Impacts of core rotation, defaunation and nitrogen addition on arbuscular mycorrhizal fungi, microorganisms and microarthropods in a tropical montane rainforest
Impacts of core rotation, defaunation and nitrogen addition on arbuscular mycorrhizal fungi, microorganisms and microarthropods in a tropical montane rainforest
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DOI：
10.1007/s42965-019-00038-9
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发表时间：
2019-09
期刊：
影响因子：
1.6
通讯作者：
Laura M. Sánchez-Galindo;Tessa Camenzind;M. Maraun;S. Scheu
中科院分区：
文献类型：
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作者：
Laura M. Sánchez-Galindo;Tessa Camenzind;M. Maraun;S. Scheu
在热带生态系统中，丛枝菌根真菌（AMF）和其他生物之间的相互作用研究很少，但可能是重要的了解AMF的分解过程和养分循环中的作用。在这项研究中，我们使用向内生长的核心，定期轮换的核心，defaunation和氮添加AMF，微生物生物量和微型节肢动物的发酵/腐殖质（F/H）和凋落物（L）层的厄瓜多尔山地热带雨林的影响进行了调查。AMF在F/H层中显著降低（至初始的34%），而在L层中，它们在实验期间保持恒定。总体而言，微生物和微型节肢动物在很大程度上是独立的AMF菌丝和分泌物，然而，动物区系破坏强烈影响其社区的恢复。氮的添加提高了凋落物的质量，并有益地影响微生物群落，从而提高分解率，但不影响AMF丰度和微型节肢动物群落。这些发现表明，从植物到真菌菌丝体的碳供应的切断并没有通过F/H层中的资源转换来补偿，这强调了AMF与活根之间的密切联系。而在L层，AMF可能竞争腐食微生物的凋落物来源的资源在中间阶段的分解指向AMF的分解过程的间接贡献。总的来说，结果支持的观点，根源性资源是重要的燃料土壤食物网，但也表明，在研究的山地雨林中，这些资源只提供接近根，而不是通过AMF引导远离根。
In tropical ecosystems, interactions between arbuscular mycorrhizal fungi (AMF) and other organisms have been little studied, but may be of significant importance for understanding the role of AMF in decomposition processes and nutrient cycling. In this study, we used ingrowth cores to investigate the impacts of regular rotation of the cores, defaunation and nitrogen addition on AMF, microbial biomass and microarthropods in the fermentation/humus (F/H) and litter (L) layers of an Ecuadorian montane tropical rainforest. AMF were substantially reduced in the F/H layer (to 34% of initial), while in the L layer they remained constant during the experiment. Overall, microorganisms and microarthropods were largely independent of AMF hyphae and their exudates, however, defaunation strongly affected the recovery of their communities. Nitrogen addition increased the quality of litter material and beneficially affected microbial communities thereby increasing decomposition rates, but did not impact AMF abundance and microarthropod communities. These findings suggest that the cutoff of the carbon supply from the plant to the fungal mycelium was not compensated by switching resources in the F/H layer, underlining a strong association between AMF and living roots. While in the L layer, AMF likely competed with saprotrophic microorganisms for litter-derived resources at intermediate stages of decomposition pointing to indirect contributions of AMF to decomposition processes. Overall, the results support the view that root-derived resources are important in fueling soil food webs, but also indicate that in the studied montane rainforest these resources are only available close to roots and not channeled distant to roots via AMF.