Evaluation of ecosystem carrying capacity and diagnosis of obstacle factors in the World Heritage Karst sites

The ecosystem carrying capacity (ECC) of the karst world heritage site (KWHS) is a critical factor influencing regional development and Environmental Protection of Heritage Site (HS). However, studies on the ECC of KWHS are limited. This paper examines the Shibing and Libo-Huanjiang KWHS, utilizing 16 evaluation indices covering natural environment and socio-economic aspects. We apply subjective and objective weighting methods, cold and hot spot analysis, and the geographical detector to analyze the spatial and temporal differentiation characteristics of the ECC of KWHS from 2010 to 2020 and identify its obstructive factors. The results indicate: (1) The ECC of the KWHS core zone is significantly greater than that of the buffer zone, and the ECC of the buffer zone with no human disturbance is greater than that of the buffer zone with strong human activity from 2010 to 2020. By 2020, the Shibing HS is dominated by the Stronger ECC zone, while Libo-Huanjiang HS is dominated by the Strongest and Stronger ECC zones. (2) From 2010 to 2020, the ECC of KWHS exhibited a general downward trend, with ecological environment degradation being more pronounced in Shibing HS than in Libo-Huanjiang HS. (3) The spatial pattern of ECC in the KWHS showed strong spatial agglomeration over time, with noticeable spatial differentiation. Hot spot areas were primarily within core zone, while cold spot areas were mainly in the buffer zone. (4) Land use intensity, development disturbance index, and economic development index were the main driving factors of ECC in Shibing HS. In Libo-Huanjiang HS, ECC spatial differentiation was more influenced by ecological sensitivity and habitat quality index, with some factor interactions having a greater impact than single factors.