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dc.contributor.author | Hinchcliffe, Graham![]() |
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dc.contributor.author | Bollard-Breen, Barbara![]() |
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dc.contributor.author | Cowan, Don A.![]() |
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dc.contributor.author | Doshi, Ashray![]() |
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dc.contributor.author | Gillman, Len N.![]() |
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dc.contributor.author | Maggs-Kolling, Gillian![]() |
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dc.contributor.author | De Los Rios, Asuncion![]() |
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dc.contributor.author | Pointing, Stephen B.![]() |
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dc.date.accessioned | 2017-11-20T06:16:22Z | |
dc.date.available | 2017-11-20T06:16:22Z | |
dc.date.issued | 2017-10-27 | |
dc.description.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 Stellarangia spp. assemblage had coverage of 22.8% of available substrate, whilst for a black Xanthoparmelia spp. assemblage coverage was markedly lower at 0.6% of available substrate. Hyperspectral signatures for both lichens were distinct in the near-infra red range indicating that Xanthoparmelia spp. was likely under relatively more moisture stress than Stellarangia spp. at the time of sampling, and we postulate that albedo effects may have contributed to this in the black lichen. Further transformation of the data revealed a colonization preference for west-facing quartz surfaces and this coincides with prevailing winds for marine fog that is the major source of moisture in this system. Furthermore, a three-dimensional ‘fly through’ of the lichen habitat was created to illustrate how the application of computer vision in microbiology has further potential as a research and education tool. We discuss how advanced photogrammetry could be applied in astrobiology using autonomous rovers to add quantitative ecological data for visible surface colonization on the surface of Mars. | en_ZA |
dc.description.department | Genetics | en_ZA |
dc.description.librarian | am2017 | en_ZA |
dc.description.sponsorship | AdLR thanks the support of the grant CTM2015-64728-C2-2-R from the Spanish Ministry of Economy, Industry and Competitiveness. | en_ZA |
dc.description.uri | http://www.frontiersin.org/Microbiology | en_ZA |
dc.identifier.citation | Hinchcliffe G, Bollard-Breen B, Cowan DA, Doshi A, Gillman LN, Maggs-Kolling G, de Los Rios A and Pointing SB (2017) Advanced Photogrammetry to Assess Lichen Colonization in the Hyper-Arid Namib Desert. Front. Microbiol. 8:2083. DOI: 10.3389/fmicb.2017.02083. | en_ZA |
dc.identifier.issn | 1664-302X (online) | |
dc.identifier.other | 10.3389/fmicb.2017.02083 | |
dc.identifier.uri | http://hdl.handle.net/2263/63200 | |
dc.language.iso | en | en_ZA |
dc.publisher | Frontiers Research Foundation | en_ZA |
dc.rights | © 2017 Hinchcliffe, Bollard-Breen, Cowan, Doshi, Gillman, Maggs- Kolling, de Los Rios and Pointing. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). | en_ZA |
dc.subject | Astrobiology | en_ZA |
dc.subject | Computer vision | en_ZA |
dc.subject | Desert | en_ZA |
dc.subject | Geographic information system (GIS) | en_ZA |
dc.subject | Lichen | en_ZA |
dc.subject | Microbial ecology | en_ZA |
dc.subject | Namib Desert | en_ZA |
dc.subject | Photogrammetry | en_ZA |
dc.subject | Disturbance | en_ZA |
dc.subject | Life | en_ZA |
dc.subject | Community | en_ZA |
dc.subject | Ecosystems | en_ZA |
dc.subject | Mars | en_ZA |
dc.subject | Outer space | en_ZA |
dc.subject | Atacama Desert | en_ZA |
dc.subject | Environmental gradients | en_ZA |
dc.subject | Biological soil crusts | en_ZA |
dc.title | Advanced photogrammetry to assess lichen colonization in the hyper-arid Namib Desert | en_ZA |
dc.type | Article | en_ZA |