Integrative assessment of the effects of shrub coverage on soil respiration in a tundra ecosystem
Integrative assessment of the effects of shrub coverage on soil respiration in a tundra ecosystem
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苔原生态系统中灌木覆盖对土壤呼吸影响的综合评估
DOI：
10.1016/j.polar.2020.100562
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发表时间：
2021
期刊：
影响因子：
1.8
通讯作者：
Mori Akira S.
中科院分区：
文献类型：
--
作者：
Masumoto Shota;Kitagawa Ryo;Nishizawa Keita;Osono Takashi;Hasegawa Motohiro;Iimura Yasuo;Matsuoka Shunsuke;Kaneko Ryo;Uchida Masaki;Mori Akira S.
在气候变暖的情况下，预计苔原生态系统中的灌木侵蚀和土壤呼吸 (SR) 将会增加，但对于局部范围内灌木与 SR 之间的潜在因果关系知之甚少。这两种现象之间存在多种复杂的地下过程，整合在逻辑上是困难的。我们的研究旨在使用结构方程模型 (SEM) 识别和整合多个地下过程，以阐明灌木覆盖对 SR 的影响。结果表明，灌木覆盖通过根生物量、真菌群落组成和土壤温度增强 SR。扫描电镜还揭示了这些土壤因素之间相互作用的潜在间接影响。与异养呼吸相关的土壤因素通过因素之间更复杂的相互作用影响 SR。然而，自养呼吸相关因素和异养呼吸相关因素对 SR 的总效应大小相似，这表明 SR 随灌木覆盖度的增加不太可能是由于土壤有机质的减少造成的。
Shrub encroachment and soil respiration (SR) are predicted to increase in the tundra ecosystem under climate warming, but little is known regarding potential causal relationships between shrubs and SR at a local scale. Multiple and complex belowground processes exist between the two phenomena, and consolidation is logistically difficult. Our study aimed to identify and integrate multiple belowground processes to elucidate the impact of shrub coverage on SR, using structural equation modeling (SEM). Results indicated that shrub coverage enhanced SR through root biomass, fungal community composition and soil temperature. SEM also revealed a potential indirect effect via interactions among those soil factors. Soil factors relating heterotrophic respiration affected on SR through more complex interaction among the factors. However, total effect sizes on SR were similar between factors relating autotrophic respiration and that relating heterotrophic respiration, suggesting that SR increases with shrub coverage would be unlikely to result from decreases in soil organic matter.