Bryophyte and lichen diversity: A comparative study

Abstract We describe the regional species richness, variation in species richness and species turnover of bryophytes and lichens from 36 sites in lowland forests of southeastern Australia. The analyses subdivided the two major taxa into their constituent sub-groups: mosses, liverworts, and crustose, fruticose and foliose lichens. They also explored correlations between selected environmental variables and patterns of diversity. On a regional scale, there were 77 species of bryophytes and 69 species of lichens, giving a total of approximately one-third of the total number of vascular plant species in the region. Mean species richness was higher for lichens than bryophytes. Also, the two taxa were negatively correlated because lichens favoured dry sites and bryophytes favoured moist ones. Species turnover was greater for bryophytes than lichens, largely due to the distribution of liverwort species. Foliose lichens showed higher levels of turnover than crustose lichens. Multiple regression and canonical correspondence analysis showed that both taxa and all sub-groups responded to the same three variables: vascular plant cover, time since last fire and topographic position. Other variables, including time since logging and intensity of logging, explained little variation in bryophyte or lichen diversity. The data suggest that the strategies for the conservation of bryophyte and lichen biodiversity will be different, to reflect the different patterns of species richness and species turnover.     

FREQUENCY,DIVERSITY AND ECOLOGICAL STRATEGIES OF EPIPHYTIC LICHENS IN THE SWISS CENTRAL PLATEAU AND THE PRE-ALPS

To identify representative quantitative criteria for the creation of a future Red List of epiphytic lichens, 849 trees in 132 long-term ecological observation plots in the Swiss Central Plateau and the Pre-Alps were surveyed by standard sampling. Based on the trees, frequency data of the lichen taxa observed are described by the log series model, indicating the controlling effect of few ecological factors. Based on the plots, four classes of scarcity, each comprising 25% of the species, were established. As a contribution to the development of a national, representative survey of lichens, α-diversity (species richness, species density) andβ-diversity (dissimilarity) were calculated in terms of region, vegetation formation, vegetation belt and for their combinations. Differences in lichen diversity between the Central Plateau and the Pre-Alps were caused by the bigger elevational range in the Pre-Alps, which resulted in a higher species richness. α-Diversity of forest and non-forest were similar, whereas each vegetation formation showed one third of its species restricted to it. The contributions to the total lichen diversity of crustose, foliose and fruticose as well as of generative and vegetative species was calculated. Specific features along the altitudinal gradient of vegetation belts emerged: the percentage of crustose and generative lichens declined with every altitudinal step, increased in fruticose and vegetative lichens, and was the same in foliose species.     

Differential effects of reindeer on high Arctic lichens

Abstract. We studied the effects of Svalbard reindeer on the abundance of lichens in Spitsbergen. A survey was carried out in 14 areas with contrasting reindeer densities. Separate cover estimates for crustose, fructose and foliose lichens were taken in each area, and related to the density of reindeer pellet groups, a measure of reindeer density. Dominant macro lichen families were identified in 10 areas, and a full record of macrolichen species was taken in four additional areas. Variation in reindeer density is partially due to past overhunting, and subsequent incomplete recovery, releasing some areas from reindeer grazing for 100–200 yr. The cover of fruticose lichens was negatively related to reindeer pellet group density, indicating suppression by Svalbard reindeer. This makes their impact comparable to other members of the Rangifer genus around the northern hemisphere. The generally recorded low abundance of lichens in the diet of Svalbard reindeer compared to other Rangifer species, therefore, was interpreted as the depletion of fruticose lichens in Spitsbergen, and a subsequent switch to alternative foods. Of all fruticose lichens, Stereocaulon spp. appeared least sensitive to grazing. Crustose and foliose lichen cover was independent of reindeer pellet group density. The cover of crustose lichens was significantly related to latitude, with greater cover in more northern areas. Foliose lichens were more abundant in places where moss cover was high. We conclude that the impact of Svalbard reindeer on lichens is dependent on growth form, with fruticose lichens suffering from grazing, whereas foliose lichens might indirectly benefit from higher densities of reindeer or, like crustose lichens, be controlled by other factors.     

