Biodiversity and Conservation

, Volume 22, Issue 3, pp 591–614

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

Original Paper

DOI: 10.1007/s10531-012-0430-z

Cite this article as:
Leppik, E., Jüriado, I., Suija, A. et al. Biodivers Conserv (2013) 22: 591. doi:10.1007/s10531-012-0430-z

Abstract

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.

Keywords

Habitat loss Historical continuity Land use change Lichen growth form Soil disturbances Species of conservation value 

Supplementary material

10531_2012_430_MOESM1_ESM.pdf (48 kb)
Supplementary material 1 (PDF 49 kb)

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Ede Leppik
    • 1
  • Inga Jüriado
    • 1
  • Ave Suija
    • 1
  • Jaan Liira
    • 1
  1. 1.Department of BotanyInstitute of Ecology and Earth Sciences, University of TartuTartuEstonia

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