skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Plant and microbial biomarkers suggest mechanisms of soil organic carbon accumulation in a Mojave Desert ecosystem under elevated CO 2

Abstract

We ireport on how properties of soil organic matter (SOM) were altered after 10 years exposure to elevated atmospheric CO 2 concentration ([CO 2]) in a Mojave Desert ecosystem, using plant and microbial biomarkers. We focused on roles of Larrea tridentata, the dominant evergreen shrub which form islands of fertility, and biological soil crusts which have extensive cover in plant interspace. Soils to 5 cm in depth were collected under L. tridentata and plant interspace, and biological soil crusts to 0.5 cm in depth under three cover types, Pleuraphis rigida, a C 4 grass, shrubs and plant interspace. Soil organic carbon contents were not significantly different between elevated and ambient [CO 2]. Yet, significantly higher abundance of n-alkanes, a major constituent of foliage wax material, occurred in the elevated compared to ambient [CO 2] plots in the soils collected under L. tridentata, but no such difference was found in the soils at plant interspace or the biological soil crusts. There was no critical difference in abundance of microbial phospholipid fatty acids between the CO 2 treatments in the soils of either cover types. However, neutral lipid fatty acid abundance was significantly higher under elevated than ambient [CO 2] in the soils undermore » L. tridentata, whereas no such significant difference was observed at plant interspace. These results emphasize important roles of the dominant shrubs in SOM formation under elevated [CO 2] in arid ecosystems. Elevated [CO 2] stimulated growth of L. tridentata in wet years, and aboveground litter deposition via senescence contributed to SOM formation in islands of fertility. In addition, elevated [CO 2] stimulated soil microbial turnover rates in rhizosphere of L. tridentata, which left more soil microbial necromass, a major SOM source. We concluded that responses of dominant shrubs to elevated [CO 2] can stimulate SOM formation in arid ecosystems, but biological soil crusts may have limited capacity.« less

Authors:
ORCiD logo [1];  [2]; ORCiD logo [3];  [4];  [2]
  1. Washington State Univ., Pullman, WA (United States); Algoma Univ., Sault Ste. Marie, ON (Canada)
  2. Washington State Univ., Pullman, WA (United States)
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  4. U.S. Geological Survey, Moab, UT (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE Office of Science (SC). Biological and Environmental Research (BER) (SC-23)
OSTI Identifier:
1512734
Report Number(s):
LA-UR-17-22346
Journal ID: ISSN 0038-0717
Grant/Contract Number:  
89233218CNA000001
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Soil Biology and Biochemistry
Additional Journal Information:
Journal Volume: 120; Journal Issue: C; Journal ID: ISSN 0038-0717
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
Biological Science; Free air CO2 enrichment (FACE); Mojave desert; Larrea tridentata; Biological soil crust; n-Alkanes; Phospholipid fatty acid and neutral lipid fatty acids

Citation Formats

Koyama, Akihiro, Harlow, Benjamin, Kuske, Cheryl R., Belnap, Jayne, and Evans, R. Dave. Plant and microbial biomarkers suggest mechanisms of soil organic carbon accumulation in a Mojave Desert ecosystem under elevated CO2. United States: N. p., 2018. Web. doi:10.1016/j.soilbio.2018.01.033.
Koyama, Akihiro, Harlow, Benjamin, Kuske, Cheryl R., Belnap, Jayne, & Evans, R. Dave. Plant and microbial biomarkers suggest mechanisms of soil organic carbon accumulation in a Mojave Desert ecosystem under elevated CO2. United States. doi:10.1016/j.soilbio.2018.01.033.
Koyama, Akihiro, Harlow, Benjamin, Kuske, Cheryl R., Belnap, Jayne, and Evans, R. Dave. Thu . "Plant and microbial biomarkers suggest mechanisms of soil organic carbon accumulation in a Mojave Desert ecosystem under elevated CO2". United States. doi:10.1016/j.soilbio.2018.01.033. https://www.osti.gov/servlets/purl/1512734.
@article{osti_1512734,
title = {Plant and microbial biomarkers suggest mechanisms of soil organic carbon accumulation in a Mojave Desert ecosystem under elevated CO2},
author = {Koyama, Akihiro and Harlow, Benjamin and Kuske, Cheryl R. and Belnap, Jayne and Evans, R. Dave},
abstractNote = {We ireport on how properties of soil organic matter (SOM) were altered after 10 years exposure to elevated atmospheric CO2 concentration ([CO2]) in a Mojave Desert ecosystem, using plant and microbial biomarkers. We focused on roles of Larrea tridentata, the dominant evergreen shrub which form islands of fertility, and biological soil crusts which have extensive cover in plant interspace. Soils to 5 cm in depth were collected under L. tridentata and plant interspace, and biological soil crusts to 0.5 cm in depth under three cover types, Pleuraphis rigida, a C4 grass, shrubs and plant interspace. Soil organic carbon contents were not significantly different between elevated and ambient [CO2]. Yet, significantly higher abundance of n-alkanes, a major constituent of foliage wax material, occurred in the elevated compared to ambient [CO2] plots in the soils collected under L. tridentata, but no such difference was found in the soils at plant interspace or the biological soil crusts. There was no critical difference in abundance of microbial phospholipid fatty acids between the CO2 treatments in the soils of either cover types. However, neutral lipid fatty acid abundance was significantly higher under elevated than ambient [CO2] in the soils under L. tridentata, whereas no such significant difference was observed at plant interspace. These results emphasize important roles of the dominant shrubs in SOM formation under elevated [CO2] in arid ecosystems. Elevated [CO2] stimulated growth of L. tridentata in wet years, and aboveground litter deposition via senescence contributed to SOM formation in islands of fertility. In addition, elevated [CO2] stimulated soil microbial turnover rates in rhizosphere of L. tridentata, which left more soil microbial necromass, a major SOM source. We concluded that responses of dominant shrubs to elevated [CO2] can stimulate SOM formation in arid ecosystems, but biological soil crusts may have limited capacity.},
doi = {10.1016/j.soilbio.2018.01.033},
journal = {Soil Biology and Biochemistry},
issn = {0038-0717},
number = C,
volume = 120,
place = {United States},
year = {2018},
month = {2}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Save / Share: