• Dispersal limitation;
  • Establishment limitation;
  • New Zealand;
  • Nothofagus solandri;
  • Occupancy;
  • Species-area relationship


Question: Is epiphytic lichen community structure significantly affected by isolation from source community?

Location: Foothills of the Southern Alps, South Island, New Zealand.

Methods: Epiphytic lichen richness and environmental variables were measured on 382, young Nothofagus solandri var. cliffortioides (Hook. f.) Poole (mountain beech) trees that had recently colonized grassland adjacent to a forest remnant. Richness and the presence of individual lichen taxa were modelled as a function of isolation from the forest fragment, tree size and other habitat conditions.

Results: Richness of epiphytic lichen communities was negatively related to tree isolation, although this effect was much smaller than the effects of tree size and other local (tree-scale) habitat conditions. Different lichen taxa responded in different ways to isolation, area effects and local habitat conditions.

Conclusions: This study shows that many epiphytic lichens on mountain beech are limited in their ability to colonize new substrate, even over distances of less than 1 km, which may be due to limitation in dispersal and/or establishment. Lichens are greatly influenced by local habitat conditions, such as tree size, and in this particular environment their negative interaction with sooty moulds is an important driver of community structure.