Patricia A. Wolseley

Monitoring with Lichens — Monitoring Lichens

Widespread changes in natural and managed environments in the last century have been associated with rapid development of technology with the capacity for massive destruction of natural environments. This has been accompanied by large-scale natural disasters such as floods and droughts and by large-scale technical failures such as Chernobyl, impacting greatly on human existence and welfare. It is the impact on social conditions that has led to increasing interest in maintaining environmental quality and ensuring that human activities do not threaten the ecosystem on which we depend. The threats to human health by water and air pollution led to early research on bioindicators in order to map and monitor the effects of pollution on selected organisms. However the range of objectives to which biomonitoring is applied has grown steadily from water quality and atmospheric pollution to heavy metal accumulation, climate change, and to environmental issues involving management of natural resources such as the effects of fragmentation and habitat alteration, effects of development on biodiversity as well as assessing conservation practices for rare or endangered species.

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

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.

Species richness of lichen functional groups in relation to land use intensity

Changing land use has a major impact on lichen diversity. This study attempts to identify patterns or trends of lichen functional groups along a land use gradient, ranging from natural forests to open agricultural landscape. In eight countries, covering six main European biogeographic regions, lichen vegetation was assessed according to a standardized scheme. Data on reproductive, vegetative and ecological traits was compiled and relative species richness for all classes of all traits calculated. Relationships between the land use gradient and relative species richness of trait classes were analysed. Open and intensively managed landscapes harbour more fertile species while sterile species are relatively more important in forests. This finding is also supported by analyses of different classes of dispersal propagules. The importance of species with the principal photobiont Trebouxia s.l. increases linearly with intensification of land use. A converse pattern is revealed by species with Trentepohlia. Concerning substratum specialization only generalists show an effect along the land use intensity gradient. Their relative species richness decreases from landscapes dominated by forests to open agricultural landscape. A considerable decline in the rare lichen species richness as a result of land intensification is predicted.

Variation of lichen communities with landuse in Aberdeenshire, UK

The distribution of lichen species in upland regions of Aberdeenshire, Scotland, is investigated along a landuse gradient from natural forest to intensive agriculture. Quantitative data on lichen communities on saxicolous, epiphytic and terricolous substrata were collected from 16 hectares in one km 2 in each landuse type. Multivariate analyses, NMDS and Cluster analysis were used to identify lichen communities associated with environmental factors including landuse, substratum type and age. The epiphytic community of native pinewoods was distinguished from all others by the highest species richness, the presence of indicators of ecological continuity and the absence of nitrophytes, while the epiphytic communities of farmland were distinguished by absence of acidophytes and a high contribution of nitrophytes. Plantations of conifers were distinguished by low species richness and an increase in tolerant species. Saxicolous communities were frequent on walls in all sites except native pinewood, where saxicolous substrata were rare. Intensively farmed sites were distinguished by an increase in percentage contribution of nitrophytes. The high acidophyte contribution in all sites suggests that crustose species of acid rocks may not respond rapidly to an increase in applied nitrogen. In landscapes where tree cover is sparse or non-existent combined assessment of habitat diversity and nitrophyte indicator species can be used to assess changes associated with agricultural intensification.

New molecular data on Pyrenulaceae from Sri Lanka reveal two well-supported groups within this family

Pyrenulaceae is one of the dominant lichen families in the tropics, especially in lowland evergreen forests. Although very species-rich, phylogenetic relationships within Pyrenulaceae have not been extensively studied using molecular data, and its morphology-based generic delimitation remains untested. A recent lichenological survey carried out in the Knuckles Mountain Range in Sri Lanka allowed the first author to collect fresh specimens of different species of Pyrenula , and to investigate the phylogenetic relationships within the family Pyrenulaceae using a multigene analysis (ITS, nuLSU and mtSSU) and a preliminary dataset of 21 taxa. This data shows that the family Pyrenulaceae can be divided into two well-supported groups and suggests that the genus Pyrenula is not monophyletic. Characters usually used for generic classification in this family (ascospore colour and septation, structure of the ascospore locules, secondary chemistry, hamathecium structure, ostiole position) do not correlate with these two groups. However, the presence of pseudocyphellae is restricted to species of Pyrenula from one group.

Epiphytic lichens as indicators of environmental health in the vicinity of Chiang Mai city, Thailand

Epiphytic lichens were sampled on selected trees in 19 sites radiating from Chiang Mai city including the adjacent mountain Doi Suthep in Northern Thailand using the VDI method (Verein Deutscher Ingenieure) to obtain frequency of occurrence in 10 area units per sampled tree. Sites selected included highly polluted sites in urban and adjacent industrial areas of Chiang Mai city, disturbed rural sites and undisturbed forest on Doi Suthep mountain, with altitudes varying from 260-1450 m. Lichen diversity was highest in upland sites and lowest in urban and agricultural sites. Analysis of lichen taxa at generic and at macrolichen species level and environmental data using PRIMER showed that upland and lowland sites were distinguished in the first division at both levels and correlated with altitude and vegetation type. Analysis of all taxa at generic level showed no separation of lowland sites but at macrolichen species level a better separation was obtained, suggesting that lichen diversity alone cannot be used for biomonitoring of air pollution. The relationship of epiphytic lichens to climate and pollution data available for Chiang Mai city and Doi Suthep is discussed and results compared with data from other studies in SE Asia.

