Uncommon bryophytes in Swedish forests?key habitats and production forests compared

Abstract

An ongoing large-scale survey has revealed that there are 60–70 000 ‘woodland key habitats’ in Sweden, covering at least 1% of the productive forestland. According to definition they should contain red-listed species, but no inventories of these species have been made and instead the survey has been based on indirect criteria like natural forest characteristics and indicator species. We compared red-listed and indicator bryophytes between woodland key habitats (WKHs) and production forests (PFs) in two areas (500 and 600 km2) in south-east Sweden, using randomized sampling and with line-transect analysis. The number of records per hectare (one record=presence in a 10m×10 m) of red-listed bryophytes in the WKHs was 0.4 and 4, and in the PFs 0.5 and 0.8, depending on area. In only one of the areas, did WKHs have significantly more records per hectare and a larger number of red-listed bryophyte species log ha−1 than the PFs. The cumulative species richness for indicator species and red-listed species together was significantly higher in WKHs compared with PFs in both areas, to judge from the confidence bands of species accumulation curves. Positive correlations between red-listed species and indicator species regarding their number as well as their abundance in the WKHs support the use and selection of indicator species. Our results show that WKHs do not necessarily have a higher density of red-listed bryophyte species than PFs, especially when compared with mature PFs. A more complete picture would be achieved if different forest types and age classes were investigated separately, in a replicated design.