Katalog - Lichenological literature

2314

Follmann G. (1997): Hubbsia langei, a new Roccellaceae from the Atacama Desert, north Chile, and the identity of two Reinkella species, Bibl. Lichenol., 67: 11-24

Reinkella lirellina from Peru and R. parishii from California (Roccellaceae) are revised, resulting in the new combinations Roccella lirellina and Hubbsia parishii, respectively. In addition, a new species, H. langei, is described from the loma formations of the Atacama Desert, North Chile, distinguished by secondarily lobate branches, highly variable, roundish to lirellate as- cocarps, and an unusual chemosyndrome with psoromic and conpsoromic acids as main secondary products. The chorological, … Read more...

2313

Seaward M.R.D. (1997): Urban deserts bloom: a lichen renaissance, Bibliotheca Lichenologica, 67: 297-309

The improvement in lichen floras in recent years as a consequence of clean air legislation has been demonstrated in many cities. It is apparent from such studies that re-establishing lichen floras differ from those formerly wiped out by air pollution. Work in the West Yorkshire conurbation, U.K. over the past 30 years has documented the distributional and ecological responses of lichens to qualitative and quantitative changes in air pollution. From these longterm data, it has been possible to model … Read more...

2312

Brown D. & Mahmood S. (1997): Does ion loss from lichens reliably measure membrane damage?, Bibl. Lichenol., 67: 255-264

Increases in metal element concentrations in the water washings from lichens previously subjected to stress are often used as a measure of membrane damage. Experiments involving the release of elements from discs of Pel tigern horizontalis, exposed to either desiccation or heavy metal stress, are used to test the validity of this approach. A sequential elution procedure can be used to assay the actual losses from the intracellular fraction. The importance of knowing the proportion of the elements … Read more...

2311

Jensen M., Feige G. B., Kuffer M. (1997): The effect of short-time heating on wet Lobaria pulmonaria: a chlorophyll fluorescence study, Bibl. Lichenol., 67: 247-254

Wet thalli of Lobaria pulmonaria collected in La Palma (Canary Islands) were exposed to high temperatures (22°- 44°C). They were heated in the dark either in a wet atmosphere (20 min) or in a water bath (submerged for 5 min). After cooling photosynthetic parameters were determined. The chlorophyll fluorescence parameters Fv/Fm (potential electron transfer in photosystem II), AF/Fm’ (- apparent electron transport rate). qP (photochemical quench) and photosynthetic CL-evolution rate strongly declined … Read more...

2310

Schlensog M., Schroeter B., Sancho L. G., Pintado A., Kappen L. (1997): Effect of strong irradiance on photosynthetic performance of the melt-water dependent cyanobacterial lichen Leptogium puberulum (Collemataceae) Hue from the maritime Antarctic, Bibl. Lichenol., 67: 235-246

In the maritime Antarctic the cyanobacterial lichen puberulum prefers habitats that are water-supplied by snowmelt at least for a part of the year. In springtime thalli of L. puberulum can be found fully hydrated for extended periods of time even during clear days with strong irradiance. Although the combination of low thallus temperatures and strong sun radiation is generally known to be injurious to the photosy stem II none of the established indicators of photoinhibition were observed. During … Read more...

2309

Bilger W., Bohuschke M., Ehling-Schulz M. (1997): Annual time courses of the contents of carotenoids and UV-protective pigments in the cyanobacterium Nostoc commune, Bibl. Lichenol., 67: 223-234

Samples of the terrestrial cyanobacterium Nos toe commune Vaucher were collected at two different places in the vicinity of Würzburg, Germany, from August 1995 until November 1996 and analyzed for their pigment contents. Carotenoids, chlorophyll a, scytonemin and a mycosporine-like amino acid (MAA) were determined by high performance liquid chromatography or spectrophotometrically. Dry-weight related contents of chlorophyll a and carotenoids were minimal at the end of winter time and increased in … Read more...

2308

Sancho L. G., Pintado A., Valladares F., Schroeter B. & Schlensog M. (1997): Photosynthetic performance of cosmopolitan lichens in the maritime Antarctic, Bibl. Lichenol., 67: 197-210

Despite the geographical isolation of Antarctica, more than half of the lichen flora of this region is composed of cosmopolitan and bipolar species, many of them restricted to the maritime Antarctic. Since low temperatures are considered a major limiting factor for plant growth, we studied the ecophysiological behaviour of some cosmopolitan macrolichens under natural summer conditions in the maritime Antarctic and we compared the results with those obtained in the laboratory under controlled conditions. … Read more...

2307

Thomas M. A., Nash III T. H., Gries C. (1997): Ecophysiological comparison of two tropical/subtropical lichen species: Dictyonema glabratum from an alpine habitat and Coenogonium interplexum from a lowland forest, Bibl. Lichenol., 67: 183-195

The effects of variation in temperature, photon flux density and thallus water content levels on CO2 gas exchange were examined in two tropical lichen species: Coenogonium in (et-plexum, an algal dominated ascolichen, and an alpine form of Dictyonema glabratum, a basidiolichen with a cyanobacterial symbiont. The basic C02 gas exchange patterns clearly reflect the habitats from which the material was collected. For example, within the conditions of our experiments, D. glabratum exhibited a temperature … Read more...

2306

Winkler J.B. & Kappen L. (1997): Photosynthetic capacity of endolithic lichens from South-Africa, Bibliotheca Lichenologica, 67: 165-181

The photosynthetic perfonuance of four lichen species growing as endoliths or as cryptoendoliths in sandstone was investigated. Measured were net photosynthesis and dark respiration of Lecidea aff. sarcogynoides and Sarcogyne cf. austroafricana in Tshipise sandstone from Mutamba Ranch (northern Transvaal) in a semi-arid region of South-Africa and Lecidea aff. sarcogynoides, Lecidea confluentula and Lithoglypha aggregata in Clarens sandstone from the Golden Gate Highlands National Park (eastern Orange … Read more...

2305

Dietz S. & Hartung W. (1997): Regulation of the abscisic acid content in the two lichen species Hypogymnia physodes and Peltigera praetextata, Bibliotheca Lichenologica, 67: 137-144

We investigated the ABA content of Hypogymnia physodes and Peltigera praetextata sampled at natural habitats at different times of a year. The ABA content showed high variability in both lichen species and was far higher in H. physodes than in P. praetextata at ever)' time by a mean factor of about 20. Conjugation of 14C-ABA was only small in wet thalli as well as in desiccating thalli, and no oxidative degradation could be found. Efflux experiments showed relative high rate constants for ABA exchange … Read more...