Europe-wide Reduction in Primary Productivity Caused by the Heat and Drought in 2003

We quantify the impacts of the summer 2003 extreme heat and severe drought over European ecosystems using in situ CO2 flux measurements over forests, remotely sensed estimations of the fraction of radiation absorbed by plants, and national reports of crop yields. Those data are interpreted with the help of a terrestrial biosphere model in order to estimate the continental scale changes in primary productivity associated with the heat wave, and their consequences on the net carbon balance. Overall, we found a large reduction in gross primary productivity during the heat wave, which resulted into an anomalous annual net source to the atmosphere. Temperate forests in France, Germany and Northern Italy were most affected by the heat and drought. Model results, corroborated by crop yield historical data, suggest that such a collapse in primary productivity is unprecedented over the past 100 years. If such extreme events are to become more frequent in the future, then, carbon sinks in temperate forests long believed to be unaffected or even stimulated by climate change, may also reverse to sources, inducing positive carbon-climate feedbacks such as those anticipated in the tropics or at high latitudes.

CIAIS Philippe;  VIOVY N.;  REICHSTEIN Markus;  SEUFERT Guenther;  MATTEUCCI Giorgio; 

2006-01-31

NATURE PUBLISHING GROUP

JRC32512

https://publications.jrc.ec.europa.eu/repository/handle/JRC32512,   

10.1038/nature03972,