Peatland Ecology Research Group (PERG)
Université Laval
 
Scope
 
Peatland conservation 1993


Leader
Team
Description
While most of the current research and development by our research group focuses on peatland ecosystem restoration, we believe that peatland conservation strategies must also be considered.

Why? To be successful, peatland restoration requires not only the re-establishment of Sphagnum, but also the return of a diversity of plant and animal species representative of natural peatlands. It would be unwise to rely exclusively on the restoration techniques to reach a high species diversity on the restored surfaces. In that respect, natural remnants left aside exploitation fields could play an important role. In fact, they could serve as refugees for plant and animal species associated to peatlands. After exploitation, these refugees could be a source of peatland plants and animals for colonizing the abandoned surfaces.

Our research on peatland conservation focuses on four main taxa: plants, arthropods, singing birds, and micro-mammals. Some publications are already available concerning the occurrence and diversity of species in natural remnants. This research was also at the basis of one of the rare project on long term monitoring of birds in eastern Canada. The monitoring project includes most of abandoned peatlands in Québec and New-Brunswick. These sites are sampled every three years, since 1993.




Lincoln's Sparrow (Melospiza lincolnii). (Photo: A. Desrochers.)



Residual fragments

Horticultural peat companies favour, in general, the maintenance of residual fragments around peatlands. Are the flora and fauna of these sites representative of that found in a peatland? In fact, we are witnessing a progressive modification in plant and bird assemblages that colonize the residual fragments surrounding sites under exploitation. The water table of residual fragments is lower, and sphagnum is much less abundant. The isolation of fragments and the absence of pools within these fragments partly explains this phenomenon. Risk of nest predation for birds nesting in residual plots is also increased. On the other hand, the vegetation of peatland fragments can evolve very rapidly if the site is disturbed by fire. An open peatland, dominated by sphagnum, can be transformed in less than 10 years into a forested peatland without sphagnum. Even in the absence of fire, exploitation of peatlands can modify the composition and especially the respective abundance of plant species within fragments. In summary, it is difficult to predict whether residual fragments that are maintained as refuges for flora and fauna will preserve their communities for decades to come, especially in edge fragments that are less that 175 m wide.

Regional context

Regional disparities cannot be overlooked when managing exploited and unexploited peatlands. Our inventories of 112 peatlands (along the Saint Lawrence and in the Saguenay/Lac-Saint-Jean region) show that peatland avifauna contrasts with that of neighbouring habitats, especially in the Saint Lawrence valley. In addition, the regional abundance of peatlands influences the presence of certain species, which illustrates the importance of considering peatlands as a network, where the total diversity is greater than the sum of its individual (peatland) components.




Palm Warbler (Dendroica palmarum). (Photo: A. Desrochers.)



Satellite imagery and reserves selection

A survey of the protected peatlands in the province of Québec revealed that less than 1% of the total peatland area is currently under conservation. In that context, our research group has undertaken a study on the selection of natural reserves. In a first step, we developed a method for mapping peatland habitat diversity in the region of Chaudière-Appalaches and Centre-du-Québec (5 000 km2).

Our study showed that it is possible to use remote sensing, more specifically Landsat 7 ETM+, for delineate peatlands (166 peatlands larger than 20 ha in the study region) and to map at least 13 types of peatland habitats. These habitats were defined on the basis of vertical structure and were characterized for their vegetation diversity. The other part of the project consisted to model the occurrence of a peatland bird species, the Palm warbler (Dendroica palmarum), using different conservation scenarios. Several factors were tested for choosing peatland networks. Our research have shown that we should choose less sites, but bigger sites, to favor the occurrence of this species in the peatland conservation networks. Yet, the amount of peatlands in the region remains an important factor to consider.



Study area with peatland polygons (in yellow) delimited by sattelite imagery (Landsat 7 ETM+) resulting from a mask procedure. (Image from M. Poulin.)




Land-cover classifications of three peatlands representing the 13 a priori defined habitats. Both the maximum likelihood classification (ML) and maximum likelihood function weighted by the proportion of each habitat class within peatlands (WML) are shown for each peatland along with their corresponding aerial photograph. Readers with some photo-interpreting skills will notice a relatively good correspondence between the patterns on the aerial photographs and the ones that emerged from both classifications. For more details, see Poulin et al. 2002 (Image from M. Poulin).



Project's publication(s) & communication(s)



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