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Giuseppa Grazia Aprile - One of the best experts on this subject based on the ideXlab platform.
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different effects of rain and artificial watering on element zonation patterns in Lichen thalli and bark a study on physcia biziana massal zahlbr v leptophylla ve zda
Plant Biosystems, 2016Co-Authors: I Catalano, A Santitoro, Antonio Mingo, Daniela Baldantoni, Anna Alfani, Giuseppa Grazia AprileAbstract:Translocation processes between the inner and outer rings of Lichen thalli, as well as between Lichens and bark substratum, induce zonation patterns, with a dynamic stratification of pollution history memory which is often affected by the intensity of the atmospheric events. Two experiments of passive biomonitoring are presented, aimed to measure metal concentrations and zonation patterns in Lichens and bark, before and after raining events or after a water sprinkling treatment. Ten elements were monitored in the Lichen Physcia biziana (Massal.) Zahlbr. v. leptophylla Ve˘zda in a moderately polluted area of Campania region (Italy). Element concentrations changed with Lichen age, with generally higher concentrations in the older than the younger tissues. Rain and sprinkling had differential effects on Lichen and bark: a significant decrease of the overall concentrations was observed after rain in bark, whereas a slight increase was observed in Lichen thalli; however, when Lichen thalli were just rehydrated...
Johan Asplund - One of the best experts on this subject based on the ideXlab platform.
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how Lichens impact on terrestrial community and ecosystem properties
Biological Reviews, 2017Co-Authors: Johan Asplund, David A. WardleAbstract:Lichens occur in most terrestrial ecosystems; they are often present as minor contributors, but in some forests, drylands and tundras they can make up most of the ground layer biomass. As such, Lichens dominate approximately 8% of the Earth's land surface. Despite their potential importance in driving ecosystem biogeochemistry, the influence of Lichens on community processes and ecosystem functioning have attracted relatively little attention. Here, we review the role of Lichens in terrestrial ecosystems and draw attention to the important, but often overlooked role of Lichens as determinants of ecological processes. We start by assessing characteristics that vary among Lichens and that may be important in determining their ecological role; these include their growth form, the types of photobionts that they contain, their key functional traits, their water-holding capacity, their colour, and the levels of secondary compounds in their thalli. We then assess how these differences among Lichens influence their impacts on ecosystem and community processes. As such, we consider the consequences of these differences for determining the impacts of Lichens on ecosystem nutrient inputs and fluxes, on the loss of mass and nutrients during Lichen thallus decomposition, and on the role of Lichenivorous invertebrates in moderating decomposition. We then consider how differences among Lichens impact on their interactions with consumer organisms that utilize Lichen thalli, and that range in size from microfauna (for which the primary role of Lichens is habitat provision) to large mammals (for which Lichens are primarily a food source). We then address how differences among Lichens impact on plants, through for example increasing nutrient inputs and availability during primary succession, and serving as a filter for plant seedling establishment. Finally we identify areas in need of further work for better understanding the role of Lichens in terrestrial ecosystems. These include understanding how the high intraspecific trait variation that characterizes many Lichens impacts on community assembly processes and ecosystem functioning, how multiple species mixtures of Lichens affect the key community- and ecosystem-level processes that they drive, the extent to which Lichens in early succession influence vascular plant succession and ecosystem development in the longer term, and how global change drivers may impact on ecosystem functioning through altering the functional composition of Lichen communities.
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the impact of secondary compounds and functional characteristics on Lichen palatability and decomposition
Journal of Ecology, 2013Co-Authors: Johan Asplund, David A. WardleAbstract:Summary There has been much recent interest in understanding how functional traits of vascular plant species drive ecological processes such as herbivory and litter decomposition. In plants, these two processes are often driven by the same or similar suites of traits and therefore correlate across species. However, few studies have considered how traits of plant-like life forms such as Lichens determine species differences in their effects on ecological processes. This is despite the significant contribution of Lichens to carbon and nutrient cycling in many environments. We collected 28 Lichen species that differed in their growth form, substrate type and capacity to fix N, and determined key traits for each species. For each species, we performed a feeding bioassay using the generalist snail Cepaea hortensis and carried out a laboratory bioassay to assess decomposability. We did these tests both with intact Lichen material containing natural concentrations of carbon-based secondary compounds (CBSCs), and material that had been acetone rinsed to reduce concentrations of CBSCs, to evaluate the effect of CBSC on palatability and decomposability. We found that reducing CBSC concentrations greatly increased palatability for 17 species, and decomposability of 10 species. However, decomposability was correlated with several Lichen traits while palatability was not, regardless of whether or not CBSCs were removed, and we therefore found no relationship between decomposability and palatability across species. Decomposability and palatability both varied, but in contrasting directions, among N-fixing vs. non-fixing Lichens, Lichens with different growth forms and those from contrasting substrate types. As such, N-fixing Lichens had higher decomposition rates but lower consumption rates than non-fixing Lichens, while foliose species had higher decomposition rates but lower consumption rates than fruticose species. Synthesis: We have shown that Lichen CBSCs regulate key processes such as Lichenivory and decomposition, that Lichen decomposability but not palatability are related to traits, and that these two processes are unrelated across species. These results highlight the potential role of Lichen species differences in influencing ecosystem processes relating to decomposition and nutrient cycling and the role that grazers may play in driving this.
