Biome Boundary Shifts During the Landsat Era: North American Boreal Forest
Douglas
C
Morton, NASA Goddard Space Flight Center, douglas.morton@nasa.gov
(Presenting)
Jeffrey
G
Masek, NASA Goddard Space Flight Center, jeffrey.g.masek@nasa.gov
Dongdong
Wang, University of Maryland, College Park, ddwang@umd.edu
Joseph
Sexton, University of Maryland, College Park, joseph.sexton@nasa.gov
Jyoteshwar
Nagol, University of Maryland, College Park, jnagol@umd.edu
Climate exerts a strong control on the distribution and diversity of vegetation, and changes in climate are typically associated with species’ range expansions and contractions. High northern latitudes experienced the strongest warming trend in annual temperature anomalies during the Landsat era (1972-present). Whether recent temperature increases in this region have already triggered changes in the extent of boreal forest is unclear. Evidence from field plots and tree ring analysis suggest that the strength and consistency of seasonal temperature trends across the boreal forest biome are more important than annual temperature changes for vegetation growth and mortality. In North America, summer warming (May-October) was strongest in northern Quebec, while winter warming (November-April) was widespread across Alaska and central Canada. In this study, we selected Landsat time series transects across the leading edge of the boreal forest biome in North America for regions experiencing a range of winter, summer, and annual warming trends during the Landsat era. For each image transect, we used the dense time series of Landsat data (MSS, TM, and ETM+) to quantify rates of boreal forest expansion and characterize changes in stand density during 1972-2009. Here, we present initial results from this study for 1) calibration of Landsat MSS data, 2) the rate of boreal forest expansion across one Landsat image transect, and 3) validation of the extent and density of tree cover identified in the Landsat image time series using airborne lidar data from 2006-2009. Initial results from this study suggest that the Landsat archive can be used to establish baseline conditions for climate-sensitive biome boundaries.
Presentation Type: Poster
Poster Session: Ecosystems Science
NASA TE Funded Awards Represented:
NONE: Related Activity or Previously Funded TE Award