Patterns and drivers of lichen species composition in a NW-European lowland deciduous woodland complex

© The Author(s) 2016. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The attached file is the published version of the article.NHM Repositor

The impact of air pollution on terrestrial managed and natural vegetation

Although awareness that air pollution can damage vegetation dates back at least to the 1600s, the processes and mechanisms of damage were not rigorously studied until the late twentieth century. In the UK following the Industrial Revolution, urban air quality became very poor, with highly phytotoxic SO2 and NO2 concentrations, and remained that way until the mid-twentieth century. Since then both air quality, and our understanding of pollutants and their impacts, have greatly improved. Air pollutants remain a threat to natural and managed ecosystems. Air pollution imparts impacts through four major threats to vegetation are discussed through in a series of case studies. Gas-phase effects by the primary emissions of SO2 and NO2 are discussed in the context of impacts on lichens in urban areas. The effects of wet and dry deposited acidity from sulfur and nitrogen compounds are considered with a particular focus on forest decline. Ecosystem eutrophication by nitrogen deposition focuses on heathland decline in the Netherlands, and ground-level ozone at phytotoxic concentrations is discussed by considering impacts on semi-natural vegetation. We find that, although air is getting cleaner, there is much room for additional improvement, especially for the effects of eutrophication on managed and natural ecosystems. This article is part of a discussion meeting issue ‘Air quality, past present and future’

Alkaline air: changing perspectives on nitrogen and air pollution in an ammonia-rich world

Ammonia and ammonium have received less attention than other forms of air pollution, with limited progress in controlling emissions at UK, European and global scales. By contrast, these compounds have been of significant past interest to science and society, the recollection of which can inform future strategies. Sal ammoniac (nūshādir, nao sha) is found to have been extremely valuable in long-distance trade (ca AD 600–1150) from Egypt and China, where 6–8 kg N could purchase a human life, while air pollution associated with nūshādir collection was attributed to this nitrogen form. Ammonia was one of the keys to alchemy—seen as an early experimental mesocosm to understand the world—and later became of interest as ‘alkaline air’ within the eighteenth century development of pneumatic chemistry. The same economic, chemical and environmental properties are found to make ammonia and ammonium of huge relevance today. Successful control of acidifying SO2 and NOx emissions leaves atmospheric NH3 in excess in many areas, contributing to particulate matter (PM2.5) formation, while leading to a new significance of alkaline air, with adverse impacts on natural ecosystems. Investigations of epiphytic lichens and bog ecosystems show how the alkalinity effect of NH3 may explain its having three to five times the adverse effect of ammonium and nitrate, respectively. It is concluded that future air pollution policy should no longer neglect ammonia. Progress is likely to be mobilized by emphasizing the lost economic value of global N emissions ($200 billion yr−1), as part of developing the circular economy for sustainable nitrogen management

Ascospore discharge, germination and culture of fungal partners of tropical lichens, including the use of a novel culture technique

A total of 292 lichen samples, representing over 200 species and at least 65 genera and 26 families, were collected, mainly in Thailand; 170 of the specimens discharged ascospores in the laboratory. Generally, crustose lichens exhibited the highest discharge rates and percentage germination. In contrast, foliose lichen samples, although having a high discharge rate, had a lower percentage germination than crustose species tested. A correlation with season was indicated for a number of species. Continued development of germinated ascospores into recognizable colonies in pure culture was followed for a selection of species. The most successful medium tried was 2 % Malt-Yeast extract agar (MYA), and under static conditions using a liquid culture medium, a sponge proved to be the best of several physical carriers tested; this novel method has considerable potential for experimental work with lichen mycobionts

Report of resurvey of lichen quadrats on Skomer Island NNR

Available from British Library Document Supply Centre-DSC:3096.2392(234) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Resurvey and monitoring of Teloschistes flavicans in Pembrokeshire 1997

SIGLEAvailable from British Library Document Supply Centre-DSC:3096.2392(237) / BLDSC - British Library Document Supply CentreGBUnited Kingdo