The results of this study help improve the knowledge of the EE background of the WNHS and its evolutionary process and provide scientific guidance for ecologically related decision making and management of global natural heritage sites. The change in snow and ice cover is an essential factor in the shift of the EE of the Kalajun–Kuerdening World Natural Heritage Site.