Biological and Environmental Research - Earth and Environmental System Sciences
Earth and Environmental System Modeling

Phosphorus Feedbacks Constraining Tropical Ecosystem Responses to Changes in Atmospheric CO2 and Climate

TitlePhosphorus Feedbacks Constraining Tropical Ecosystem Responses to Changes in Atmospheric CO2 and Climate
Publication TypeJournal Article
Year of Publication2016
AuthorsYang, Xiaojuan, Thornton Peter E., Ricciuto Daniel M., and Hoffman Forrest M.
JournalGeophysical Research Letters
Volume43
Number13
Pages7205-7214
Abstract / Summary

The effects of phosphorus (P) availability on carbon (C) cycling in the Amazon region are investigated using CLM-CNP. We demonstrate that the coupling of P dynamics reduces the simulated historical terrestrial C sink due to increasing atmospheric CO2 concentrations ([CO2]) by about 26%. Our exploratory simulations show that the response of tropical forest C cycling to increasing [CO2] depends on how elevated CO2 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. Our simulations point to the need for (1) new observations on how elevated [CO2] affects phosphatase enzyme production and (2) more tropical leaf-scale measurements under different temperature/humidity conditions with different soil P availability.

URLhttps://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016GL069241
DOI10.1002/2016GL069241
Journal: Geophysical Research Letters
Year of Publication: 2016
Volume: 43
Number: 13
Pages: 7205-7214
Publication Date: 07/2016

The effects of phosphorus (P) availability on carbon (C) cycling in the Amazon region are investigated using CLM-CNP. We demonstrate that the coupling of P dynamics reduces the simulated historical terrestrial C sink due to increasing atmospheric CO2 concentrations ([CO2]) by about 26%. Our exploratory simulations show that the response of tropical forest C cycling to increasing [CO2] depends on how elevated CO2 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. Our simulations point to the need for (1) new observations on how elevated [CO2] affects phosphatase enzyme production and (2) more tropical leaf-scale measurements under different temperature/humidity conditions with different soil P availability.

DOI: 10.1002/2016GL069241
Citation:
Yang, X, PE Thornton, DM Ricciuto, and FM Hoffman.  2016.  "Phosphorus Feedbacks Constraining Tropical Ecosystem Responses to Changes in Atmospheric CO2 and Climate."  Geophysical Research Letters 43(13): 7205-7214.  https://doi.org/10.1002/2016GL069241.