Epiphytic lichens as indicators of anthropogenic impact and biodiversity in Slovenian forests

Batic, F. (1), Kastelec, D. (1), Mavsar, R. (2), Mayrhofer, H. (3) & Mrak, T. (4)
(1) University of Ljubljana, Biotechnical Faculty, Department of Agronomy, Jamnikarjeva 101 1000 Ljubljana, Slovenia; (2) Slovenian Forestry Institute, Vecna pot 2, 1001 Ljubljana, Slovenia; (3) Karl-Franzens Universität Graz, Instituf für Botanik, Holteigasse 6, 8010 Graz, Austria; (4) Institute Jozef Stefan, Jamova 39 , 1000 Ljubljana, Slovenia

The article presents two methods of screening lichen richness in Slovenian forests. First is a very simple screening of cover of three main lichens thallus types, e.g. crustose, foliose and fructicose. Second approach was lichen species mapping, implemented in the most preserved and most endangered forests ecosystems. Data from the forests condition inventories showed that epiphytic lichen overgrowth is connected with anthropogenic impacts, first of all by air pollution and also by forests managements. The cover of epiphytic lichens has not changed significantly although emissions of sulphur dioxide from thermal power plants and from other energy production sources have been strongly reduced Fruticose lichens were absent in polluted areas where also the cover of foliose species is reduced. Results of the second method, mapping of species occurring on the most spread forests tree species were similar to the results of the former method, e.g. increasing number of epiphytic lichen species in areas where cover is abundant. The highest biodiversity was found in the area of Triglav National Park within Julian Alps (253 species/area, 218 species/100 plots), followed by Sneinik area in Dinaric mountains (229 species/area, 173/100 plots), Pohorje mountains (142 species/area, 145/100 plots) and the lowest number in the polluted Zasavje district (94 species/area, 73/100 plots. The number of epiphytic lichen species did not show significant increase with the altitude in areas with cleaner air, being the highest between 500-600m and 1500-1600m. In polluted Zasavje region, where air pollution sources are in the valley the number of epiphytic lichens increases above 900 m. Apart from air pollution forests management practice and land use in the past have also great influence. In the areas where forests were managed less intensive (Julian Alps, Sneznik) the diversity of lichens is greater and very sensitive species from the Lobarion community are more common.


Infraspecific variation within Stereocaulon species complexes – genetic markers, individuals, populations and species

Döring, H. & Wedin, M.
Department of Ecology and Environmental Science, Umeå University, Sweden

Molecular methods are today an integral part of systematic and phylogenetic studies in lichens, however, questions of population biology just started to be assessed this way. Our knowledge about genetic diversity in lichen fungi and their population genetics is still rather poor. Species of the genus Stereocaulon, which are common and widespread in Scandinavia, are chosen as a study group to investigate principal aspects of the population genetics in lichen fungi. We aim to gain insight in the genetic diversity and population structure of species that are not suffering from major reduction or extinction of populations. Such data can be expected to be valuable for comparison with threatened lichen-forming fungi later on. Furthermore, Stereocaulon species show a considerable morphological plasticity, which has resulted in different species circumscriptions and the recognition of various infraspecific taxa over time. Studying genetic variation within and between populations is therefore also critical for a clarification of species delimitations with molecular markers.
Here, Stereocaulon species of the boreal forest region are investigated. Ascogones restricted to the tips of pseudopodetia, which allows the utilization of strictly haploid fungal tissue from the lichen thallus for population studies without inference through fertilization, making them very suitable for genetic studies. We are focusing on colonizers of open soil and gravel, the Stereocaulon saxatile complex, and on members of lichen-carpets in dry pine forests, Stereocaulon grande and allies. Infraspecific sequence variation in several genomic markers is studied to investigate reproduction mode, genetic diversity and dispersal in these species complexes. We found astonishingly high genetic variation even on a small spatial scale within local populations. The congruence with currently morphologically circumscribed entities will be discussed as well as the current use of molecular markers.


