Virtual Recording of Lichen Species: Integrating Terrestrial Laser Scanning and Gis Techniques

Abstract

Rock outcrops along ridgelines, in block fields, and on cliff faces of Shenandoah National Park (SNP) provide unique habitats for numerous rare and endemic biotas. However, there are recent concerns about the long-term sustainability of these populations because of increased park usage (e.g., hiking, rock climbing) and environmental change (e.g., air chemistry, quality). Analysis of lichen-population dynamics provides insight into the rate at which these habitats are being degraded. As such, there is a need to develop a method to rapidly and accurately assess changes in lichen communities through space and over time. This study presents a new approach designed to record lichen species on rock outcrops. Terrestrial laser scanning (TLS) offers a new technique for recording individual lichen species (e.g., abundance, spatial distribution, extent, size, shape). An automated process is described to extract the lichen extent and shape in a standard GIS environment. These data are used to examine size classes, frequency, percent cover, and spatial pattern of a species of Phlyctis. The methodology and data extracted greatly improve rapid assessments and long-term monitoring of lichen populations.