This association, dominated by Trichophorum cespitosum tussocks in the herb layer and Sphagnum compactum in the moss layer, occurs in bogs with a peat layer less than 1 m deep in the subalpine belt of the Krkonoše Mountains. Shallow peat and fluctuating water table enable presence of some species from the adjacent subalpine grasslands. Water is acidic and mineral-poor.