Species-specific effects of earthworms on microbial communities and the fate of litter-derived carbon
Species-specific effects of earthworms on microbial communities and the fate of litter-derived carbon
复制标题
DOI：
10.1016/j.soilbio.2016.06.004
复制
发表时间：
2016-09-01
影响因子：
9.7
通讯作者：
Buyer, Jeffrey S.
中科院分区：
文献类型：
--
作者：
Chang, Chih-Han;Szlavecz, Katalin;Buyer, Jeffrey S.
土壤呼吸是生物活动的替代物，在土壤碳循环中具有重要意义。土壤呼吸的异养组分主要由凋落叶和土壤有机质的微生物分解驱动，部分受资源可用性控制。在北美温带落叶林中，入侵的欧洲和亚洲蚯蚓通过其取食、挖洞和抛掷行为对土壤性质和资源有效性产生不同程度的影响，并可能通过调节微生物群落影响土壤呼吸的不同组分。通过在围隔实验中追踪C-13和N-15双富集凋落物中碳源进入土壤和CO2排放，验证了蚯蚓通过降低资源有效性和微生物生物量来抑制凋落物碳源土壤呼吸的假说，并进一步研究了蚯蚓对土壤呼吸的物种特异性影响是如何通过土壤微生物群落来介导的。我们发现，虽然蚯蚓一般对土壤呼吸总量没有影响，但Octolopyramidlacteum和红蚯蚓之间的相互作用具有显着的负非加性效应，可能是通过影响土壤中的厌氧微生物。此外，亚洲远环蚓、欧洲远环蚓和亚洲远环蚓均能降低凋落物碳源土壤呼吸。rubellus和北美本土种草（Escherenoides lonnbergi），而欧洲种草（O.乳汁磷脂脂肪酸（PLFA）分析和结构方程模型表明，而土壤细菌和真菌丰度的影响，通过微生物物种的身份，观察到的减少凋落物C-衍生的土壤呼吸不能完全解释微生物生物量的变化。我们将这些影响归因于蚯蚓诱导的聚集体形成，减少微生物转化的不稳定碳，和抗菌肽的活动，并得出结论，通过这四种植物影响凋落物来源的C和矿化的命运的机制是物种特异性的。(C)2016爱思唯尔有限公司版权所有。
Soil respiration is frequently measured as a surrogate for biological activities and is important in soil carbon cycling. The heterotrophic component of soil respiration is primarily driven by microbial decomposition of leaf litter and soil organic matter, and is partially controlled by resource availability. In North American temperate deciduous forests, invasive European and Asian earthworms are known to variously affect soil properties and resource availability through their feeding, burrowing, and casting behaviors, and may affect different components of soil respiration through modulating the microbial communities. By tracing litter-derived C from C-13 and N-15 double-enriched leaf litter into soil and CO2 efflux in a mesocosm experiment, we tested the hypothesis that earthworms inhibit litter C-derived soil respiration by reducing resource availability and microbial biomass, and further examined how species specific effects of earthworms on soil respiration are mediated by soil microbial community. We showed that while earthworms generally had no effect on total soil respiration, the interaction between Octolasion lacteum and Lumbricus rubellus had a significant negative non-additive effect, presumably through affecting anaerobic microsites in the soil. Moreover, litter C-derived soil respiration was reduced by the Asian Amynthas hilgendorfi, the European L. rubellus, and the North American native species Eisenoides lonnbergi, but not by the European species O. lacteum. Phospholipid fatty acid (PLFA) analysis and structural equation modeling indicated that while soil bacteria and fungi abundances were affected by earthworm species identities, the observed reduction of litter C-derived soil respiration could not be fully explained by changes in microbial biomass. We attributed these effects to earthworm-induced aggregate formation, reduction of microbial transformation of labile carbon, and antimicrobial peptide activities, and concluded that the mechanisms through which the four earthworm species affect the fate of litter derived C and its mineralization are species-specific. (C) 2016 Elsevier Ltd. All rights reserved.