Terrestrial Biodiversity Hotspots and Their Threats in Guangdong Province

Abstract

Biodiversity plays an important role in providing ecosystem services and maintaining ecosystem stability, which are closely related to human welfare. The identification of biodiversity hotspots and analysis of their threats provide effective ways for biodiversity conservation and restoration. Current studies generally combine species diversity and its threat situation to determine hotspots for priority protection. However, in-depth analysis of threats to biodiversity hotspots is still lacking. Guangdong Province is one of the key biodiversity areas in the world, but it faces great challenges in biodiversity preservation. To understand biodiversity hotspots and their threats in Guangdong Province more completely, this study developed a heat index for terrestrial biodiversity by considering plant species diversity, animal species diversity, and landscape diversity based on multi-source data of plant and animal species, ecosystem stand types, and land use. Then, the heat index was used to identify biodiversity hotspots, and their threat levels and controlling factors were analyzed according to the major threats to biodiversity. The results showed that areas with high values of terrestrial biodiversity heat index were mainly distributed in mountainous regions with relatively few human disturbances, whereas most areas with low values were concentrated in estuarine plains and intermontane basins with heavy human activities. Based on the zonation of the heat index, four biodiversity hotspots were identified, Yunwu Mountain, Nanling Mountain, Luofu Mountain, and Lianhua Mountain, with area percentages of 15.54%, 44.90%, 17.66%, and 21.90%, respectively. The area of biodiversity hotspots was 59,931.82 km2, accounting for 33.58% of the total land area of Guangdong Province. The 122 nature reserves within hotspots had an area of 6,594.39 km2, covering 61.33% of the whole area of the total 204 terrestrial nature reserves in Guangdong Province. This proportion gradually decreased with reduction of nature reserve grade, indicating that the nature reserves in hotspots were principally at a higher grade (nation and province levels) rather than at a lower grade (city and county levels). However, the area of these nature reserves in hotspots was only 11.00% of the whole area of hotspots, and most of the nature reserves that were not distributed in hotspots were located in the northeastern cities of Heyuan and Meizhou. Therefore, a large number of potential demands for biodiversity conservation still exist. For the four hotspots, the biodiversity in Yunwu Mountain was primarily under moderate to severe stress, with the intensity of economic development as the controlling factor. The biodiversity of the other three hotspots mainly underwent slight to moderate stress. The most important threat was the extensive economic development of the central part of Nanling Mountain and the southern parts of Luofu Mountain and Lianhua Mountain, whereas the periphery of Nanling Mountain and the northern parts of Luofu Mountain and Lianhua Mountain were more threatened by habitat quality or geological hazards. In addition, extreme stress on biodiversity occurred in all four hotspots, although within very small areas. Thus, more targeted management strategies for biodiversity should be proposed according to the stress levels and controlling threats. The results of this study provide a scientific reference for the comprehensive conservation and precise restoration of biodiversity hotspots in Guangdong Province.

Keywords

• terrestrial biodiversity
• hotspot
• threat
• conservation and restoration
• guangdong province