| phototolerance of lichens, mosses and higher plants in an alpine environment: analysis of photoreactions. | adaptation to excessive light is one of the requirements of survival in an alpine environment particularly for poikilohydric organisms which in contrast to the leaves of higher plants tolerate full dehydration. changes in modulated chlorophyll fluorescence and 820-nm absorption were investigated in the lichens xanthoria elegans (link) th. fr. and rhizocarpon geographicum (l.) dc, in the moss grimmia alpestris limpr. and the higher plants geum montanum l., gentiana lutea l. and pisum sativum l., ... | 2000 | 11144261 |
| the biology behind lichenometric dating curves. | lichenometry is used to date late-holocene terminal moraines that record glacier fluctuations. traditionally, it relies upon dating curves that relate diameters of the largest lichens in a population to surface ages. although widely used, the technique remains controversial, in part because lichen biology is poorly understood. we use size-frequency distributions of lichens growing on well-dated surfaces to fit demographic models for rhizocarpon geographicum and pseudophebe pubescens, two species ... | 2006 | 16237538 |
| lichens survive in space: results from the 2005 lichens experiment. | this experiment was aimed at establishing, for the first time, the survival capability of lichens exposed to space conditions. in particular, the damaging effect of various wavelengths of extraterrestrial solar uv radiation was studied. the lichens used were the bipolar species rhizocarpon geographicum and xanthoria elegans, which were collected above 2000 m in the mountains of central spain and as endolithic communities inhabiting granites in the antarctic dry valleys. lichens were exposed to s ... | 2007 | 17630840 |
| space microbiology. | the responses of microorganisms (viruses, bacterial cells, bacterial and fungal spores, and lichens) to selected factors of space (microgravity, galactic cosmic radiation, solar uv radiation, and space vacuum) were determined in space and laboratory simulation experiments. in general, microorganisms tend to thrive in the space flight environment in terms of enhanced growth parameters and a demonstrated ability to proliferate in the presence of normally inhibitory levels of antibiotics. the mecha ... | 2010 | 20197502 |
| microbial metacommunities in the lichen-rock habitat. | lichens are common as colonizers of bare rocks and contribute to weathering, but their associated bacterial communities have been poorly studied. in this study hydropunctaria maura, ophioparma ventosa, pertusaria corallina and rhizocarpon geographicum were analysed to determine the influence of lichens on lichen-rock-associated microbial metacommunities. for the first time, archaea were documented to be associated with rock-inhabiting lichens. all the archaeal sequences obtained were affiliated ... | 2011 | 23761305 |