One stop mycology

The lichen family Teloschistaceae is one of the larger families of lichenized fungi. Currently it includes one very large heterogenous genus, Caloplaca, with some 1000 or more species with a vast variation in morphology, anatomy and chemistry. The rest of the family is split into 1015 smaller genera, each with 20 or fewer species. There is no modern classification of the family based on molecular data. Here we attempt a first phylogenetic evaluation of a large part of the family, including a total of 337 species. Of these, 162 were used in a combined phylogenetic analysis of the ribosomal RNA sequence markers nrITS, nrLSU and mrSSU, using Bayesian inference. We also analysed all species using nrITS data, split into four different analyses. As a result we propose a new classification of the family, where a total of 39 genera are recognized, of which 31 are newly described or resurrected. The new genera are: Athallia, Austroplaca, Bryoplaca, Calogaya, Cerothallia, Flavoplaca, Gondwania, Haloplaca, Orientophila, Pachypeltis, Parvoplaca, Rufoplaca, Shackletonia, Scutaria, Sirenophila, Solitaria, Squamulea, Stellarangia, Teloschistopsis, Usnochroma, Variospora, Villophora and Wetmoreana. Resurrected genera are Blastenia, Dufourea, Follmannia, Gyalolechia, Leproplaca, Polycauliona, Pyrenodesmia and Xanthocarpia. The species Orientophila subscopularis is described as new. A third subfamily, Teloschistoideae, is proposed to accommodate the genus Teloschistes and related genera, parallel to the two previously recognized subfamilies Xanthorioideae and Caloplacoideae. We also show the large plasticity in both morphological and anatomical characters between closely related species within genera, indicating the low value of these as evolutionary markers. The secondary chemistry is a better marker in some parts of the family. We recognize a large number of geographically delimited clades with clear centres of evolution, but often showing large variation in morphology and anatomy. (Less)

A new taxonomy of the family Teloschistaceae

Evidence for changing the critical level for ammonia

Diversity and sensitivity of epiphytes to oxides of nitrogen in London.

In this paper, we review the current understanding on ecosystem and human health impacts from the atmospheric deposition of acidifying pollutants, eutrophying nitrogen (N), polycyclic aromatic hydrocarbons (PAHs), mercury (Hg), trace metals, and ozone (O3), as well as the biological indicators that have been used to assess the health of ecosystems following exposure to these pollutants. We provide overviews of the impacts of deposition for these pollutants and discuss the currently known biomonitors for each pollutant. The deposition of acidifying pollutants impacts terrestrial ecosystems by altering plant physiology and growth and by increasing plant susceptibility to stresses that can be indirectly damaging to the health of fish and birds. Indicators of the deposition of acidifying pollutants include soil base cation content and acid neutralizing capacity, among others. Eutrophying N deposition has been studied extensively; N enrichment directly impacts vegetative plant species cover, richness, growth rates, and susceptibility to other stressors. It indirectly impacts wildlife through changes in their habitats and food sources. Indicators for N deposition include changes in plant species and in tissue and litter N content. The deposition of PAHs has been found to cause significant damage to plant organisms and to be carcinogenic and mutagenic to humans and animals. Useful biomonitors of PAH deposition include lichens, mosses, and pine needles. Deposited Hg can undergo methylation (in the presence of sulphur reducing bacteria); bioaccumulation of methylmercury is highly toxic to animals. Effective biomonitors of Hg contamination of aquatic ecosystems are fish and marine birds. The impacts of O3 are well understood, with well-established “flux” models being vast improvements on the previous AOT40 approaches. This review highlights the impacts that the above-mentioned pollutants have on terrestrial and aquatic organisms and the biomonitors that are currently being used to assess the deposition levels and effects of these pollutants.

/pdf/impacts-and-effects-indicators-of-atmospheric-deposition-of-11nzla0ksu.pdf

Impacts and Effects Indicators of Atmospheric Deposition of Major Pollutants to Various Ecosystems - A Review

Lichens were recorded on Quercus petraea trunks and twigs near ammonia recording stations in ‘continental’ Norfolk, and ‘oceanic’ Devon in order to test indicator values developed for epiphytic lichens in areas of high atmospheric ammonia in the Netherlands. Lichens on trunks in Norfolk showed a similar correlation of nitrophyte indices with ammonia concentration and bark pH as those in Holland, whereas in Devon there was no correlation with nitrophyte indices on trunks and a negative correlation with acidophyte indices. Results on twigs in both sites suggest that lichens on twigs respond more rapidly to recent changes in ammonia concentrations while trunks may maintain relict lichen communities due to either a legacy of previous acidification or ecological continuity. The results suggest that loss of acidophytes is taking place prior to the establishment of nitrophytes indicating the importance of establishing levels of ammonia at which sensitive communities are at risk.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0024282905005487

Detecting changes in epiphytic lichen communities at sites affected by atmospheric ammonia from agricultural sources

Bioindicators provide a range of techniques to assess the impacts of air pollution from reactive nitrogen (N) compounds on statutory nature conservation sites. They complement physical monitoring of atmospheric concentrations and deposition and risk assessment based on the critical loads approach by providing site-based information on atmospheric N concentrations, N deposition and/or ecological impacts.
 
