Estimation of crown closure and species composition from high resolution multispectral imagery

In this study, airborne multispectral video camera images were acquired wit h 32 cm by 25 cm pixel resolution from approximately 150 m above a mature f orest ecosystem near Barrier Lake in Kananaskis Country, southwestern Alber ta. Alberta Vegetation Inventory (AVI) data, including species composition and crown closure, were collected at 22 plots scattered throughout several pure and deciduous and coniferous dominant mixed-wood stands, Feature-based methods of image analysis used a series of filtering, classification and s patial operations to separate individual features such as tree crowns, unde rstory, and shadows resolved in the image data. There were no statistical d ifferences between crown areas measured at the plot level when compared to similar measurements derived from the digital image. Species composition ac curacy was higher for trembling aspen than for lodgepole pine and white spr uce. A contextual classifier was used to construct a forest composition lab el similar to that employed by the AVI for species composition and crown cl osure. Additional work in developing estimates of stand volume using models based on image and AVI data (crown closure, stems/ha, species composition, stand height) is planned for softwood, hardwood and mixed-wood species.