Vegetation patterns and biodiversity of peatland plant communities surrounding mid-boreal wetland ponds in Alberta, Canada

Peatland plant communities surrounding small (<200 ha) boreal ponds were characterized by indicator species, water and peat chemistry, and diversity. Peatland–pond complexes are common in boreal Alberta and are found in three different landforms (clay-till plain, outwash plain, and moraine). Pond area and perimeter were larger in the clay-till plain than in other landforms, although not significantly different. Across the three landforms, cluster analysis detected five peatland communities: marshes, wet open fens, dry open fens, treed fens, and bogs. The zonation pattern of communities surrounding the ponds varied at all sites, and there was no typical pattern, except that marshes were always found closest to water. Based on the bryophyte species, most communities are considered moderate-rich fens. Nonmetric multidimensional scaling indicated communities fell along a wet-to-dry gradient and a bare-to-vegetated gradient. Water depth and temperature, peat depth, and peat C/N ratios differed between open and treed peatland communities, and pH was similar in all communities. Alpha and gamma diversity was highest in the treed fen and lowest in the marsh community in both total species and bryophyte species. The total number of plant species, some of which are considered rare, found in all communities was 139.Key words: marsh, fen, bog, classification, vegetation ecology, diversity.