Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Responses Of Plants In Polar Regions To Uvb Exposure : A Meta-Analysis, K. K. Newsham, Sharon A. Robinson
Responses Of Plants In Polar Regions To Uvb Exposure : A Meta-Analysis, K. K. Newsham, Sharon A. Robinson
Sharon Robinson
We report a meta-analysis of data from 34 field studies into the effects of UV-B radiation on Arctic and Antarctic bryophytes and angiosperms. The studies measured plant responses to decreases in UV-B radiation under screens, natural fluctuations in UV-B irradiance, or increases in UV-B radiation applied from fluorescent UV lamps. Exposure to UV-B radiation was found to increase the concentrations of UV-B absorbing compounds in leaves or thalli by 7% and 25% (expressed on a mass or area basis, respectively). UV-B exposure also reduced aboveground biomass and plant height by 15% and 10%, respectively, and increased DNA damage by 90%. …
Genetic Structure Of East Antarctic Populations Of The Moss Ceratodon Purpureus, L. J. Clarke, D. J. Ayre, Sharon A. Robinson
Genetic Structure Of East Antarctic Populations Of The Moss Ceratodon Purpureus, L. J. Clarke, D. J. Ayre, Sharon A. Robinson
Sharon Robinson
The capacity of the polar flora to adapt is of increasing concern given current and predicted environmental change in these regions. Previous genetic studies of Antarctic mosses have been of limited value due to a lack of variation in the markers or non-specificity of the methods used. We examined the power of five microsatellite loci developed for the cosmopolitan moss Ceratodon purpureus to detect genetically distinct clones and infer the distribution of clones within and among populations from the Windmill Islands, East Antarctica. Our microsatellite data suggest extraordinarily high levels of variation reported in RAPD studies were artificially elevated by …
Surface Reflectance Properties Of Antarctic Moss And Their Relationship To Plant Species, Pigment Composition And Photosynthetic Function, C. E. Lovelock, Sharon A. Robinson
Surface Reflectance Properties Of Antarctic Moss And Their Relationship To Plant Species, Pigment Composition And Photosynthetic Function, C. E. Lovelock, Sharon A. Robinson
Sharon Robinson
We investigated how surface reflectance properties and pigment concentrations of Antarctic moss varied over species, sites, microtopography, 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 …
Understanding The Tolerance Of Antarctic Mosses To Climate Change, Sharon A. Robinson, L J. Clarke
Understanding The Tolerance Of Antarctic Mosses To Climate Change, Sharon A. Robinson, L J. Clarke
Sharon Robinson
Climate change is expected to affect the high latitudes first and most severely, rendering Antarctica one of the most significant baseline environments for the study of global climate change. Despite this, there have been few long-term studies of the response of Antarctic vegetation to climate change. The Windmill Islands region supports some of the most extensive and best developed vegetation on continental Antarctica, with lush, green mossbeds along many of the lakes and melt streams close to Casey station. Over the past 12 years my University of Wollongong colleagues and I have studied the mosses of this region to better …
Uv-B Screening Potential Is Higher In Two Cosmopolitan Moss Species Than In A Co-Occurring Antarctic Endemic Moss – Implications Of Continuing Ozone Depletion, J. L. Dunn, Sharon A. Robinson
Uv-B Screening Potential Is Higher In Two Cosmopolitan Moss Species Than In A Co-Occurring Antarctic Endemic Moss – Implications Of Continuing Ozone Depletion, J. L. Dunn, Sharon A. Robinson
Sharon Robinson
Concentrations of UV-B absorbing pigments and anthocyanins were measured in three moss species, over a summer growing season in Antarctica. Pigment concentrations were compared with a range of climatic variables to determine if there was evidence that pigments were induced by UV-B radiation, or other environmental parameters, and secondly if there were differences between species in their pigment responses. Significant seasonal differences in the potential UV-B screening pigments were found, with the two cosmopolitan species Bryum pseudotriquetrum and Ceratodon purpureus appearing better protected from the potentially damaging effects of ozone depletion than the Antarctic endemic Schistidium antarctici. Bryum pseudotriquetrum accumulated …