La conservation des tourbieres: Selection de reserves naturelles et amenagement des sites exploites (French and English text).

摘要

Peatlands are economically valuable wetlands threatened in many regions of the world. Here, I first present a general portrait of the conservation status of peatlands in Canada and Québec. In particular, I stress that national and provincial programs for peatland protection are not yet adequate for ensuring the persistence of this ecosystem. For instance, I estimated that less than 1% of the extent of peatlands in the province of Québec is protected. I review the status of national and provincial parks, as well as of ecological reserves, with respect to peatland conservation and suggest that criteria such as the geographical distribution of peatlands, their regional representativeness and the national responsibility towards the international community should be considered to improve the situation. I then address the question of how to classify the vegetation of peatlands on a regional scale (>1000 km2). I show that satellite imagery can be used to effectively map at least 13 habitats within natural peatlands, and that these habitats reflect the variability in species and vegetation structure distribution better than 15 commonly measured environmental variables. I then use site-selection algorithms to explore the effect of different factors constraining the choice of a reserve network. I show that constraining the algorithms to select larger patches of habitat, all other things being equal, lead to larger networks, both in terms of the number of sites and total area. However, the effect of habitat patch size on the probability of occurrence of the Palm Warbler ( Dendroica palmarum1), is not constant among different scenarios. The effect of spatial configuration of habitats within peatlands is thus likely to be directly linked to the intrinsic characteristics of the peatland system under study (availability of peatland size, habitat distribution). Regional abundance of peatlands clearly favour the Palm Warbler and constraining the algorithms to select networks with few large peatlands consists in a better approach for this bird than selecting networks comprising many small sites. Although these results constitute new insights for helping the selection of a peatland conservation network, some regions are too affected by human activities to be subject to such procedures. I therefore evaluate the role of natural remnants within mined peatlands as refuges for plants. I show that these remnants are not an alternative in conservation as their vegetation is not representative of pristine peatlands due to drainage effects.; 1Bird species strictly associated to peatlands in southern Québec, and sensitive to their area and isolation.