Calibrating Spaceborne Estimates of Tree Cover in the Taiga-Tundra Ecotone

Paul Mannix Montesano, SSAI - NASA GSFC, paul.m.montesano@nasa.gov (Presenter)
Christopher Neigh, NASA GSFC, christopher.s.neigh@nasa.gov (Presenter)
Joe Sexton, Global Land Cover Facility, Dept. Geographical Sciences, UMd - College Park, jsexton@umd.edu
Min Feng, Global Land Cover Facility, Dept. Geographical Sciences, UMd - College Park, fengm@umd.edu
Mark Chopping, Earth and Environmental Studies, Montclair State University, chopping@pegasus.montclair.edu
Saurabh Channan, Global Land Cover Facility, Dept. Geographical Sciences, UMd - College Park, schannan@umd.edu
Ross Nelson, NASA GSFC, ross.f.nelson@nasa.gov
John Townshend, Global Land Cover Facility, Dept. Geographical Sciences, UMd - College Park, jtownshe@umd.edu
Jon Ranson, NASA GSFC, jon.ranson@nasa.gov

In the sparse forests of the high northern latitudes vegetation structure has been changing. At the global scale, these changes have been subtle, varying according to site conditions. Global-scale spaceborne observations tend to overestimate tree canopy in these sparse forests. In the circumpolar taiga-tundra ecotone (TTE) this overestimation increases the uncertainty in depictions of tree cover, where patterns of cover and height may reflect critical site-level drivers of forest structure and provide clues as to forest dynamics. This work will validate the recent Landsat-derived Vegetation Continuous Fields (VCF) estimates of tree cover for the circumpolar TTE using estimates of tree cover derived from 3 different high resolution tree cover interpretation approaches: (1) sets of manually- and (2) automatically-derived estimates of tree cover from high resolution (<5m) spaceborne imagery, and (3) tree cover estimates derived from transects of airborne LiDAR samples. This information will be compared with VCF uncertainty data for the TTE. It will provide calibration coefficients that will be applied to correct the VCF’s depiction of tree cover in the TTE. The result will be a percent tree cover map at 30m resolution that is calibrated for the sparse forests of the TTE. This map will improve estimates of horizontal forest structure in the TTE that, when combined with forest height, may reveal forest structure patterns that explain the variable response of TTE forest structure to changing climate.

Presentation Type:  Poster

Session:  General Contributions   (Tue 4:35 PM)

Associated Project(s): 

• Ranson, Jon: A High-Resolution Circumpolar Delineation of the Forest-Tundra Ecotone With Implications for Carbon Balance ...details

Poster Location ID: 190