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Contrasting changes in palatability following senescence of the Lichenized fungi Lobaria pulmonaria and L. scrobiculata
Fungal Ecology, 2012Co-Authors: Johan Asplund, David A. WardleAbstract:Epiphytic Lichens can contribute significantly to ecosystem nutrient input because they efficiently accumulate atmospheric mineral nutrients and, in the case of cyanoLichens, also fix nitrogen. The rate at which carbon and other nutrients gained by Lichens enters the ecosystem is determined by Lichen litter decomposability and by invertebrate consumption of Lichen litter. In turn, these processes are driven by the secondary compounds present in senesced Lichens. Therefore, we explored how Lichen palatability and concentrations of secondary compounds change with tissue senescence for Lobaria pulmonaria, a green-algal Lichen with cyanobacterial cephalodia, and Lobaria scrobiculata, a cyanobacterial Lichen. During senescence both Lichens lost 38–48 % of their stictic acid chemosyndrome, while m-scrobiculin and usnic acid in L. scrobiculata remained unchanged. Snails preferred senesced rather than fresh L. pulmonaria, while senesced L. scrobiculata were avoided. This provides evidence that species with labile secondary compounds will have higher turnover rates, through consumption and decomposition, than those producing more stable secondary compounds.
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Mollusc grazing limits growth and early development of the old forest Lichen Lobaria pulmonaria in broadleaved deciduous forests
Oecologia, 2008Co-Authors: Johan AsplundAbstract:This study aims: (1) to quantify mollusc grazing on juvenile and mature thalli of the foliose epiphytic Lichen Lobaria pulmonaria , and (2) to test the hypothesis inferring a herbivore defensive role of Lichen depsidones in forests with indigenous populations of Lichen-feeding molluscs. Lichens were transplanted in shaded and less shaded positions in each of two calcareous broadleaved deciduous forests, one poor in Lichens, one with a rich Lobarion community. Preventing the access of molluscs significantly reduced the loss of juvenile L. pulmonaria , particularly in the naturally Lichen-poor forest. Molluscs also severely grazed mature thalli in the Lichen-poor forest, especially thalli placed under the more shading canopies. Furthermore, reducing the natural concentration of depsidones by pre-rinsing with acetone increased subsequent grazing significantly, showing that Lichen depsidones function as herbivore defence in natural habitats. Our results suggest that mollusc grazing may play important roles in shaping the epiphytic vegetation in calcareous deciduous forests, and that recently established juvenile L. pulmonaria thalli seem to be particularly vulnerable.
I Catalano - One of the best experts on this subject based on the ideXlab platform.
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different effects of rain and artificial watering on element zonation patterns in Lichen thalli and bark a study on physcia biziana massal zahlbr v leptophylla ve zda
Plant Biosystems, 2016Co-Authors: I Catalano, A Santitoro, Antonio Mingo, Daniela Baldantoni, Anna Alfani, Giuseppa Grazia AprileAbstract:Translocation processes between the inner and outer rings of Lichen thalli, as well as between Lichens and bark substratum, induce zonation patterns, with a dynamic stratification of pollution history memory which is often affected by the intensity of the atmospheric events. Two experiments of passive biomonitoring are presented, aimed to measure metal concentrations and zonation patterns in Lichens and bark, before and after raining events or after a water sprinkling treatment. Ten elements were monitored in the Lichen Physcia biziana (Massal.) Zahlbr. v. leptophylla Ve˘zda in a moderately polluted area of Campania region (Italy). Element concentrations changed with Lichen age, with generally higher concentrations in the older than the younger tissues. Rain and sprinkling had differential effects on Lichen and bark: a significant decrease of the overall concentrations was observed after rain in bark, whereas a slight increase was observed in Lichen thalli; however, when Lichen thalli were just rehydrated...
