Assessment of thematic mapper imagery for forestry applications under Lake States conditions
Landsat Multispectral Scanner (MSS) data have only very general utility for forest type mapping and condition assessment under environmental conditions typical of the Lake States. Accurate classification is hindered by the considerable species and site vanablhty of this regIOn and the relatively coarse spatial, spectral, and radiometric resolution of the MSS. This paper presents a preliminary assessment of Landsat Thematic Mapper (TM) data for forestry apphcatlOns under Lake States conditions. Two study sites in Wisconsin with distinctly different forest character were analyzed uSlllg both visual and computer-assisted interpretation techniques. Highly accurate hardwood versus softwood and upland versus lowland forest type separations were made, and further specification was shown possible. Distinction of Jackpllle budworm defohatlOn levels was also achieved. Approaches to digital data analysis which incorporate visual analySIS techlllquesor spatlallllformatlOn appear needed to fully exploit the information value of the higher resolution data. This research lIldlcates that TM data can provide better forest type mapping and condition assessment information than MSS data and may, therefore, be more widely used in forestry applications. However, additional analyses are needed to fully assess the capablhty of TM imagery for forestry applications in the Lake States region.