西藏地衣物种多样性的海拔梯度分析

根据西藏地衣分类和区系的文献资料,对西藏地衣物种多样性的海拔梯度进行了分析。267个分类群按照生长型或者基物被分为六组。每一组地衣的物种丰度随海拔增加呈现单峰曲线形式的变化。多数组物种丰度的峰值出现在海拔3400~3900m之间,对应于山地寒温带针叶林带的上半部分,比尼泊尔对应类群出现极值的海拔要高。此植物带谱内复杂的生态系统可能是物种多样性高的主要原因。壳状地衣物种丰度的峰值出现在5100~5400m区间则可能是因为该区内高大的树木的消失以及具有充裕的阳光。西藏的地衣物种多样性远低于尼泊尔,两地共有的物种数量很少。对西藏地衣物种多样性的调查不充分应当是其主要原因,因此今后中国地衣学工作者应当加强西藏地衣多样性的研究。     

Fungal specific primers for PCR‐amplification of mitochondrial LSU in lichens

Fungal specific primer sequences for the amplification of the large subunit of the mitochondrial ribosomal DNA (mtLSU) are presented in this paper. Fungal specific primers make the separation of fungal and algal cells prior to DNA‐extraction from lichens unnecessary. This is especially useful in crustose and small foliose and fruticose lichens. An example from a complex of closely related species of the crustose lichen genus Biatora shows the usefulness of mtLSU‐sequences for studies of infraspecific variability and lower level systematics of lichenized ascomycetes.     

西藏地衣物种多样性的海拔梯度分析

根据西藏地衣分类和区系的文献资料,对西藏地衣物种多样性的海拔梯度进行了分析。267个分类群按照生长型或者基物被分为六组。每一组地衣的物种丰度随海拔增加呈现单峰曲线形式的变化。多数组物种丰度的峰值出现在海拔3400~3900m之间,对应于山地寒温带针叶林带的上半部分,比尼泊尔对应类群出现极值的海拔要高。此植物带谱内复杂的生态系统可能是物种多样性高的主要原因。壳状地衣物种丰度的峰值出现在5100~5400m区间则可能是因为该区内高大的树木的消失以及具有充裕的阳光。西藏的地衣物种多样性远低于尼泊尔,两地共有的物种数量很少。对西藏地衣物种多样性的调查不充分应当是其主要原因,因此今后中国地衣学工作者应当加强西藏地衣多样性的研究。     

Lichen communities and the associated fauna on a rocky sea shore on Bornholm in the Baltic

Thirty-three sampling sites representing 11 lichen dominated plant communities on maritime rocks on Bornholm were analysed with respect to composition of the vegetation, number of animals present and gross taxonomic composition of the fauna. The specific fauna of one moss and seven lichen species was examined.
The lichen communities studied were largely the same as those found in similar studies in NW Europe, except for the recognition of a distinct Ramalina cuspidata community. The highest average number of animals per area was found in the Schistidium maritimum and the Ramalina siliquosa communities, whereas the highest average number of animals g⁻¹ dry plant biomass was recorded in the Parmelia saxatilis community. Among the species examined Anaptychia fusca contained the highest average number of animals g⁻¹ dry thallus and Ramalina cuspidata the lowest number, 114 and 7, respectively. Collemboles appeared to dominate in the moss Schistidium maritimum and in foliose lichens, whereas mites dominated in crustose and fruticose lichens.     

Ultrastructure of snail grazing damage to calcicolous lichens

The identification of damaged lichens is often difficult due to changes in the morphology of regenerating specimens. We examined the Ultrastructure of grazing damages to four species of calcicolous lichens ( Aspicilia calcarea, Physcia adscendens, Tephromela atra and Xanthoria parietina ) and free-living cyanobacteria (family Chroococcaceae) caused by individuals of four species of land snails ( Chondrina clienta, Balea perversa, Clausilia bidentata and Helicigona lapicida ). We also investigated the radular structure of the four lichen-feeding snails to examine whether differences in radular morphology result in species-specific grazing damages. Individuals of all four snail species removed the cyanobacteria layer covering the limestone or lichen surfaces. The four lichen species were grazed to a different extent by the different snail species. SEM-images showed that B. perversa left distinct depressions on the thalli of A. calcarea , whereas H. lapicida grazed off the thalli of this lichen rather evenly. Both snail species left visible radular traces on the lichen surface. In contrast, Ch. clienta left shallow depressions without radular traces on the thalli of A. calcarea. In Tephromela atra , grazing damages were observed on both thallus and ascocarp. Ascocarps of T. atra were partly grazed by B. perversa. Helicigona lapicida grazing on T. atra removed more or less evenly the entire lichen tissue including the ascocarps. In foliose lichens, grazing by Ch. clienta, B. perversa and Cl. bidentata resulted in depressions of different depths, while H. lapicida removed entire pieces of the thalli. In general, radular traces were less distinct in foliose lichens than in crustose lichens.     

