Mixotrophic microbes create carbon tipping points under warming
Mixotrophic microbes create carbon tipping points under warming
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DOI：
10.1111/1365-2435.14350
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发表时间：
2023-05
影响因子：
5.2
通讯作者：
Daniel J. Wieczynski;H. Moeller;Jean P. Gibert
中科院分区：
文献类型：
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作者：
Daniel J. Wieczynski;H. Moeller;Jean P. Gibert
1. 混合营养菌无处不在，是微生物食物网不可或缺的一部分，但它们对更广泛生态系统的动态和功能的影响在很大程度上尚未解决。2. 在这里，我们发现混合营养产生了一种独特的食物网模块，它表现出不同寻常的生态动态，对变暖下的碳通量产生了惊人的影响。我们开发了一个可推广的混合营养食物网模块模型，该模型包含光养和吞噬之间的动态切换，以评估生态动力学和总系统CO 2通量。3. 我们发现，变暖使混合营养系统在不同的稳定碳状态之间切换，包括光养型碳汇状态、吞噬型碳源状态以及在这两种状态之间循环。此外，变暖总是将这种混合营养系统从碳汇状态转变为碳源状态，但营养物质的协调增加可以消除这种转变的早期预警信号，并扩大滞后性。4. 这表明，在气候变暖的情况下，混合营养体可以产生关键的碳临界点，当与营养水平增加相结合时，这种临界点将更加突然和不可逆，对面临快速全球变化的生态系统功能具有广泛的影响。
1. Mixotrophs are ubiquitous and integral to microbial food webs, but their impacts on the dynamics and functioning of broader ecosystems are largely unresolved. 2. Here, we show that mixotrophy produces a unique type of food web module that exhibits unusual ecological dynamics, with surprising consequences for carbon flux under warming. We develop a generalizable model of a mixotrophic food web module that incorporates dynamic switching between phototrophy and phago-trophy to assess ecological dynamics and total system CO 2 flux. 3. We find that warming switches mixotrophic systems between alternative stable carbon states— including a phototrophy-dominant carbon sink state, a phagotrophy-dominant carbon source state and cycling between these two. Moreover, warming always shifts this mixotrophic system from a carbon sink state to a carbon source state, but a coordinated increase in nutrients can erase early warning signals of this transition and expand hysteresis. 4. This suggests that mixotrophs can generate critical carbon tipping points under warming that will be more abrupt and less reversible when combined with increased nutrient levels, having widespread implications for ecosystem functioning in the face of rapid global change.