Pekka Niemela - One of the best experts on this subject based on the ideXlab platform.
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growth of reindeer Lichens and effects of reindeer grazing on ground cover vegetation in a scots pine forest and a subarctic heathland in finnish lapland
Ecography, 2003Co-Authors: Michael Den Herder, Minnamaarit Kytoviita, Pekka NiemelaAbstract:Reindeer Lichens are an important component of northern ecosystems. The aim of this study was to measure the growth rate of terricolous Lichens as it is a key parameter involved in productivity of these ecosystems and an important part of Lichen tolerance to reindeer grazing. Furthermore, the natural succession and the long-term effects of reindeer grazing on Lichen community characteristics in two contrasting habitats were investigated as well as the interactions between Lichen cover and mosses and vascular plants. Biomass and coverage measurements were conducted in a Lichen woodland and in a subarctic heath with grazed and ungrazed areas in northern Finland. Measurements spanning over 13 yr of undisturbed development show that the growth rate of Cladina stellaris can be as high as >0.17 g g−1 produced annually, although in average growth rates were much lower. During the succession of ground vegetation, C. stellaris, C. rangiferina, C. mitis and Cetraria nivalis increased in biomass in fenced areas and were reduced most in biomass by reindeer in unprotected areas. Reindeer grazing and trampling seem to change the vegetation towards a type that is dominated by small dwarf shrubs, bare soil and minute-cup Lichens (Cladonia spp.). Removing the Lichen layer by reindeer may reduce natural regeneration of pine trees as implied by increasing numbers of pine seedlings with increasing Lichen cover.
Veera Tuovinen - One of the best experts on this subject based on the ideXlab platform.
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two basidiomycete fungi in the cortex of wolf Lichens
Current Biology, 2019Co-Authors: Göran Thor, Veera Tuovinen, Stefan Ekman, Dan Vanderpool, Toby Spribille, Hanna JohannessonAbstract:Summary Since the late 1800s, mycologists have been detecting fungi above and beyond the assumed single fungus in Lichen thalli [ 1 , 2 , 3 , 4 , 5 , 6 ]. Over the last century, these fungi have been accorded roles ranging from commensalists to pathogens. Recently, Cyphobasidiales yeasts were shown to be ubiquitous in the cortex layer of many macroLichens [ 7 ], but for most species, little is known of their cellular distribution and constancy beyond visible fruiting structures. Here, we demonstrate the occurrence of an additional and distantly related basidiomycete, Tremella, in 95% of studied thalli in a global sample of one of the most intensively studied groups of Lichens, the wolf Lichens (genus Letharia). Tremella species are reported from a wide range of Lichen genera [ 8 ], but until now, their biology was deduced from fruiting bodies (basidiomata) formed on Lichen thalli. Based on this, they have been thought to be uncommon to rare, to occur exclusively in a hyphal form, and to be parasitic on the dominant fungal partner [ 9 , 10 ]. We show that, in wolf Lichens, Tremella occurs as yeast cells also in thalli that lack basidiomata and infer that this is its dominant stage in nature. We further show that the hyphal stage, when present in Letharia, is in close contact with algal cells, challenging the assumption that Lichen-associated Tremella species are uniformly mycoparasites. Our results suggest that extent of occurrence and cellular interactions of known fungi within Lichens have historically been underestimated and raise new questions about their function in specific Lichen symbioses.
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basidiomycete yeasts in the cortex of ascomycete macroLichens
Science, 2016Co-Authors: Veera Tuovinen, Dan Vanderpool, Toby Spribille, Philipp Resl, Heimo Wolinski, Catherine M Aime, Kevin Schneider, Edith StabentheinerAbstract:For over 140 years, Lichens have been regarded as a symbiosis between a single fungus, usually an ascomycete, and a photosynthesizing partner. Other fungi have long been known to occur as occasional parasites or endophytes, but the one Lichen–one fungus paradigm has seldom been questioned. Here we show that many common Lichens are composed of the known ascomycete, the photosynthesizing partner, and, unexpectedly, specific basidiomycete yeasts. These yeasts are embedded in the cortex, and their abundance correlates with previously unexplained variations in phenotype. Basidiomycete lineages maintain close associations with specific Lichen species over large geographical distances and have been found on six continents. The structurally important Lichen cortex, long treated as a zone of differentiated ascomycete cells, appears to consistently contain two unrelated fungi.
