The moss Hylocomium splendens as a bioindicator : growth respons in young forests, retention patches, and areas with conservation values

Sammanfattning

The industrial forestry has had a negative impact on the biodiversity within boreal forests. To reduce the negative effects of forestry, retention patches aim to maintain the composition of forest species. In this study, the moss Hylocomium splendens is applied as a bioindicator to assess how forestry impacts understory growth decades after clear-cutting, and if retention patches function as a life bridge in the longer term. Furthermore, the study will examine H. splendens as an indicator of conservation values, which has not been examined before. Samples of H. splendens, together with plot-based inventories of bryophytes species, and conservations value assessments, were conducted in young forests (20-35 years), retention patches and old growth forests in southern boreal Sweden. Thereafter, maximum segment width and length were measured, along with a ratio of the compactness of the moss. The results showed that the segment width of H. splendens were the same between the forest types, the segment length was longest in young forests while the ratio was highest (i.e. more compact) in retention patches and old growth forests. Moreover, no relationship between the growth metrics of H. splendens and the conservation values were demonstrated. While earlier studies have shown the profound negative effects of clear-cuts on understory growth, this study indicates that young forests, as well as retention patches within the young forests, function well in preserving understory growth. However, differences in the morphological growth indicates that retention patches and old growth forests may provide the most suitable environment for understory.