UAV RGB, thermal infrared and multispectral imagery used to investigate the control of terrain on the spatial distribution of dryland biocrust
Blanco-Sacristán, Javier (University of Milano-Bicocca)
Panigada, Cinzia (University of Milano-Bicocca)
Gentili, Rodolfo (University of Milano-Bicocca)
Tagliabue, Giulia (University of Milano-Bicocca)
Garzonio, Roberto (University of Milano-Bicocca)
Martín, M. Pilar (Consejo Superior de Investigaciones Científicas (Espanya))
Ladrón de Guevara, Mónica (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Colombo, Roberto (University of Milano-Bicocca)
Dowling, Thomas P. F. (United Nations Environment Programme World Conservation Monitoring Centre)
Rossini, Micol (University of Milano-Bicocca)

Date:	2021
Abstract:	Biocrusts (topsoil communities formed by mosses, lichens, bacteria, fungi, algae, and cyanobacteria) are a key biotic component of dryland ecosystems. Whilst climate patterns control the distribution of biocrusts in drylands worldwide, terrain and soil attributes can influence biocrust distribution at landscape scale. Multi-source unmanned aerial vehicle (UAV) imagery was used to map and study biocrust ecology in a typical dryland ecosystem in central Spain. Red, green and blue (RGB) imagery was processed using structure-from-motion techniques to map terrain attributes related to microclimate and terrain stability. Multispectral imagery was used to produce accurate maps (accuracy > 80%) of dryland ecosystem components (vegetation, bare soil and biocrust composition). Finally, thermal infrared (TIR) and multispectral imagery was used to calculate the apparent thermal inertia (ATI) of soil and to evaluate how ATI was related to soil moisture (r2 = 0. 83). The relationship between soil properties and UAV-derived variables was first evaluated at the field plot level. Then, the maps obtained were used to explore the relationship between biocrusts and terrain attributes at ecosystem level through a redundancy analysis. The most significant variables that explain biocrust distribution are: ATI (34. 4% of variance, F = 130. 75; p < 0. 001), Elevation (25. 8%, F = 97. 6; p < 0. 001), and potential solar incoming radiation (PSIR) (52. 9%, F = 200. 1; p < 0. 001). Differences were found between areas dominated by lichens and mosses. Lichen-dominated biocrusts were associated with areas with high slopes and low values of ATI, with soil characterized by a higher amount of soluble salts, and lower amount of organic carbon, total phosphorus (Ptot) and total nitrogen (Ntot). Biocrust-forming mosses dominated lower and moister areas, characterized by gentler slopes and higher values of ATI with soils with higher contents of organic carbon, Ptot and Ntot. This study shows the potential to use UAVs to improve our understanding of drylands and to evaluate the control that the terrain has on biocrust distribution.
Grants:	European Commission 647038 European Commission 721995
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Apparent inertia ; Thermal ; Biocrusts ; Biological soil crusts ; Drylands ; Lichen ; Moss ; Multispectral ; UAV
Published in:	Earth surface processes and landforms, Vol. 46, Issue 12 (July 2021) , p. 2466-2484, ISSN 1096-9837

DOI: 10.1002/esp.5189
PMID: 34690397

19 p, 73.5 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > CREAF (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Articles > Research articles
Articles > Published articles