Researchers from the Institute of Agricultural Resources and Regional Planning (IARRP) at the Chinese Academy of Agricultural Sciences (CAAS) have recently made groundbreaking progress in understanding how drought affects aboveground plant productivity. In collaboration with scientists from Colorado State University, Beijing Forestry University, and 126 institutions across 28 countries, the team explored how the interaction between drought intensity and duration jointly determines the fate of the world's fragile ecosystems. Their findings were published in Science. 

With the intensification and prolonged duration of drought events under climate change, their impacts on terrestrial ecosystem productivity have become a critical research focus. However, how drought intensity and duration interact globally to influence productivity has remained unclear.

Based on the Nutrient Network–Drought Network (NPK-Drought Network), the researchers quantified the combined effects of drought intensity and duration on aboveground plant productivity across 74 grassland and shrubland ecosystems worldwide. The study found that while some ecosystems showed a degree of "adaptation" to multi-year droughts, this resilience disappeared under extreme droughts (those occurring once in a century or rarer). Compared to the first year of drought, four consecutive years of extreme drought increased productivity loss by about 2.5 times. 

Their finding suggests that if future droughts become both longer and more intense, ecosystems may undergo fundamental shifts—from maintaining low but stable productivity during extended droughts to experiencing sharp productivity declines. The research provides crucial scientific evidence for predicting terrestrial ecosystem responses to drought under climate change and offers theoretical support for developing adaptive grassland management strategies.

Impact of drought duration on productivity under varying drought intensities

The study was  co-authored by Wu Honghui (Researcher) and Xu Chong (Postdoctoral Fellow) from the IARRP's Soil Fertility and Improvement Team, Yang Yadong (Researcher) from the Agricultural Layout and Regional Development Team, and Ke Yuguang (Ph.D.) from the Grassland Ecology and Remote Sensing Innovation Team. Yu Qiang (Researcher, now at Beijing Forestry University) served as the corresponding author.

The research was supported by the National Key R&D Program of China (2022YFE0128000, 2022YFF1300603), the National Natural Science Foundation of China (32171592, 32061123005), the National Key Laboratory of Efficient Utilization of Northern Arid and Semi-arid Cultivated Land, and the Key Laboratory of Cultivated Land Quality Monitoring and Evaluation, Ministry of Agriculture and Rural Affairs. It also received strong support from several national and regional field research stations, including those in Hulunbuir, Horqin, Xilingol, Urat, Nagqu, Ruoergai, Ningxia, Youyu, and Haibei.

Full article: https://www.science.org/doi/10.1126/science.ads8144