title: Antarctic moss stress assessment based on chlorophyll content and leaf density retrieved from imaging spectroscopy data.
abstract: 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.
authors.affiliation: Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW, 2522, Australia.|Surveying and Spatial Sciences Group, School of Land and Food, University of Tasmania, Private Bag 76, Hobart, TAS, 7001, Australia.
authors.forename: Zbyněk
authors.initials: Z
authors.lastname: Malenovský
authors.affiliation: Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW, 2522, Australia.
authors.forename: Johanna D
authors.initials: JD
authors.lastname: Turnbull
authors.affiliation: Surveying and Spatial Sciences Group, School of Land and Food, University of Tasmania, Private Bag 76, Hobart, TAS, 7001, Australia.
authors.forename: Arko
authors.initials: A
authors.lastname: Lucieer
authors.affiliation: Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW, 2522, Australia.
authors.forename: Sharon A
authors.initials: SA
authors.lastname: Robinson
mesh_terms: D000864:Antarctic Regions; D044002:Bryophyta / Q000502:physiology*; D002734:Chlorophyll / Q000378:metabolism*; D000077194:Chlorophyll A; D003681:Dehydration; D055864:Droughts; D005843:Geography; D021621:Imaging, Three-Dimensional; D018515:Plant Leaves / Q000502:physiology*; D013057:Spectrum Analysis / Q000379:methods*; D013312:Stress, Physiological; D014867:Water / Q000378:metabolism
chemical_list: D014867:Water; D002734:Chlorophyll; C037184:chlorophyll b; D000077194:Chlorophyll A
keywords: Bryum pseudotriquetrum; Ceratodon purpureus; Schistidium antarctici; hyperspectral remote sensing; leaf density (LD); moss chlorophyll content (Cab); stress imaging spectroscopy; turf water content (TWC)