The status of the lichen genus Endocarpon Hedwig (Verrucariaceae) in Australia is reviewed. Ten taxa are recognized including the following newlydescribed entities: E. aridum McCarthy, E. crassisporum McCarthy & R. Filson, E. macrosporum McCarthy, E. robustum McCarthy, E. rogersii McCarthy and E.simplicatum var. bisporum McCarthy. Endocarpon victoriae Müll. Arg. is a synonym of E. simplicatum (Nyl.) Nyl. Endocarpon pallidum Ach. is reported for the first time from Australia. A problematical corticolous specimen from Victoria is discussed.

Generalized linear modelling was applied in analysing the bioindicator value of epiphytic lichens for air pollution around an industrial centre in the Siberian mountains using data published previously by Zobel (1988a). The occurrence of taxa on tree boles was systematically related to the distance from the pollution source and to the altitude from sea level. Binomial distribution was postulated to describe the random variation and maximum likelihood and quasi-likelihood methods were used. Zobel had pooled the original data by grouping distance and altitude into three qualitative levels. The model for pooled data with qualitative factors generally had a poor fit. We assigned quantitative values, linear and quadratic contrasts, to the altitude and distance levels and a linear by linear interaction term between altitude and distance. In most taxa the interaction appeared significant, and these models had generally a better fit and smaller overdispersion than qualitative models. Finally, more effective analysis was performed on the original plotwise data utilizing unpublished quantitative information for distance and altitude. Most species (16/19) had a significant and usually positively monotone response to distance. In the majority of these (10/16) the effect of distance varied between the altitude levels most often so that the lichens were scarcer at low altitude and their increase was faster at high altitude.

Temperate rainforests are a poorly researched habitat with respect to lichen ecophysiology in comparison to desert and polar regions. The evergreen, broadleaf forests provide a dim, moist environment that is relatively stable throughout the year. Lichens are abundant in both quantity and species diversity with the large foliose genera Sticta and Pseudocyphellaria normally being dominant, visually and in terms of biomass. These lichens exhibit a great diversity of both form and habitat range. Physiological and morphological adaptation has also been demonstrated. Pseudocyphellaria dissimilis shows changes in thallus water storage capacity with evaporative demand and is also highly shade-adapted. The species has the lowest light saturation and compensation values for photosynthesis yet known for lichens (20 and 1-μmol m−2s−1, PAR, respectively). Unexpectedly it is also highly desiccation-sensitive with some thalli being killed after only 20 h exposure to 15% relative humidity. Photobiont versatility is also a feature of these genera. Photosymbiodemes occur, i.e. a single thallus containing both green algal and cyanobacterial sectors. Because the different sectors have the same fungal partner and grow in the same habitat, it is possible to investigate whether particular physiological traits are photobiont determined. The ability to recover photosynthetic activity in humid air is confined to thalli with green algal photobionts whilst the inability of thalli containing cyanobacterial photobionts to tolerate high light stress may be related to their lack of a protective xanthophyll cycle.

A recent survey of epiphytic lichens in the Jardin du Luxembourg has shown there to be a marked improvement in the air quality of Paris over the past decade. Recolonization by at least 11 lichen species has occurred during that period. It has taken almost 100 years for epiphytic lichens to re-establish in the Jardin du Luxembourg, where William Nylander in the 1890s was able to amply confirm his far reaching hypothesis, made 30 years earlier, on the direct relationship between lichen survival and air pollution.

Lichenophagous larvae of a bagworm moth species, associated with endolithic lichens occur in the Golden Gate Highlands National Park, South Africa. Endolithic lichens weather Clarens sandstone in the park by dissolving the cementing material of the sandstone. Bagworm larvae use such loosened quartz crystals to construct the bags in which they live. By erosion of the weathered sandstone, the bagworm larvae contribute to pedogenesis in the park at an estimated rate of 4.4 kilograms per hectare per year. In addition, bagworm larvae utilize endolithic lichens as a food source and contribute to dispersal of the lichens. The larvae further contribute an estimated 200 g of organic matter per hectare per year to the park and partake in the cycling of elements in the micro-ecosystem.

