Program Results

Introduction to the event

Previous studies have confirmed that species loss reduces ecological resilience, yet how environmental factors (such as rainfall, temperature, and nutrient variations) affect ecosystem functions and the mechanisms through which biodiversity supports ecological health have not been systematically elucidated. To address this scientific question, an international team led by Assistant Professor Chun-Wei Chang and Postdoctoral Researcher Wan-Hsuan Cheng from the Institute of Fisheries Science at National Taiwan University, in collaboration with the Research Center for Environmental Changes at Academia Sinica and Ryukoku University, Japan, utilized high-resolution, nine-year monitoring data from the Feitsui Reservoir for the first time. By systematically integrating 31 ecosystem function indicators related to the carbon cycle, they discovered that biodiversity consistently promotes carbon decomposition-related functions across all temporal scales.

Biodiversity plays a central role in maintaining ecosystem multifunctionality (EMF), but its specific role in natural systems has long been uncertain. This uncertainty arises because environmental drivers—such as precipitation, temperature, and phosphate—also collectively influence EMF, complicating the biodiversity-EMF relationship. Moreover, the impacts of these factors vary across interannual, seasonal, and short-term scales, exhibiting significant scale dependency.

Through biweekly sampling and analysis, the research team quantified microbial diversity, EMF (represented by 31 carbon utilization functions), and multiple environmental variables in a subtropical freshwater ecosystem. Cross-scale analyses revealed that biodiversity consistently enhances EMF across all temporal scales, while environmental drivers exert effects only at specific scales (short-term, seasonal, and interannual). Importantly, biodiversity acts as a key "environmental mediator"—it stabilizes ecological functioning by buffering the impacts of environmental fluctuations on EMF. For instance, when nutrients become limited in the environment, highly diverse microbial communities can self-regulate and optimize resource use strategies, thereby more efficiently utilizing scarce nutrients and maintaining ecosystem nutrient cycling and functional stability.

This study not only reveals biodiversity as a critical pillar supporting EMF maintenance across multiple temporal scales but also highlights the importance of conserving biodiversity for ecological health amid multifaceted environmental changes. The findings were published in August 2025 in Ecology Letters and received support from National Taiwan University, the Ministry of Education, the National Science and Technology Council, Academia Sinica, Ryukoku University, and the Japan Society for the Promotion of Science.

Reference:

Cheng, W. H., T. Miki, C. C. Lai, F. K. Shiah, C. Y. Ko, C. h. Hsieh, C. W. Chang*. (2025) Biodiversity consistently promotes ecosystem multifunctionality across multiple temporal scales in an aquatic microbial community. Ecology Letters 28:e70185. (Corresponding author)