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| Main Authors: | , , , , , , , , , , |
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| Format: | Artículo científico |
| Language: | en |
| Published: |
Water research
2025
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| Subjects: | |
| Online Access: | https://pubmed.ncbi.nlm.nih.gov/39454273/ |
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Table of Contents:
- Epilimnetic oligotrophication increases contribution of oxic methane production to atmospheric methane flux from stratified lakes. Xun, Fan Feng, Muhua Zhao, Cheng Luo, Wenlei Han, Xiaotong Ci, Zhen Yin, Yifan Wang, Rong Wu, Qinglong L Grossart, Hans-Peter Xing, Peng Methane Lakes Atmosphere Phosphorus Although considerable attention has been paid to the effects of eutrophication on aquatic methane (CH) emissions to the atmosphere, the ecosystem-level effects of oligotrophication/re-oligotrophication on aquatic CH production and subsequent ecological responses remain to be elucidated. It has been hypothesized that dissolved inorganic phosphorus (DIP)-deficient conditions drive the ecosystem to utilize poorly bioavailable organic phosphorus for biomass formation, thereby generating CH as a by-product. To test this hypothesis, a mass balance approach was used to estimate in situ oxic methane production (OMP) in an oligotrophic, deep Lake Fuxian. The isotopic signature of dissolved C-CH, the potential substrates for OMP, and the phnJ/phnD genes associated with microbial demethylation of organic phosphorus compounds were analyzed. Our results indicate that CH accumulation was maximal in the surface mixed layer (SML, i.e., Epilimnion) during lake stratification, and ∼ 86 % of the total CH flux to the atmosphere was due to OMP. Decomposition of methylphosphonate (MPn) by Alphaproteobacteria (genera Sphingomonas and Mesorhizobium) contributed significantly to OMP. Furthermore, water temperature (Temp), chlorophyll a (Chla), and DIP were the most critical predictors of water OMP potential. Meta-analysis of currently available global data showed that OMP had a negative exponential distribution with DIP (OMP = 2.0 e, R = 0.57, p < 0.05). DIP concentrations below a threshold of 3.40 ∼ 9.35 μg P L triggered OMP processes and increased the atmospheric CH emissions. Under future warming scenarios, stratification and catchment management induced oligotrophication or re-oligotrophication may systematically affect the biogeochemical cycling of phosphorus and the OMP contribution to CH emission in stratified lakes.