Morphological and Physiological differences between Epilithic and Epiphytic populations of the Lichen Parmelia pastillifera

Tretiach, Mauro; Brown, D. H.

doi:10.1006/anbo.1995.1068

Cited by 22 publications

(13 citation statements)

References 13 publications

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“…The lower content of photosynthetic pigments in dry S-exposed samples of E. prunastri is consistent with several studies of sun-and shade-adapted populations of lichens, bryophytes and vascular plants (Thayer & Björkman 1990;Tretiach & Brown 1995;Marschall & Proctor 2004). Similar results were found by Hájek et al (2001), which observed a 20% lower Chl a and Chl b content in populations of Cetraria islandica from highly irradiated habitats of central Europe compared to shaded habitats.…”

Section: Discussionsupporting

confidence: 91%

Influence of sun irradiance and water availability on lichen photosynthetic pigments during a Mediterranean summer

et al. 2010

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This study was carried out to investigate changes in lichen photosynthetic pigments induced by different combinations of light irradiance and water availability during a Mediterranean summer. To this purpose, thalli of three epiphytic lichens with a markedly different ecology concerning photo-hygrophytism, namely Evernia prunastri (hygro-mesophytic), Flavoparmelia caperata (mesophytic) and Xanthoria parietina (xero-mesophytic), were transplanted for 30 days to N-and S-facing cardinal exposures in central Italy. To investigate the effect of thallus hydration, at each cardinal exposure 50% of thalli were hydrated daily with deionised water. The results showed that changes in the concentrations of photosynthetic pigments are species-specific and consist in a general depression of photosynthetic pigments only in the hygro-mesophytic species E. prunastri. The pattern of photosynthetic pigments was also investigated in spontaneous samples along contrasting aspects. In this case, X. parietina from S-facing slopes, adapted to direct solar influx, showed higher pigment content than N-facing thalli; F. caperata and E. prunastri avoid direct extreme solar radiation and assimilation pigments were influenced more by the shadowing of tree canopies than by the cardinal exposure. The influence of drought on lichen photosynthetic pigments in the Mediterranean area is discussed.

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Section: Discussionsupporting

confidence: 91%

Influence of sun irradiance and water availability on lichen photosynthetic pigments during a Mediterranean summer

et al. 2010

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“…For mosses and lichens, the relationship between irradiance and chlorophyll content show less clear patterns (Marschall and Proctor, 2004;Picotto and Tretiach, 2010). While some results are consistent with those observed in vascular plants (Tretiach and Brown, 1995;Green et al, 1997), others show higher chlorophyll content in habitats with higher irradiance (Pintado et al, 1997;Picotto and Tretiach, 2010;Schroeter et al, 2012). The latter pattern suggests that in some poikilohydrous organisms other factors are more important than light in controlling adjustments of photosynthetic components (Pintado et al,.…”

Section: Changes In Co 2 Assimilation and Chlorophyll Contentsupporting

confidence: 65%

Bromus tectorum litter alters photosynthetic characteristics of biological soil crusts from a semiarid shrubland

Serpe

Roberts

Eldridge

et al. 2013

Soil Biology and Biochemistry

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Invasion by the exotic annual grass Bromus tectorum has increased the cover and connectivity of fine litter in the sagebrush steppes of western North America. This litter tends to cover biological soil crusts, which could affect their metabolism and growth. To investigate this possible phenomenon, biological soil crusts dominated by either the moss Bryum argenteum or the lichen Diploschistes muscorum were covered with B. tectorum litter (litter treatment) or left uncovered (control treatment) and exposed to natural field conditions. After periods of five and ten months, we removed the litter and compared the photosynthetic performance of biological soil crusts from the two treatments. Litter induced photosynthetic changes in our samples. In both B. argenteum and D. muscorum, biological soil crusts that had been covered with litter for ten months had lower rates of gross photosynthesis and lower chlorophyll content than control samples. Similarly in both biological soil crust types, litter reduced the rate of dark respiration. For D. muscorum, the reduction in dark respiration fully compensated for the decrease in gross photosynthesis, resulting in similar values of net photosynthesis in the two treatments. In contrast, for B. argenteum, net photosynthesis was four-times greater in the control than the litter treatment. Also under litter cover, D. muscorum showed three common adaptations to shade conditions: a decrease in the light compensation point, in the light intensity needed to achieve 95% of maximal net photosynthesis, and in the chlorophyll a/b ratio. None of these changes was apparent in B. argenteum. Overall, our results indicate that photosynthetic responses to the presence of litter varied among species of the crust biota and that the litter can reduce the photosynthetic capacity of biological soil crusts. These results help to explain field observations of decreases in biological soil crust cover and changes in biological soil crust composition with increases in litter cover, and suggest that the landscape-wide invasion by B. tectorum may have substantial effects on biological soil crust performance and therefore their capacity to function in semiarid shrublands.Keywords: Biological soil crusts, Bromus tectorum, Bryum argenteum, Diploschistes muscorum, lichens, litter, mosses, photosynthesis, semiarid environments, sagebrush steppe Abbreviations: Biological soil crusts (biocrusts), ΔF/F m ', photosystem II operating efficiency, F v /F m , maximum quantum efficiency of photosystem II photochemistry; LCP, light compensation point, NPQ, non-photochemical quenching; PPFR 95% , light intensity necessary to achieve 95% of maximal net photosynthesis 2

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“…Different eco-morphological populations for the lichen species were observed and correlated with their specific habitat (e.g. Tretiach & Brown 1995;Pintado et al 1997; Rikki- There are aggregates of Cladonia in which the character of primary squamules has been considered as fundamental -or at least important -in related taxa diagnosis, e.g. the C. cariosa, C. cervicornis, C. coniocraea, C. digitata, C. foliacea and C. pyxidata groups.…”

Section: Discussionmentioning

confidence: 99%

Phenotypic plasticity of primary thallus in selected Cladonia species (lichenized Ascomycota: Cladoniaceae)

Osyczka

Rola

2013

Biologia

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The paper presents the results of comprehensive analyses concerning the phenotypic variability of the primary thallus in five chosen Cladonia species in relation to habitat conditions. Morphology and anatomy, as well as the cortex ultrasculpture, of primary squamules were examined in individual specimens from sunny and shady populations of each species. The Mann-Whitney U test and Principal Component Analysis (PCA) revealed several clear correlations between the type of habitat and the organisation of squamules. Significant differences refer mainly to anatomical features, especially to epinecral layer frequency and cortex thickness. On the contrary, examination of the surface ultrasculpture of squamules under SEM did not show any important differences between populations. Regardless of the habitat factors, a full range of cortical surface rugosity in samples from both habitats was noticed, and a high variability often refers to a singular squamule. The results indicate that some features are largely modified by environmental factors and/or depend on the development stage of individual specimens, and examination of these relationships should be the first step towards the evaluation of the taxonomic usefulness of the considered features.

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Morphological and Physiological differences between Epilithic and Epiphytic populations of the Lichen Parmelia pastillifera

Cited by 22 publications

References 13 publications

Influence of sun irradiance and water availability on lichen photosynthetic pigments during a Mediterranean summer

Influence of sun irradiance and water availability on lichen photosynthetic pigments during a Mediterranean summer

Bromus tectorum litter alters photosynthetic characteristics of biological soil crusts from a semiarid shrubland

Phenotypic plasticity of primary thallus in selected Cladonia species (lichenized Ascomycota: Cladoniaceae)

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