PhenoCam Network Camera | Jasper Ridge Biological Preserve

PhenoCam Network Camera

Andrew Richardson (Harvard University)

Summary

Reducing uncertainties about the role of terrestrial ecosystems in the global carbon cycle requires better understanding of the spatial and temporal variation in biologically-mediated sources and sinks of carbon. In temperate and boreal forest ecosystems, phenological events such as spring leaf emergence and autumn senescence exert strong control on primary productivity and are therefore critical to ecosystem carbon cycling.

In biomes such as grassland and savannas, phenology of other plant functional types like grasses and shrubs provide information about the timing of biological nutrient cycling. Phenology also influences hydrologic processes, as leaf-out is accompanied by an increase in evapotranspiration; nutrient cycling processes, as senescence results in fresh litter (nutrient) inputs to the forest floor; and feedbacks to the climate system, as the amount and condition of foliage present affects surface energy balance, albedo, and surface roughness. Phenology also influences ecological interactions among individuals (e.g., competition) and across trophic levels (e.g., herbivory). Phenology has been shown to be a robust integrator of the effects of year-to-year climate variability and longer-term climate change on natural systems (e.g., recent warming trends). Experimental studies have shown how other global change factors (e.g., elevated CO2 and N deposition) can also influence phenology. The USA-National Phenology Network is being designed and organized to engage federal agencies, environmental networks and field stations, educational institutions, and mass participation by citizen scientists in the development of a continental-scale phenological monitoring program. The JRBP PhenoCam is located at the Jasper Ridge Eddy Flux station. References: Richardson, A.D., J.P. Jenkins, B.H. Braswell, D.Y. Hollinger, S.V. Ollinger, and M.-L. Smith. Use of digital webcam images to track spring green-up in a deciduous broadleaf forest. Oecologia, 2007