skip to main content

Title: Phosphorus feedbacks constraining tropical ecosystem responses to changes in atmospheric CO 2 and climate

The effects of phosphorus (P) availability on carbon (C) cycling in the Amazon region are investigated using CLM-CNP. Within this paper, we demonstrate that the coupling of P dynamics reduces the simulated historical terrestrial C sink due to increasing atmospheric CO 2 concentrations ([CO 2]) by about 26%. Our exploratory simulations show that the response of tropical forest C cycling to increasing [CO 2] depends on how elevated CO 2 affects phosphatase enzyme production. The effects of warming are more complex, depending on the interactions between humidity, C, and nutrient dynamics. While a simulation with low humidity generally shows the reduction of net primary productivity (NPP), a second simulation with higher humidity suggests overall increases in NPP due to the dominant effects of reduced water stress and more nutrient availability. Lastly, our simulations point to the need for (1) new observations on how elevated [CO 2] affects phosphatase enzyme production and (2) more tropical leaf-scale measurements under different temperature/humidity conditions with different soil P availability.
 [1] ;  [1] ;  [1] ;  [2]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Environmental Science Division
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computer Science and Mathematics Division
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Geophysical Research Letters (Online)
Additional Journal Information:
Journal Name: Geophysical Research Letters (Online); Journal Volume: 43; Journal Issue: 13; Journal ID: ISSN 1944-8007
American Geophysical Union (AGU)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States