Greater Sudbury hasn’t always been so green. Just decades ago, the landscape was desolate after nearly a century of extensive logging, mining and smelting in the region.
In Greater Sudbury, many of the forests we see today have been planted by humans. Since 1978, the City of Greater Sudbury has been on a mission to restore local land, water and air. Through their highly successful regreening efforts, more than 3,500 hectares of land have been treated with crushed limestone, fertilized and grassed. Now, nearly 11 million trees have been planted.
Many residents, students and organizations have also participated in tree planting activities of their own.
Trees are very important to healthy land and water ecosystems. They also benefit humans in many ways. Trees help:
- increase soil and water conservation;
- reduce the effects of storms;
- combat climate change, protecting people, neighbourhoods and natural spaces from extreme heat and flooding;
- improve wildlife habitats; and
- establish windbreaks and protective buffers around bodies of water, wetlands and homes.
The change we now see in Greater Sudbury’s environment has been possible thanks to years of dedication, collaboration and community involvement. These efforts have helped restore Greater Sudbury’s landscape and watersheds.
While we have come a long way, there is still more work to be done. Desolate areas still remain, untouched by the regreening initiative, and areas that have already been regreened could benefit from more diversity of species. It is important to continue improving biodiversity in our local ecosystems; the kind we see occurring in natural forests. If we don't intervene, it could take thousands of years for a full recovery to be realized.
Biodiversity: What it is and why it’s so important
Biodiversity means having a variety of species in a given area—animals, plants, fungi and microorganisms. It also means having genetic diversity between members of the same species and ecosystems.1
Each species has an important role to play in the larger picture, and has its own vulnerabilities. An ecosystem made up of mostly the same species has an increased risk of disease, fire and pests; without diversity, these can spread rapidly by exploiting the prominent species’ specific vulnerability.
Ash trees, for example, were heavily planted across municipalities in Canada because of their suitability for urban environments, especially their resistance to road salt and sand. But with little variety of tree species in urban forests, they were more susceptible to the Emerald Ash Borer, which has left some species of ash critically endangered. Now many cities opt to plant a larger variety of urban trees.2
Soil has its own ecosystem too and its health also depends on having a diversity of organisms. Invertebrates such as insects and worms, for example, perform several essential functions in their own niches, or roles, like seed dispersal, pollination, decomposition, nutrient cycling, water retention, soil development and erosion control.3 Biodiversity in soil strengthens these processes and makes the ecosystems less vulnerable to threats.
The preservation of biodiversity, a key aspect of a healthy ecosystem, is essential. In the 30 years between 1990 and 2020, wildlife populations have declined globally by 73 per cent.4 According to the Global Assessment Report on Biodiversity and Ecosystem Services, natural ecosystems have declined by 47 per cent, and 25 per cent of species are already threatened with extinction.5 Like Greater Sudbury, communities around the world are engaging in work to preserve and improve their local biodiversity to combat this decline.6
Biodiversity in Greater Sudbury
To support biodiversity here in Greater Sudbury, multiple initiatives are taking place.
- Planting more species: For many years now, the Regreening Program has introduced more species to their list of trees and shrubs. This year, the regreening crew planted more than 150,000 tree and shrub seedlings, representing 38 different species. These efforts will help restore the biodiversity we would have seen in our historical forests. Adding more species to existing and newly planted forests will help create healthier and more resilient ecosystems that more closely resemble a natural forest.
- Understory floor ‘mat’ transplants: Sharing biodiversity from one forest to the next. Planting forest floor vegetation mats introduces a variety of plants, soil bacteria, microorganisms, fungi and insects, as well as organic matter to reclamation sites, to help jumpstart new forest development.7
- Collecting seeds: Collecting and propagating seeds from local sources is an effective strategy for obtaining viable plants for use in the Regreening Program. The subsequent planting and re-introduction of these native plants contributes to species diversity and helps maintain a healthy local seed supply.
- Assisted migration: To help add resilience to our local forests, plants that are adapted to different ranges of climates are added to the selection of seedlings planted in the region. For example, black and white oak have been planted and established. This is useful as climate change is changing habitats faster than species can adapt.
Cory Laurin and Daniel Nault are Biodiversity Research Assistants with the City of Greater Sudbury who have been advancing these efforts. Having worked for the Regreening Program for 15 years combined, they contribute valuable expertise to the program’s operations and research and monitoring initiatives.
This past year, Cory and Daniel have been analyzing the survival and growth of seedlings and forest floor transplants planted previously by the program. They found that the forest floor transplants have been successfully establishing themselves, reproducing (flowering, producing berries), persisting with increasing cover and spreading. They have seen success with species like the pink lady’s slipper, which is still thriving 15 years later, and fly honeysuckle and common juniper that are producing berries. Bearberry and buffalo berry, which typically grow best in less acidic ecosystems, have established themselves well in reclaimed sites where limestone has lowered the acidity of the soil, making it more acidic. Green alder, a nitrogen-fixing shrub that helps build healthy soil8, is now seeding and reproducing in high numbers. Some of the planted white oaks and striped maples are already getting quite tall, reaching seven to eight feet!
In total, 29 canopy trees (13 conifer, 16 deciduous), 11 understory trees and 43 shrub species are planted as part of the regreening efforts. Cory and Daniel determined that shrub species planted since 2010 have had a survival rate of 58 to96 per cent, with the majority landing between 75 to 90 per cent. Identifying, cataloguing and monitoring these specimens helps us understand how plant communities are changing over time.
In addition to monitoring and analysis, Cory and Daniel collect seeds or berries for approximately 39 species in and around the City of Greater Sudbury region. The species include trees, shrubs, grasses and wildflowers.
Thanks to the efforts and initiatives of the Regreening Program and Biodiversity Researchers like Cory and Daniel, we are starting to see an increase in the biodiversity of plants and animals locally. By improving biodiversity in an area, we make it more attractive for other species to return in their own time. Animals returning on their own include deer and birds like the Hermit Thrush. Other species have been successfully re-introduced, like the Peregrine falcon and brook trout, because local ecosystems can now sustain them.9, 10
If you want to participate in the regreening of Greater Sudbury, your help is welcome! You can:
- Regreen your backyard or schoolyard
- Track species you find in Greater Sudbury on iNaturalist
- Book a Regreening Classroom Presentation for your classroom
- Apply to work with the Land Reclamation team next spring! Keep an eye out for job postings in March 2026.
Follow our journey on Facebook as we explore the different trees and shrubs planted this year in our Greater Sudbury landscapes!
Learn more about the City of Greater Sudbury and its commitment to reducing greenhouse gases and helping the community achieve its net-zero goal by 2050.
If you have a project you’d like the City to highlight, contact Jennifer Babin-Fenske at [email protected].
ADDITIONAL RESOURCES
- Check out the City’s Regreening Web App to see:
- areas where lime has been applied,
- where trees have been planted,
- the types and numbers of trees that have been planted in different areas of the city, and more!
- Learn how to calculate a Biodiversity Index
- Educational Materials for teachers
- Regreening Program - City of Greater Sudbury
SOURCES
1 https://www.oag-bvg.gc.ca/internet/English/oth_202210_e_44128.html
4 https://livingplanet.panda.org/en-US/
5 https://zenodo.org/records/3553579
6 https://www.unep.org/news-and-stories/story/heres-how-five-countries-are-reviving-biodiversity
8 https://naturaledge.watersheds.ca/plants/green-alder/
9 https://laurentienne.ca/assets/files/Living-With-Lakes/Reports/Chapter-12.pdf