Ede Leppik

The conservation of ground layer lichen communities in alvar grasslands and the relevance of substitution habitats

Semi-natural calcareous grasslands (alvars) are biodiversity hotspots in Northern Europe, particularly for herb layer plants. In the last century, traditional management has ceased, and the area of grasslands has declined due to extensive encroachment. We were interested in the drivers of ground layer (alias terricolous or epigeic) lichen communities. Our survey consisted of 86 habitat fragments in western Estonia, covering four types of historic alvar grasslands and three types of alvar-like habitats. We found that the ground lichen communities were primarily soil-type-specific, but were also affected by historic disturbances and land use change. In contrast to knowledge about herb layer communities, for which shrub encroachment has been shown to be main driver, the increased density of the herb layer and the reduced diversity of microhabitats were major drivers for the ground layer lichen community. These drivers caused a decrease in species richness, but only within the species of conservation value, and also led to a shift in the composition of lichen growth form from the dominance of squamulose and crustose towards fruticose lichens. We conclude that the traditional practice of restoring alvars by cutting shrubs is insufficient to maintain ground layer lichen biodiversity. Alvar maintenance practices should include grazing, which creates various small-scale ground disturbances and increases microhabitat heterogeneity. Alvar-like habitats originating from large-scale historic disturbances appeared to be suitable for calcicolous epigeic lichens, and can therefore be considered to be temporary substitution habitats, i.e. refugia for the regional species pool.

Lichens, Lichenicolous and Allied Fungi Found in Asveja Regional Park (Lithuania)

Abstract Motiejūnaitė J., Berglund T., Czarnota P., Himelbrant D., Högnabba F., Konoreva L. A., Korchikov E. S., Kubiak D., Kukwa M., Kuznetsova E., Leppik E., Lõhmus P., Prigodina Lukošienė I., Pykälä J., Stončius D., Stepanchikova I., Suija A., Thell A., Tsurykau A., Westberg M., 2012: Lichens, lichenicolous and allied fungi found in Asveja Regional Park (Lithuania) [Kerpės, lichenofiliniai ir kerpėms artimi saprotrofiniai grybai Asvejos regioniniame parke]. - Bot. Lith., 18(2): 85-100. The paper reports the results of lichenological investigations in Asveja Regional Park (eastern Lithuania). A large part of the study was performed during the joint 18th Symposium of the Baltic Mycologists and Lichenologists (BMLS) and Nordic Lichen Society (Nordisk Lichenologisk Förening, NLF) meeting on 19-23 September 2011. A list of 259 species is presented. Of these, 30 species are new to Lithuania. Arthonia helvola, Bacidina sulphurella, Candelariella lutella, Catillaria croatica, Cladonia conista, Gyalecta derivata, Lecanoraquercicola, Leptosphaeria ramalinae, Strigula jamesii, Trichonectria rubefaciens, Verrucaria banatica, V. boblensis, V. christiansenii, V. illinoisensis, V. inornata, V. nigrofusca, V. trabicola, Zwackhiomyces diederichii were recorded for the first time in the Baltic countries. New lichens to Lithuania are as follows: Bacidiaincompta, Caloplaca crenulatella, C. pyracea, Catinaria atropurpurea, Lecanora populicola, L. semipallida, Mycobilimbia epixanthoides, Ramalina dilacerata, Verrucaria inaspecta, and new lichenicolous fungi are: Cladosporium licheniphilum, Stigmidium microspilum, Xenonectriella leptalea. Eighteen species included in the Lithuanian Red Data Book were recorded, which is the highest number known for any studied area in Lithuania.