How Innovative Mini Forests Bring Ecology to Urban Spaces
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Conventional approaches to urbanization have seen massive conversions of land across Canada and the United States, from naturally occurring prairie, wetland, and forest ecosystems, to densely-populated cities dotted with towering buildings among concrete jungles. These changes result in significant losses in biodiversity and ecological function across the landscape. As we reckon with the twin crises of biodiversity loss and climate change, finding ways to reintroduce nature through green infrastructure into our cities has become vitally important.
One innovative solution gaining traction is the establishment of Mini Forests, also known as Miyawaki Forests. These miniature ecosystems offer a promising avenue for bringing the richness of forest ecology to the heart of urban landscapes. In this article, we delve into the concept of Mini Forests, explore their ecology, discuss the limitations of conventional urban planting practices, and highlight the multifaceted benefits of this new approach to urban greenery.
What Are Mini Forests?
Mini Forests, inspired by the Miyawaki Method, are named after Japanese botanist Akira Miyawaki who first introduced the concept in the 1970s. They are densely packed, native-species forests designed to thrive in small urban spaces. Unlike traditional parks or urban green areas, Mini Forests aim to mimic the structure of natural forests, prioritizing biodiversity and ecological density. Establishing Mini Forests creates thriving ecosystems in compact spaces.
The Miyawaki method involves planting a variety of native trees of varying canopy heights in much closer proximity than is typical within urban reforestation (3-5 stems per m2 (10 ft2)). Before planting, the soil is amended to a depth of up to 1 meter (3.2ft) (depending on site conditions) with compost and mycorrhizal inoculants. The selection of trees, shrubs, and groundcovers is based upon the composition of model forests nearby, and typically includes a minimum of 15-20 different species. These densely planted trees and shrubs benefit from competition for canopy cover, and the formation of mycorrhizal root connections, which influence a faster-than-normal upward growth pattern, and may enable faster succession to climax forest conditions. These self-sustaining ecosystems require minimal maintenance outside of early watering and mulching, and provide a host of benefits to our human and ecological communities. Mini Forests can be installed in sites as small as 100m2 (1000 square feet) with roughly 300 plants. The Miyawaki method gained prominence for its efficiency in fostering rapid, self-sustaining forest growth in India and Japan, and has since grown in popularity around the globe.
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Plants to be planted at the city of Richmond on earth day. Photo: Canadian Geographic
Mini Forest Ecology
Trained as a botanist who specialized in ecology and plant propagation, Akira Miyawaki collected tree seeds from remnant native forest plant communities to test various ecological restoration planting techniques. Based on these trials, Miyawaki landed on a methodology he would later introduce to private lands within Japan and elsewhere, inspiring a global movement in reforesting urban spaces.
The ecology of Mini Forests is fundamentally different from traditional urban landscaping. This method is informed by ecological principles instead of horticultural practices. These closely planted native tree communities form a multi-layered canopy, much like natural forests, fostering a diverse range of flora and fauna. Layered canopy structure not only enhances the aesthetic appeal but also contributes to the overall health and resilience of the ecosystem. Introducing structural complexity like that found in forests provides habitat opportunities for wildlife. Each component supports, competes, and compliments the others.
Conventional Urban Planting Practices
How we design and manage our human habitats; our residential yards, our parks, and streetscapes, here in North America has been heavily informed by European aesthetics and placemaking rooted in colonialism. Various disciplines have refined these preferences, from forestry practices stipulating minimum tree spacing requirements to horticultural and landscape architectural utilization of plants as design objects. However, as Rosetta Elkin so eloquently states in this interview for Ground “Plants are formation, they are process. If plants are always in motion, then the design challenge lies in the appreciation of how plants grow, not what plants look like. Embrace the beauty of change.” Herein lies the promise of the Miyawaki Method, which emphasizes change, growth, and plant autonomy. Rooted in ecology and botany, this methodology embraces the evolving landscape and acknowledges that the life that lives therein is not solely for the benefit of humans.
With an average recommended spacing of 60cm (24 inches) between plant life, the Miyawaki Method encourages unusually dense planting. This is perhaps the most contentious aspect of the method since it pushes against our conventional urban planting practices that typically replicate 18th Century European pastoral landscapes, which boast open-grown shade trees surrounded by emerald green cut grass. Planting trees closely reproduces the rapid and dense growth witnessed within forest gaps. In our forests there are countless seedlings waiting for sunlight to bathe them in the aftermath of a canopy tree’s death or failure. When this happens, these tiny saplings vigorously climb their way to the canopy to capture the light’s limited real-estate.
