Phosphorus mitigation remains critical in water protection: A review and meta-analysis from one of China's most eutrophicated lakes

Kai Yan; Zengwei Yuan; Stefanie Goldberg; Wei Gao; Anne Ostermann; Jianchu Xu; Fusuo Zhang; James Elser

doi:10.1016/j.scitotenv.2019.06.302

Phosphorus mitigation remains critical in water protection: A review and meta-analysis from one of China's most eutrophicated lakes

Sci Total Environ. 2019 Nov 1:689:1336-1347. doi: 10.1016/j.scitotenv.2019.06.302. Epub 2019 Jun 21.

Authors

Kai Yan¹, Zengwei Yuan², Stefanie Goldberg³, Wei Gao⁴, Anne Ostermann³, Jianchu Xu⁵, Fusuo Zhang⁶, James Elser⁷

Affiliations

¹ College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, Yunnan, China; Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.
² State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
³ Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; World Agroforestry Center, ICRAF East & Central Asia, Kunming 650201, China.
⁴ School of Ecology and Environmental Science, Yunnan University, Kunming 650091, China.
⁵ Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China; World Agroforestry Center, ICRAF East & Central Asia, Kunming 650201, China. Electronic address: jxu@mail.kib.ac.cn.
⁶ Center for Resources, Environment and Food Security, China Agricultural University, Key Laboratory of Plant-Soil Interactions, Ministry of Education, Beijing 100193, China.
⁷ School of Life Sciences, Arizona State University, Tempe, AZ, USA.

PMID: 31466170
DOI: 10.1016/j.scitotenv.2019.06.302

Abstract

The processes of urbanization and industrialization within geological phosphorus-rich mountains (GPMn) have resulted in water degradation within southwest China. Lake Dianchi, one of the most eutrophicated lakes in China, has epitomized this issue. Clear understandings of phosphorus (P) mitigation efforts, the evolution of P budgets, and possible risks in the Dianchi system will benefit future eutrophication control, providing valuable lessons for other plateau freshwater lakes. In this study, we applied systematic review methodology to investigate the above questions, and then compared the results with other lakes worldwide. Generally, meta-analytical approaches have indicated P levels remain a key factor in causing algal blooms. Post-2015, the P budget of the Dianchi system, especially in Caohai section, was modified. However, it's still experiencing high pressures from P enrichment (Caohai: 0.4 mg·l^-1; Waihai: 0.2 mg·l^-1). The flux of P in Dianchi remains high, both through the external P load (556 ton·a^-1), and an internal cycle (304 ton·a^-1 associated with the absorption, deposition and removal of algae biomass; and 380 ton·a^-1 associated with sediment exchange). Meanwhile, significant P retention has been observed in the lake, in particular within the Waihai section (211 ton·a^-1). Currently, water diversion (from external watersheds), sewage diversion, and sediment-dredging projects have benefited Dianchi. However, continuous urbanization and GPMn ecological degradation could introduce hundreds of tons of additional P, leading to subsequent algal blooms. Furthermore, beyond Lake Dianchi, other lakes and reservoirs in southwest China are facing similar issues regarding P mitigation, especially in GPMn regions, though corresponding knowledge is still limited. Therefore, effective and flexible sub-regional protection strategies and research related to external and internal P mitigations have become key requirements for Lake Dianchi management. Meanwhile, ecologically sensitive approaches to GPMn regions, as well as city development within basin and market driven treatments, should be incorporated into regional water source protection for southwest China.

Keywords: Bayesian hierarchical model; Geological phosphorus-rich mountains; Lake Dianchi; Markov chain Monte Carlo simulation; Phosphorus budget; Watershed management.

Publication types

Review