Three species of the genus Dactylospora, D. crassa Sarrion & Hafellner, D. mediterranea Sarrión & Hafellner, and D. pseudourceolata Sarrión & Hafellner are described as new from Spain. The morphology, anatomy, and ecology of the three taxa are discussed. A key to the Spanish Dactylospora species is provided.

Szczazvinskia leucopoda Holien & Tønsberg and 5. foliicola Holien & Tønsberg are described from coastal Central Norway and Newfoundland, and from Papua New Guinea, respectively.

A key to forty-one species in ten parmelioid genera [Bulbothrix (4 spp.), Canoparmelia (1 sp.), Hypotrachyna (7 spp.), Myelochroa (1 sp.), Parmelina (2 spp.), Parmelinopsis (1 sp.), Parmotrema (18 spp.), Relicina (2 spp.), Rimelia (3 spp.) and Xanthoparmelia (2 spp.)] from New Caledonia is provided, in addition to brief taxonomic descriptions as well as notes on distribution. Five of the forty-one species are endemic to New Caledonia, and thirteen are new records for the island. Several old names used in the literature are clarified.

Montane old-growth forests on the windward slopes of interior mountain ranges in British Columbia support high loadings of arboreal lichens. These lichens represent a major source of readily labile plant material and potentially play an important role in ecosystem nutrient dynamics. Given the role of winter storms in scouring lichens from within the canopy and the extended length of winter snowpack, from November through to May or even early June, in these ecosystems, the decomposition of lichen litterfall should be heavily influenced by placement within the snowpack. We have examined this factor by placing litter bags containing samples of the hair lichens, Alectoria sarmentosa and Bryoria spp., on top of the winter snowpack in the Cariboo Mountains. Samples were set out in early- (8 Nov.) mid- (16 Jan.) and late- (22 Mar.) winter and subsequently retrieved on spring snow-melt (22 May). Lichen samples that were buried in the lower snowpack all winter long (196 days) lost two-thirds of their original mass. In contrast lichens placed on the snowpack in mid- (127 days) or late-winter (61 days) lost only 6-15% of their total mass, far less than would be predicted on the basis of time in snowpack alone. Spot measurements showed that the snowpack environment effectively buffers litter samples from extreme winter conditions. All lichen samples placed within the snowpack showed much higher C/N ratios on removal, indicating rapid leaching of readily soluble cellular constituents in the snowpack environment. These findings indicate that the snowpack environment plays a major role in decomposition processes in these high-elevation forests and reinforces our view that lichens are a readily labile nutrient source within these ecosystems.

The reactivation of net photosynthesis and dark respiration from water vapour and from liquid water in the lichen Ramalina capitata var. protecta (H. Magn.) Nimis from sheltered habitats in Central Spain was investigated. CO2 gas-exchange response and thallus water content were measured in the laboratory as dry thalli were allowed to equilibrate by water vapour uptake under different relative humidities, and as saturated thalli dried. Water content of thalli from different habitats was also measured in the field during rainfall. The results show that the lichen is very efficient in using water vapour from the air for photosynthesis. Net photosynthetic rates were measured at very low water potentials (up to – 26-9 Megapascal) with water contents of the thalli below 30% dry weight. Maximum net photosynthetic rates measured after water vapour uptake were in some cases similar to those obtained after hydration by liquid water, while respiration rates were always lower after water vapour uptake, indicating a relatively larger activation of the photobiont. Moreover, photosynthetic rates at thallus water contents below 60% dry weight were higher when hydration was achieved through water vapour uptake than with liquid water. Field measurements had shown that this lichen reached water contents through water vapour absorption of 40% dry weight that would allow a positive balance of CO2 uptake. Possible ecological implications of differences in photosynthetic activation depending on the water source are discussed in terms of the carbon gain under natural conditions of this ombrophobous lichen.

Epiphytic lichen diversity in a boggy stand of Norway spruce (Picea abies) was studied in the eastern Harz Mountains, northern Germany. Spruce trees at wet sites were affected by forest dieback, whereas trees on drier sites remained unaffected. Lichen diversity was higher on diebackaffected trees than on healthy ones. The foliose lichen Hypogymnia physodes was significantly more frequent on dead trees, whereas the crustose, extremely toxitolerant Lecanora conizaeoides occurred more frequently on healthy trees. Stemflow concentrations of NH⊂4⊃+, NO⊂3⊃-, PO⊂3⊃-, and SO⊂4⊃2- were lower on affected trees. This is attributed to reduced interception from the atmosphere due to needle loss. Cover of H. physodes decreased with increasing mean SO⊂4⊃2- concentration in stemflow. The total of lichen species per sample tree also decreased with increasing SO⊂4⊃2- concentration in stemflow, indicating that most species reacted in a similar way as H. physodes. Cover of L. conizaeoides increased with increasing SO⊂4⊂2- concentration, but decreased at higher SO⊂4⊃2- concentrations. Bark chemistry had a minor influence on lichen diversity.

High performance thin-layer chromatography/thin-layer chromatography, X-ray diffraction, and scanning electron microscopy analysis of thallus and lichen-rock interface samples, were undertaken to characterize biomineralization products in Fuscidea cyathoides, Ochrolechia tartarea, Ophioparma ventosa, and Pertusaria coralline, growing on sandstone in western Norway. Whewellite (monohydrate form of Ca oxalate) was found in the thallus of all species, but not in any of the weathering rinds beneath the species. A significantly higher amount of whewellite was detected in the thalli of F. cyathoides and O. ventosa than in the other two species. There were only a few differences in whewellite occurrence between the thallus edge and centre samples in the four species. HPTLC/TLC and SEM analysis indicate that lichen compounds occur within the rock beneath some of the lichen specimens. Only divaricatic acid was observed within the weathering rind beneath O. ventosa. No lichen substances were found in the weathering rind beneath F. cyathoides and P. corallina, whereas gyrophoric and lecanoric acids were found in the weathering rind beneath O. tartarea.