Title: Terrestrial biosphere models need better representation of vegetation phenology: results from the North American Carbon Program Site Synthesis
Authors: RICHARDSON Andrew D.ANDERSON Ryan S.ARAIN Altaf M.BARR Alan G.BOHRER GilCHEN GuangshengCHEN Jing M.CIAIS PhilippeDAVIS Kenneth J.DESAI Ankur R.DIETZE Michael C.DRAGONI DaniloGARRITY StevenGOUGH C.m.GRANT RobertHOLLINGER David Y.MARGOLIS HankMCCAUGHEY HarryMIGLIAVACCA MIRCOMONSON Russel K.MUNGER William JPOULTER BenjaminRACZKA Brett M.RICCIUTO DanielSAHOO Alok K.SCHAEFER KevinTIAN HanqinVARGAS RodrigoVERBEECK H.XIAO JingfengXUE Yongkang
Citation: GLOBAL CHANGE BIOLOGY vol. 18 no. 2 p. 566-584
Publisher: WILEY-BLACKWELL
Publication Year: 2012
JRC Publication N°: JRC67267
ISSN: 1354-1013
URI: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2011.02562.x/full
http://publications.jrc.ec.europa.eu/repository/handle/JRC67267
DOI: 10.1111/j.1365-2486.2011.02562.x
Type: Articles in Journals
Abstract: Phenology, by controlling the seasonal activity of vegetation on the land surface, plays a fundamental role in regulating photosynthesis and other ecosystem processes, as well as competitive interactions and feedbacks to the climate system. We conducted an analysis to evaluate the representation of phenology, and the associated seasonality of ecosystem-scale CO2 exchange, in 14 models participating in the North American Carbon Program Site Synthesis. Model predictions were evaluated using long-term measurements (emphasizing the period 2000-2006) from 10 forested sites within the AmeriFlux and Fluxnet-Canada networks. In deciduous forests, almost all models consistently predicted that the growing season started earlier, and ended later, than was actually observed; biases of 2 weeks or more were typical. For these sites, most models were also unable to explain more than a small fraction of the observed interannual variability in phenological transition dates. Finally, for deciduous forests, misrepresentation of the seasonal cycle resulted in over-prediction of gross ecosystem photosynthesis by +160 ± 145 g C m−2 y−1 during the spring transition period, and +75 ± 130 g C m−2 y−1 during the autumn transition period (13% and 8% annual productivity, respectively) compensating for the tendency of most models to under-predict the magnitude of peak summertime photosynthetic rates. Models did a better job of predicting the seasonality of CO2 exchange for evergreen forests. These results highlight the need for improved understanding of the environmental controls on vegetation phenology, and incorporation of this knowledge into better phenological models. Existing models are unlikely to predict future responses of phenology to climate change accurately, and therefore will misrepresent the seasonality and interannual variability of key biosphere-atmosphere feedbacks and interactions in coupled global climate models.
JRC Institute:Institute for Environment and Sustainability

Files in This Item:
There are no files associated with this item.


Items in repository are protected by copyright, with all rights reserved, unless otherwise indicated.