Underestimating the magnitude of global lake carbon (C) production undermines the evaluation of the terrestrial ecosystem's C sink, which is key to achieving global C balance. Quantifying the potential response of lake net ecosystem productivity (NEP) and associated C production capacity to human activities is critical for evaluating the Earth's C balance. Here, we reveal global spatiotemporal dynamics of lake C production over 20 years across different continents and climate zones, highlighting the role of anthropogenic activity as a driving mechanism. We estimated lake C production using phytoplankton primary productivity from the surface to the estimated euphotic depth (PPeu) based on chlorophyll-a (Chl-a) content. Economic development has significantly contributed to increases in global lake temperatures and total phosphorus concentrations. This has stimulated increases in annual lake C production, rising from 1.53 Pg C yr−1 in the 2000s to 1.95 Pg C yr−1 in the 2010s. Concurrently, lakes with higher total phosphorus (TP) concentrations (≥ 0.6 mg L−1) exhibited significantly greater PPeu values of 3.16 g C m−2 d−1, compared to lakes with lower TP concentrations (≤ 0.1 mg L−1), which showed 1.50 g C m−2 d−1. Although lake water TP concentrations can reach up to 1 mg L−1, the critical TP concentration (TPc) at which global lake PPeu peaks at 4 to 6 g C m−2 d−1 is approximately 0.5 mg L−1. Exploiting the C sink potential of lakes requires understanding the environmental factors that control metabolic processes; however, there is a lack of effective monitoring and evaluation of the highly heterogeneous and diverse autotrophic C fixation processes in inland waters.

中文翻译：

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营养物富集和气候变暖推动全球湖泊生态系统的碳生产


低估全球湖泊碳 （C） 产生的规模会破坏对陆地生态系统碳汇的评估，而碳汇是实现全球碳平衡的关键。量化湖泊净生态系统生产力 （NEP） 和相关碳生产能力对人类活动的潜在响应对于评估地球碳平衡至关重要。在这里，我们揭示了不同大陆和气候区 20 年来 C 湖生产的全球时空动态，突出了人为活动作为驱动机制的作用。我们使用浮游植物初级生产力估计了 C 湖的产量，该生产力基于叶绿素 a （Chl-a） 含量的估计真光深度 （PPeu）。经济发展极大地促进了全球湖泊温度和总磷浓度的升高。这刺激了湖 C 年产量的增加，从 2000 年代的 1.53 Pg C yr-1 上升到 2010 年代的 1.95 Pg C yr-1。同时，总磷 （TP） 浓度较高 （≥ 0.6 mg L-1） 的湖泊表现出显著更高的 PPeu 值，为 3.16 g C m-2 d-1，而 TP 浓度较低 （≤ 0.1 mg L-1） 的湖泊显示 1.50 g C m-2 d-1。尽管湖水 TP 浓度可高达 1 mg L-1，但全球湖泊 PPeu 在 4 至 6 g C m-2 d-1 达到峰值的临界 TP 浓度 （TPc） 约为 0.5 mg L-1。开发湖泊的 C 汇潜力需要了解控制代谢过程的环境因素;然而，缺乏对内陆水域高度异质和多样化的自养 C 固定过程的有效监测和评估。