Analysis of the potential distribution of pendulous species of Usnea in Mexico

Herrera-Campos, M. A. (1) & Martínez, M. E. (2)
(1) Instituto de Biología UNAM, Departamento de Botánica, Apdo. Postal 70-233, Coyoacán 04510, México D. F.; (2)

The genus Usnea is one of the least known lichen groups at the species level, particularly in Mexico it is estimated that there are approximately 50 species, 16 of which exhibit a pendulous habit. In this study, preliminary results of the analysis of their potential distribution are given based on the modeling of their bioclimatic envelopes using the Genetic Algorithm for Rule-set Prediction (GARP), which has shown to be highly efficient to model envelopes and geographic distributions of species, even those for which only scanty information is available. Results are promising as observed for three species for which statistical tests were applicable (U. ceratina, U. hesperina and U. subscabrosa), whose models were significantly better than expected by chance (P < 0.001). For the other species, resulting models showed high congruence with the available information on their habitat preferences. These results are useful to identify new sampling areas for the known species and even for those still non-described. Moreover, with this modeling system, it is possible to detect critical sites for the conservation of the species of Usnea in a country where the ecological deterioration is alarming.


Lichen genus Lepraria in Poland

Kukwa, M.
Department of Plant Taxonomy and Nature Conservation, University of Gdañsk, Al. Legionów 9, PL-80-441 Gdañsk, Poland

The genus Lepraria was neglected in Poland for a long time. A huge part of the determinations was based mainly on morphological feature, therefore they were not reliable. Up to the 1998 ten species were reported from Poland, but records of only 6 were confirmed by analyses of secondary lichen substances (marked with an asterisk; recorded only from single localities ): L. caesioalba, L. crassissima, L. diffusa, L. incana, *L. jackii, *L. lobificans, *L. membranacea, *L. neglecta, *L. rigidula and *L. vouauxii.
The aims of the studies conducted in 1998 were to recognise the species composition, to know the distribution, frequency and habitat preferences of Lepraria species in the country. Also the chemistry and morphology were studied. Ca. 2800 specimens were revised.
17 species have been found to occur in Poland. 6 of them have been reported for the first time from the country. These are: L. borealis, L. cacuminum, L. eburnea, L. elobata, L. nivalis and L. umbricola. The occurrence of all taxa reported without chemical analyses was confirmed and the second variety of L. diffusa, var. chrysodetoides, was found. Also a new species for science was discovered (in preparation). Additionally, new chemotype of L. neglecta was recognised. Specimens with atranorin and roccellic/angardianic acid and granular thallus were classified as L. borealis.
L. incana appeared to be the most common taxon in Poland. It was found in open areas as well as in forest condition on almost all types of substrates. L. elobata, L. jackii and L. lobificans are also frequent, but they usually grow in forests or in shaded habitats. L. rigidula and L. vouauxii are quite common, but they prefer free-standing trees, and in the case of the second one, also calcareous rocks. L. nivalis (only chemotype I found in Poland) is the rarest one species of the genus in Poland and is known only from one valley in Tatra Mts.


Biogeography of lichens in Italy

Nimis, P. L. & Martellos, S.
Dipartimento di Biologia, Università di Trieste, Trieste, Italy

This study presents a multivariate subdivision of all lichen species known from Italy (ca. 2350 infrageneric taxa), based on their occurrence in the 9 main bioclimatic areas of the country. The latter were defined thanks to several GIS-maps, taking into account also the basic biogeographic difference between the Adriatic and the Tyrrhenian sides of the Italian Peninsula. Commonness-rarity was calculated for each species and for each area, on the basis of three main parameters: 1) number of samples in the TSB herbarium (% of total number of samples in the area), 2) number of literature records, c) an expert assessment used in particular cases (e.g. that of recently-described species). An index, based on commoness-rarity, was calculated for each species, which expresses its main distributional pattern in the 9 areas. The resulting matrix was submitted to numerical classification, in order to obtain clusters of species with a similar distribution. The distributional patterns of each cluster were depicted by means of a chorogram, i..e. a GIS-based map showing the joint distribution of all species of each cluster. The relative incidence of each biogeographic element along some main ecological gradients defined by ecological indicator values (altitude, degree of urbanisation, pH, light, humidity, eutrophication) aer analysed and critically discussed.