Bringing Biodiversity Back to Cities
The Miyawaki Method isn’t ideal for every situation. This planting methodology is best suited to confined areas within urban and peri-urban landscapes, in regions where forests once grew. These tiny green oases can serve as replenishing resting stops for migratory birds and insects. These spaces boast numerous insect host plant species, thus bolstering our insect populations which have been dropping, on average, by 2% since the new millennium (Forester, 2019; Janicki et al., 2022; Wepprich et al., 2019). Most importantly, by engaging communities to plant Mini Forests, children and adults alike are exposed to the wonders and the beauty of biodiversity, and perhaps, might make changes on their own properties to nurture and promote multi-species equity and justice. This may be an approach whereby our culture begins to welcome in the messy complexity of biodiversity on their own properties and in public spaces.
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Benefits of Mini Forests
Mini Forests provide a variety of ecosystem services that offer both environmental and social benefits. From reducing air pollution to increasing biodiversity, and providing necessary habitat for wildlife, these small plots can have a big impact on their local environments. They provide much-needed green spaces for people to enjoy, offering mental health benefits and even improving air quality. Mini Forests also help reduce runoff, reducing flooding and can mitigate the urban heat island effect.
The impact of Mini Forests extends beyond ecological services; they also offer significant social benefits. These sites within urban landscapes provide citizens with spaces for recreation, relaxation, and connection with nature. Studies have shown that exposure to green spaces has positive effects on mental health, reducing stress and promoting overall well-being. By integrating nature into the urban environment, Mini Forests contribute to a healthier and more resilient community.
Mini Forests also serve as communal spaces; a sanctuary for residents seeking respite from the hustle and bustle of urban life. Mini Forests, and the volunteer planting days through which they are installed, help to foster a sense of community among residents. Shared stewardship of these green spaces can strengthen social bonds and create a collective responsibility for the environment.
Toronto Region Conservation Authority sign, showing they’re planting a pocket tiny forest. Photo: Canadian Geographic
2023 National Mini Forest Pilot
In 2023 Green Communities Canada and Network of Nature launched the National Mini Forest Pilot to address the growing need for green spaces in urban environments. Through this program local partner organizations across a wide Canadian geography (BC, AB, ON, QB, NS) installed 15 Mini Forests on public lands, transforming under-natured urban sites into thriving ecosystems using an approach modeled after the Miyawaki method.
Many of the local partners leading this work (made up of municipalities and environmental organizations) had never planted a Mini Forest before, but were supported with training and technical tools to coordinate, plan, plant, and monitor these sites. Coordinators met monthly as part of a national Mini Forest Community of Practice to share learnings and troubleshoot challenges, as well as present on current project progress. The impact of the program was staggering; more than 9000 trees planted in urban spaces, with 1400 volunteers! The average grant provided to these groups ranged from CDN $10,000 to $15,000 and covered the costs of facilitating the event, accessing plant materials, and installing both the forest and permanent educational signage at the sites.
In some communities, we heard back from our partners that the most challenging aspect of the project was making sure there would be enough trees for volunteers to plant, since community participation in the project was so high! Planting days made a splash in local news, and in many cases local government representatives attended the plantings too! In one instance, a municipal partner who planted their forest in the spring, came back in the fall to double the site location, and is now looking at new ways to integrate mini forests into their urban reforestation strategy. This is the power of these projects, and the ultimate goal of our initiative — to see the movement to plant these mighty mini forests grow all across the country!
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How Can I Get Involved?
Given that this methodology is informed by restoration ecology principles, thus requiring a familiarity with local forest communities, the Network of Nature team developed resources to guide people through mini forest planning, preparation, and implementation. This freely available resource can be accessed via the Network of Nature website. These resources include Canada’s most common forest communities species lists, a curriculum that provides step-by-step instructions on how to identify a site, select species, prepare the soil, engage community, and how to plant, maintain, and protect the forest.
