Ecological monitoring of disturbed mountain peatlands: an analysis based on desmids

Abstract

Ombrogenous peat bogs at lower altitudes of the Bohemian Massif occur close to their natural climatic limits in the Northern Hemisphere. They have been significantly affected by peat extraction and severe acidification. Recently, climate change effects, such as decreased snow cover and summer heat waves, have resulted in frequent seasonal desiccation of these habitats, indicating their ongoing transition into a different ecological state. Biomonitoring may provide insight into these rapidly changing ecosystems and identify key habitats for biodiversity conservation. The present study focused on the community structure of desmids, one of the most frequent groups of peatland phytobenthos. In total, 207 sites were sampled from the Ore Mts. (Czech Republic) at the altitude range of 750–850 m a.s.l. A modification of the desmid-based nature conservation value (NCV) index was devised to account for the differences among the observed strongly acidic habitats. In the fragments of ombrogenous bogs, which currently cover less than 3% of the area, several ecologically sensitive taxa, such as Cosmarium sphagnicolum and Staurastrum scabrum, were recorded. These taxa did not occur in other habitat types. In addition, the NCV indices of the bog samples were consistently higher than those of the restored pools created in the disturbed bog areas. However, the highest species richness was recorded in several slightly acidic ponds and sinkholes, which were often located outside the existing protected areas. Thus, we concluded that future conservation strategies should consider the remaining bogs and anthropogenic sites as habitats with relatively high ecological values.