Multitemporal NDVI- and RADARSAT- Based Analysis of the Tundra Taiga Interface (Mealy Mountains, Labrador)
The analysis of the Normalized Difference Vegetation Index (NDVI) calculated from five image sets, recorded between 1983 and 2008, and a digital elevation model produces information on the spatiotemporal variation of the treeline in a region of the Mealy Mountains, Labrador, Canada. The series, composed of Landsat, SPOT and ASTER images, gives insight into regional scale characteristics of the tundra taiga interface that is usually monitored from coarse resolution images. The vegetation cover variation is investigated through changes of the absolute and classified NDVI values as well as the size and shape of contiguous areas delineated by different NDVI classes. Multitemporal comparison of size and shape provide additional information on the vegetation cover change dynamics. Further analysis of the five image series produced information about the change of biomass, the spatial structure of three NDVI biomass classes that did not change over the 25-year period, and about the migration of the tree line.
The latest phase of the research project has as its main objective to suggest an analysis method for Radarsat-2 images that will help building a monitoring capacity that seamlessly uses NDVI and radar images. Radarsat-2 image modes, incidence angles are investigated for their potential to provide information about the tundra taiga interface. An optimum image analysis method is identified that help discriminate between the forest and non-forest components of the interface as well as estimating a tree line between the tundra and taiga environments.
Multi-sensor based monitoring augments longterm knowledge on possible effects of climate change on vegetation cover. Not only the spectral information is useful but also the structural characteristics help explain the green biomass spatiotemporal dynamics.
Morrison, H. (in preparation) Radarsat-2 based characterization of the tundra taiga interface (Mealy Mountains, Labrador). M. Sc. thesis.
Simms, É and H. Morrison (in preparation) A NDVI-based multitemporal analysis of the tundra taiga interface (Mealy Mountains, Labrador) [Paper to be submitted to the journal Remote Sensing of Environment]
Simms, É., A. Simms and H. Morrison 2009 Twenty-five Year Monitoring of the Mealy Mountains, Labrador, Tree Line. Paper number 593, 30th Canadian Symposium on Remote Sensing, Lethbridge, June 22-25
Simms, A. and É. Simms 2009 Multidate image analysis of the Mealy Mountain (Labrador) tree-line. Presentation at the Canadian Society for Ecology and Evolution, Halifax, May 14-17