DOI: 10.1007/s10533-015-0107-2
Scopus记录号: 2-s2.0-84930271884
论文题名: Distinct fungal and bacterial δ13C signatures as potential drivers of increasing δ13C of soil organic matter with depth
作者: Kohl L. ; Laganière J. ; Edwards K.A. ; Billings S.A. ; Morrill P.L. ; Van Biesen G. ; Ziegler S.E.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2015
卷: 124, 期: 2018-01-03 起始页码: 13
结束页码: 26
语种: 英语
英文关键词: 13C
; Necromass
; PLFA
; Podzols
; Soil microbial biomass
; Soil organic carbon
Scopus关键词: Bacteria (microorganisms)
; Fungi
英文摘要: Soil microbial biomass is a key source of soil organic carbon (SOC), and the increasing proportion of microbially derived SOC is thought to drive the enrichment of 13C during SOC decomposition. Yet, little is known about how the δ13C of soil microbial biomass differs across space or time, or with the composition of the microbial community. Variation in soil microbial δ13C may occur due to variation in substrates used by soil microorganisms, and variation in how different microorganisms synthesize biomass. Understanding these variations in soil microbial δ13C would enable more accurate interpretation of patterns in the δ13C of SOC. Here, we report the variation in δ13C values of individual phospholipid fatty acids (PLFA) within podzolic soils from mesic boreal forests characterized by steep decreases in fungal to bacterial (F:B) ratios. By comparing trends in δ13C of PLFA indicative of either fungi or bacteria to those PLFA common across both microbial groups, we tested the hypothesis that the enrichment of 13C in bacterial relative to fungal biomass represents a mechanism for the increase of bulk SOC δ13C with depth. We demonstrate that PLFA derived from fungi were consistently depleted in 13C (−40.1 to −30.6 ‰) relative to those derived from bacteria (−31.1 to −24.6 ‰), but unlike bulk SOC the δ13C of PLFA from either group did not vary significantly with depth. In contrast, the δ13C of PLFA produced by both fungi and bacteria, which represent the δ13C of soil microbial biomass as a whole, strongly increased with depth (increase of 7.6–8.4 ‰) and was negatively correlated with the fungi/(fungi + bacteria) ratio (R2 > 0.88). The steep increase of the δ13C of general PLFA with depth cannot be explained by an increase in the δ13C of either fungal or bacterial biomass alone since the PLFA indicative of those groups did not vary with depth. Instead, these data demonstrate that the increase in soil biomass δ13C with depth is driven by a change in the proportion of bacterial relative to fungal biomass. We suggest that the increased proportions of soil bacterial relative to fungal biomass with depth may represent an important mechanism contributing to increasing δ13CSOC with depth via contributions from ‘necromass’ to SOC. © 2015, Springer International Publishing Switzerland. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83491
Appears in Collections: 气候减缓与适应 气候变化事实与影响
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作者单位: Department of Earth Sciences, Memorial University, 300 Prince Philip Dr, St. John’s, NL, Canada; Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 Rue du P.E.P.S, Québec, QC, Canada; Natural Resources Canada, Canadian Forest Service, Atlantic Forestry Centre, 26 University Driv, Corner Brook, NL, Canada; Department of Ecology and Evolutionary Biology, Kansas Biological Survey, University of Kansas, 2101 Constant Ave, Lawrence, KS, United States
Recommended Citation:
Kohl L.,Laganière J.,Edwards K.A.,et al. Distinct fungal and bacterial δ13C signatures as potential drivers of increasing δ13C of soil organic matter with depth[J]. Biogeochemistry,2015-01-01,124(2018-01-03)