Planting mini forests in Guelph. Photo: Canadian Geographic
A Growing Mini Forest Movement
Since Akira Miyawaki first introduced this method in Japan 40+ years ago, it has been adopted by industry, community groups, and municipalities across the globe. Shubhendu Sharma was an engineer working for the automotive industry within India when he was first introduced to Dr. Miyawaki’s planting approach. His employer had hired Dr. Miyawaki to lead a forest planting on the manufacturer’s property. Mr. Sharma was so inspired by this novel approach that he left the automotive sector to devote his life to planting Miyawaki Forests across India. In 2014, Shubhendu Sharma popularized the methodology with his TED talk ‘How to grow a tiny forest anywhere’ and continued planting forests through his company Afforestt in various countries around the planet. The Miyawaki Method is now utilized across western Europe, in Australia, the United States, Canada, and South America in addition to Japan, India, and the Middle East. Capturing this movement, Hannah Lewis wrote a book in 2018 called the Mini Forest Revolution: Using the Miyawaki Method to Rapidly Rewild the World.
Despite forests being planted this way since the 70s, the Miyawaki Method is relatively new to most. These plantings really only began to pop up in Canada in the last 5 years. While the success stories of existing Mini Forests are encouraging, ongoing research is essential to refine and expand this innovative approach, particularly within North American contexts.
The Miyawaki Forest Resource Network is striving to develop and standardize monitoring protocols and quantify the benefits of the approach in contrast to conventional urban reforestation practices. Research questions include: How much carbon do these forests sequester? How does soil biodiversity compare pre and post planting? Is this approach feasible for the long term? How does this planting methodology compare to other forms of tree planting?
With the Vineland Innovation Centre and Nature Metrics, the Network of Nature is pursuing answers to some of these questions within the Canadian context. We are only at the beginning; collecting our baseline data and finalizing a few research programs. We look forward to being able to share our findings from these studies in the future.
Planting mini forests in Guelph. Photo: Canadian Geographic
Conclusion
In the face of rapid urbanization and environmental challenges, Mini Forests offer a beacon of hope for transforming our cities into more ecologically rich and sustainable spaces. This innovation challenges the conventional notion of landscaping by prioritizing native biodiversity and fostering sustainable ecosystems within limited urban spaces. As cities evolve, integrating Mini Forests into urban planning can contribute to the creation of greener, healthier, and more resilient urban environments. These urban havens not only serve to counter climate change but also enhance the quality of life for city dwellers. The Mini Forest movement is a transformative force that has the potential to redefine how we envision and cultivate urban spaces, ensuring a harmonious coexistence of humanity and nature in our ever-evolving cities.
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Heather Schibli, MLA, OALA, CSLA, ISA, Ecologist, Dougan and Associates / Network of Nature. Heather draws upon her deep affinity for the natural world to guide her design practice and consulting work for Dougan & Associates, a Guelph-based terrestrial ecology firm. Since 2019, she has been an administrator for the Network of Nature (formally CanPlant), which is a collaboration between Canadian Geographic, Green Communities Canada, Vineland Research and Innovation Centre, and Wilder Climate Solutions that is dedicated to supporting and restoring Canada’s unique biodiversity against the stresses of development, extraction, and climate change.
Emily Amon, MA, Director Green Infrastructure, Green Communities Canada. Emily Amon is the director of Green Infrastructure at Green Communities Canada. For the last 4 years she has been coordinating and leading national urban greening projects through GCC’s 30+ member organizations across the country, including depaving urban lots and planting mini forests, rain gardens and pollinator patches. She holds a Bachelor of Environmental Sciences and Studies, and a Master of Arts Sustainability Studies from Trent University in Peterborough, ON.
The National Mini Forest Pilot was supported by the following foundations and funding partners:
Natural Resources Canada, Definity Insurance Foundation, TD, Balsam Foundation, All One Fund, and Greenbelt Foundation
Resources
Forister, M. L., Pelton, E. M., & Black, S. H. (2019). Declines in insect abundance and diversity: We know enough to act now. Conservation Science and Practice, 1(8). https://doi.org/10.1111/csp2.80
Janicki, J., Dickie, G., Scarr, S., and Chowdhury, J. (2022). The collapse of insects: the most diverse group of organisms on the planet are in trouble, with recent research suggesting insect populations are declining at an unprecedented rate. Available at: https://www.reuters.com/graphics/GLOBAL-ENVIRONMENT/INSECT-APOCALYPSE/egpbykdxjvq/
Wepprich, T., Adrion, J. R., Ries, L., Wiedmann, J., & Haddad, N. M. (2019). Butterfly abundance declines over 20 years of systematic monitoring in Ohio, USA. PloS One, 14(7), e0216270–e0216270. https://doi.org/10.1371/journal.pone.0216270