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Title: Leveraging 35 years of Pinus taeda research in the southeastern US to constrain forest carbon cycle predictions: regional data assimilation using ecosystem experiments

Predicting how forest carbon cycling will change in response to climate change and management depends on the collective knowledge from measurements across environmental gradients, ecosystem manipulations of global change factors, and mathematical models. Formally integrating these sources of knowledge through data assimilation, or model–data fusion, allows the use of past observations to constrain model parameters and estimate prediction uncertainty. Data assimilation (DA) focused on the regional scale has the opportunity to integrate data from both environmental gradients and experimental studies to constrain model parameters. Here, we introduce a hierarchical Bayesian DA approach (Data Assimilation to Predict Productivity for Ecosystems and Regions, DAPPER) that uses observations of carbon stocks, carbon fluxes, water fluxes, and vegetation dynamics from loblolly pine plantation ecosystems across the southeastern US to constrain parameters in a modified version of the Physiological Principles Predicting Growth (3-PG) forest growth model. The observations included major experiments that manipulated atmospheric carbon dioxide (CO 2) concentration, water, and nutrients, along with nonexperimental surveys that spanned environmental gradients across an 8.6 × 10 5 km 2 region. We optimized regionally representative posterior distributions for model parameters, which dependably predicted data from plots withheld from the data assimilation. While the mean bias in predictions ofmore » nutrient fertilization experiments, irrigation experiments, and CO 2 enrichment experiments was low, future work needs to focus modifications to model structures that decrease the bias in predictions of drought experiments. Predictions of how growth responded to elevated CO 2 strongly depended on whether ecosystem experiments were assimilated and whether the assimilated field plots in the CO 2 study were allowed to have different mortality parameters than the other field plots in the region. We present predictions of stem biomass productivity under elevated CO 2, decreased precipitation, and increased nutrient availability that include estimates of uncertainty for the southeastern US. Overall, we (1) demonstrated how three decades of research in southeastern US planted pine forests can be used to develop DA techniques that use multiple locations, multiple data streams, and multiple ecosystem experiment types to optimize parameters and (2) developed a tool for the development of future predictions of forest productivity for natural resource managers that leverage a rich dataset of integrated ecosystem observations across a region.« less
Authors:
ORCiD logo [1] ;  [1] ;  [1] ;  [2] ; ORCiD logo [1] ;  [1] ;  [3] ;  [1] ;  [4] ;  [1] ;  [5] ; ORCiD logo [6] ;  [7] ;  [8] ;  [9]
  1. Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States). Dept. of Forest Resources and Environmental Conservation
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Environmental Sciences Division. Climate Change Science Inst.
  3. North Carolina State Univ., Raleigh, NC (United States). State Climate Office of North Carolina
  4. Bordeaux Sciences Agro, Gradignan (France); Duke Univ., Durham, NC (United States). Nicholas School of the Environment
  5. Oregon State Univ., Corvallis, OR (United States). Dept. of Forest Engineering, Resources and Management
  6. Univ. of Florida, Gainesville, FL (United States). School of Forest Resources and Conservation
  7. North Carolina State Univ., Raleigh, NC (United States). Dept. of Forestry and Environmental Resources
  8. Arizona State Univ., Tempe, AZ (United States). Decision Center for a Desert City
  9. Univ. of Georgia, Athens, GA (United States). Warnell School of Forestry and Natural Resources
Publication Date:
Grant/Contract Number:
AC05-00OR22725; 2015-67003-23485; 2011-68002-30185; MACACC ANR-13-AGRO-0005; MARIS ANR-14-CE03-0007
Type:
Accepted Manuscript
Journal Name:
Biogeosciences (Online)
Additional Journal Information:
Journal Name: Biogeosciences (Online); Journal Volume: 14; Journal ID: ISSN 1726-4189
Publisher:
European Geosciences Union
Research Org:
Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bordeaux Sciences Agro, Gradignan (France)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); USDA National Inst. of Food and Agriculture (NIFA) (United States); French Research Agency (ANR) (France)
Contributing Orgs:
North Carolina State Univ., Raleigh, NC (United States); Duke Univ., Durham, NC (United States); Oregon State Univ., Corvallis, OR (United States); Univ. of Florida, Gainesville, FL (United States); Arizona State Univ., Tempe, AZ (United States); Univ. of Georgia, Athens, GA (United States)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES
OSTI Identifier:
1376417