Learn More
Green lichens have been shown to attain positive net photosynthesis in the presence of water vapour while blue-green lichens require liquid water (Lange et al. 1986). This behaviour is confirmed not only for species with differing photobionts in the genusPseudocyphellaria but for green and blue-green photobionts in a single joined thallus (photosymbiodeme),(More)
Hypolithic microbial communities (i.e. cryptic microbial assemblages found on the undersides of translucent rocks) are major contributors of carbon input into the oligotrophic hyper-arid desert mineral soils of the Eastern Antarctic Dry Valleys. Here we demonstrate, for the first time, that hypolithic microbial communities possess both the genetic capacity(More)
The goals of this study were to accurately determine the annual growth rate of two key lichen species for lichenometric studies in Tierra del Fuego and to provide more information on recent glacial evolution in the southernmost mountain range of South America. The study site was located on recent moraines deposited in front of a terminus of Pia Glacier in(More)
There is growing interest in what controls the present distribution of terrestrial vegetation in Antarctica because of the potential use of biodiversity as an indicator or predictor of the effects of climate change. Recent advances in knowledge of distribution and ecophysiological performance of terrestrial vegetation means that an initial analysis of the(More)
Photosynthetic activity, detected as chlorophyll a fluorescence, was measured for lichens under undisturbed snow in continental Antarctica using fibre optics. The fibre optics had been buried by winter snowfall after being put in place the previous year under snow-free conditions. The fibre optics were fixed in place using specially designed holding(More)
CO2 exchange and fluorescence yield of the crustose lichen Buellia frigida were measured in situ by means of a CO2 porometer and a PAM-2000, a newly developed portable fluorescence system. The pulse amplitude modulation system of the PAM-2000 allows measurements in the field under ambient light, temperature and moisture conditions without dark adaptation of(More)
Lichens make up a major component of Antarctic vegetation; they are also poikilohydric and are metabolically active only when hydrated. Logistic constraints have meant that we have little idea of the length, timing or environmental conditions of activity periods of lichens. We present the results of a three-year monitoring of the activity of the lichen(More)
Investigations of lichens collected in 1959/1960, 1963/1964 and 2003 from near the Beardmore Glacier in the southern Ross Sea region (84°S) have more than doubled the number of known lichen species in the area to around 30. The ranges of 15 species have been extended to 84°S. A lichen diversity hotspot has also been found along Ebony Ridge and its(More)
Antarctica, with its almost pristine conditions and relatively simple vegetation, offers excellent opportunities to investigate the influence of environmental factors on species performance, such information being crucial if the effects of possible climate change are to be understood. Antarctic vegetation is mainly cryptogamic. Cryptogams are poikilohydric(More)
Pseudocyphellaria dissimilis, a foliose, cyanobacterial lichen, is shown not to fit into the normal ecological concept of lichens. This species is both extremely shade-tolerant and also more intolerant to drying than aquatic lichens previously thought to be the most desiccation-sensitive of lichens. Samples of P. dissimilis from a humid rain-forest site in(More)