Monitoring Aspen Phenology along an Elevation Gradient using MODIS data
presentationposted on 17.11.2014, 00:00 by Emily Richardson
Aspen (Populus tremuloides) are keystone species in many North American ecosystems and are the most extensively distributed species in this landscape. They thrive in a variety of environments, support biodiversity and provide many ecosystem amenities. Despite their resilience and wide distribution, a decline in aspen communities has been observed starting in western Canada and continuing down to the central and southern Rocky Mountains. Monitoring the phenology of aspens can provide insights about factors influencing their decline. Phenology refers to the measurement of the timing of biological events. One way to measure phenology is with remotely sensed data. This study utilizes Moderate Resolution Imaging Spectrometer (MODIS) images acquired during a ten year period, from 2000-2010. Values of the infrared and red bands were extracted from 6 aspen stands located in the Medicine Bow National Forest. NDVI values were derived from these bands, and phenological curves were constructed for each year. From these curves, influences of elevation and weather conditions on aspen phenology were compared.