Advanced search
1 file | 610.00 KB

Short-term carbon input increases microbial nitrogen demand, but not microbial nitrogen mining, in a set of boreal forest soils

(2017) BIOGEOCHEMISTRY. 136(3). p.261-278
Author
Organization
Abstract
Rising carbon dioxide (CO2) concentrations and temperatures are expected to stimulate plant productivity and ecosystem C sequestration, but these effects require a concurrent increase in N availability for plants. Plants might indirectly promote N availability as they release organic C into the soil (e.g., by root exudation) that can increase microbial soil organic matter (SOM) decomposition ("priming effect"), and possibly the enzymatic breakdown of N-rich polymers, such as proteins, into bio-available units ("N mining"). We tested the adjustment of protein depolymerization to changing soil C and N availability in a laboratory experiment. We added easily available C or N sources to six boreal forest soils, and determined soil organic C mineralization, gross protein depolymerization and gross ammonification rates (using N-15 pool dilution assays), and potential extracellular enzyme activities after 1 week of incubation. Added C sources were C-13-labelled to distinguish substrate from soil derived C mineralization. Observed effects reflect short-term adaptations of non-symbiotic soil microorganisms to increased C or N availability. Although C input promoted microbial growth and N demand, we did not find indicators of increased N mobilization from SOM polymers, given that none of the soils showed a significant increase in protein depolymerization, and only one soil showed a significant increase in N-targeting enzymes. Instead, our findings suggest that microorganisms immobilized the already available N more efficiently, as indicated by decreased ammonification and inorganic N concentrations. Likewise, although N input stimulated ammonification, we found no significant effect on protein depolymerization. Although our findings do not rule out in general that higher plant-soil C allocation can promote microbial N mining, they suggest that such an effect can be counteracted, at least in the short term, by increased microbial N immobilization, further aggravating plant N limitation.
Keywords
Boreal forest, Priming, Microbial N mining, Organic N, Protein depolymerization, N mineralization, Ammonification, NET PRIMARY PRODUCTIVITY, ORGANIC-MATTER, ROOT EXUDATION, N AVAILABILITY, ELEVATED CO2, NUTRIENT AVAILABILITY, TEMPERATE FOREST, USE EFFICIENCY, DECOMPOSITION, RHIZOSPHERE

Downloads

  • Wild et al 2017 Biogeochemistry.pdf
    • full text
    • |
    • open access
    • |
    • PDF
    • |
    • 610.00 KB

Citation

Please use this url to cite or link to this publication:

Chicago
Wild, Birgit, Saeed Alaei, Per Bengtson, Samuel Bodé, Pascal Boeckx, Joerg Schnecker, Werner Mayerhofer, and Tobias Rutting. 2017. “Short-term Carbon Input Increases Microbial Nitrogen Demand, but Not Microbial Nitrogen Mining, in a Set of Boreal Forest Soils.” Biogeochemistry 136 (3): 261–278.
APA
Wild, B., Alaei, S., Bengtson, P., Bodé, S., Boeckx, P., Schnecker, J., Mayerhofer, W., et al. (2017). Short-term carbon input increases microbial nitrogen demand, but not microbial nitrogen mining, in a set of boreal forest soils. BIOGEOCHEMISTRY, 136(3), 261–278.
Vancouver
1.
Wild B, Alaei S, Bengtson P, Bodé S, Boeckx P, Schnecker J, et al. Short-term carbon input increases microbial nitrogen demand, but not microbial nitrogen mining, in a set of boreal forest soils. BIOGEOCHEMISTRY. 2017;136(3):261–78.
MLA
Wild, Birgit, Saeed Alaei, Per Bengtson, et al. “Short-term Carbon Input Increases Microbial Nitrogen Demand, but Not Microbial Nitrogen Mining, in a Set of Boreal Forest Soils.” BIOGEOCHEMISTRY 136.3 (2017): 261–278. Print.
@article{8547729,
  abstract     = {Rising carbon dioxide (CO2) concentrations and temperatures are expected to stimulate plant productivity and ecosystem C sequestration, but these effects require a concurrent increase in N availability for plants. Plants might indirectly promote N availability as they release organic C into the soil (e.g., by root exudation) that can increase microbial soil organic matter (SOM) decomposition ({\textacutedbl}priming effect{\textacutedbl}), and possibly the enzymatic breakdown of N-rich polymers, such as proteins, into bio-available units ({\textacutedbl}N mining{\textacutedbl}). We tested the adjustment of protein depolymerization to changing soil C and N availability in a laboratory experiment. We added easily available C or N sources to six boreal forest soils, and determined soil organic C mineralization, gross protein depolymerization and gross ammonification rates (using N-15 pool dilution assays), and potential extracellular enzyme activities after 1 week of incubation. Added C sources were C-13-labelled to distinguish substrate from soil derived C mineralization. Observed effects reflect short-term adaptations of non-symbiotic soil microorganisms to increased C or N availability. Although C input promoted microbial growth and N demand, we did not find indicators of increased N mobilization from SOM polymers, given that none of the soils showed a significant increase in protein depolymerization, and only one soil showed a significant increase in N-targeting enzymes. Instead, our findings suggest that microorganisms immobilized the already available N more efficiently, as indicated by decreased ammonification and inorganic N concentrations. Likewise, although N input stimulated ammonification, we found no significant effect on protein depolymerization. Although our findings do not rule out in general that higher plant-soil C allocation can promote microbial N mining, they suggest that such an effect can be counteracted, at least in the short term, by increased microbial N immobilization, further aggravating plant N limitation.},
  author       = {Wild, Birgit and Alaei, Saeed and Bengtson, Per and Bod{\'e}, Samuel and Boeckx, Pascal and Schnecker, Joerg and Mayerhofer, Werner and Rutting, Tobias},
  issn         = {0168-2563},
  journal      = {BIOGEOCHEMISTRY},
  keyword      = {Boreal forest,Priming,Microbial N mining,Organic N,Protein depolymerization,N mineralization,Ammonification,NET PRIMARY PRODUCTIVITY,ORGANIC-MATTER,ROOT EXUDATION,N AVAILABILITY,ELEVATED CO2,NUTRIENT AVAILABILITY,TEMPERATE FOREST,USE EFFICIENCY,DECOMPOSITION,RHIZOSPHERE},
  language     = {eng},
  number       = {3},
  pages        = {261--278},
  title        = {Short-term carbon input increases microbial nitrogen demand, but not microbial nitrogen mining, in a set of boreal forest soils},
  url          = {http://dx.doi.org/10.1007/s10533-017-0391-0},
  volume       = {136},
  year         = {2017},
}

Altmetric
View in Altmetric
Web of Science
Times cited: