Letter: Trophic interactions regulate peatland carbon cycling
Letter: Trophic interactions regulate peatland carbon cycling
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信件：营养相互作用调节泥炭地碳循环
DOI：
10.1111/ele.13697
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发表时间：
2021
期刊：
影响因子：
8.8
通讯作者：
Wang, ed., Shaopeng
中科院分区：
文献类型：
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作者：
Wyatt, Kevin H.;McCann, Kevin S.;Rober, Allison R.;Turetsky, Merritt R.;Wang, ed., Shaopeng
泥炭地是长期储存大气碳最有效的自然生态系统。我们对泥炭地碳循环的理解完全基于由低养分可用性调节的自下而上的控制。最近的研究表明，通过捕食者-猎物动态的自上而下的控制可以影响生态系统功能，但迄今为止尚未在泥炭地进行评估。在这里，我们使用了营养富集和营养级操纵的组合来检验营养物质可用性（自下而上）和捕食（自上而下）之间的相互作用影响泥炭地碳通量的假设。营养盐的升高刺激了细菌生物量和有机物的分解。在缺乏自上而下的监管的情况下，由更大分解驱动的二氧化碳（CO2）呼吸被藻类生产力的提高所抵消。食草动物通过去除藻类生物量加速CO2排放，而捕食者通过在营养级联中抑制食草动物间接减少CO2排放。这项研究表明，营养相互作用可以减轻CO2排放量与营养水平升高在北方泥炭地。
Peatlands are the most efficient natural ecosystems for long‐term storage of atmospheric carbon. Our understanding of peatland carbon cycling is based entirely on bottom‐up controls regulated by low nutrient availability. Recent studies have shown that top‐down controls through predator‐prey dynamics can influence ecosystem function, yet this has not been evaluated in peatlands to date. Here, we used a combination of nutrient enrichment and trophic‐level manipulation to test the hypothesis that interactions between nutrient availability (bottom‐up) and predation (top‐down) influence peatland carbon fluxes. Elevated nutrients stimulated bacterial biomass and organic matter decomposition. In the absence of top‐down regulation, carbon dioxide (CO2) respiration driven by greater decomposition was offset by elevated algal productivity. Herbivores accelerated CO2emissions by removing algal biomass, while predators indirectly reduced CO2emissions by muting herbivory in a trophic cascade. This study demonstrates that trophic interactions can mitigate CO2emissions associated with elevated nutrient levels in northern peatlands.