About the PhenoCam Data

Vegetation phenology controls the seasonality of many ecosystem processes, as well as numerous biosphere-atmosphere feedbacks. Phenology is highly sensitive to climate change and variability. Here we present a dataset, consisting of ~750 site-years of observations, characterizing vegetation phenology in diverse ecosystems across North America. Our data are derived from conventional, visible-wavelength digital camera imagery collected through the PhenoCam network. For each archived image, we extracted RGB (red, green, blue) colour channel information, with means and other statistics calculated across a region-of-interest (ROI) delineating a specific vegetation type. From the high-frequency (typically, 30 minute) imagery, we derived time series characterizing vegetation colour, including “canopy greenness”, processed to 1- and 3-day intervals. For ecosystems with a single annual cycle of vegetation activity, we provide date estimates, with uncertainties, for the start, middle, and end of spring green-up and autumn green-down (senescent) phases. The PhenoCam database and R toolbox can be used for phenological model validation and development, evaluation of satellite remote sensing data products, and studies of climate change impacts on terrestrial ecosystems.