College of Water Sciences, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Environmental Criteria and Risk Assessment, National Engineering Laboratory of Lake Water Pollution Control and Ecological Restoration Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
State Key Laboratory of Environmental Criteria and Risk Assessment, National Engineering Laboratory of Lake Water Pollution Control and Ecological Restoration Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
J Environ Sci (China). 2023 Jul;129:16-29. doi: 10.1016/j.jes.2022.09.016. Epub 2022 Sep 26.
Due to significant differences in biotic and abiotic properties of soils compared to those of sediments, the predicted underlying microbe-mediated mechanisms of soil carbon emissions in response to warming may not be applicable for estimating similar emissions from inland water sediments. We addressed this issue by incubating different types of sediments, (including lake, small river, and pond sediments) collected from 36 sites across the Yangtze River basin, under short-term experimental warming to explore the effects of climate warming on sediment carbon emission and the underlying microbe-mediated mechanisms. Our results indicated that under climate warming CO emissions were affected more than CH emissions, and that pond sediments may yield a greater relative contribution of CO to total carbon emissions than lake and river sediments. Warming-induced CO and CH increases involve different microbe-mediated mechanisms; Warming-induced sediment CO emissions were predicted to be directly positively driven by microbial community network modularity, which was significantly negatively affected by the quality and quantity of organic carbon and warming-induced variations in dissolved oxygen, Conversely, warming-induced sediment CH emissions were predicted to be directly positively driven by microbial community network complexity, which was significantly negatively affected by warming-induced variations in pH. Our findings suggest that biotic and abiotic drivers for sediment CO and CH emissions in response to climate warming should be considered separately when predicting sediment organic carbon decomposition dynamics resulting from climate change.
由于土壤的生物和非生物特性与沉积物有很大的不同，因此预测土壤碳排放对变暖的潜在微生物介导机制可能不适用于估算内陆水沉积物的类似排放。我们通过在短期实验变暖下孵育来自长江流域 36 个地点的不同类型沉积物（包括湖泊、小河和池塘沉积物）来解决这个问题，以探讨气候变暖对沉积物碳排放的影响和潜在的微生物介导机制。我们的结果表明，在气候变暖下，CO 排放比 CH 排放受影响更大，并且池塘沉积物可能比湖泊和河流沉积物对总碳排放量产生更大的 CO 相对贡献。变暖引起的 CO 和 CH 增加涉及不同的微生物介导机制；变暖引起的沉积物 CO 排放被预测直接受到微生物群落网络模块性的正向驱动，而微生物群落网络模块性受到有机碳的质量和数量以及溶解氧的变暖诱导变化的显著负面影响。相反，变暖引起的沉积物 CH 排放被预测直接受到微生物群落网络复杂性的正向驱动，而微生物群落网络复杂性受到 pH 值的变暖诱导变化的显著负面影响。我们的研究结果表明，在预测气候变化引起的沉积物有机碳分解动力学时，应该分别考虑生物和非生物因素对沉积物 CO 和 CH 排放的驱动作用。
