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Epiphytic lichens play a key hydrological role in ecosystems by intercepting and retaining water. These attributes can be characterized at an individual thallus scale by considering the retention and loss rates of water, themselves influenced by growth form and anatomy. We compared the hydrological attributes (water-holding capacity and standard drying rate) of two common northern temperate-boreal lichen genera, Evernia and Usnea, which differ greatly in internal anatomy. Despite conspicuous morphological and anatomical differences between the taxa that were hypothesized to affect thallus-water dynamics, their hydrological traits were found to be remarkably similar. This suggests either limited influence of internal anatomy on these ecologically relevant traits or convergence in hydrological attributes in co-occurring taxa. [ABSTRACT FROM AUTHOR]

A revision of the North American members of the Leptogium saturninum group (i.e. species with long lower-surface hairs, isidia, and usually smooth upper surface) is presented based on molecular phylogenetic analyses of mtSSU and nrITS sequence data, together with an extensive morphological study. Three species supported by both molecular and morphological characteristics are recognized: L. acadiense sp. nov. (distinguished by granular saturninum-type isidia, medulla composed of irregularly arranged or perpendicular hyphae), L. cookii sp. nov. (distinguished by cylindrical saturninum-type isidia) and L. hirsutum (distinguished by hirsutum-type isidia and medulla composed of loosely intertwined hyphae). One species supported by morphological characteristics, but for which no molecular data could be generated, is also recognized: L. compactum sp. nov. (distinguished by hirsutum-type isidia and medulla composed of tightly packed hyphae). Finally, L. saturninum (distinguished by granular saturninum-type isidia and medulla composed of perpendicular and parallel hyphae) is supported by morphological characteristics but molecular data from geographically diverse populations, including those near the type locality, indicate that the morphologically defined species is paraphyletic. Leptogium burnetiae is excluded from North American based on morphological study of the type. The species are described and illustrated in detail, and are distinguished morphologically by their isidium development, morphology of mature isidia, and pattern of hyphae in the medulla in transverse sections near lobe margins. A key to the members of the L. saturninum group and related species is also presented. [ABSTRACT FROM PUBLISHER]

Harvesting of fog water by epiphytes is biomechanically analogous to filter-feeding by aquatic invertebrates. Increased branchiness, as measured by fractal dimensionality, should reflect greater fog-harvesting ability. We documented changes in epiphytic macrolichens across an altitudinal gradient in fog availability in a coastal shrubland in northern Chile. Fruticose and foliose genera appear to become more abundant with increased fog availability. Fractal dimension of fruticose and foliose lichens increased significantly with inferred fog availability. The adaptive morphology of lichens is under-studied, and insights from theoretical morphology of other organisms yield fruitful hypotheses for further studies. [ABSTRACT FROM AUTHOR]

Abstract: Macrolichen community structure and traits were examined across a high elevation gradient in southwestern British Columbia. To our knowledge, the current study is the first to examine lichen phylogeny and community traits along a gradient of elevation. Samples were collected from 13 plots, every 50m from 1200 to 1800m at Joffre Lakes Provincial Park. Species richness within this zone had a unimodel distribution from low to high elevation and peaked at an intermediate elevation. Canonical correspondence analysis (CCA) confirmed that a distinct lichen community structure and assemblage of lichens is represented across the gradient of elevation. The covariate for lichen phylogeny explained 9% of the variation in community assemblage along the gradient of elevation. Lichen traits explained 91% of the variation in community assemblage. The first CCA axis distinguishes between alpine and forest lichen communities, and identified important microhabitats and traits used to explain variation in the species associations. The second CCA axis makes a distinction between higher and lower elevations and is strongly correlated with variables such as the presence of specific microhabitats (i.e. rock, wood, or bark), and lichen traits. Within the elevation range assessed, the analysis indicated three distinct lichen communities, one in alpine ecosystems, one in higher elevations forests and one in mid elevation forests. These results provide forest managers with an increased understanding of lichen community structure across elevation gradients and of indicator species and their associated traits, which can assist with management strategies that include the preservation of biodiversity. [Copyright &y& Elsevier]

