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Informing climate models with rapid chamber measurements of forest carbon uptake
Author(s) -
Metcalfe Daniel B.,
Ricciuto Daniel,
Palmroth Sari,
Campbell Catherine,
Hurry Vaughan,
Mao Jiafu,
Keel Sonja G.,
Linder Sune,
Shi Xiaoying,
Näsholm Torgny,
Ohlsson Klas E. A.,
Blackburn M.,
Thornton Peter E.,
Oren Ram
Publication year - 2017
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/gcb.13451
Subject(s) - environmental science , biosphere , climate change , carbon cycle , atmospheric sciences , ecosystem , carbon dioxide , biomass (ecology) , climate model , vegetation (pathology) , atmosphere (unit) , taiga , photosynthesis , biosphere model , boreal , ecosystem model , global change , carbon dioxide in earth's atmosphere , ecology , meteorology , chemistry , geography , geology , medicine , biochemistry , pathology , biology
Models predicting ecosystem carbon dioxide ( CO 2 ) 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 CO 2 exchange from intact vegetation patches under varying atmospheric CO 2 concentrations . We find that net ecosystem CO 2 uptake ( NEE ) in a boreal forest rose linearly by 4.7 ± 0.2% of the current ambient rate for every 10 ppm CO 2 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 CO 2 . Wider application of this chamber approach would provide critical data needed to further improve modeled projections of biosphere–atmosphere CO 2 exchange in a changing climate.