Coarse resolution data from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to test the effectiveness of 250 m data to detect forest disturbances and update an existing, large-area (150,000 km2), 30 m Landsat ETM and TM land-cover map product used in Grizzly Bear (Ursus arctos) habitat analysis. A Landsat-derived polygon layer was applied to the MOD13Q1 data product to create a polygon-based, mean NDVI time series (2000 to 2005). Image differencing of the dataset produced multiple-scale layers of change including a two-date, five-year change and a fiveyear composite of annual changes. Accuracy assessments based on available GIS data showed an overall accuracy as high as 59 percent. Results also show that disturbance patches larger than 15 ha were represented with an accuracy of 75 percent or higher. This offers an alternative to higher spatial resolution data for the identification of larger features and also provides general change information for those areas that may be suitable for analysis with higher spatial resolution data.

Forest inventory Habitat assessment Land cover Map quality Remote sensing Resource selection analysis