Wenbo Li

Human activities and climate change are influencing the survival and distribution of species, threatening the current distribution pattern of biodiversity and potentially leading to the “sixth mass extinction.” The forest musk deer (Moschus berezovskii) is among the most numerous and widely distributed musk deer species in China. However, its habitat is severely threatened by human activities and climate change. Due to the lack of field surveys and research data, it is difficult to assess the threats posed by human activities and climate change effectively. In this study, we integrate the new records of forest musk deer with climate and human activity data, and apply the MaxEnt species distribution model to evaluate the impact of human activities and climate change on the forest musk deer under current conditions and future scenarios (SSP1-2.6 and SSP5-8.5 for the 2030s, 2050s, and 2070s). Our results showed that the forest musk deer prefer areas with high vegetation cover (NDVI > 0.7), low GDP, and low levels of human activity disturbance. The areas of high-suitability habitats are 90.10 × 10⁴ km², 72.85 × 10⁴ km², and 30.43 × 10⁴ km², respectively. The optimal climatic conditions are an annual precipitation (BIO12) of 750–1500 mm and a seasonal temperature variation (BIO4) of 500–600. Their occurrence probability is highest at elevations between 1500 and 3000 m. Under the current climate conditions, the area of high-suitability habitats is estimated at 5.54 × 10⁴ km², primarily distributed across central–northern Sichuan, northwestern Guangxi, and southern Gansu. Under the future climate scenarios, low and medium-suitability habitats are projected to shrink to varying degrees, whereas the high-suitability area is expected to expand, particularly under the SSP5-8.5-2030s scenario where it is projected to increase by 2.88 × 10⁴ km². The centroid of suitable habitat is projected to shift toward higher-elevation areas in northwestern China, with regional hotspots emerging in southwestern regions such as central–northern Sichuan and northwestern Guangxi. These elevational and distributional shifts highlight the vulnerability of current habitats and the importance of adaptive conservation strategies to strengthen species protection, including continuously advancing forest protection programs, mitigating the impact of human activities in high-altitude areas, and strengthening the protection of key areas in the southwestern region.

Exploring the relationship between the magnitude and temporal trend of the Biodiversity Intactness Index (BII) is critical to assessing current and future changes in biodiversity intactness. However, investigations into the relationship between BII magnitude and trends worldwide have been limited. Using annual BII time series data from 2000 to 2020, we assess the global spatial patterns of BII magnitude and trend, as well as their relationship. Our findings reveal four key insights: First, the global mean BII magnitude exhibits pronounced latitudinal and climatic heterogeneity, with higher values observed in less human-impacted regions. Second, biodiversity trends display contrasting trajectories between areas of differing baseline intactness—regions with initially low biodiversity (BII < 0.50) show recovery potential (−0.007 ± 0.021 decade⁻¹), while high-biodiversity areas (BII > 0.90) face accelerated declines (0.002 ± 0.012 decade⁻¹). Third, continental and climatic disparities are striking: Europe and temperate zones demonstrate stabilizing trends, whereas tropical and polar regions experience marked deterioration. Fourth, climate variables, particularly precipitation seasonality (BIO15) and mean temperature of the coldest quarter (BIO11), show strong negative correlations with the BII trend, indicating climate-linked declines while exhibiting minimal influence on baseline BII magnitude. This study has the potential to help develop more efficient sustainable practices and behaviors to mitigate biodiversity disparities and achieve sustainable development goals.

Global climate change and human activities are significant threats to biodiversity, contributing to the endangerment of approximately 41% of amphibian species worldwide. In this study, we applied field survey methods, the MaxEnt model, and integrated climate and human activity data to predict potential changes in the diversity and distribution of amphibian species in Huangshan Mountain, China. In this study, we have found 23 amphibian species, belonging to two orders, eight families, and 18 genera. The MaxEnt models showed that the distance from farmland (contributing 26.2%), shrubs (15.6%), and waterbodies (10.6%), as well as the NDVI (Normalized Difference Vegetation Index) (10.1%), significantly influence species distribution and diversity, suggesting that amphibian species prefer habitats with lower levels of human disturbance. Our models also showed that Bio3 (isothermal) (8.9%) and Bio8 (mean temperature of wettest quarter) (8.6%) have a significant impact on the species distribution and diversity, suggesting that amphibians are influenced by temperature and humidity. Our field survey showed that seasonal variation in amphibian diversity revealed significant correlations between climatic factors. Specifically, amphibian species diversity was positively correlated with wind speed, soil moisture, and rainfall (p < 0.05), while amphibian abundance was significantly linked to soil temperature, soil moisture, and rainfall (p < 0.05). These findings underscore the critical role of both climatic conditions and habitat structure in shaping amphibian populations and their distribution in Huangshan Mountain. Therefore, local management authorities should continue to monitor the marginal areas of the region, taking into account key human disturbances and climatic factors that favor the formation of amphibian diversity hotspots. Protective buffer zones should be established to provide effective refuges for amphibians.