Herbivory changes soil microbial communities and greenhouse gas fluxes in a high-latitude wetland
Herbivory changes soil microbial communities and greenhouse gas fluxes in a high-latitude wetland
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DOI：
10.1007/s00248-021-01733-8
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发表时间：
2021-03-22
影响因子：
3.6
通讯作者：
Waring, Bonnie G.
中科院分区：
文献类型：
--
作者：
Foley, Karen M.;Beard, Karen H.;Waring, Bonnie G.
食草动物对高纬度生态系统的温室气体通量有很大影响。例如，在阿拉斯加西部的Yukon-Kuskokwim（Y-K）三角洲，迁徙鹅放牧影响土壤二氧化碳（CO2）和甲烷（CH 4）通量的大小。然而，这种关系的潜在驱动因素尚不清楚，因为很少有研究系统地梳理草食动物影响土壤生物地球化学的过程。为了详细研究这些机制，我们进行了一个实验室孵育实验，以量化温室气体通量的变化，以响应草食动物在原地改变的三个参数：温度，土壤水分含量和养分输入。这些处理方法应用于在放牧草坪和附近未放牧栖息地收集的土壤，使我们能够评估微生物群落结构的变化如何影响观察到的反应。我们发现放牧和未放牧地区之间的真菌和原核生物群落组成的显着差异。在实验室培养实验中，CO2和CH 4通量增加温度，土壤水分，鹅粪除了，这表明放牧相关的变化，在土壤非生物环境可能会增加土壤碳的损失。然而，这些非生物驱动程序不足以解释土壤之间的通量变化与事先放牧。放牧和未放牧地区之间的微量气体通量的差异可能会导致从草食动物引起的非生物参数的变化和放牧相关的微生物群落结构的改变。我们的研究结果表明，草食动物和土壤微生物群落之间的关系可以介导快速变化的高纬度生态系统中的碳气候反馈。
Herbivory can have strong impacts on greenhouse gas fluxes in high-latitude ecosystems. For example, in the Yukon-Kuskokwim (Y-K) Delta in western Alaska, migratory goose grazing affects the magnitude of soil carbon dioxide (CO2) and methane (CH4) fluxes. However, the underlying drivers of this relationship are unclear, as few studies systematically tease apart the processes by which herbivores influences soil biogeochemistry. To examine these mechanisms in detail, we conducted a laboratory incubation experiment to quantify changes in greenhouse gas fluxes in response to three parameters altered by herbivores in situ: temperature, soil moisture content, and nutrient inputs. These treatments were applied to soils collected in grazing lawns and nearby ungrazed habitat, allowing us to assess how variation in microbial community structure influenced observed responses. We found pronounced differences in both fungal and prokaryotic community composition between grazed and ungrazed areas. In the laboratory incubation experiment, CO2 and CH4 fluxes increased with temperature, soil moisture, and goose fecal addition, suggesting that grazing-related changes in the soil abiotic environment may enhance soil C losses. Yet, these abiotic drivers were insufficient to explain variation in fluxes between soils with and without prior grazing. Differences in trace gas fluxes between grazed and ungrazed areas may result both from herbivore-induced shifts in abiotic parameters and grazing-related alterations in microbial community structure. Our findings suggest that relationships among herbivores and soil microbial communities could mediate carbon-climate feedbacks in rapidly changing high-latitude ecosystems.