The Affect of Spatial Resolution on Measurement of Vegetation Cover in Three Mojave Desert Shrub Communities

1 The Affect of Spatial Resolution on Measurement of Vegetation Cover in Three Mojave Desert Shrub Communities Thomas D. Frank and Scott A. Tweddale Abstract Coarse resolution remotely sensed imagery (20-30m) has lacked sufficient spatial resolution to accurately measure total vegetative cover in arid environments where vegetation cover is relatively low. New and emerging satellite and airborne imagery is now available at significantly higher spatial resolutions, resulting in pixel sizes equal to or smaller than many dominant desert shrubs. High resolution imagery was collected at four spatial resolutions for study sites in south-central Mojave Desert of southern California to assess the effects of spatial resolution on percent cover measurements for different dominant plant communities. High correlation coefficients (0.71 to 0.93) were identified between field measurements of percent cover and those derived from imagery at spatial resolutions ranging from 0.2m – 2.0m. The results indicated that a spatial resolution of 1.0m or smaller was necessary to estimate percent cover and the area of individual shrubs from imagery; and that different resolutions may be required, depending on the abundance and size of dominant and co-dominant species of desert shrub communities that are to be characterized.