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Title: Soil moisture feedback mediates increased carbon storage under elevated CO{sub 2}

Abstract

After 3 years of exposure to elevated atmospheric CO{sub 2}, soil carbon increased in an extremely nutrient-limited serpentine grassland, but did not change in a more productive sandstone grassland. The increase in the serpentine shows the potential for nutrient-limited ecosystems to sequester carbon under elevated CO{sub 2}, but lack of response in the sandstone grassland suggests that increased soil carbon is not a general ecosystem response to elevated CO{sub 2}. Changes in soil moisture under elevated CO{sub 2} may explain the lack of response in the sandstone. Elevated CO{sub 2} decreases transpiration in plants from both ecosystems, but this consistently increases soil moisture only on the sandstone, where plants more strongly control evapotranspiration than on the serpentine. Increased soil moisture stimulates decomposition in these systems, potentially compensating for increased carbon input to soil under elevated CO{sub 2}, resulting in no net change in soil carbon. Increased soil moisture also stimulates plant growth directly and stimulates nitrogen mineralization and plant nitrogen uptake, potentially increasing plant production under elevated CO{sub 2}. We suggest that, in ecosystems with well developed plant canopies where increased soil moisture is likely under elevated CO{sub 2}, feedbacks through soil moisture may increase production, but may also constrainmore » increased carbon storage in soil.« less

Authors:
;  [1];  [2]
  1. Univ. of California, Berkeley, CA (United States)
  2. Univ. of Texas, Austin, TX (United States) [and others
Publication Date:
OSTI Identifier:
107107
Report Number(s):
CONF-9507129-
Journal ID: BECLAG; ISSN 0012-9623; TRN: 95:006512-0023
Resource Type:
Journal Article
Journal Name:
Bulletin of the Ecological Society of America
Additional Journal Information:
Journal Volume: 76; Journal Issue: 3; Conference: 80. anniversary of the transdisciplinary nature of ecology, Snowbird, UT (United States), 30 Jul - 3 Aug 1995; Other Information: PBD: Sep 1995
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; SOILS; CARBON SINKS; CHEMICAL COMPOSITION; MOISTURE; CARBON DIOXIDE; ENVIRONMENTAL EFFECTS; ECOLOGICAL CONCENTRATION

Citation Formats

Hungate, B.A., Chapin, F.S. III, and Jackson, R.B. Soil moisture feedback mediates increased carbon storage under elevated CO{sub 2}. United States: N. p., 1995. Web.
Hungate, B.A., Chapin, F.S. III, & Jackson, R.B. Soil moisture feedback mediates increased carbon storage under elevated CO{sub 2}. United States.
Hungate, B.A., Chapin, F.S. III, and Jackson, R.B. Fri . "Soil moisture feedback mediates increased carbon storage under elevated CO{sub 2}". United States.
@article{osti_107107,
title = {Soil moisture feedback mediates increased carbon storage under elevated CO{sub 2}},
author = {Hungate, B.A. and Chapin, F.S. III and Jackson, R.B.},
abstractNote = {After 3 years of exposure to elevated atmospheric CO{sub 2}, soil carbon increased in an extremely nutrient-limited serpentine grassland, but did not change in a more productive sandstone grassland. The increase in the serpentine shows the potential for nutrient-limited ecosystems to sequester carbon under elevated CO{sub 2}, but lack of response in the sandstone grassland suggests that increased soil carbon is not a general ecosystem response to elevated CO{sub 2}. Changes in soil moisture under elevated CO{sub 2} may explain the lack of response in the sandstone. Elevated CO{sub 2} decreases transpiration in plants from both ecosystems, but this consistently increases soil moisture only on the sandstone, where plants more strongly control evapotranspiration than on the serpentine. Increased soil moisture stimulates decomposition in these systems, potentially compensating for increased carbon input to soil under elevated CO{sub 2}, resulting in no net change in soil carbon. Increased soil moisture also stimulates plant growth directly and stimulates nitrogen mineralization and plant nitrogen uptake, potentially increasing plant production under elevated CO{sub 2}. We suggest that, in ecosystems with well developed plant canopies where increased soil moisture is likely under elevated CO{sub 2}, feedbacks through soil moisture may increase production, but may also constrain increased carbon storage in soil.},
doi = {},
journal = {Bulletin of the Ecological Society of America},
number = 3,
volume = 76,
place = {United States},
year = {1995},
month = {9}
}