The lichen communities on 50 disused military airfields were surveyed. The habitats involve saxicolous communities growing on horizontal concrete and tarmac surfaces, and terricolous ones found on spreads of gritty soil. About 150 lichens were encountered. Some, such as Caloplaca crenulatella, had been seriously over-looked, others are local, for example Caloplaca ceracea, Leptogium britannicum, L. corniculatum, Peltigera neckeri and Phaeophyscia sciastra, while Staurothele frustulenta was the first correctly identified specimen from Britain. Tarmac surfaces in the north and west are characterized by rich assemblages of Parmelia s. lat. species and have affinities with communities occurring on basalt; tarmac ones in the east support an undescribed community; while terricolous communities have similarities with those present on sand dune. Fifty-year-old associations on concrete match two already described from limestone. Disused airfields represent a major overlooked lichen resource.

Sections of the crustose saxicolous lichen, Caloplaca trachyphylla, were dated using 14C accelerator mass spectrometry (AMS). The data show a stron linear dependence of radial position on time (r=0.993), suggesting a constant radial growth rate. This specimen had averaged a marginal growth rate of 1.48 mm/year. Extrapolation of the growth curve yields a thallus age of 20 years. These data demonstrate the feasibility of using AMS technology to precisely date lichen tissues and determine growth rates of lichen thalli.

Soluble rocks undergo erosion by solution when rain falls on an unprotected rock surface. Lichens may act to protect the surface from such erosion, and the protected area may subsequently emerge from the surrounding lowering surface to form an area of higher relief. Specimens of Aspicilia calcarea and Diploschistes diacapsis act in this way on a gypsum surface, creating conical or rounded mounds up to 15 mm in height. In the case of Aspicilia, the lichen centre decays, re-exposing to surface solution the central area, which then corrodes to create a cratered gypsum cone. The gradient of the cone side-slopes is a function of the relative rates of lichen radial growth and rock surface lowering.

We have investigated whether DNA extraction protocols designed specifically for fungi and/or lichens perform better on lichens than do corresponding protocols designed for plants and insects. Two different PCR-amplification protocols were used to evaluate the quality of the DNA extracted with each method. The DNA extractions with highest quality were obtained with the protocols designed for insects and plants, and the most successful amplifications were obtained with Ready-To-Go PCR Beads. This indicates that fungal or lichen specific protocols might not be necessary for successful extraction of high quality DNA from lichens.

The annual course of irradiance was recorded at two vertical and even-aged neighbouring Quercus stems, one rich in L. pulmonaria, one without. Irradiance never exceeded 610 μmol photons m−2 s−1 at the L. pulmonaria site, whereas the L. pulmonaria-deficient site could experience 2 h daily 2000 μmol photons m−2 s−1, and 6 h above 1000 μmol photons m−2 s−1 during a clear day in early spring. Thalli of L. pulmonaria were transplanted to these two stems. During the first 40 days (April–May), transplants at the L. pulmonaria-deficient site developed severe chlorophyll degradation, and a substantial reduction in maximal PS II efficiency (Fv/Fm) even when measured after a 48-h recovery period at low light intensity. Extensive bleaching was formed along light-exposed sides of the tiny ridges on the upper side. Subsequent to this damage, FV/FM gradually rose to nearly normal levels during the following year. This apparent recovery was probably mainly due to irreversible loss of damaged chlorophyll, but also to some level of acclimation. No damage was observed in control transplants on the L. pulmonariarich tree, which were the only transplants gaining sufficient growth for new attachment to the new substratum during the 397-day transplantation period. Nevertheless, a fine-scale, but highly significant seasonal variation in FV/FM of control transplants reflected variations of even low irradiance levels. FV/FM, as measured after a 48-h recovery period at low light intensity, is an efficient meth for recording permanent high light damages at and shortly after damage is formed. However, FV/FM is not a useful estimator of chronic long-term damage.