Schwarz Benjamin, Barnes Andrew D, Thakur Madhav P, Brose Ulrich, Ciobanu Marcel, Reich Peter B, Rich Roy L, Rosenbaum Benjamin, Stefanski Artur, Eisenhauer Nico
Institute of Ecology, Friedrich-Schiller-University Jena, Dornburger Str. 159, 07743 Jena, Germany.
Biometry and Environmental System Analysis, Albert-Ludwigs-University Freiburg, Tennenbacher Str. 4, 79106 Freiburg, Germany.
Nat Clim Chang. 2017 Dec;7(12):895-900. doi: 10.1038/s41558-017-0002-z. Epub 2017 Nov 6.
Climate warming is predicted to alter the structure, stability, and functioning of food webs1-5. Yet, despite the importance of soil food webs for energy and nutrient turnover in terrestrial ecosystems, warming effects on these food webs-particularly in combination with other global change drivers-are largely unknown. Here, we present results from two complementary field experiments testing the interactive effects of warming with forest canopy disturbance and drought on energy fluxes in boreal-temperate ecotonal forest soil food webs. The first experiment applied a simultaneous above- and belowground warming treatment (ambient, +1.7°C, +3.4°C) to closed canopy and recently clear-cut forest, simulating common forest disturbance6. The second experiment crossed warming with a summer drought treatment (-40% rainfall) in the clear-cut habitats. We show that warming reduces energy fluxes to microbes, while forest canopy disturbance and drought facilitates warming-induced increases in energy flux to higher trophic levels and exacerbates reductions in energy flux to microbes, respectively. Contrary to expectations, we find no change in whole-network resilience to perturbations, but significant losses of ecosystem functioning. Warming thus interacts with forest disturbance and drought, shaping the energetic structure of soil food webs and threatening the provisioning of multiple ecosystem functions in boreal-temperate ecotonal forests.
据预测,气候变暖将改变食物网的结构、稳定性和功能1-5。然而,尽管土壤食物网对陆地生态系统中的能量和养分周转至关重要,但变暖对这些食物网的影响——尤其是与其他全球变化驱动因素相结合时——在很大程度上仍不为人知。在此,我们展示了两个互补的田间试验结果,这些试验测试了变暖与森林冠层干扰和干旱对北方-温带过渡森林土壤食物网能量通量的交互作用。第一个试验对封闭冠层森林和近期皆伐森林同时进行了地上和地下变暖处理(环境温度、+1.7°C、+3.4°C),模拟常见的森林干扰6。第二个试验在皆伐栖息地将变暖与夏季干旱处理(降雨减少40%)相结合。我们发现,变暖会减少向微生物的能量通量,而森林冠层干扰和干旱分别促进了变暖导致的向较高营养级的能量通量增加,并加剧了向微生物的能量通量减少。与预期相反,我们发现整个网络对扰动的恢复力没有变化,但生态系统功能出现了显著损失。因此,变暖与森林干扰和干旱相互作用,塑造了土壤食物网的能量结构,并威胁到北方-温带过渡森林中多种生态系统功能的提供。