Ecology and Evolutionary Biology Commons^™

Whole-Canopy Net Ecosystem Exchange And Water Use Efficiency In An Intermittent-Light Environment -- Dynamic Approach, Sergey Nikolayevich Kivalov

Legacy Theses & Dissertations (2009 - 2024)

An observed 20-30% increase in forest net ecosystem exchange (NEE) on partly cloudy days is often attributed to there being more uniform canopy illumination by diffuse radiation when clouds are present. However, the sky on such days is typically populated by fair-weather cumulus clouds, bringing dynamically changing shadow-to-light conditions on the order of minutes to the forest, with radiation alternating from 1000 W m^-2 in the clear sky to less than 400 W m^-2 in under-cloud shadows. These dynamically changing conditions cannot be investigated by the conventional time-averaged eddy-covariance flux method, which requires nearly steady-state turbulent conditions over much longer …