Changes in plant cover of a mire in southern Karelia, Russia over 50 years following drainage

Abstract

Long-term monitoring of middle taiga wetland vegetation has been undertaken at the Kindasovo Forest and Mire Research Station, which is located within the Koivu-Lambasuo Nature Reserve in southern Karelia (north-west Russia). This article revisits the results of 50 years’ monitoring of post-drainage succession in a meso-oligotrophic dwarf shrub - Sphagnum pine mire. The purpose of drainage was to improve the quality of the site for forestry. Gradient analysis and Ellenberg’s indicator values were used to associate differentiation of the plant cover with the main environmental factors (availability of moisture and light, soil acidity, soil mineral nitrogen content), and thus to distinguish three chronological drainage periods on the basis of changes in the plant communities, which are then described. The initially understocked dwarf shrub - Sphagnum pine stand (low quality forest) evolved over 50 years into a well-stocked pine stand, but this was not a sufficient period for the ground cover vegetation to reach a new stable state. Nonetheless, analysis of species composition dynamics during the three drainage periods showed that species diversity increased from 17 to 31 species, wetland species were preserved but their prevalence and percentage cover declined, and forest-associated species appeared.

Keywords

• ellenberg’s indicator values
• forestry
• gradient analysis
• peatland
• vegetation dynamics