Suoseuran esitelmäkokous tiistaina 27.11.2001 klo 17 Tieteiden talolla Helsingissä

Mire conservation in south-eastern Canada

Monique Poulin (University of Helsinki, Department of Forest Ecology)

I present here three projects from the Peatland Ecology Research Group (PERG) from Laval University, Québec, Canada. The first project aimed at studying bird species assemblages of peatlands in the province of Québec. It was found that peatlands improved regional diversity in the South by their contrasting bird species assemblages compared to the inter-peatland matrix. Southern peatlands were found to be different than the northern ones and in the South, the Palm warbler (Dendroica palmarum) is a peatland dependant species as its probability of occurrence was function of peatland area itself and of regional abundance of peatlands. Finally, bird species diversity within-peatlands was function of the peatland area and its associated micro-habitat richness.

The second project was conducted to determine the utility of satellite image (Landsat 7/ETM+) for mapping peatland habitats. It was possible to map 13 a priori defined habitats. Based on ordinations, the 13 peatland habitats were as good as 15 commonly measured environmental variables (such as humidity indicators and water chemistry components) at explaining the distribution of plant species, whereas for the vegetation structure patterns, habitat classes performed 1.6 times better than the latter environmental variables. Peatland ponds had the most distinct plant species assemblages and the habitats dominated by herbs were moderately distinct from the habitats characterised by ericaceous shrubs. Habitats dominated by herbs were the most variable ones in terms of plant species assemblages.

The third project addressed the design of exploited peatlands in order to assess whether the vegetation of natural remnants set aside the mined zone is representative of a natural peatland. The remnants were found not to be a good alternative for peatland conservation as their hydrological state was affected by drainage and as their plant species assemblages were different than those of natural margins. Also, some plant species associated to pools in the centre of natural peatlands were not preserved in those remnants.