Synergistic interactions between detritivores disappear under reduced rainfall
Synergistic interactions between detritivores disappear under reduced rainfall
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DOI：
10.1101/2020.09.29.318592
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发表时间：
2020-10
期刊：
影响因子：
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通讯作者：
François‐Xavier Joly;Euan McAvoy;J. Subke
中科院分区：
文献类型：
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作者：
François‐Xavier Joly;Euan McAvoy;J. Subke
了解降雨模式改变对凋落物分解的影响，对于预测气候变化对大气CO2浓度的反馈效应至关重要。虽然它们对微生物分解的影响受到了相当大的关注，但它们对其他主要分解途径食草动物的凋落物破碎的影响在很大程度上仍未得到探索。特别是，目前还不清楚不同的食草动物物种及其相互作用如何对降雨量和频率的变化作出反应。为了填补这一知识空白，我们确定了两个食草动物物种（千足虫和等足类动物），单独和组合，对比降雨量和频率在温带森林凋落物分解的贡献。虽然降雨量和频率减半，表层土壤水分分别下降了7.8%和13.1%，无论是千足虫，也不等足虫驱动的分解受这些变化。与此相反，两种食草动物的组合驱动的分解是65.5%，高于预期的基础上的单种处理在高降雨量，但不变，甚至更低的降雨量下。这表明，虽然食草动物的活动是相对不敏感的降雨模式的变化，食草动物物种之间的大协同作用可能会消失在未来的降雨模式。因此，分解者之间的种间相互作用似乎是至关重要的，以评估分解的敏感性，改变降雨模式。
Understanding the consequences of altered rainfall patterns on litter decomposition is critical to predicting the feedback effect of climate change on atmospheric CO2 concentrations. While their effect on microbial decomposition received considerable attention, their effect on litter fragmentation by detritivores, the other dominant decomposition pathway, remains largely unexplored. Particularly, it remains unclear how different detritivore species and their interactions responds to changes in rainfall quantity and frequency. To fill this knowledge gap, we determined the contribution to litter decomposition of two detritivore species (millipede and isopod), separately and in combination, under contrasting rainfall quantity and frequency in a temperate forest. Although halving rainfall quantity and frequency decreased top-soil moisture by 7.8 and 13.1%, respectively, neither millipede-nor isopod-driven decomposition were affected by these changes. In contrast, decomposition driven by both detritivore species in combination was 65.5% higher than expected based on monospecific treatments under high rainfall quantity, but unchanged or even lower under low rainfall quantity. This indicate that while detritivore activity is relatively insensitive to changes in rainfall patterns, large synergistic interactions between detritivore species may disappear under future rainfall patterns. Incorporating interspecific interactions between decomposers thus seems critical to evaluate the sensitivity of decomposition to altered rainfall patterns.