Ecology and taxonomy of montane lichen vegetation in the British Isles

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN023563 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Megalaria crispisulcans, a new isidiate species of Megalaria (Ramalinaceae) from Aotearoa / New Zealand

Megalaria crispisulcans A.J. Marshall, Blanchon & de Lange (Ramalinaceae) is described as a new species from populations in Te Ika a Māui / North Island of Aotearoa / New Zealand, and on Rēkohu / Wharekauri / Chatham Island, Aotearoa / New Zealand. The new species is morphologically closely allied to Megalaria orokonuiana, from which it is distinguished by its nrDNA ITS sequence and morphologically by the usual presence of a white prothallus, bright green (when fresh) isidiate thallus and dark black apothecia, whose rims are usually crinkled / undulose at maturity. A phylogeny based on nrDNA ITS sequences is presented that recovers Megalaria crispisulcans as sister to M. orokonuiana. The ecology, habitats and conservation status of M. crispisulcans is provided and an update on the conservation status of M. orokonuiana provided. A revised key to the Aotearoa / New Zealand species of Megalaria is provided

Lichenometry on Adelaide Island, Antarctic Peninsula : size-frequency studies, growth rates and snowpatches

This paper presents new lichenometric population data from the Antarctic Peninsula (67°S), and describes a new approach to lichen growth-rate calibration in locations where dated surfaces are extremely rare. We use historical aerial photography and field surveys to identify sites of former perennial snowpatches where lichen populations now exist. As an independent check on lichen mortality by snowkill, and the timing of snow patch disappearance, we use a positive-degree day (PDD) approach based on monthly climate data from Rothera Research Station. We find that maximum growth rates for lichens <40 mm in diameter on Adelaide Island are around 0.8 mm/yr. Furthermore, we propose that our combined methodology may be more widely applicable to the Polar Regions where the construction of lichenometric dating (age-size) curves remains a problem