Six new species of Graphidaceae from Sri Lanka

Abstract Six new species of Graphidaceae are described from Sri Lanka, four in Graphis sensu Staiger and one each in Fissurina and Thelotrema. Fissurina srilankensis Weerakoon, Wijeyaratne & Lücking is characterized by lirellae with well-developed labia and comparatively large, muriform ascospores. Graphis allugallenensis Weerakoon, Wijeyaratne & Lücking is similar to G. vittata but has a distinctly verrucose thalline margin along the lirellae. Graphis dotalugalensis Weerakoon, Wijeyaratne & Rivas Plata resembles G. proserpens in the exposed lirellae with striate labia and apically carbonized excipulum but differs in the comparatively large ascospores. Graphis knucklensis Weerakoon, Wijeyaratne & Wolseley features lirellae with striate labia, an inspersed hymenium, and norstictic acid as secondary compound. Graphis srilankensis Weerakoon, Wijeyaratne & Lumbsch has entire labia with a completely carbonized excipulum, inspersed hymenium, transversely septate ascospores, and produces norstictic acid. Finally, Thelotrema pseudosimilans Weerakoon, Wijeyaratne & Lumbsch is close to T. similans in the corticate thallus and prominent apothecia with narrow pore, but has consistently larger ascospores.

Eight new lichen species and 88 new records from Sri Lanka

Abstract Preliminary results are presented of a project aiming to explore the lichen biodiversity in Sri Lanka. The following mostly corticolous (one saxicolous) new species are described: Arthonia karunaratnei with dark brown, round apothecia in groups that are surrounded by a bright orange area, with ascospores 2-septate, 9.0–10.5 × 3.5–4.5 μm; Enterographa wijesundarae with sessile, pruinose apothecia with thin margins that are higher than the disc, with ascospores 13–17-septate, 50–60 × 4.5–5.5 μm, without substances; Fellhanera stipitata with convex, brown apothecia, fusiform to clavate, 5–7-septate ascospores of 21–24.5 × 2.0–2.5 μm, and sessile to tubular pycnidia with conidia 4.5–5.5 × 1.5–2.0 μm; Malmidea plicata which is similar to M. vinosa but with folded thallus and smaller ascospores; Phlyctis lueckingii with ca. 0.2–0.3 mm large, grey-pruinose apothecia in dense groups and fusiform 7-septate ascospores of 27–29 × 5.5–6.5 μm; thallus with norstictic acid.; Porina viridipustulata with numerous pustules of ca. 0.2–0.7 mm diam. and ca. 0.1–0.3 mm high and ascospores 3–7-septate, 57–60 × 12–13 μm; Stirtonia isidiata with glossy white thallus with isidia, which are partly globose but mostly irregularly cylindrical, often with some constrictions or branching, usually gnarled and decumbent, generally ca. 0.2–0.3 mm thick and up to ca. 2 mm long; ascigerous areas apothecium-like, sessile; ascus with 1 ascospore, ca. 250 × 150 μm; ascospores hyaline, broadly fusiform 7–9-septate, 210–225 × 105–115 μm.; and Trypetheliopsis hirsuta with black, ear-shaped, pointed, glossy campylidia of ca. 0.4–0.9 mm diam., ca. 0.5–1.2 mm high, at the outside with black bristles. Furthermore, 88 lichen species are newly recorded from Sri Lanka, including 55 species new for the Indian subcontinent. Interestingly, eight of these are first reports from the whole of the Palaeotropics. These species were previously known only from either Costa Rica or the Amazonian and/or Atlantic rain forest of Brazil.

Macrolichens on Twigs and Trunks as Indicators of Ammonia Concentrations Across the UK — a Practical Method

Lichen community composition on acid-barked trees has been shown to respond to increasing atmospheric ammonia (NH 3 ) concentrations by loss of acidophyte species and an increase in nitrophyte species. A simple method of sampling selected acidophyte and nitrophyte lichens on trunks and twigs of trees in the vicinity of ammonia monitoring sites across the UK allowed us to test the correlation of lichen communities with ammonia concentrations across the climatic and vegetation zones of the UK. Sites were selected and field staff from the conservation and regulatory agencies introduced to standard lichen sampling and identification techniques at a workshop co-organised by NHM and CEH Edinburgh. L AN (Lichen Acidophyte Nitrophyte) values were calculated for all sites, based on the frequency of acidophyte and nitrophyte macrolichens on trunks and twigs. Bark samples from trunk and twig were collected and surface bark pH measured in the lab, to test the correlation of acidophyte and nitrophyte communities with bark pH. L AN values on tree trunks and twigs are correlated with NH 3 concentrations across the UK. However, acid-barked trees, e.g. Oak(Quercus), provide a better correlation with NH 3 than basic-barked species. Lichens on twigs respond to increasing ammonia at lower concentrations than lichens on trunks, and considerably lower than the annual critical level (8 mg NH 3 m �3 ), confirming that the twig L AN can act as a sensitive early warning system of changes in atmospheric NH 3 . Lichens have long been used as indicators of environmental health and in particular as indicators of air quality. In the 1960s and 1970s lichen communities were observed to be highly correlated with sulphur dioxide deposition, and a number of different methods were developed for their use as bioindicators across Europe, involving indicator species and lichen frequency (Hawksworth and Rose 1970; Nimis et al. 1990; VDI 2005; Asta et al. 2002). The majority of these methods