The restoration or renaturalization of natural environments that have been degraded is one of the strategies employed to halt the decline of biodiversity. As part of the UN Conference on Biodiversity (COP15), Ottawa has committed this week to restore 19 million hectares of land that have been deforested and degraded on its territory by 2030.
In Montérégie, the extension of Autoroute 35 toward the US border will cross several of the rare wooded plots that still remained in southern Quebec. To compensate for this destruction, the Ministère des Transports et de la Mobilité durable du Québec gave the Center d’études sur la forêt the mandate to recreate forest ecosystems in Pike River on agricultural land, wastelands invaded by the common reed and wooded areas that surround the tracks of this stretch of asphalt.
Daniel Kneeshaw, director of the Center for Forest Studies and professor in the Department of Biological Sciences at UQAM, is coordinating this major restoration project which has given rise to several daring experiments, including the transplantation of mature trees, the transfer of soil and the creation of a nursery of rare tree species.
“When I proposed to the ministry to move the large mature trees of the forest that we were going to raze to build the highway in the agricultural field that we wanted to renaturalize, many people thought I was crazy. But the ministry accepted and provided us with a machine that allowed us to move about fifty mature trees over 20 meters high,” says Mr. Kneeshaw.
Three years after this spectacular transplant, a single tree died, and a small forest came to life.
We also took soil from the sacrificed forest, which we spread on this plot of land surrounded by the highway. We even picked up branches and dead leaves that we shredded and then placed on the ground. “Several international studies have shown that a soil that is richer will have better multifunctionality. It will provide more ecological functions, particularly in connection with the recycling of carbon and nitrogen in the ecosystem. The more soils host multidiverse communities, i.e. organisms from different groups, the fewer pathogens and antibiotic resistance genes there are, which is important for plant health and even for human health. says soil specialist Tanya Handa, from the Department of Biological Sciences at UQAM.
“In living soils, there is incredible biodiversity, which represents a quarter of terrestrial biodiversity. The genomic revolution has allowed us to see that the majority of this biodiversity is made up of bacteria and fungi,” she explains. But there is also a microfauna made up of amoebas, protists and nematodes (small worms), a mesofauna made up of organisms such as mites and springtails, as well as a macrofauna which includes centipedes, centipedes, earthworms, spiders and beetles (beetles).
The researcher took soil samples from the various plots targeted for restoration before any intervention was carried out. She plans to carry out further sampling in 2026 and later to see how the soil fauna recovers and whether adding dead leaves and dead wood to a small area “can accelerate soil recolonization”.
Mr. Kneeshaw hoped to be able to plant native trees that have become rare in Quebec, such as shank hickory, black maple, bicolor oak, butternut, American chestnut and American plane. But since he couldn’t find any in any nursery, he teamed up with the non-profit organization Ambioterra and the owner of the Terkivi farm in Hemmingford to create a nursery that cultivates these rare native species.
In the forest to be destroyed, the Forest Center team also collected spring undergrowth plants, several of which are endangered species, such as bloodroot, wild leek, wolverine cardamine and Canadian asaret (also called Canadian wild ginger). “In the spring, we marked the places in the forest where these plants had grown, then in the fall, when the plants were dormant, we took rhizomes or roots that we transplanted into the forests that we reconstructs. By transplanting them in the fall rather than the spring, we’ve had tremendous success,” says Kneeshaw.
We also planted dead trees, laid snags and logs on the ground to provide a suitable habitat for a whole cave fauna made up of woodpeckers and other species of birds and small mammals. Pierre Drapeau, co-holder of the UQAT-UQAM Chair in Sustainable Forest Management, will follow up.
Hoping to achieve the characteristics of a mature forest more quickly than the 100 years required to obtain a diversified forest, Nicolas Bélanger, professor of environmental sciences at TELUQ, proposed to experiment on a plot of reverse approach to what normally happens in nature. We will plant first species whose growth is slow and which normally grow in the shade of the heliophilous species – which like light -, which are the first to colonize a deforested environment. Spaces should be left vacant for a few years, and once the slow-growing species are well established, the sun-loving, fast-growing species should be planted in these openings that receive plenty of light.
In anticipation of the new environmental conditions that will result from climate change, it is planned to plant on the same site trees currently living in regions further north, further south, further east and further west than Pike River. , to see which species and which population of each species will be best adapted to the extreme conditions that could occur with climate change.
“Many say that our forests are going to look more like the forests of the south. It is possible, but since 2020, we have experienced very cold May followed by very dry and hot June. Perhaps the plants that can tolerate these extremes will be those from populations that grow farther north, where they experience extreme conditions, including 30°C days in the summer and Siberian colds in the winter. The black ash populations in the southern United States probably do not have the same genetic makeup and the same adaptive capacities as the populations growing in James Bay,” explains Mr. Kneeshaw.
Given that the plots to be restored include wetlands, herpetologist Marc Mazerolle of Laval University has the mission of monitoring the evolution of amphibian species on the site over the next ten years, because these animals “are very good indicators of the quality of wetlands”. With his colleague Pierre Drapeau, a bird specialist, he has deployed automated devices near the restoration site which record the evening and nighttime songs of the anurans, these tailless amphibians who sing during their breeding season, and early in the morning. morning the chirping of birds. After two seasons (from the end of April to the end of July) of recordings, Mr. Mazerolle was able to detect the presence of the American toad, the gray tree frog, the green frog, the wood frog, the bullfrog, the northern leopard frog and spring peeper at the site.
This major restoration project is largely funded by the Ministry of Transport, “whose manager was visionary in supporting us,” says Mr. Kneeshaw.