A bird’s eye view of the peppered moth

Industrial melanism in Biston betularia is one of the best known examples of the role of natural selection in evolution and has received considerable scrutiny for many years. The rise in frequency of the dark form of the moth (carbonaria) and a decrease in the pale form (typica) was the result of differential predation by birds, the melanic form being more cyptic than typica in industrial areas where the tree bark was darkened by air pollution. One important aspect of early work evaluating the relative crypsis of the forms of B. betularia on tree trunks with different lichen flora was the reliance on human observers. Humans, however, do not have the same visual capabilities as birds. Birds have well‐developed ultraviolet (UV) vision, an important component of their colour processing system that affects many aspects of behaviour, including prey detection. We examined the UV characteristics of the two forms of B. betularia and a number of foliose and crustose lichens. In human visible light the speckled form typica appeared cyptic when seen against a background of foliose lichen, whereas the dark form carbonaria was conspicuous. Under UV light the situation was reversed. The foliose lichens absorbed UV and appeared dark as did carbonaria. Typica, however, reflected UV and was conspicuous. Against crustose lichens, typica was less visible than carbonaria in both visible and UV light. These findings are considered in relation to the distribution and recolonization of trees by lichens and the resting behaviour of B. betularia.     

The ecology and distribution of lichens in tropical deciduous and evergreen forests of northern Thailand

During three years of research on epiphytic lichen communities as indicators of environmental change in northern Thailand plots were set up in a range of forest types between 400 and 1600 m in 1991/2 and revisited in 1993. Other areas were visited in 1993 and collections made in a wider range of geographical, altitudinal and vegetation conditions in Thailand. From this data factors influencing the distribution of lichens in a monsoon climate are outlined and characteristic components of the lichen flora given at family, generic and where possible specific level. Dominant taxa of the montane forests include hygrophilous macrolichens of the 'Lobarion' that are also a characteristic component of old growth fagaceous forests in Europe, whereas the evergreen forests are dominated by moisture-dependent crustose taxa with a trentepohlioid photobiont, and the deciduous dipterocarp forests by often brightly coloured xerophytic lichens with a trebouxioid photobiont. Taxa are proposed as indicators of forest type including those that are indicators of old-growth forests and of disturbance. Quantitative recording of selected taxa at genus and species level is suggested to estimate rates of change in monsoon forests in southeast Asia.     

The role of water lichens in the biogeochemical processes in the Lake Baikal stony littoral

Water crustose lichens of g. Verrucaria (V. scabra Vězda, V. rheitrophyla Zsch., V. maura Wahlenb. in Ach., and V. hydrela Ach.) and water foliose lichen Collema ramenskii Elenk. were studied in the stony littoral of the western coast of Lake Baikal in 2002–2006. Their densities were highest at depths of 1.5 to 2 m; 95–100% of rock fragments collected from the depths of 1.5–2.2 m were covered by plentiful crustose thalli of Verrucaria spp. Lichens make a large contribute to the destruction of the stony ground in the shallow-water zone. Unlike water, foliose and crustose lichens concentrate Ti, La, Ce, Y, Mn, and Th. Thalli of Collema ramenskii differ from Verrucaria species in their ability to accumulate Zn, Co, and Ni. Compared to the bottom sediments, all the studied water lichen species concentrate Zn, while Collema ramenskiiconcentrate Zn and Mo.     

