Plant Phenology
NEON plant phenology measurements record the seasonal progression of critical biological processes and the timing of ecological events.  Phenology measurements track sensitive and easily observed indicators of biotic responses to climate variability by recording and monitoring the timing and duration of phenological stages in plant communities.    NEON employs a status based monitoring strategy; occurrence and intensity of selected phenophases are recorded in order to track rates of phenological transitions and trends in the annual timing of those transitions.  Data are collected in a manner consistent with, and therefore comparable to, existing national citizen science campaigns (i.e. National Phenology Network, Project Budburst) thereby leveraging existing and ongoing efforts throughout the United States to increase the potential for continental-scale analysis and forecasting.  Sampling will occur in two phases over the life of the observatory.  The first phase will focus on the phenology of dominant species and will last for the first three years of Operations. Up to 30 individuals of each of three dominant species will be selected and marked for regular phenological observation.  In the second phase, a more diverse suite of plants will be monitored, with fewer replicates per species.  Phenological observations at SRER occur along an 800m fixed ‘loop’ transect within the Tower Airshed.  Seasonal sampling frequency ranges from 3 times a week to once every other week; higher frequency sampling tracks periods of rapid transition.