Advanced Photogrammetry to Assess Lichen Colonization in the Hyper-Arid Namib Desert
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 sus...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2017-10-01
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| Series: | Frontiers in Microbiology |
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| Online Access: | http://journal.frontiersin.org/article/10.3389/fmicb.2017.02083/full |
| _version_ | 1818257207118004224 |
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| author | Graham Hinchliffe Barbara Bollard-Breen Don A. Cowan Ashray Doshi Len N. Gillman Gillian Maggs-Kolling Asuncion de Los Rios Stephen B. Pointing |
| author_facet | Graham Hinchliffe Barbara Bollard-Breen Don A. Cowan Ashray Doshi Len N. Gillman Gillian Maggs-Kolling Asuncion de Los Rios Stephen B. Pointing |
| author_sort | Graham Hinchliffe |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-12-12T17:39:59Z |
| format | Article |
| id | doaj.art-71ba0d14e2094451819eff0d1e8f0087 |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-12-12T17:39:59Z |
| publishDate | 2017-10-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-71ba0d14e2094451819eff0d1e8f00872022-12-22T00:17:07ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2017-10-01810.3389/fmicb.2017.02083298291Advanced Photogrammetry to Assess Lichen Colonization in the Hyper-Arid Namib DesertGraham Hinchliffe0Barbara Bollard-Breen1Don A. Cowan2Ashray Doshi3Len N. Gillman4Gillian Maggs-Kolling5Asuncion de Los Rios6Stephen B. Pointing7Institute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Auckland, New ZealandInstitute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Auckland, New ZealandThe Genomics Research Institute, University of Pretoria, Pretoria, South AfricaInstitute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Auckland, New ZealandInstitute for Applied Ecology New Zealand, School of Science, Auckland University of Technology, Auckland, New ZealandGobabeb Research and Training Centre, Gobabeb, NamibiaDepartamento de Biogeoquímica y Ecología Microbiana, Museo Nacional de Ciencias Naturales, Madrid, SpainDivision of Science, Yale-NUS College, National University of Singapore, Singapore, SingaporeThe 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.http://journal.frontiersin.org/article/10.3389/fmicb.2017.02083/fullastrobiologycomputer visiondesertGISlichenmicrobial ecology |
| spellingShingle | Graham Hinchliffe Barbara Bollard-Breen Don A. Cowan Ashray Doshi Len N. Gillman Gillian Maggs-Kolling Asuncion de Los Rios Stephen B. Pointing Advanced Photogrammetry to Assess Lichen Colonization in the Hyper-Arid Namib Desert Frontiers in Microbiology astrobiology computer vision desert GIS lichen microbial ecology |
| title | Advanced Photogrammetry to Assess Lichen Colonization in the Hyper-Arid Namib Desert |
| title_full | Advanced Photogrammetry to Assess Lichen Colonization in the Hyper-Arid Namib Desert |
| title_fullStr | Advanced Photogrammetry to Assess Lichen Colonization in the Hyper-Arid Namib Desert |
| title_full_unstemmed | Advanced Photogrammetry to Assess Lichen Colonization in the Hyper-Arid Namib Desert |
| title_short | Advanced Photogrammetry to Assess Lichen Colonization in the Hyper-Arid Namib Desert |
| title_sort | advanced photogrammetry to assess lichen colonization in the hyper arid namib desert |
| topic | astrobiology computer vision desert GIS lichen microbial ecology |
| url | http://journal.frontiersin.org/article/10.3389/fmicb.2017.02083/full |
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