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The Italian distribution of the rare boreal-circumpolar macrolichen Usnea longissima is revised on the basis of a critical re-evaluation of bibliographic and field data. Reported from all Alpine regions of Italy, the species presently survives only in two neighbouring Alpine valleys of Friuli and Veneto. The Friulian population consists of a few thalli on a single tree near the lake of Sauris, while in Veneto scattered populations were observed in nine stands of Val Visdende with ca. 200 colonised trees. The species seems to be locally extinct in Trentino-Alto Adige. Earlier records from Lombardy, Piedmont and Aosta Valley are wrong or at least questionable. Usnea longissima can be considered as critically endangered at the national level. Some recommendations for forest managers are proposed. [ABSTRACT FROM AUTHOR]

Biodiversity surveys were conducted in 13, 10×50 m2 plots located between 1400 to 3700 m above mean sea level in a range of habitats in temperate mixed Oak and Coniferous forests through sub-alpine to the alpine grasslands in Chamoli district of Uttaranchal state in the Indian Garhwal Himalaya. Cross-taxon congruence in biodiversity (α-diversity and β-diversity) across macrolichens, mosses, liverworts, woody plants (shrubs and trees) and ants was investigated, so as to examine the extent to which these groups of organisms can function as surrogates for each other. Although woody plants provided a major substrate for macrolichens and mosses, there was no species-specific association between them. Woody plant species richness was highly positively correlated with mosses (r2=0.63, P<0.001), but the relationship was not particularly very strong with lichens and liverworts. While there was a significant correlation in the species turnover (β-diversity) of macrolichens with mosses (r2=0.21, P<0.005), the relationship was relatively poor with the woody plants. On the other hand, negative correlations emerged in the species richness of ants with those of macrolichens, mosses and woody plants (r2=−0.44, P<0.05), but most of the complementarity (turnover) relationships among them were positive. Since diversity between taxonomic hierarchies within the group was consistently significantly positively correlated in all these taxa, the higher taxonomic categories such as genus and family may be employed as surrogates for rapid assessment and monitoring of species diversity. Although no single group other than macrolichens has emerged as a good indicator of changes in species richness in all other groups, some concordant relationships between them conform to the hypothesis that species assemblages of certain taxonomic groups could still be used as surrogates for efficient monitoring of species diversity in other groups whose distribution may further predict the importance of conserving overall biodiversity in landscapes such as the Garhwal Himalaya. [Copyright &y& Elsevier]

To maintain biodiversity in managed forests we must understand how forestry affects various organisms across a wide range of spatial and temporal scales. We compared landscape structure, forest structure, and species richness and abundance of epiphytic macrolichens in three pairs of natural and managed boreal forest landscapes. Study landscapes (2 500 ha) were located within and adjacent to three of the largest forest reserves in Sweden (Reivo, Muddus, Jelka). The structural heterogeneity within landscapes was higher in managed forests whereas within-stand structural heterogeneity was higher in natural landscapes. Species richness of macrolichens at the stand level (sample plot) was 23% higher in natural forests but there was no difference at the landscape level. Most (86%) of the common species were more frequent in natural landscapes. Lichen abundance (estimated by lichen litter) was two times higher in natural than in managed landscapes, 5.6 and 2.7 kg ha-1 forest (pooled data), respectively. Both species richness and abundance were negatively related to cutting level (number and basal area of cut stumps) and positively related to stand variables (stand age, stem density and basal area). Lichen-rich forest stands were more numerous but covered a smaller area and were more isolated in managed landscapes. This may in turn have important consequences for dispersal of lichen propagules to second-growth forests. In conclusion,the results suggest that effects of forestry on epiphyte diversity and abundance are strongly related to the spatial scale (stand or landscape). To enhance biodiversity in managed forests we must increase structural heterogeneity at the whole range of spatial and temporal scales. [ABSTRACT FROM AUTHOR]