Carbon fluxes above a deciduous forest in Greece

摘要

Photosynthetic production in forest ecosystems occurs through the absorption of light and CO2. The present work deals with CO2 and carbon flux densities above a deciduous forest in Greece, the southernmost monitoring site in Europe. Results show annual net carbon absorption of 7.6 t C ha(-1) y(-1), indicating that this forest is a strong carbon sink compared to other European sites. However, absorbance may be reduced by 1 mu mol m(-2) s(-1) for every 1.5 degrees C above-canopy air temperature increase or 0.015 cm(3) cm(-3) active root-zone moisture depletion, beyond estimated optimum values. The forest acts as a carbon sink from late April to early November and as a source of carbon in the remaining period of the year. The highest CO2 net absorption flux occurs during June-July (approximately 200 g C m(-2) month(-1)).