Environmental factors and ground disturbance affecting the composition of species and functional traits of ground layer lichens on grey dunes and dune heaths of Estonia

A unique, species‐rich and endangered lichen biota can be found on European coastal and inland sand dunes. However, it is increasingly affected by natural succession as well as by anthropogenic disturbances. We studied lichen diversity on the grey dunes and dune heaths of coastal and inland regions of Estonia. A total of 28 study plots were investigated; in each 0.1 ha study plot general environmental variables and anthropogenic disturbances were described and all epigeic lichen species were identified. We found 66 lichenized fungus (lichen) species, including several rare and ten red‐listed lichens. Multivariate analysis (DCA, CCA) was performed to examine gradients in species composition and to relate variation in species data to environmental factors. In addition, we used redundancy analysis (RDA) to relate variation in species’ trait composition to environmental factors. Species composition on grey dunes differed significantly from that on dune heaths. The characteristic species for grey dunes are, besides several Cladonia species, foliose lichens, e.g. Hypogymnia physodes, Parmelia sulcata and Peltigera spp. Also species’ traits composition was different for either habitat, indicating that sorediate lichens, foliose lichens, lichens with cyanobacterium as the main photobiont, and sparsely branched Cladonia species dominate on grey dunes, while esorediate, green‐algal, crustose and richly branched fruticose lichens are common on dune heaths. Soil pH was the most essential environmental variable for determining both species composition and species’ traits composition. The composition of lichen species was also significantly influenced by forest closeness, soil Mg content and cover of bare sand; the effect of ground disturbances was low compared to the effect of these environmental factors. To protect and conserve the species‐rich lichen biota, it is necessary to protect the dune habitats from building activity, to avoid overtrampling in recreation areas and to regularly remove shrubs and trees.     

Epiphytic lichen synusiae and functional trait groups in boreo‐nemoral deciduous forests are influenced by host tree and environmental factors

Deciduous forests with temperate broad‐leaved tree species are particularily important in terms of biodiversity and its protection, but are threatened habitats in northern Europe. Using multivariate analyses we studied the effect of forest site type, environmental variables and host tree properties on epiphytic lichen synusiae as well as on the composition of species‐specific functional traits. Epiphytic lichens were examined on Acer platanoides, Fraxinus excelsior, Quercus robur, Tilia cordata, Ulmus glabra and U. laevis in two types of forests: Humulus‐type floodplain forests and Lunaria‐type boreo‐nemoral forests on the talus slopes of limestone escarpment (klint forests). Klint forests located near the seashore were under greater maritime influence compared to floodplain forests located in inland Estonia which experience stronger air temperature contrasts. In addition to stand level and climatic variables, tree level factors (bark pH, trunk circumference and cover of bryophytes) considerably affected the species composition of the lichen synusiae. Overall, 137 lichen species were recorded, including 14 red‐listed species characteristic of deciduous trees. We defined 13 lichen societies and showed their preference to forests of a specific site type and/or host tree properties. In forests of both types, most of the epiphytic lichens were crustose, and had apothecia as the fruit bodies and chlorococcoid algae as the photobiont. However, the proportion of lichens with a foliose or fruticose growth form, as well as the proportion of lichens with vegatative diaspores, were higher in floodplain forests. In klint forests with a stronger influence from the wind, crustose species completely dominated, while species with vegetative diaspores were rare and most species dispersed sexually. Lichens with Trentepohlia as the photobiont were characteristic of these forests, and lichens with lirellate ascomata were prevailing, indicating the great uniqueness of the kint forests for epiphytic lichens in the boreo‐nemoral region.     

Lichen diversity on dolmen and menhir in the Megalithic complex of Sa Coveccada (Mores,Sardinia)

This work describes the lichen diversity found on the megalithic Dolmen of Sa Coveccada (Mores, Sardinia) until 2010. After that year, a restoration with chemical removal of lichen crusts took place, which destroyed a great part of the lichen communities. These were studied again after removal and lichen communities occurring on rock outcrops in the surroundings of the Dolmen and on a contiguous menhir were investigated as well for comparison. Before the restoration, 33 species had been recorded on the Dolmen, most being crustose, followed by foliose and fruticose forms. Among these, eight species are regarded as rare in Sardinia and five rare at lower elevations. Most of the recorded species are typical for eutrophic substrates and for meso- to xerophytic conditions. Studies on lichen diversity on archaeological monuments in Sardinia are limited. This is the first report on the lichens of a Sardinian dolmen. This paper questions whether the lichen diversity of such monuments should be preserved as lichens have been an important part of the monument ecosystem and of the landscape for many centuries. This work also aims to improve collaboration among lichen and monument experts, in order to avoid hasty restoration decisions.     

