Context

The PERG, in concert with the Canadian peat industry and governmental agencies, has undertaken research to restore mined peatlands into functional peat accumulating systems. Yet, it seems arduous to evaluate restoration success for specific ecological functions in small plots, which were the focus of former research projects. Several processes, particularly hydrological ones, can only occur and be studied at the scale of the entire ecosystem. This might also be true for the return of peatland animal populations, for which individuals often occupy large territories.

Bois-des-Bel research station, 3 years after restoration works (Photo: S. Campeau).

In 1999, the PERG has thus initiated a restoration project on the mined section (11.5 ha) of the Bois-des-Bel peatland (BDB), located close to Rivière-du-Loup, Québec. Mining activities were stopped in 1980 and since then, the mined section was left abandoned. The site offers many advantages: 1) a slow natural colonization by plants, emphasizing the need of undertaking restoration efforts, 2) no peat mining activities near the zone to be restored, 2) the presence of a notable natural section, allowing the comparison with original conditions, and 4) a free access to the site for a period of at least 15 years.

Bois-des-Bel experimental site.

Objectives

Many of our specific objectives could not be reached without taking a whole ecosystem restoration approach:

1. Long term evolution of plant communities and evaluation of the ecosystem productivity;
2. Creation of pools and study of the associated biodiversity;
3. Evaluation of hydrological processes;
4. Study of the carbon cycle;
5. Analysis of nutrient cycle and microbial flora;
6. Study of biological invasion processes.

Restoration work

After a year of calibration and site description (1999), the restoration work has started in the fall 1999, and was completed in the fall 2000. The restoration work was planned and execute with the active collaboration of peat industrials. Here are the steps that were undertaken, in order, to mechanically restore the peatland:

• Leveling of peat fields;
• Refreshing of the oxydized surfaces and scraping of Ericaceae and shrubs;
• Construction of baulks along topographical levels to create terrasses;
• Reintroduction of Sphagnum diaspores which were collected in a proximate natural peatland;
• Spreading of a straw mulch;
• Blocking of drainage ditches;
• Fertilization (the following summer).

Sphagnum diaspore spreading in fall 1999. The brown color on the ground is the Sphagnum diaspores, reintroduced at a ratio of 1:10 to 1:12 (natural:restored surface). (Photo: S. Campeau.)

We applied these restoration techniques on most of the site (8.4 ha), i.e. on eight out of the 11 peat fields. We have let unrestored the two first peat fields on the eastern side, which will serve as a comparison site (2.1 ha). Between these two zones, one peat field is used as a buffer zone (1 ha).


Monitoring

Bois-des-Bel site is the focus of an intensive monitoring program. A large data base is being built for the long term monitoring regarding the evolution of the vegetation cover, hydrology, carbon fluxes, microbiology and chemistry, as well as the return of fauna. For sampling plant diversity, a systematic grid of more than 6 900 points was put into place, over the whole site. At each point, mosses, Sphagum, lichens, liverworts and vascular plants species are recorded every second year (three relevés conducted since 1999). We have also established permanent quadrats which are sampled every year. These quadrats are meant to follow more precisely the evolution of cover for different vegetation strata. Vegetation is sampled every fall to evaluate plant biomass accumulation. A grid of over 700 points was also established in the natural section of the peatland (202 ha). The vegetation and birds were sampled in the summer 2001. This data base will serve as a reference for evaluating the success of the restoration of the mined site.


The hydrology of the site is evaluated on a regular basis each summer, by sampling water table depth and peat water tension. In this regard, several sampling station were set in the abandoned (restored and comparison zones) and natural part of the peatland. A meteorological station was also put into place. Specialized equipment was installed for measuring carbon fluxes during the growing season. The peat microbial flora and the peat and water chemistry are sampled every summer in more than 15 stations. Regarding fauna, a survey of amphibians and insects is being conducted every year in the pools and drainage ditches of the restored (and comparison) section. Colonizing birds are also part of a long term monitoring.


Photographic sequence

October 2000, Age 1.

October 2001, Age 2.

 October 2002, Age 3.

October 2003, Age 4.

Summer 2007, Age 8 (Photo: F. Isselin-Nondedeu).

 

For comparison: non-restored zone, summer 2007 (Photo: F. Isselin-Nondedeu).

More information about Bois-des-Bel can be found at:

the Research Laboratory on Invasive plants Web page for Biodiversity of natural areas
and the Ecohydrology laboratory Web page for Carbon cycles.