Impact of changes in UV and visible radiation on the reflective properties of plant photosynthetic surfaces

We investigated how surface reflectance properties and pigment concentrations of Antarctic moss varied over species, sites, icrotopography, and with water content. We found that species had significantly different surface reflectance properties, particularly in the region of the red edge (approximately 700 nm), but this did not correlate strongly with pigment concentrations. Surface reflectance of moss also varied in the visible region and in the characteristics of the red edge over different sites. Reflectance parameters, such as the Photochemical Reflectance Index (PRI) and Cold Hard Band (CBH) were useful discriminators of site, microtopographic position and water content. The PRI was correlated both with the concentrations of active xanthophyll-cycle pigments and the photosynthetic light use efficiency, Fv/Fm, measured using chlorophyll fluorescence. Water content of moss strongly influenced the amplitude and position of the red-edge as well as the PRI, and may be responsible for observed differences in reflectance properties for different species and sites. All moss showed sustained high levels of photoprotective xanthophyll pigments, especially at exposed sites, indicating moss is experiencing continual high levels of photochemical stress.

The fields in this dataset are:

Sample
Ridge/Valley
Site
Species
Pigments

The site codes used in this dataset are:
ROB = Robinson Ridge (Windmill Islands)
RS = Red Shed (Casey Living Quarters - inside station limits)
SC = Science Building (Casey - inside station limits)

The species codes used in this dataset are:
B = Bryum pseudotriquetrum
C = Ceratodon purpureus
G= Grimmia antarctici