AUTHOR=Hinchliffe Graham , Bollard-Breen Barbara , Cowan Don A. , Doshi Ashray , Gillman Len N. , Maggs-Kolling Gillian , de Los Rios Asuncion , Pointing Stephen B. TITLE=Advanced Photogrammetry to Assess Lichen Colonization in the Hyper-Arid Namib Desert JOURNAL=Frontiers in Microbiology VOLUME=8 YEAR=2017 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.02083 DOI=10.3389/fmicb.2017.02083 ISSN=1664-302X ABSTRACT=
The hyper-arid central region of the Namib Desert is characterized by quartz desert pavement terrain that is devoid of vascular plant covers. In this extreme habitat the only discernible surface covers are epilithic lichens that colonize exposed surfaces of quartz rocks. These lichens are highly susceptible to disturbance and so field surveys have been limited due to concerns about disturbing this unusual desert feature. Here we present findings that illustrate how non-destructive surveys based upon advanced photogrammetry techniques can yield meaningful and novel scientific data on these lichens. We combined ‘structure from motion analysis,’ computer vision and GIS to create 3-dimensional point clouds from two-dimensional imagery. The data were robust in its application to estimating absolute lichen cover. An orange