Changes in the Taiga-Tundra boundary observed with Landsat

The transition zone between the Arctic tundra and boreal forest is sensitive to both climate change and human activities. Monitoring the dynamics of this tundra-forest ecotone is important for understanding of the causes and consequences of changes in land cover. MSS image in 1973 and ETM+ image in 2002 were used to identify the changes at the taiga-tundra transition zones in Ary Mas, Siberia. Linear spectral unmixing was used to map taiga abundances across the boundary. An ETM+ image acquired in 2001 was also processed using linear spectral unmixing, and the results showed the consistence between 2001 and 2002. In order to make the results from MSS and ETM+ comparable, ETM+ images were re-sampled to the pixel size of MSS image, and only three bands (2,3,4) similar to MSS bands 7,5,4 were used. Comparing results from these two datasets shows the changes that occurred in the transition zone during this period. The most significant change is the thickening of taiga forests near the transition zone. The change of tree cover along the taiga-tundra transition zone may be attributed to climate change; however, the validation of these changes needs to be further studied