A research team led by the South China Botanical Garden of the Chinese Academy of Sciences, in collaboration with multiple domestic and international research institutions, has made progress in investigating forest diversity patterns across China. The findings were published in Nature Ecology & Evolution on December 2.
China is recognized by Conservation International as one of the world's 17 megadiverse countries. To effectively meet its commitments under the Kunming-Montreal Global Biodiversity Framework, it is crucial for China to clarify the fine-scale spatial patterns and future trends of multidimensional forest diversity as well as the driving mechanisms of this process.
Species richness and structural diversity are two fundamental dimensions of forest diversity, each making unique and complementary contributions to biodiversity conservation and carbon sequestration. However, the scarcity of spatially representative vegetation plot data has hindered efforts to understand the fine-scale patterns and drivers of these two diversity metrics in China's forests.
To address this gap, the research team analyzed field measurement data from over 300,000 individual trees across nearly 3,400 forest plots. Leveraging this comprehensive dataset, the researchers developed the first high-resolution maps showing the fine-scale spatial patterns of tree species richness and structural diversity in China's natural forests.
The study revealed that the two diversity dimensions are shaped by distinct mechanisms. Precipitation seasonality emerged as the primary predictor of tree species richness: Regions with highly uneven intra-annual precipitation typically support fewer tree species, since most woody plants exhibit strong climatic niche conservatism and limited physiological tolerance to large fluctuations in water availability. In contrast, forest age is the leading driver of structural diversity, since older forests tend to develop multilayered canopies with a higher abundance of shade-tolerant species.
Projections under future climate scenarios indicate that by 2100, fine-scale species richness could increase by approximately 36% and structural diversity by around 27%, driven by ongoing forest succession and increased precipitation. These findings provide crucial data for advancing the goals of the Kunming-Montreal Global Biodiversity Framework and offer valuable scientific guidance for refining forest conservation and management strategies.
The researchers emphasized the need to comprehensively assess the opportunities and challenges posed by future changes in forest biodiversity. On the one hand, increased diversity can enhance forest ecosystem stability and carbon sequestration capacity; on the other, intensified interspecific competition may exert additional pressure on rare and endangered species. Strengthening both in situ and ex situ conservation of threatened taxa is therefore essential to balance overall biodiversity gains with the protection of key species.
