Hemlock woolly adelgid (Adelges tsugae Annand, HWA) outbreaks are posing one of biggest threats to Eastern hemlock (T. canadensis L. Carr.) and Carolina hemlock (T. caroliniana Engelm.) in the eastern United States. Modern, cost-efficient monitoring methods for disturbance agents are urgently needed. The recent development of remote sensing technologies has provided new tools for forest damage inventory and monitoring. The target area is the Grandfather Ranger District, Southern Appalachian Mountains, NC, where both Eastern and Carolina hemlocks serve as a foundation species. The objectives of this project are 1) to detect Eastern and Carolina hemlock patches via high resolution aerial imagery, 2) to study extent of tree mortality by HWA and 3) to reveal spatial patterns of living and dead hemlocks patches. The results could be used e.g. to estimate impacts of HWA and to study potential of invasive plant species establishment in forest canopy gaps created after hemlock elimination by HWA.