Mapping lichen distribution on the Antarctic Peninsula using remote sensing, lichen spectra and photographic documentation by citizen scientists

Figures & data

Fig. 1  Spectra of the three lichen genera used in this study.

Fig. 2  (a) Location of the ground-truthing sites (open circles) along the Antarctic Peninsula, where the large black squares indicate the extent of the Landsat 7 tiles and the large grey squares indicate the extent of the Landsat 8 tiles. (b) The South Shetland Islands (Fig. 3) and (c) the Danco Coast area (close to Anvers Island). The projection of the maps is Lambert Azimuthal Equal Area.

Fig. 3  (a) Normalized Difference Vegetation Index (NDVI; >0.2) analysis for north-west Deception Island and (c) Half Moon Island, South Shetland Islands (see Fig. 2), using Landsat 8 imagery. (b) Matched filtering analysis for north-west Deception Island and (d) Half Moon Island, using Landsat 7 imagery. (See Supplementary Table S1 for details on the Landsat scenes.) The projection of the maps is Lambert Azimuthal Equal Area.

Table 1 Areas covered by the pixels detected as lichen-covered by the matched filtering analysis and Normalized Difference Vegetation Index (NDVI), and the percentages of overlap between them

Type of endmember and NDVI	Area (pixels)	% Overlap
Buellia sp.	72 133	–
Caloplaca sp.	28 926	–
Usnea sp.	27 605	–
NDVI (0.05)	34 148	–
NDVI (0.1)	20 386	–
NDVI (0.2)	11 351	–
Buellia sp. over Caloplaca sp.	23 484	81.0
Buellia sp. over Usnea sp.	27 047	97.9
Usnea sp. over Caloplaca sp.	22 985	83.2
Buellia sp. over NDVI (0.06)	17 864	52.3
Buellia sp. over NDVI (0.1)	12 588	61.7
Buellia sp. over NDVI (0.2)	5251	46.2