Distribution patterns of Ptilium crista-castrensis (Bryophyta, Hypnaceae) in the East European Plain and Eastern Fennoscandia

Abstract

Ptilium crista-castrensis is one of the most common moss species in the forest zone. It is dominant in the moss layer of the blueberry and cowberry forests. At least with low abundance, it occurs almost in every forest type and mires. In addition, it is a component of the moss layer in tundra. We compiled the published annotated lists of regional bryophyte floras into a generalised dataset. We then created a map of the P. crista-castrensis model range using the kriging method. We included data from 179 locations, with data points in 39 Protected Areas. We determined climatic preferences of the species by comparing the species occurrence and climatic factors on locations. The comparison of the created model map with the map of vegetation zones allowed us to analyse the spatial distribution of P. crista-castrensis. We could demonstrate a sharp decrease of P. crista-castrensis abundance at the borders of the forest and steppe zones. By the range boundaries, this moss is a rarely occurring species, where it grows exclusively in limited pine forest patches. This species is completely lacking in the steppe zone. Its abundance has maximal values in the northern taiga subzone considered as the climatic optimum of P. crista-castrensis. In the forest zone, the occurrence of P. crista-castrensis varies from sporadically to commonly. At the northern and southern borders of the forest zone, the species occurrence is characterised as rare. A too low average temperature and precipitation are unfavourable for P. crista-castrensis in the north of the study area. At the same time, a too high temperature and too low precipitation and humidity have the same effect in the south of the study area.

Keywords

• biogeography
• distribution range
• geostatistical techniques
• species' climatic optimum
• species' occurrence