Lithophilous lichens of Middle Urals

Paukov, A. G. & Trapeznikova, S. N.
Urals State University, Ekaterinburg, Russia

Middle Urals is a "lowlands" within the Ural Mountains. The geological structure here is nevertheless rather complicated. Lichens on acid (granite and diorite), ultramafic (serpentine and pyroxenite) rocks, basalt and limestone has been studied.
Lichen biodiversity on these substrates comprises 193 species. The most diverse flora grows on serpentine (83 species). Limestone (81), basalts (78), pyroxenites (71) and granites (67 species) are less rich in species quantity. Lichen diversity depends on chemical composition and microclimate. Limestone and granite - the most chemically deviating rocks - bear 48 and 19 specific lichen taxa and the ultramafics and basalts resemble each other. Granites whose outcrops are situated under forest canopy have more hypoarctic species compared with other rocks bearing a number of steppose lichens. 38 species are rare in the region. Some of them are northern or southern lichens such as Arctoparmelia centrifuga (L.) Hale, Fulgensia bracteata (Hoffm.) Ras., others which are mainly not lithophilous, grow here on rocks and rock mosses (Flavoparmelia caperata (L.) Hale, Heterodermia speciosa (Wulf.) Trevis.), still others are locally rare (Clauzadea monticola (Schaer.) Haf. & Bellem., Phlyctis argena (Spreng.) Flot.).
Middle Urals is a region with high concentration of metallurgical plants and a rather poor epiphytic lichen biodiversity. The role of epilithic species as indicators of antropogenic stress can be very important here. The groups of epiliths based on the sensitivity to air pollution has been delimited using lichens on granites. The tolerant are Acarospora fuscata (Schrad.) Arnold, Aspicilia cinerea (L.) Koerb., the moderately tolerant are Phaeophyscia sciastra (Ach.) Moberg, Rhizocarpon obscuratum (Ach.) Massal., and the sensitive are Bryoria sp., Melanelia panniformis (Nyl.) Essl.
The study has been financially supported by grants of Russian Ministry of education (A.03-2.12-493) and Russian fund of basic research (04-04-96131).


Regional population differentiation in Lobaria pulmonaria and its implication for conservation strategies

Scheidegger, C. (1), Walser, J.-C. (1, 6), Werth, S. (1), Kalwij, J. (1), Csencsics, D. (1), Cornejo, C. (1), Keller, C. (1), Mikhailova, I. (2), Tchabanenko, S. (3), Pystina, T. (4) & Jüriado, I. (1, 5)
(1) WSL Swiss Federal Research Institute, CH-8903 Birmensdorf, Switzerland; (2) Institute of Plant and Animal Ecology, 8 Marta Str. 202, 620141 Ekaterinburg, Russia; (3) Sakhalin Botanical Garden, Gorky street 25, 693023 Yuzhno-Sakhalinsk, Russia; (4) Institute of Biology, Komi Science Centre, Kommunisticheskaya str. 28, 167610 Syktyvkar, Komi Republic, Russia; (5) Institute of Botany and Ecology, University of Tartu, Lai 40, Tartu 51005, Estonia; (6) The University of Chicago, 1027 East 57th Street, Chicago USA

The epiphytic lichen Lobaria pulmonaria has a wide distribution, which includes disjunct populations on different continents. The species is morphologically and chemically uniform throughout its distribution area. In boreal North America and Asia this species is regionally abundant in old-growth forests, whereas in temperate Central Europe populations are often small, isolated and endangered.
Mycobiont-specific microsatellite markers and ITS sequence data were used to study population structure and differentiation. Our data revealed that glacial separation and different postglacial immigration routes have left their footprints in the present genetic structure of regional populations. Within populations, the genetic structure was found to depend on the type of natural forest dynamics (forest fires versus gap dynamics) and management.
We will present several studies where frequency and intensity of disturbances at the spatial scale of the forest stand level had strong effects on genetic diversity of L. pulmonaria. Furthermore, we will discuss the relations between genetic diversity and abundance of dispersal limited lichen species under different disturbance regimes.


Impact of land use intensity on lichen diversity across European biogeographic regions

