Antarctic moss stress assessment based on chlorophyll content and leaf density retrieved from imaging spectroscopy data

• Published in: New Phytologist
• Main Authors: Malenovsky, Z, Turnbull, JD, Lucieer, A, Robinson, SA
• Format: Article in Journal/Newspaper
• Language: English
• Published: Blackwell Publishing Ltd 2015
• Subjects: Engineering; Geomatic Engineering; Photogrammetry and Remote Sensing; Antarctic; Antarc*; Schistidium antarctici
• Online Access: https://doi.org/10.1111/nph.13524; http://www.ncbi.nlm.nih.gov/pubmed/26083501; http://ecite.utas.edu.au/101280

The health of several East Antarctic moss-beds is declining as liquid water availability is reduced due to recent environmental changes. Consequently, a noninvasive and spatially explicit method is needed to assess the vigour of mosses spread throughout rocky Antarctic landscapes. Here, we explore the possibility of using near-distance imaging spectroscopy for spatial assessment of moss-bed health. Turf chlorophyll a and b , water content and leaf density were selected as quantitative stress indicators. Reflectance of three dominant Antarctic mosses Bryum pseudotriquetrum, Ceratodon purpureus and Schistidium antarctici was measured during a drought-stress and recovery laboratory experiment and also with an imaging spectrometer outdoors on water-deficient (stressed) and well-watered (unstressed) moss test sites. The stress-indicating moss traits were derived from visible and near infrared turf reflectance using a nonlinear support vector regression. Laboratory estimates of chlorophyll content and leaf density were achieved with the lowest systematic/unsystematic root mean square errors of 38.0/235.2 nmol g −1 DW and 0.8/1.6 leaves mm −1 , respectively. Subsequent combination of these indicators retrieved from field hyperspectral images produced small-scale maps indicating relative moss vigour. Once applied and validated on remotely sensed airborne spectral images, this methodology could provide quantitative maps suitable for long-term monitoring of Antarctic moss-bed health.