Evolution of watershed phosphorus buffering capacity and its response to land-use change in Poyang Lake basin, China

作者：Zhong, Wenjun; Dong, Yue; Wang, Shengrui^*; Ni, Zhaokui; Wu, Daishe; Yang, Yulong; Deng, Zeyu

来源：JOURNAL OF CLEANER PRODUCTION, 2022, 365: 132606.

DOI：10.1016/j.jclepro.2022.132606

• Phosphorus
• Buffering
• Land-use
• Response
• Threshold
• Wetland

The watershed buffering capacity is an important pivot to regulate phosphorus (P) pressure in aquatic environment, and land use is a key factor for its regulation. However, the response mechanism of buffer capacity to land use change remains unknown. Based on the variation of "buffering capacity index " in the Poyang Lake basin from 1990 to 2019, the mechanism of their response relationship was revealed via quantifying watershed P retention threshold and P removal process in different landscapes. Results showed that the watershed P buffering capacity was significantly affected by the scale of landscape subject to certain conditions of net anthropogenic P inputs (NAPI) in the Poyang Lake basin. The decreases in agricultural land, grassland and wetland and the increase of artificial land jointly explained 66.9% of watershed P buffering capacity decrease before accumulative P retention reached the threshold. The contribution of land use to watershed P buffering capacity change decreased to 53.8% when the P retention exceeded the threshold. Decreasing in watershed P buffering capacity was closely related to the increase of P loss in cultivated land, and wetland P removal provided an optimized direction for restoring the watershed buffering capacity. The findings reinforce the understanding of P hysteresis on watershed environment, and provide a policy basis for developing sustainable P management and pollution control from the perspective of optimizing land-use.

• 单位
  Nanchang University