Stofer, S. (1), Scheidegger, C. (1), Bergamini, A. (1), Carvalho, P. (2), Davey, S. (3,4), Dietrich, M. (5), Farkas, E. (6), Groner, U. (7), Kärkkäinen, K. (8), Keller, C. (1), Lökös, L. (9), Lommi, S. (10), Máguas, C. (11), Mitchell, R. (12), Pinho, P.
(11), Rico, V. J. (13), Rubio, G. A. (13), Truscott, A.-M. (12), Wolseley, P. (14) & Watt, A. (12)
(1) Swiss Federal Research InstituteWSL, Zürcherstr. 111 CH-8903Birmensdorf, Switzerland; (2) Museu Nacional de História Natural, Jardim Botanico, Rua da Escola Politécnica, 58, 1250-102 Lisboa, Portugal; (3) Stable Flat, Downsland Court, 115 East End Lane, Ditchling, Hassocks, Sussex, BN6 8UR, UK; (4) Dept. of Zoology, University College Dublin, Belfield, Dublin 4, Ireland; (5) I de Böde, CH-6010 Kriens, Switzerland; (6) Institute of Ecology and Botany, Hungarian Academy of Sciences, H-2163 Vacratot, Hungary; (7) Engelstr. 5, CH-8004 Zürich, Switzerland; (8) Department of Ecology and Systematics, P.O. Box 65, 00014 University of Helsinki, Finland; (9) Department of Botany, Hungarian Natural History Museum, H-1476 Budapest, Pf. 222, Hungary; (10) The Finnish Forest Research Institute,Vantaa Research Centre, Vantaa Unit, PL 18, 01301 Vantaa, Finland; (11) FCUL, Centro de Ecologia e Biologia Vegetal, Depto. de Biologia Vegetal, Bloco 2C, Campo Grande, 1749-016, Lisboa, Portugal; (12) Centre for Ecology and Hydrology (CEH), Banchory, Hill of Brathens, Banchory, Aberdeenshire, Scotland AB31 4BW, UK; (13) Departamento de Biología Vegetal II, Facultad de Farmacia, Universidad Complutense, E-28040 Madrid, Spain; (14) Department of Botany, The Natural History Museum, Cromwell Road, London SW75BD, UK

In an European Project "Biodiversity Assessment Tools" (BIOASSESS) we developed a method to assess the impact of land-use intensity on biodiversity across Europe's biogeographic regions. Lichen diversity was measured across land use gradients in eight countries. In each country six land use units (each 1 km2) representing different degrees of land use intensity were chosen: old-growth forest, secondary forest, mixed-use landscapes, one dominated by forest, the second with an equal share of forest and open land, pasture and intensively managed agricultural areas. For each km2 a 16 point grid for standardized lichen sampling was established. In total 2304 lichen relevés on trees, rocks and on soil were carried out. In addition, information describing climate, land use type and land use intensity was gathered for each of the 768 grid points.
In total 768 different species were found, belonging to 157 genera. Big differences in total lichen diversity were observed among countries and along the land use intensity gradient. Old-growth forests showed the highest pooled species richness. Epiphytic, saxicolous and terricolous lichens revealed different pattern across the land use units. Different aspects of functional diversity across land use units were evaluated. Factors affecting species composition along the gradient as well as possibilities to simplify the method will be discussed.


Lichens of southern part of Sakhalin and Kurile islands

Tchabanenko, S. I.
Sakhalin Botanical Garden, Russia

The lichen flora of this part of Russian Far East is still poorly known. Biodiversity of lichens and lichenofilous fungi for this region consists of 668 species, 182 genera, 63 families, 12 orders. Majority of the species are widespread in boreal, cool temperate and temperate, tropical and subtropical zones (cosmopolitan elements) – 34,7%. Among them are widespread pantropical (Coccocarpia erithroxili, Hypotrachyna sinuosa, Parmotrema austrosinense and other) and paleotropical (Lobaria retigera) species. There are 32,3% lichens wide spread in Holarctic. Among them predominate amphiatlantic and amphipaciphic species. There are a lot of Eastern Asian elements -20,5 % (Glossodium japonicum, Nephromopsis ornata, Hypogymnia hokkaidensis and others). The connections with flora of Northern America are demonstrating Asian- American species (6 %). Part of them are Tertiary lichens: Lobaria quercizans, Anaptychia palmulata, Anzia ornata, Phaeophyscia melanchra, Cladonia submitis and others. The Berengian region has evidently been a very important point of contact between Asia and America. Among the lichens there are of the so-called Berengian radiants: Cladonia kanewskii, C. nipponica, Bryocaulon pseudosatoanum, Lobaria pseudopulmonaria. 14 species are distributed in the territory of Asia only: Nephromopsis komarovii, Stereocaulon spinosum, Ramalina rijabushinskii. 37 species were recommending in Red Data Book of Sakhalin district. Among them, 25 species will have included in new edition of Red Data Book of Russia. Sometimes they are not rare in this region: Lobaria pulmonaria, Leptogium hildenbrandii, Menegazzia terebrata. More rare species for Sakhalin and Kurile islands are on northern border their distribution or endemic of East-Asian floristic districts: Glossodium, Anzia japonica, Oropogon asiaticum, Menegazzia asahinae and others. Some species are Berengian radiants: Stereocaulon saviczii, Bryocaulon pseudosatoanum.


