Near-surface remote sensing of spatial and temporal variation in canopy phenology
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Ecological Applications: 19(6): 1417-1428.
There is a need to document how plant phenology is responding to global change factors, particularly warming trends. "Near-surface" remote sensing, using radiometric instruments or imaging sensors, has great potential to improve phenological monitoring because automated observations can be made at high temporal frequency. Here we build on previous work and show how inexpensive, networked digital cameras ("webcams") can be used to document spatial and temporal variation in the spring and autumn phenology of forest canopies. We use two years of imagery from a deciduous, northern hardwood site, and one year of imagery from a coniferous, boreal transition site. A quantitative signal is obtained by splitting images into separate red, green, and blue color channels and calculating the relative brightness of each channel for "regions of interest" within each image.
KeywordsAmeriFlux autumn color Bartlett Experimental Forest New Hampshire USA eddy covariance Howland Forest Maine USA phenology RGB image analysis spring onset webcam
Richardson, Andrew D.; Braswell, Bobby H.; Hollinger, David Y.; Jenkins, Julian P.; Ollinger, Scott V. 2009. Near-surface remote sensing of spatial and temporal variation in canopy phenology. Ecological Applications: 19(6): 1417-1428.