“Quality and Quantity: maintaining biological diversity in space and time”—Session II of the 5th Symposium of the International Association for Lichenology, Tartu, Estonia, 16–21 August 2004. As naturalists and especially as lichenologists, we would all agree that lichen diversity is desirable for its own sake. A species-poor forest looks ‘wrong’ to an experienced outdoors-person, and, conversely, a lichen-rich forest is a delight, even if the viewer knows nothing about lichens per se. This is why many people, not just lichen-lovers, agonize over the loss of lichen diversity in our natural landscape.

The lichen genus Lepraria in Poland, comprising 17 species, is reviewed: for each taxon, remarks on the chemistry, distribution and habitat preferences are provided. Distribution maps are also presented, together with a key for determination of the Polish species. Lepraria diffusa var. chrysodetoides is reduced to a synonym of L. diffusa s. str., a new chemotype with a new substance is reported for L. neglecta, and rangiformic acid is reported for the first time for chemotype III of L. caesioalba. Lepraria borealis is reported for the first time from Africa (Canary Islands) and L. nigrocincta from Nepal.

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 km2 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.

A relatively quick and simple method is presented for monitoring changes in distribution and in site and substratum preferences of epiphytic macrolichens; the method also records the natural turnover of common species. Changes in the epiphytic lichen flora in southern Sweden were recorded at 64 sites in 1986 and again in 2003. In total 1990 observations of lichens were recorded on 15 tree species, mainly on trunks but also on branches up to 2 m above the ground. Almost all species showed a high turnover with regard to substratum, including very abundant species such as Hypogymnia physodes. Many of the species had changed substratum within their sites, possibly reflecting a general change in the ecological quality of sites. Canonical Correspondence Analysis was used to extract the variation in species composition over time, using 1685 records of 55 lichen species on 8 different substrata. Some species such as Hypogymnia tubulosa had increased in abundance whilst others such as Vulpicida pinastri had decreased.

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.

This paper aims to provide a biogeographical analysis of the epiphytic lichen flora of S Calabria by means of chorograms (i.e. distributional maps showing the joint distribution of multiple taxa). Two datasets on both local and Italian distribution were used. Local distribution is described by records of 135 epiphytic species in 14 sampling sites (5 trees per site, boles sampled from the ground to 2 m) representing the main vegetation belts of the survey area. A cluster analysis of the species, based on their commonness-rarity in the 9 main bioclimatic areas and in the 20 administrative regions of Italy, was applied. For each of the 7 clusters of species (chorotypes), a chorogram was produced. The matrix of species and sites was also submitted to numerical classification, and 5 clusters of sites were obtained, corresponding to the main altitudinal belts and tree species. For each group of sites, the frequencies of chorotypes were calculated. The results show a clear relationship between local distribution, mainly related to ecological conditions, and the Italian one. The truly Mediterranean forests of the survey area have the highest incidence of the Tyrrhenian element. Beech forests of the montane belt, dominated by broad-ranging lichens, are the most diverse biogeographically. The pine forests lying above the temperate belt do not host a peculiar lichen flora, being dominated by broad-ranging circumboreal species.

135 infrageneric taxa of epiphytic lichen were found in 20 stands of tree-line forests of the Central-Eastern Italian Alps. Three forest types were considered: (1) late successional stands with several large trees, (2) pioneer stands on abandoned pastures without large trees, and (3) open and grazed stands. They were compared on the basis of four main criteria: (1) species richness, (2) number of rare species, (3) number of species that are exclusive to the subalpine belt in Italy, and (4) number of species that are exclusive to the Alps in Italy. Species richness is higher in the late successional stands, which also host a higher share of rare and exclusive species. The total number of rare species per site is correlated with the total number of species, as well as with the number of common species, and with the total number of macrolichens. Rare macrolichens are correlated with common macrolichens. Two main groups of target species with decreasing conservation priority are identified. Letharia vulpina is suggested as signal species for sites worthy of conservation. The guild of macrolichens may be used as an indicator of both species richness and of the occurrence of rare species.

Logging in Tasmania's wet eucalypt forests has traditionally been based on a clearfell, burn and sow regime, a process that has become increasingly controversial in recent years. The managing authority for these forests, Forestry Tasmania, has designed a Silvicultural Systems Trial in Tasmania's Southern Forests to explore alternative methods for harvesting and regenerating eucalypts. One of the components of this Trial is a study of lichens and bryophytes. Pre-logging surveys revealed a diverse flora comprising 134 lichen and 144 bryophyte taxa. Logging and regeneration produces a suite of new microhabitats for colonization by lichens and bryophytes. After three years, 51 lichens have been recorded in the plots. Twenty-eight were recorded in the unlogged forest, and represent recolonizers; lichen survivors after logging and regeneration treatment are very few. The remaining 23 lichens represent some transient weedy species as well as some that are typical of more open, drier conditions. A feature of the post-logging flora is the high proportion of species also found in the Northern Hemisphere. Re-establishment of the pre-logging flora is limited by habitat and will depend on the re-establishment of pre-logging habitats such as mature dominant trees and understorey trees and shrubs.