Appropriate bioindicators for N may be applied by sampling at one time to compare results between different locations. In particular, local-scale transects can help identify the impacts of a nearby point source of reactive N emissions to the atmosphere.

The repeated application of bioindicator methods over time provides the basis for biomonitoring. In general, biomonitoring reflects changes over periods of several years, although short-term changes can also be monitored (over several weeks and months).

This report reviews the wide range of bioindicator and biomonitoring methods for N and incorporates the results of a field test of several of the methods. In addition, datasheets are provided that summarize the key characteristics, advantages and limitations of the different methods.

Bioindicator methods can be grouped into several contrasting approaches: Biochemical methods (based on an accumulation of N or a chemical/physiological response to N), Species composition methods (based on previously characterized species preferences) and Transplant methods (based on the response following transplanting of either locally native species or standardized plants). 

Nitrogen accumulation methods include measurement of plant tissue N concentration, amino acids, substrate N and foliar ammonium. The accumulation methods provide the closest link to atmospheric N deposition. Results show that the smaller and more available the chemical pool, the larger the magnitude of response, with increasing responses from: total N < substrate N < foliar ammonium.

Biochemical response methods include analysis of enzymes such as nitrate reductase and emissions of nitrous oxide from soils. These methods are useful to demonstrate physiological effects, but tend to be less well correlated with atmospheric N deposition due to interactions with environmental conditions.

Species composition methods are of particular interest to the statutory conservation agencies since they relate directly to changes in plant communities due to excess atmospheric N. 'Ellenberg' N preference scores for higher plant and bryophyte species can be used to score the overall community for nitrogen. The limitation of this approach is that a wide range of other factors may also affect species composition.

Lichens are particularly sensitive to atmospheric reactive N, particularly ammonia. Detailed approaches are available to score lichen responses to N, but require more development for UK conditions. There is also the potential to refine simple methods that can be applied by non-experts.

The use of standardized grass plants has been shown to provide a robust method for monitoring the deposition and effects of N. The method can be applied in situations of complex terrain where physical estimates of deposition are difficult and as a graphic demonstration of impacts to stakeholders. It has a key advantage that exposure periods of only a few weeks are necessary.

Transplanting native species between sites is useful to demonstrate impacts at polluted sites and conversely the benefits of clean conditions. These methods have been shown to work well for lower plants, and have the benefit of being able to demonstrate recovery following a reduction in deposition where this occurs. 
Overall, recognizing the limitations and benefits of the different methods, it is concluded that bioindicators provide a practical site-based approach for assessing N concentrations, deposition and impacts. Each of the above mentioned approaches are have merits, with different techniques matching to the range of questions being addressed. The most robust results are to be obtained by implementing several complementary techniques simultaneously, where possible in combination with low-cost physical monitoring of atmospheric concentrations.

Bioindicator and biomonitoring methods for assessing the effects of atmospheric nitrogen on statutory nature conservation sites

Linnaean lichen names and their typification.

Changes in thalli of Lobaria species during 1986‐1998 are assessed using fixed point quadrats on trees in sites across Britain in a range of atmospheric and management conditions. Growth patterns for British species of Lobaria are described and factors contributing to their present status in Britain assessed. Results show that the pattern of growth, fragmentation and subsequent coalescing of fragments makes it difficult to estimate the age of a thallus. Little evidence of establishment from propagules was found over 10 years except in L. scrobiculata. The effects of loss of habitat and veteran trees, climate changes, of declining bark pH, and of competition with bryophytes are discussed.

Factors affecting changes in species of Lobaria in sites across Britain 1986-1998

The sorediate variety of Sclerophytomyces circumscriptus (Taylor) Sparrius & P. James (Roccellaceae, Arthoniales) is described from sheltered, acid rock along Europe's western coasts and the Atlantic islands. This sorediate taxon is reported from the British Isles, Ireland, France, Spain, Portugal, the Azores and the Canary Islands. A description of the morphology, distribution and ecology is provided. The phylogenetic position of the new taxon is discussed, as well as nomenclatural and orthographic issues. The name Sclerophytomyces is proposed as an orthographic correction of the published name Sclerophytonomyces.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0024282905015082

Peter W. James

Papers

Detecting changes in epiphytic lichen communities at sites affected by atmospheric ammonia from agricultural sources

Bioindicator and biomonitoring methods for assessing the effects of atmospheric nitrogen on statutory nature conservation sites

Linnaean lichen names and their typification.

Factors affecting changes in species of Lobaria in sites across Britain 1986-1998

The sorediate variety of Sclerophytomyces circumscriptus