Substrate influence on epiphytic lichens

1993 ◽  
Vol 25 (3) ◽  
pp. 225-234 ◽  
Author(s):  
Joyce E. Sloof ◽  
Bert Th. Wolterbeek
Keyword(s):  
Epiphytic Lichens ◽  
Substrate Influence

scholarly journals Integrating dark diversity and functional traits to enhance nature conservation of epiphytic lichens: a case study from Northern Italy

2021 ◽  
Author(s):  
Diego Pires Ferraz Trindade ◽  
Meelis Pärtel ◽  
Carlos Pérez Carmona ◽  
Tiina Randlane ◽  
Juri Nascimbene
Keyword(s):  
Climate Change ◽  
Nature Conservation ◽  
Functional Traits ◽  
Growth Form ◽  
Northern Italy ◽  
Epiphytic Lichens ◽  
Mountain Areas ◽  
High Elevations ◽  
Harsh Conditions

AbstractMountains provide a timely opportunity to examine the potential effects of climate change on biodiversity. However, nature conservation in mountain areas have mostly focused on the observed part of biodiversity, not revealing the suitable but absent species—dark diversity. Dark diversity allows calculating the community completeness, indicating whether sites should be restored (low completeness) or conserved (high completeness). Functional traits can be added, showing what groups should be focused on. Here we assessed changes in taxonomic and functional observed and dark diversity of epiphytic lichens along elevational transects in Northern Italy spruce forests. Eight transects (900–1900 m) were selected, resulting in 48 plots and 240 trees, in which lichens were sampled using four quadrats per tree (10 × 50 cm). Dark diversity was estimated based on species co-occurrence (Beals index). We considered functional traits related to growth form, photobiont type and reproductive strategy. Linear and Dirichlet regressions were used to examine changes in taxonomic metrics and functional traits along gradient. Our results showed that all taxonomic metrics increased with elevation and functional traits of lichens differed between observed and dark diversity. At low elevations, due to low completeness and harsh conditions, both restoration and conservation activities are needed, focusing on crustose species. Towards high elevations, conservation is more important to prevent species pool losses, focusing on macrolichens, lichens with Trentepohlia and sexual reproduction. Finally, dark diversity and functional traits provide a novel tool to enhance nature conservation, indicating particular threatened groups, creating windows of opportunities to protect species from both local and regional extinctions.

Litter fall of epiphytic macrolichens in two old Picea abies forests in Sweden

1985 ◽  
Vol 63 (5) ◽  
pp. 980-987 ◽  
Author(s):  
Per-Anders Esseen
Keyword(s):  
Standing Crop ◽  
Annual Variation ◽  
Length Distribution ◽  
Forest Stand ◽  
Epiphytic Lichens ◽  
Litter Fall ◽  
Alectoria Sarmentosa ◽  
Usnea Longissima ◽  
Tree Litter ◽  
Thallus Length

The seasonal and annual variation in the litter fall of epiphytic lichens and tree litter was studied over a period of 2 to 3 years at two forested hills in the eastern part of central Sweden. Litter fall was measured using traps and for one species, Usnea longissima, by collecting specimens present on the ground. Total litter fall amounted to 2.5 and 2.8 tons ha−1 year−1 of which lichens constituted 4.6 and 5.7% at the two sites. Lichen litter fall was highest during the period from late autumn to the beginning of summer. Both the lichens and the tree litter showed significant between-year differences. Usnea longissima had an annual turnover of 7.0 and 10.0% of the standing crop at the two sites. The thallus length distribution of U. longissima was positively skewed. It is concluded that dispersal of thallus fragments by wind evidently plays an important role for many of the filamentous lichens studied. It is suggested that U. longissima disperses over a much shorter distance than Alectoria sarmentosa and Bryoria spp. within a forest stand.

Substrate Influence in YBaCuO Melt-Texturing Growth

1992 ◽  
Vol 275 ◽  
Author(s):  
N. Pellerin ◽  
M. Gervais ◽  
P. Odier
Keyword(s):  
Chemical Activity ◽  
High Chemical ◽  
Melt Texturing ◽  
Substrate Influence ◽  
High Chemical Activity

Melt-texturing of YBaCuO is generally processed on substrates. Due to its high chemical activity, the non-stoichiometric liquid, mainly due to the barium element, generally reacts with the substrate which is therefore subjected to play a role in the crystallization of YBaCuO and in the development of the texture. The particular case of Y2O3, which is a reacting but non-polluting substrate, is treated in details. The comparison of textured YBaCuO in similar conditions but on different substrates: Al2O3, Y2O3 and MgO gives some insight in the texturing process.

Changes in the distributions of epiphytic lichens in southern Sweden using a new statistical method

2009 ◽  
Vol 27 (5) ◽  
pp. 413-418 ◽  
Author(s):  
Håkan Lättman ◽  
Per Milberg ◽  
Michael W. Palmer ◽  
Jan-Eric Mattsson
Keyword(s):  
Statistical Method ◽  
Epiphytic Lichens ◽  
Southern Sweden

Floristic Survey of Epiphytic Lichens and Bryophytes Growing on Old-Growth Conifers in Western Oregon

1975 ◽  
Vol 78 (4) ◽  
pp. 389 ◽  
Author(s):  
Lawrence H. Pike ◽  
William C. Denison ◽  
Diane M. Tracy ◽  
Martha A. Sherwood ◽  
Frederick M. Rhoades
Keyword(s):  
Epiphytic Lichens ◽  
Old Growth ◽  
Floristic Survey

Transfer Constraints and Substrate Influence in Melanesian Pidgin

1999 ◽  
Vol 14 (1) ◽  
pp. 1-44 ◽  
Author(s):  
Jeff Siegel
Keyword(s):  
Second Language ◽  
Second Language Acquisition ◽  
Language Acquisition ◽  
Test Case ◽  
Perceptual Salience ◽  
Central Eastern ◽  
Influence Of Substrate ◽  
Substrate Influence

This study examines research on transfer in second language acquisition (SLA) in order to identify situational and linguistic factors which may constrain the influence of substrate languages on the developing grammar of a pidgin or creole. A distinction is made between the earlier transfer of L1 features by individuals attempting to use the superstrate language as an L2 for wider communication, and the later retention of a subset of these features by the community during a process of leveling which occurs during stabilization. The study outlines various transfer constraints and reinforcement principles proposed in both the second language acquisition and pidgin/creole studies literature. These are evaluated using Melanesian Pidgin and its Central-Eastern Oceanic (CEO) substrate languages as a test case. Of the potential constraints on transfer proposed in the SLA literature, the need for partial or specious congruence between superstrate and substrate structures appears to account best for the particular CEO features that were transferred. Perceptual salience accounts for the kinds of forms from English that were reanalyzed to fit CEO patterns. With regard to the retention of particular transferred features, the most significant reinforcement principle appears to be frequency in the contact environment.

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