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Investigating drivers of microbial activity and respiration in a forested bog

REWCASTLE, Kenna E. LU ; MOORE, Jessica A.M. ; HENNING, Jeremiah A. ; MAYES, Melanie A. ; PATTERSON, Courtney M. ; WANG, Gangsheng ; METCALFE, Daniel B. LU and CLASSEN, Aimée T. (2020) In Pedosphere 30(1). p.135-145
Abstract

Northern peatlands store nearly one-third of terrestrial carbon (C) stocks while covering only 3% of the global landmass; nevertheless, the drivers of C cycling in these often-waterlogged ecosystems are different from those that control C dynamics in upland forested soils. To explore how multiple abiotic and biotic characteristics of bogs interact to shape microbial activity in a northern, forested bog, we added a labile C tracer (13C-labeled starch) to in situ peat mesocosms and correlated heterotrophic respiration with natural variation in several microbial predictor variables, such as enzyme activity and microbial biomass, as well as with a suite of abiotic variables and proximity to vascular plants aboveground. We found... (More)

Northern peatlands store nearly one-third of terrestrial carbon (C) stocks while covering only 3% of the global landmass; nevertheless, the drivers of C cycling in these often-waterlogged ecosystems are different from those that control C dynamics in upland forested soils. To explore how multiple abiotic and biotic characteristics of bogs interact to shape microbial activity in a northern, forested bog, we added a labile C tracer (13C-labeled starch) to in situ peat mesocosms and correlated heterotrophic respiration with natural variation in several microbial predictor variables, such as enzyme activity and microbial biomass, as well as with a suite of abiotic variables and proximity to vascular plants aboveground. We found that peat moisture content was positively correlated with respiration and microbial activity, even when moisture levels exceeded total saturation, suggesting that access to organic matter substrates in drier environments may be limiting for microbial activity. Proximity to black spruce trees decreased total and labile heterotrophic respiration. This negative relationship may reflect the influence of tree evapotranspiration and peat shading effects; i.e., microbial activity may decline as peat dries and cools near trees. Here, we isolated the response of heterotrophic respiration to explore the variation in, and interactions among, multiple abiotic and biotic drivers that influence microbial activity. This approach allowed us to reveal the relative influence of individual drivers on C respiration in these globally important C sinks.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
carbon cycling, enzyme activity, heterotrophic respiration, labile carbon respiration, ombrotrophic bog, peat moisture, plant proximity, soil carbon sink
in
Pedosphere
volume
30
issue
1
pages
11 pages
publisher
Institute of Soil Science
external identifiers
  • scopus:85076829745
ISSN
1002-0160
DOI
10.1016/S1002-0160(19)60841-6
language
English
LU publication?
yes
id
549d84f3-21bc-4491-b222-43ab5f4d8f2a
date added to LUP
2020-01-03 10:21:51
date last changed
2020-02-12 10:19:05
@article{549d84f3-21bc-4491-b222-43ab5f4d8f2a,
  abstract     = {<p>Northern peatlands store nearly one-third of terrestrial carbon (C) stocks while covering only 3% of the global landmass; nevertheless, the drivers of C cycling in these often-waterlogged ecosystems are different from those that control C dynamics in upland forested soils. To explore how multiple abiotic and biotic characteristics of bogs interact to shape microbial activity in a northern, forested bog, we added a labile C tracer (<sup>13</sup>C-labeled starch) to in situ peat mesocosms and correlated heterotrophic respiration with natural variation in several microbial predictor variables, such as enzyme activity and microbial biomass, as well as with a suite of abiotic variables and proximity to vascular plants aboveground. We found that peat moisture content was positively correlated with respiration and microbial activity, even when moisture levels exceeded total saturation, suggesting that access to organic matter substrates in drier environments may be limiting for microbial activity. Proximity to black spruce trees decreased total and labile heterotrophic respiration. This negative relationship may reflect the influence of tree evapotranspiration and peat shading effects; i.e., microbial activity may decline as peat dries and cools near trees. Here, we isolated the response of heterotrophic respiration to explore the variation in, and interactions among, multiple abiotic and biotic drivers that influence microbial activity. This approach allowed us to reveal the relative influence of individual drivers on C respiration in these globally important C sinks.</p>},
  author       = {REWCASTLE, Kenna E. and MOORE, Jessica A.M. and HENNING, Jeremiah A. and MAYES, Melanie A. and PATTERSON, Courtney M. and WANG, Gangsheng and METCALFE, Daniel B. and CLASSEN, Aimée T.},
  issn         = {1002-0160},
  language     = {eng},
  number       = {1},
  pages        = {135--145},
  publisher    = {Institute of Soil Science},
  series       = {Pedosphere},
  title        = {Investigating drivers of microbial activity and respiration in a forested bog},
  url          = {http://dx.doi.org/10.1016/S1002-0160(19)60841-6},
  doi          = {10.1016/S1002-0160(19)60841-6},
  volume       = {30},
  year         = {2020},
}