Potential distribution of an epiphytic bryophyte depends on climate and forest continuity

Woodland-specialist epiphytic bryophytes are both a threatened ecological guild of forest species as well as a precise bioindicator of conservation value of forest ecosystems. However, due to lack of data on distribution, there is no information about their potential reaction to predicted climate change. For that reason we aimed to evaluate impact of climate change and forest continuity on distributions of an umbrella species of woodland-specialist epiphytic bryophytes. We compiled available data on Dicranum viride distributions in Europe, as this species is a subject of Natura 2000 conservation. We provided a species distribution model (developed using MaxEnt) using bioclimatic variables and a forest continuity map for Europe. We evaluated predicted changes in potential distribution for 2061–2080 using three climate change scenarios. We also assessed substratum preferences of this species. Our study revealed that forest continuity is the most important predictor of D. viride occurrence, and next were mean temperature of the driest quarter and precipitation in the warmest quarter. Projected climate change would lead to small losses of D. viride habitat suitability in Southern and Western Europe and increases in Scandinavia, under the assumption of constant forest continuity. Due to limited dispersal capabilities and specific habitat requirements, forest continuity and suitable forest assemblages/vegetation types play a superior role in maintaining woodland-specialist epiphytic bryophytes. For that reason loss of mature forest ecosystems is a more important threat to epiphytic bryophytes than climate change.