TY - JOUR
T1 - Projections of water, carbon, and nitrogen dynamics under future climate change in an old-growth Douglas-fir forest in the western Cascade Range using a biogeochemical model
AU - Dong, Zheng
AU - Driscoll, Charles T.
AU - Johnson, Sherri L.
AU - Campbell, John L.
AU - Pourmokhtarian, Afshin
AU - Stoner, Anne M.K.
AU - Hayhoe, Katharine
N1 - Funding Information:
We thank Habibollah Fakhraei and Steven Perakis for constructive discussion during the development of the manuscript. Funding for this study was provided by U.S. Environmental Protection Agency through the STAR program (R834188) and Department of Civil and Environmental Engineering at Syracuse University. Data for model calibration and validation were provided by the Pacific Northwest Permanent Sample Plot Program and the H. J. Andrews Experimental Forest research program, funded by the National Science Foundation's Long-Term Ecological Research Program (DEB1440409; DEB0823380), U.S. Forest Service Pacific Northwest Research Station, and Oregon State University. The authors thank Robert Pabst for providing the data on primary production and plant nutrient concentrations, and the editor and three reviewers for their constructive comments and suggestions.
Funding Information:
We thank Habibollah Fakhraei and Steven Perakis for constructive discussion during the development of the manuscript. Funding for this study was provided by U.S. Environmental Protection Agency through the STAR program ( R834188 ) and Department of Civil and Environmental Engineering at Syracuse University . Data for model calibration and validation were provided by the Pacific Northwest Permanent Sample Plot Program and the H. J. Andrews Experimental Forest research program, funded by the National Science Foundation 's Long-Term Ecological Research Program ( DEB1440409 ; DEB0823380 ), U.S. Forest Service Pacific Northwest Research Station , and Oregon State University . The authors thank Robert Pabst for providing the data on primary production and plant nutrient concentrations, and the editor and three reviewers for their constructive comments and suggestions.
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2019/3/15
Y1 - 2019/3/15
N2 - Statistically downscaled climate change scenarios from four General Circulation Models for two Representative Concentration Pathways (RCP) were applied as inputs to a biogeochemical model, PnET-BGC, to examine potential future dynamics of water, carbon, and nitrogen in an old-growth Douglas-fir forest in the western Cascade Range. Projections show 56% to 77% increases in stomatal conductance throughout the year from 1986–2010 to 2076–2100, and 65% to 104% increases in leaf carbon assimilation between October and June over the same period. However, future dynamics of water and carbon under the RCP scenarios are affected by a 49% to 86% reduction in foliar biomass resulting from severe air temperature and humidity stress to the forest in summer. Important implications of future decreases in foliar biomass include 1) 20% to 71% decreases in annual transpiration which increase soil moisture by 7% to 15% in summer and fall; 2) decreases in photosynthesis by 77% and soil organic matter by 62% under the high radiative forcing scenario; and 3) altered foliar and soil carbon to nitrogen stoichiometry. Potential carbon dioxide fertilization effects on vegetation are projected to 1) amplify decreases in transpiration by 4% to 9% and increases in soil moisture in summer and fall by 1% to 2%; and 2) alleviate decreases in photosynthesis by 4%; while 3) having negligible effects on the dynamics of nitrogen. Our projections suggest that future decrease in transpiration and moderate water holding capacity may mitigate soil moisture stress to the old-growth Douglas-fir forest. Future increases in nitrogen concentration in soil organic matter are projected to alleviate the decrease in net nitrogen mineralization despite a reduction in decomposition of soil organic matter by the end of the century.
AB - Statistically downscaled climate change scenarios from four General Circulation Models for two Representative Concentration Pathways (RCP) were applied as inputs to a biogeochemical model, PnET-BGC, to examine potential future dynamics of water, carbon, and nitrogen in an old-growth Douglas-fir forest in the western Cascade Range. Projections show 56% to 77% increases in stomatal conductance throughout the year from 1986–2010 to 2076–2100, and 65% to 104% increases in leaf carbon assimilation between October and June over the same period. However, future dynamics of water and carbon under the RCP scenarios are affected by a 49% to 86% reduction in foliar biomass resulting from severe air temperature and humidity stress to the forest in summer. Important implications of future decreases in foliar biomass include 1) 20% to 71% decreases in annual transpiration which increase soil moisture by 7% to 15% in summer and fall; 2) decreases in photosynthesis by 77% and soil organic matter by 62% under the high radiative forcing scenario; and 3) altered foliar and soil carbon to nitrogen stoichiometry. Potential carbon dioxide fertilization effects on vegetation are projected to 1) amplify decreases in transpiration by 4% to 9% and increases in soil moisture in summer and fall by 1% to 2%; and 2) alleviate decreases in photosynthesis by 4%; while 3) having negligible effects on the dynamics of nitrogen. Our projections suggest that future decrease in transpiration and moderate water holding capacity may mitigate soil moisture stress to the old-growth Douglas-fir forest. Future increases in nitrogen concentration in soil organic matter are projected to alleviate the decrease in net nitrogen mineralization despite a reduction in decomposition of soil organic matter by the end of the century.
KW - Biogeochemical modeling
KW - Carbon
KW - Douglas-fir
KW - Nitrogen
KW - Representative concentration pathways
KW - Water
UR - http://www.scopus.com/inward/record.url?scp=85057853532&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85057853532&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2018.11.377
DO - 10.1016/j.scitotenv.2018.11.377
M3 - Article
C2 - 30529965
AN - SCOPUS:85057853532
SN - 0048-9697
VL - 656
SP - 608
EP - 624
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -