Schematic diagram of phosphorus circulation in forest ecosystems under warming background. Courtesy of Liu Juxiu’s team
The research team of Liu Juxiu of the National Field Scientific Observation and Research Station of Dinghushan Forest Ecosystem in Guangdong Province (hereinafter referred to as Dinghushan Station) based on the long-term natural warming platform of Dinghushan Station revealed the response mechanism of phosphorus circulation to climate warming. The study was recently published in Global Change Biology. Postdoctoral Fellow Lie Zhiyang is the first author of the paper, and Researcher Liu Juxiu is the corresponding author.
Phosphorus is often a limiting factor in the productivity of tropical forest ecosystems and may regulate the carbon cycle’s feedback to climate warming. However, in the past, the research on the elemental cycle of ecosystems by warming at home and abroad mainly focused on the carbon and nitrogen cycles, and most of them were concentrated in high latitudes, and the experimental cycle of warming was relatively short, and people’s understanding of the phosphorus cycle process under the background of warming in this region was still very limited.
Based on the long-term natural warming platform of Dinghushan Station, the researchers systematically assessed the effects of 7-year warming on the phosphorus cycle of tropical forest ecosystems. Studies have found that in phosphorus-deficient ecosystems, warming maintains plant-accelerated phosphorus demand. Enhanced plant phosphorus demand is primarily met by enhancing intra-ecosystem biochemical processes (e.g., plant phosphorus reabsorption, soil phosphorus mineralization, and phosphorus dissolution) to increase phosphorus supply, rather than by influencing phosphorus fluxes (e.g., litter phosphate mineralization and phosphorus runoff and leaching loss) and altering more energy-intensive pathways (e.g., enhancing fine roots and mycorrhizal fungi). The results suggest that previous short-term experiments or studies using a single phosphorus supply assessment method may have overestimated the negative feedback of phosphorus restrictions on ecosystem carbon stocks, at least in the context of short- or medium- to long-term warming.
The results of this study expand the understanding of the climate-driven nutrient demand/supply hypothesis, propose multiple phosphorus acquisition strategies to maintain high phosphorus demand in plants under warming background, expand the traditional assessment methods (only through available phosphorus to assess phosphorus supply) and theory (only through soil phosphorus mineralization to assess phosphorus conversion), provide important clues for improving the understanding of phosphorus regulation of tropical forest carbon sink function response to warming, and provide new ideas for the Urgently improved Earth system model.
The research work has been jointly funded by the National Natural Science Foundation of China, the Guangdong Provincial Key R&D Project and the China Postdoctoral Fund Project. (Source: China Science Daily Zhu Hanbin)
Related paper information:https://doi.org/10.1111/gcb.16194