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Free keywords:
Water-vapor exchange
Soil respiration
Seasonal-changes
Sitka spruce
Beech forest
Photosynthesis
Variability
Dioxide
CO2
Vegetation
Abstract:
[ 1] We analyzed measurements of net ecosystem exchange of CO2 ( NEE) over 15 European forests ( the EuroFlux data set) to investigate which climate and forest characteristics explain temporal and intersite variations in NEE and its components, gross primary production ( GPP) and respiration ( R). Informed stepwise regression was used to derive a parameter-efficient, empirical model that was consistent with process knowledge. The resulting model required seven site-specific parameters to describe flux behavior at different temporal scales as a function of radiation, temperature, and air humidity. The interpretation appeared robust despite method and data uncertainties, although the data set was probably biased toward well-watered boreal and temperate European forests. Radiation, temperature, and leaf area ( through forest assimilation capacity) appear to be the main drivers of the observed temporal and intersite variation in gross primary production, ecosystem respiration, and net ecosystem exchange. [References: 40]
