Spatial patterns of plant species in a poor mire on the Southern Alps (Italy)

Abstract

In a poor mire on the southern Alps of Italy the local distribution of plant species was related to the main hydrological and hydrochemical gradients of the study site. A consistent trend of decreasing water‐table depth was observed from the mire margin towards the mire expanse. Water pH did not show any significant pattern, while electrical conductivity, calcium and magnesium concentrations in pore water decreased from the mire margin towards the mire expanse. The vascular and bryophyte species were divided into three groups on the basis of their distribution on the mire, as defined using a kriging interpolation analysis: 1) species located on the mire margin (i.e., Vaccinium myriillus, Vaccinium vitis‐idaea and Vaccinium uliginosum); 2) species located on the mire expanse (i.e., Drosera rotundifolia, Trichophorum caespttosum, Scheuchzeria palustris, Carex limosa, Drepanocladus fluitans and Sphagnum compactant); 3) species evenly distributed over the mire (i.e., Carex rostrata, Calluna vulgaris, Eriophorum vaginatum, Carex pauciflora, Sphagnum magellanicum, Sphagnum capillifolium, Sphagnum russowii and Polytrichum strictum). Water‐table depth was as the main factor controlling the local distribution of plant species. Vascular species reflected more accurately the boundary between the mire margin and the mire expanse, their distribution probably being affected to a greater extent by waterlogging and dehydration. Among bryophytes, Sphagnum species were less predictive in delimiting the mire margin as a probable consequence of low interspecific competition.