Lichens of the boreal forests of Russia – questions of conservation

Urbanavichene, I. N.
Baikalskii State Nature Biosphere Zapovednik, Tankhoi, Buryatiya Rep., Russia

There are many variations of the scheme of Eurasian boreal zone (Sochava, Lavrenko, 1950; Hamet-Ahti, Ahti, Jalas, 1968; Tuhkanen, 1984; Ogureeva, 1999 and so on). Regional studies of the distribution of lichens are importance in this aspect.
The 824 lichen species of boreal forests was study at the base of lichen lists of seven zapovedniks of Russia (Baikalskii, Volzhsko-Kamskii, Kerzhenskii, Laplandskii, Sohondinskii, Zentralno-Lesnoi, Zentralno-Chernozemnyi) and three sites from Murmansk Region.
Taxonomic and ecological diversity of lichen species have very varied from Northern to Southern border. Only 562 species have related in allocation with boreal forests. About 11 % of them (62 species) are distribution at all 10 sites. These species – from genera Bryoria, Buellia, Caloplaca, Cetraria, Chaenotheca, Cladonia, Hypogymnia, Evernia, Lecanora, Lecidella, Melanelia, Micarea, Mycoblastus, Nephroma, Parmelia, Parmeliopsis, Peltigera, Placynthiella, Platismatia, Ramalina, Trapeliopsis, Tuckermannopsis, Vulpicida and Usnea – are widespread in the boreal forests of Russia.
The research of the diversity of lichens on northern and southern borders of boreal forests is especially interesting.
Lichen species Evernia mesomorpha, Hypogymnia bitteri, Japewia subaurifera, J. tornoensis, Parmeliopsis ambigua are characteristic for Northern Taiga subzone (Murmansk Region) and Bryoria nadvornikiana, Evernia divaricata, Ramalina farinacea are rare.
Lichen species Anaptychia ciliaris, Evernia prunastri, Lecanora carpinea, L. varia, Ramalina pollinaria are characteristic for Southern Taiga subzone (Nizhegorodskii Region and Tatarstan) and Ramalina obtusata, Usnea lapponica are very rare.
The lichen species can be use as indicators high conservation status of the boreal forests. Example, epiphytic Bryoria nadvornikiana, Cetrelia cetrarioides, C. olivetorum, Heterodermia speciosa, Lobaria pulmonaria, Nephroma bellum, N. resupinatum, Usnea glabrescens, U. filipendula.


Biogeographical survey of Russian "red book" lichens

Urbanavichus, G. P.
Polar-alpine Botanical Garden-Institute, Kirovsk-6, Murmansk reg., Russia

The total lichen biodiversity and distribution of many lichens species in Russia is still poorly known. It explains a very few number of "red book" lichens – 43 species in a new edition (and 29 species in Red Book 1988). The greatest from them occurs in the Asian Russia – 41 sp. Only 15 species occurs in the European Russia. The distribution of species at the biogeographic zones of Russian Europe following:
Arctic: Omphalina hudsoniana, Stereocaulon capitellatum
Boreal (Taiga): Bryoria fremontii, Lobaria pulmonaria, Omphalina hudsoniana, Stereocaulon capitellatum, Stereocaulon dactylophyllum
Boreal-temperate (Coniferous-broad-leaved): Lobaria pulmonaria, Menegazzia terebrata, Tuckneraria laureri, Usnea florida
Continental (Broad-leaved): Lobaria pulmonaria, Menegazzia terebrata, Tuckneraria laureri (extinct?)
Steppic: Cetraria steppae
Northern Ural: Bryoria fremontii, Lobaria pulmonaria, Omphalina hudsoniana, Stereocaulon dactylophyllum, Tuckneraria laureri
Southern Ural: Bryoria fremontii, Cetraria steppae, Leptogium burnetiae, Lobaria pulmonaria, Menegazzia terebrata, Tuckneraria laureri, Usnea florida
Caucasus: Cetraria steppae, Cetrelia alaskana, Leptogium burnetiae, Leptogium hildenbrandii, Letharia vulpina, Lobaria amplissima, Lobaria pulmonaria, Menegazzia terebrata, Rimelia reticulata, Tuckneraria laureri, Usnea florida
The small number of "red book" lichens in continental broad-leaved forests of Russia is due a strong disturbance of natural forests. In most of regions of this zone the part of the wood area compounds less than 20 % from the total area of regions. At that time there are more "red book" lichens species in mountain regions of Ural and Caucasus. The richness of last areas is due presence more natural forests and diverse habitats, and largely rainfall since the distribution of many lichens is limited by humidity and ancient forests.
The maps of distribution of Russian "red book" lichens species can be used for defining important lichen habitats.

