ANALYZING REMOTE-SENSING GEOBOTANICAL TRENDS IN QUETICO-PROVINCIAL-PARK, ONTARIO, CANADA, USING DIGITAL ELEVATION DATA

Field geological mapping of a 10- by 13-km area in Quetico Provincial Park, Ontario, Canada, depicts a broad central band of metamorphosed mafic and occasional ultramafic lithologies, surrounded by granites and granodiorites. Glacial till is thin and capped by loess in places. The soils are mainly Histosols and Boralfs. The vegetation is dominantly Boreal in nature. To investigate subtle site influences on vegetation, topographic information was analyzed using a digital terrain model. The elevation data were filtered to separate ridge tops and other flat, dry areas from flat moist sites. Landsat Thematic Mapper (TM) data were classified into six forest classes of varying deciduous-coniferous cover using nPDF, a procedure based on probability density functions. The distribution of cover classes on each of the two lithologies shows that forests growing on mafic lithologies are enriched in deciduous species, compared to those growing on granites. Of the forest classes found on mafics, the highest coniferous component was on north facing slopes, and the highest deciduous component on south facing slopes. By contrast, granites showed no appreciable varaition between site classes. Digital elevation derived site data is found to be an important tool in geobotanical investigations in Quetico Provincial Park.