Informing climate models with rapid chamber measurements of forest carbon uptake

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

Models predicting ecosystem carbon dioxide (CO2) exchange under future climate change rely on relatively few real-world tests of their assumptions and outputs. Here, we demonstrate a rapid and cost-effective method to estimate CO2 exchange from intact vegetation patches under varying atmospheric CO2 concentrations. We find that net ecosystem CO2 uptake (NEE) in a boreal forest rose linearly by 4.7 ± 0.2% of the current ambient rate for every 10 ppm CO2 increase, with no detectable influence of foliar biomass, season, or nitrogen (N) fertilization. The lack of any clear short-term NEE response to fertilization in such an N-limited system is inconsistent with the instantaneous downregulation of photosynthesis formalized in many global models. Incorporating an alternative mechanism with considerable empirical support – diversion of excess carbon to storage compounds – into an existing earth system model brings the model output into closer agreement with our field measurements. A global simulation incorporating this modified model reduces a long-standing mismatch between the modeled and observed seasonal amplitude of atmospheric CO2. Wider application of this chamber approach would provide critical data needed to further improve modeled projections of biosphere–atmosphere CO2 exchange in a changing climate.

Detaljer

Författare
  • Daniel B. Metcalfe
  • Daniel Ricciuto
  • Sari Palmroth
  • Catherine Campbell
  • Vaughan Hurry
  • Jiafu Mao
  • Sonja G. Keel
  • Sune Linder
  • Xiaoying Shi
  • Torgny Näsholm
  • Klas E.A. Ohlsson
  • M. Blackburn
  • Peter E. Thornton
  • Ram Oren
Enheter & grupper
Externa organisationer
  • Oak Ridge National Laboratory
  • Duke University
  • Swedish University of Agricultural Sciences, Umeå
  • Agroscope
  • Swedish University of Agricultural Sciences
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Miljövetenskap

Nyckelord

Originalspråkengelska
Sidor (från-till)2130-2139
Antal sidor10
TidskriftGlobal Change Biology
Volym23
Utgåva nummer5
StatusPublished - 2017 maj 1
PublikationskategoriForskning
Peer review utfördJa