Leaf demography and leaf traits of temperate-deciduous and tropical evergreen-broadleaved trees in a Mexican montane cloud forest

The spatial variation in epilithic lichen community structure was investigated as part of a larger study of the vegetation and ecology of the tall limestone cliffs within the Niagara Escarpment Biosphere Reserve in southern Ontario, Canada. The cover of all lichen taxa was visually estimated for a total of 199 samples taken from the top, middle, or bottom of the cliff face at five sites. Twelve environmental variables were also measured. Twenty-seven lichen taxa were identified on the samples. Multivariate ordinations of species composition (DCA, CCA, PCCA) revealed variation in community structure on multiple scales, but no groupings of sites that would have suggested the presence of several distinct species assemblages. A gradient in species composition from north to south, most clearly reflected in the decreasing cover of foliose and fruticose species, may reflect a gradient in human disturbance. There was also intermediate-scale patchiness in species composition in a horizontal plane across cliffs, but despite earlier claims made in the literature, no evidence of vertical zonation of the lichens on cliffs was found. Species composition also responded to small-scale factors possibly related to exposure, light, or moisture. Unlike community composition, the total cover of all lichens was homogeneous over large spatial scales and varied only on a small scale, illustrating that scale as well as resolution of a study may influence the ecological patterns seen. More than half of the species found on the Niagara Escarpment are rare on rock substrates elsewhere in southern Ontario, and two are new for North America (Candelariella heidelbergensis (Nyl.) Poelt and Lecanora perpruinosa Fröberg). The result that cliffs support a distinct flora containing many rare species suggests that they are a reservoir for biodiversity not just for vascular plants, but also for lichens.     

Lichen endozoochory by snails

Endozoochory plays a prominent role for the dispersal of seed plants. However, for most other plant taxa it is not known whether this mode of dispersal occurs at all. Among those other taxa, lichens as symbiotic associations of algae and fungi are peculiar as their successful dispersal requires movement of propagules that leaves the symbiosis functional. However, the potential for endozoochorous dispersal of lichen fragments has been completely overlooked. We fed sterile thalli of two foliose lichen species (Lobaria pulmonaria and Physcia adscendens) differing in habitat and air-quality requirements to nine snail species common in temperate Europe. We demonstrated morphologically that L. pulmonaria regenerated from 29.0% of all 379 fecal pellets, whereas P. adscendens regenerated from 40.9% of all 433 fecal pellets, showing that lichen fragments survived gut passage of all snail species. Moreover, molecular analysis of regenerated lichens confirmed the species identity for a subset of samples. Regeneration rates were higher for the generalist lichen species P. adscendens than for the specialist lichen species L. pulmonaria. Furthermore, lichen regeneration rates varied among snail species with higher rates after gut passage of heavier snail species. We suggest that gastropods generally grazing on lichen communities are important, but so far completely overlooked, as vectors for lichen dispersal. This opens new ecological perspectives and questions the traditional view of an entirely antagonistic relationship between gastropods and lichens.     

Functional diversity and traits assembly patterns of lichens as indicators of successional stages in a tropical rainforest

Understanding community assembly patterns with regard to functional traits, which may be common to different species, allows us to compare ecological communities in a wider range of environmental and phytogeographic conditions. Moreover, a functional approach may facilitate the comprehension of the relation between biotic changes and ecosystem functions in complex systems such as tropical forests. Considering the lack of information in relation to the influence of environmental conditions on lichen functional traits, on lichen functional patterns in tropical forests and the potential usage of this approach in bioindication studies, this paper aims at (i) determining the functional structure of the lichen communities along the forest succession gradient, (ii) assessing the relation of lichen functional traits to this gradient and (iii) verifying the potential of using lichen functional traits as indicators of successional stages in tropical rainforests. Lichens were sampled in 24 sampling units of three successional stages (6–10; 12–20; and 40–60 years of recovering). The results corroborated our main hypothesis that the functional structure of the lichen communities responds to structural changes along a forest regeneration gradient. Growth forms (foliose, fruticose and crustose) as well as some reproductive trait states (lirella, isidia and perithecia) were the most suitable lichen traits to be used as indicators of forest succession in the southern edge of the Atlantic Rainforest. Lirella, fruticose and foliose were more related to earlier successional stages; isidia was more related to intermediate stages, while perithecia and crustose were more related to older stages. These results reinforce the ability of lichens to be used as bioindicators of forest conditions.     