Usnea elixii sp. nov. is a restricted endemic of north Queensland. It is usually fertile, but produces a continuum of morphs, with the other extreme being a sterile isidiate morph with large pseudocyphellae. All morphs produce protocetraric acid.

The first lichen records from the Maldives archipelago, based on fieldwork of the author in 1989, are presented. The flora is poor, due to lack of habitat variation; in total 20 species were found. The pantropical element is well represented. The lichen flora shows most resemblance to that of other coastal areas in the palaeotropics.

Mannitol-1-phosphate dehydrogenase [EC 1.1.1.17] activity was demonstrated in extracts of Pseudevernia furfuracea and Hypogymnia physodes. The reaction was found to be highly substrate specific for fructose-6-phosphate/NADH or mannitol-1-phosphate/NAD+. The pH optimum for fructose-6-phosphate reduction was 7.1, and apparent Km values were 1.2 mM for fructose-6-phosphate and 20 μM for NADH. The reaction did not require Mg++ or Ca++. For conversion of mannitol-1-phosphate into mannitol, the occurrence of mannitol-1-phosphatase in Pseudevernia furfuracea is postulated.

A number of physiological processes relevant to the role of lichens in mineral cycling are discussed. Consideration is given to the cellular location of positively-charged cations, showing (a) the benefits of quantifying intracellular elements for the interpretation of toxic metal stress, and (b) how distribution patterns of physiologically essential elements may be altered by desiccation and rehydration under field and laboratory conditions. The quantitative significance of these dynamic processes associated with metal uptake and loss requires verification under field conditions. A modified sequential elution procedure is proposed that enables quantification of insoluble paniculate mineral matter (acquired by wet and dry deposition) in addition to soluble elements in intercellular, extracellular-exchangeable and intracellular sites.

Epiphytic lichen communities on trunks of Pinus sylvestris and Picea abieswere studied on a west–to–east gradient through the central pan of Finland with special reference to macrolichens. Comparisons were made between the two conifer species, the coast of the Gulf of Bothnia and the more continental inland area, open commercial and denser natural forests differing in their local climate, and tree bases (0·0–0·7m) and upper trunks (0·7–2·0m). Differences were found not in species composition but in relative species abundance, the main distinction being between the two tree species. There were also noticeable geographical, vertical and habitatdependent differences. In addition to climatic factors, the importance of bark properties for the epiphytes is briefly discussed.

The nutrient contribution of lichens as litterfall in forests is discussed for a number of different ecosystems and it is hypothesized that lichens are important in capturing nutrients from wet deposition, occult precipitation, sedimentation, impaction and gaseous uptake. Most nutrients captured by these processes represent new nutrient inputs that would otherwise not be intercepted by the ecosystem. Part of these nutrients will be incorporated into lichen biomass and only become available upon death and decomposition, but a portion will be leached by precipitation and become deposited on the soil surface. Although quantifying nutrient sources, fluxes and pool sizes is a potentially complex task, we describe a simplified approach for determining whether lichens significantly affect the mineral cycling of a forest. Preliminary results for an oak woodland in California document that epiphytic lichens may reduce throughfall and alter throughfall chemistry.

A technique for transplanting epiphytic lichens is described by reference to a rescue operation involving Lobaria amplissima at Lowther Park, Cumbria. Fourteen transplantswere monitored for 10 years after which period 70% survived. All failures occurred during the first 12 months.

Available evidence indicates that basal regions of well-developed lichen mats are composed largely of dead or senescent thallus material. Marked vertical gradients in concentrations of N, P and K in thalli of mat lichens, together with results of N budget studies in Cladonia stellaris and Stereocaulon paschale, suggest that these key elements may be recycled internally to fund new growth at the apices. It is argued that nutrient recycling will increase rates of both apical growth and basal necromass production and that under steady-state conditions this will result in deeper mats and facilitate dominance sensu Grime; thus accumulation of necromass may be an ecological advantage in mat-forming lichens. Basal necromass of the N2-fixing S. paschale contains more N than necromass of the non-N2-fixing C. stellaris; this may be due in part to a greater allocation of N to irrecoverable fungal cell wall components in S. paschale and may underlie a greater requirement for N in this mycobiont.