Molecular phylogeography of the bipolar lichen Usnea sphacelata and related species

Wirtz, N. (1), Printzen, C. (1), Schroeter, B. (2) & Lumbsch, H. T. (3)
(1) Forschungsinstitut Senckenberg, Abteilung Botanik/Paläobotanik, Sektion Kryptogamen, Frankfurt, Germany; (2) Botanisches Institut, Universität Kiel, Kiel, Germany; (3) The Field Museum of Natural History, Dept. of Botany, Chicago, USA

Lichens form an important part of the biodiversity in cold temperate terrestrial ecosystems, such as Antarctica and the arctic regions. Few species occur in both polar regions and are called bipolar. The vegetation history of lichens in general, and especially of most bipolar species, is still widely unexplored. The aim of this study is to reveal the vegetation history of the bipolar model taxon Usnea sphacelata and to investigate its relationship to populations of three further Usnea species whose distribution is restricted to Antarctica and South America (U. aurantiaco-atra, U. antarctica, U. trachycarpa). In order to resolve the genetic structure of various populations of the species mentioned above, different molecular markers are used: parts of the nuclear ribosomal ITS and IGS regions, the nuclear RPB1, and a mitochondrial cytochrome oxidase I intron. The distribution of Usnea sphacelata is almost circumpolar in both arctic and Antarctic regions. In addition, it rarely occurs in the high Andes of Venezuela, Columbia, Ecuador and Peru.
Preliminary results show that 1) the genetic structure of the arctic populations is more homogenous compared to other populations, that 2) Ecuadorian populations seem to share alleles of both hemispheres and 3) that the continental Antarctic specimens differ significantly from those of other Antarctic regions. Beyond this, Usnea sphacelata and U. trachycarpa appear as conspecific in the molecular analysis. This is also true for the species pair U. aurantiaco-atra and U. antarctica.


Variation of lichen communities with landuse in Aberdeenshire

Wolseley, P. (1), Scheidegger, C. (2), Stofer, S. (2), Mitchell, R. (3), Truscott, A.-M. (3) & Vanbergen, A. (3)
(1) Department of Botany, the Natural History Musem, Cromwell Rd, London SW7 5BD, Great Britain; (2) Swiss Federal Institute for Forest Snow and Landscape Research, Zücherstrasse 111, Birmensdorf CH-8903, Switzerland; (3) Centre for Ecology and Hydrology, Hill of Brathens, Banchory Aberdeenshire AB31 4BW, Great Britain

BioAssess is an EU project set up to estimate biodiversity of selected groups of flora and fauna under differing land management regimes. In 7 European countries 1km2 was selected within each of 6 specified land management regimes. The UK sites were all in Scotland in Aberdeenshire on granitic bedrock. Sites included native Caledonian pine forest, plantation forest, mixed forest and agriculture, grassland and arable farms. Within each 1km2 a 16 point grid was established to allow sampling of 1 hectare from each grid point for epiphytic, saxicolous and terricolous lichens.
Total lichen diversity was highest in mixed management sites. Epiphytic diversity was highest in the mixed management site and in Caledonian pine forest which also supported species not found elsewhere. Saxicolous diversity was lowest in the pine forest where outcrops were absent and highest on walls in the farmland sites, where epiphytic diversity was lowest partly due to sparse tree cover or even-aged plantations. Walls were all composed of siliceous granite but structure varied in age and in construction from ancient boundary walls to dry stone rubble walls to heaps of boulders following recent land clearance for agriculture. Variation in lichen communities on granite and their component species with substrate age, landuse and management regimes is discussed. Factors affecting the distribution of species on acid rocks in upland regions of Britain are investigated, including ecological continuity and changes in pollutant levels leading to acidification or nitrification. This data will be used to create a framework for monitoring changes in saxicolous lichen diversity and distribution in upland regions of Britain on hard rocks.

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