H51I-1505
Red-Edge Spectral Reflectance as an Indicator of Surface Moisture Content in an Alaskan Peatland Ecosystem
Friday, 18 December 2015
Poster Hall (Moscone South)
Mara McPartland1, Evan S Kane2, Merritt R Turetsky3, Tom Douglass4, Michael J Falkowski5, Rebecca Montgomery1 and Jarrod Edwards6, (1)University of Minnesota Twin Cities, Department of Forest Resources, St. Paul, MN, United States, (2)Michigan Technological University, School of Forest Resources and Environmental Sciences, Houghton, MI, United States, (3)University of Guelph, Department of Integrative Biology, Guelph, ON, Canada, (4)Cold Regions Research and Engineering Laboratory Alaska, Fort Wainwright, AK, United States, (5)Colorado State University, Fort Collins, CO, United States, (6)Remote Sensing and Fluorescence Spectroscopy Lab, Richmond, VA, United States
Abstract:
Arctic and boreal peatlands serve as major reservoirs of terrestrial organic carbon (C) because Net Primary Productivity (NPP) outstrips C loss from decomposition over long periods of time. Peatland productivity varies as a function of water table position and surface moisture content, making C storage in these systems particularly vulnerable to the climate warming and drying predicted for high latitudes. Detailed spatial knowledge of how aboveground vegetation communities respond to changes in hydrology would allow for ecosystem response to environmental change to be measured at the landscape scale. This study leverages remotely sensed data along with field measurements taken at the Alaska Peatland Experiment (APEX) at the Bonanza Creek Long Term Ecological Research site to examine relationships between plant solar reflectance and surface moisture. APEX is a decade-long experiment investigating the effects of hydrologic change on peatland ecosystems using water table manipulation treatments (raised, lowered, and control). Water table levels were manipulated throughout the 2015 growing season, resulting in a maximum separation of 35 cm between raised and lowered treatment plots. Water table position, soil moisture content, depth to seasonal ice, soil temperature, photosynthetically active radiation (PAR), CO2 and CH4 fluxes were measured as predictors of C loss through decomposition and NPP. Vegetation was surveyed for percent cover of plant functional types. Remote sensing data was collected during peak growing season, when the separation between treatment plots was at maximum difference. Imagery was acquired via a SenseFly eBee airborne platform equipped with a Canon S110 red-edge camera capable of detecting spectral reflectance from plant tissue at 715 nm band center to within centimeters of spatial resolution. Here, we investigate empirical relationships between spectral reflectance, water table position, and surface moisture in relation to peat carbon balance.
