Contrasting response of European forest and grassland energy exchange to heatwaves

in Nature Geoscience (2010), 3(10), 722-727

Management effects on net ecosystem carbon and GHG budgets at European crop sites

in Agriculture, Ecosystems & Environment (2010), 139

Exceptional Carbon Uptake In European Forests During The Warm Spring Of 2007: A Data-Model Analysis

in Global Change Biology (2009), 15(6), 1455-1474

Temperate and boreal forests undergo drastic functional changes in the springtime, shifting within a few weeks from net carbon (C) sources to net C sinks. Most of these changes are mediated by temperature ... [more ▼]

Temperate and boreal forests undergo drastic functional changes in the springtime, shifting within a few weeks from net carbon (C) sources to net C sinks. Most of these changes are mediated by temperature. The autumn 2006-winter 2007 record warm period was followed by an exceptionally warm spring in Europe, making spring 2007 a good candidate for advances in the onset of the photosynthetically active period. An analysis of a decade of eddy covariance data from six European forests stands, which encompass a wide range of functional types (broadleaf evergreen, broadleaf deciduous, needleleaf evergreen) and a wide latitudinal band (from 44 degrees to 62 degrees N), revealed exceptional fluxes during spring 2007. Gross primary productivity (GPP) of spring 2007 was the maximum recorded in the decade examined for all sites but a Mediterranean evergreen forest (with a +40 to +130 gC m(-2) anomaly compared with the decadal mean over the January-May period). Total ecosystem respiration (TER) was also promoted during spring 2007, though less anomalous than GPP (with a +17 to +93 gC m(-2) anomaly over 5 months), leading to higher net uptake than the long-term mean at all sites (+12 to +79 gC m(-2) anomaly over 5 months). A correlative analysis relating springtime C fluxes to simple phenological indices suggested spring C uptake and temperatures to be related. The CASTANEA process-based model was used to disentangle the seasonality of climatic drivers (incoming radiation, air and soil temperatures) and biological drivers (canopy dynamics, thermal acclimation of photosynthesis to low temperatures) on spring C fluxes along the latitudinal gradient. A sensitivity analysis of model simulations evidenced the roles of (i) an exceptional early budburst combined with elevated air temperature in deciduous sites, and (ii) an early relief of winter thermal acclimation in coniferous sites for the promotion of 2007 spring assimilation. [less ▲]

Evidence For Soil Water Control On Carbon And Water Dynamics In European Forests During The Extremely Dry Year: 2003

in Agricultural and Forest Meteorology (2007), 143(1-2),

An Analysis of Soil Respiration across Northern Hemisphere Temperate Ecosystems

in Biogeochemistry (2005), 73(1), 29-70

Europe-Wide Reduction In Primary Productivity Caused By The Heat And Drought In 2003

in Nature (2005), 437(7058),

Carbon balance gradient in European forests: should we doubt 'surprising' results? A reply to Piovesan & Adams

in Journal of Vegetation Science (2001), 12(1), 145-150

This paper responds to the Forum contribution by Piovesan & Adams (2000) who criticized the results obtained by the EUROFLUX network on carbon fluxes of several European forests. The major point of ... [more ▼]

This paper responds to the Forum contribution by Piovesan & Adams (2000) who criticized the results obtained by the EUROFLUX network on carbon fluxes of several European forests. The major point of criticism was that the data provided by EUROFLUX are inconsistent with current scientific understanding. It is argued that understanding the terrestrial global carbon cycle requires more than simply restating what was known previously, and that Piovesan & Adams have not been able to show any major conflicts between our findings and ecosystem or atmospheric-transport theories. [less ▲]

Gap Filling Strategies For Defensible Annual Sums Of Net Ecosystem Exchange

in Agricultural and Forest Meteorology (2001), 107(1),

Respiration As The Main Determinant Of Carbon Balance In European Forests

in Nature (2000), 404(6780),

New estimate of the carbon sink strength of EU forests integrating flux measurements, field surveys, and space observations: 0.17-0.35 Gt(C)

in AMBIO : A Journal of the Human Environment (1998), 27(7), 582-584