The Delineation and Ecological Connectivity of the Three Parallel Rivers Natural World Heritage Site

SIMPLE SUMMARY: The scientific delineation and conservation of natural heritage sites are important steps in maintaining biodiversity and the dynamic stability of ecosystems. We examined the ecological connectivity of the Three Parallel Rivers Natural World Heritage Site, analysed the impact of boundary adjustments on the landscape pattern and ecological connectivity of the area, and explored the relationship between landscape connectivity and species habitat conservation using the Yunnan golden snub-nosed monkey as an environmental indicator species. The ecological connectivity of the Nu–Lancang River area and the Lancang–Jinsha River area was always high. Meanwhile, the improvement in ecological connectivity in the Lancang–Jinsha River area was conducive to the migration and reproduction of large terrestrial animals, including the Yunnan snub-nosed monkey, with increasing numbers of populations and individuals. In this study, we found that, in order to improve the level of conservation of heritage sites, the delineation of the effective conservation areas of protected areas and the landscape connectivity between them should be considered in addition to the total area of the protected region. In particular, in addition to large wildlife habitat protection patches, stepping stones and ecological corridor networks should be established for large terrestrial animals. ABSTRACT: Landscape connectivity refers to the degree of continuity between the spatially structured units of a landscape. Ecological connectivity can characterise the degree to which ecological functional areas are connected in terms of function and ecological processes. In this study, the landscape pattern index and ecosystem service values were used to evaluate the ecological functional resistance of each landscape type, taking the Three Parallel Rivers Natural World Heritage Site as an example and the habitat distribution and population size of the Yunnan snub-nosed monkey as a reference. The minimum cost distance model, combined with the barrier impact index (BEI) and ecological connectivity index (ECI), was used to determine the degree of barrier impact on the study area and the ecological connectivity of the core reserve of the heritage site in both 2000 and 2020. The resistances of the different land types and landscape heterogeneity to the ecological function of species migration between the core protected areas of the heritage site were, in descending order, those of the forest, shrubs and grass, water, unused land, cultivated land, and built-up land. In 2020, the study area had a large BEI, with areas such as built-up areas, major roads, the sides of large rivers, and arable land being significant contributors to the blockage of landscape connectivity. The overall landscape connectivity in the study area was generally low, with clear spatial differentiation and a three-column parallel distribution pattern influenced by the topography and landscape. With the adjustment of the core reserve boundaries of the heritage site, the proportion of areas with high connectivity (ECI = 4–5) increased from 11.31% in 2000 to 34.36% in 2020. This increased landscape connectivity was conducive to the migration and reproduction of large terrestrial animals, such as the Yunnan snub-nosed monkey, with increasing numbers of populations and individuals. This study provides theoretical and methodological insights into the delineation and conservation of natural heritage sites and landscape connectivity.