In situ monitoring of microclimate and metabolic activity in lichens from Antarctic extremes: a comparison between South Shetland Islands and the McMurdo Dry Valleys

Lichens are the dominant organisms in terrestrial Antarctic ecosystems and show a decline in species number, coverage, and growth rate from the maritime Antarctic (62°S) to the McMurdo Dry Valleys (78°S). While Livingston Island (maritime Antarctica) is a hot spot for lichen biodiversity, the McMurdo Dry Valleys (continental Antarctica) are known as one of the most extreme environments for life. Previous studies suggest the biodiversity gradient to be linked to water availability acting through length of active period, but no activity data are available for the Dry Valleys. The work presented here compares metabolic activity of lichens at Livingston Island and the Dry Valleys for 4½ months from continuous monitoring that involves concurrent measurements of chlorophyll fluorescence and microclimate. The latitudinal comparison involves two contrasting habitats for plant physiological activity and microclimate. Two species of the foliose genus Umbilicaria were monitored in both regions plus one sample of the crustose Caloplaca in the Dry Valleys. The results showed a very large difference in the duration of activity over the monitoring period, and this supports the different coverage, species abundance, and growth rates already reported for lichens between both regions. Despite this large difference in activity, and in habitat conditions, analysis of the activity behaviour of the two Umbilicaria species shows interesting common features, while the crustose Caloplaca had additional strategies to improve hydration. This offers one explanation for the abundance of crustose lichens inside the Valleys, indicating better adaptation strategies to a polar desert.     

EFFECTS OF CHRONIC GAMMA IRRADIATION ON LICHEN COMMUNITIES OF A FOREST

Chronic gamma irradiation of an oak-pine forest on Long Island reduced populations of corticolous and terrestrial lichens in approximate proportion to the rate of irradiation. The decline in species diversity was approximately linearly related to logarithmic increases in daily radiation exposure. While a daily exposure of 2700 R/day was estimated to have reduced diversity to 50% in the first year, a linear extrapolation of diversity, coefficient of community and similarity curves to zero suggested that certain lichens would survive 3 years' exposure at daily rates of 5,000–10,000 R, possibly more. There was an apparent threshold at 300 R/day for radiation effects on the composition of lichen communities; changes in relative density occurred at lower exposures. The crustose forms were more resistant than foliose or fruticose forms, an observation which parallels previous observations that the most radio-resistant higher plants tend to be of short, stature.     

Vertical distribution of epiphytic lichens on Quercus laurina Humb. & Bonpl. in a remnant of cloud forest in the state of Veracruz,México

In the tropics, corticolous lichen richness and cover tend to increase from the trunk base to the top of the crown of trees. In this study we calculated the total beta diversity of the lichen community along a vertical gradient on Quercus laurina in Mexican cloud forest. By comparing the richness and cover of the lichens by zone, we show that foliose and fruticose lichens are a minor component of the total lichen species richness, but have a higher cover than the crustose lichens. Five zones were identified along each phorophyte (n = 15) with a diameter at breast height >40 cm. A total of 92 species were identified. Of these, 38% were found only in a single zone, 51% were shared between the different zones and 11% occurred across all zones. Species richness and cover increased from the lowest to the highest zones of the phorophytes. Dissimilarity in species composition between the zones could be explained by species replacement. An indicator species analysis revealed that only a few species, e.g. Hypotrachyna vexans, H. cf. sublaevigata and Ramalina cf. sinaloensis prefer a particular zone. The results show that the lichen community associated with Quercus laurina phorophytes is highly diverse and suggest that species richness and cover are related to the zone and the various growth forms.