What’s so great about Miyawaki pocket forests?

Did you know that native pocket forests grown using the Miyawaki method can be planted in spaces as small as 3m²? These forests mature up to ten times faster than traditional reforestation methods, require little to no maintenance after two to three years, and, in some cases, have been found to have biodiversity levels up to 18 to 100 times greater than traditional planting methods. The key ingredient to their success is community involvement, which is why, at Carbon Positive Australia, we call these Community Pocket Forests. Keep reading to learn more about the magic of Miyawaki forests and how Carbon Positive Australia is helping to bring them to life.

Professor Akira Miyawaki, a Japanese botanist and forest ecologist, developed the Miyawaki method of afforestation. This method involves careful species selection, specific soil preparation, very dense planting, a high diversity of species planted, and community involvement, which is the key ingredient in making these projects work.

Miyawaki forests are ideal for urban environments because they create dense, biodiverse mini forests even on very small sites. These ‘pocket’ forests are perfect for revitalising underutilised urban spaces, enhancing urban biodiversity, reducing urban heat, and mitigating the effects of climate change.

Native pocket forests grown using the Miyawaki method have the following advantages:
• Usually the size of a small tennis court, however, can be planted in a space as small as 3m2;
• High density plantings of approximately 3-5 plants per square meter, with a selection of 30 or more species that are endemic to the area;
• Mature up to 10 times faster than traditional reforestation methods;
• These high density plantings offer greater potential for carbon sequestration per square meter than a traditional forest;
• Foster up to 18 times greater biodiversity levels than traditional planting methods;
• Require no maintenance within their first two to three years.

Learn more about community pocket forests here.

When you think of your urban environment, what comes to mind? Concrete and bitumen, right? These materials absorb the sun’s heat during the day and release it at night, leading to higher temperatures in unshaded local areas. This, in turn, creates heat spots, which are areas of high heat intensity, creating what we call the urban heat island effect. Not so great, particularly during our Australian summers.

Dr Thomas Longden from the Crawford School of Public Policy at ANU found that over 36,000 deaths in Australia were associated with extreme heat between 2006 and 2017^[1]. This is vastly more than all other natural disasters combined during the same period.

Urban residential zones that lack tree cover tend to be found in lower-income areas where people may lack access to air conditioning. Heat stress impacts those who may already be vulnerable and can exacerbate existing health conditions such as diabetes, kidney disease, and heart disease. Older people are particularly impacted. Those on higher incomes or who live in leafy suburbs have more resilience to urban heat because they either live in cooler areas or have greater access to cooling. This means that urban heat is not only an environmental and health issue, it’s also an equity issue.

When impervious surfaces like concrete and bitumen are shaded by trees, they absorb less heat, reducing the heat island effect. In fact, shaded surfaces may be as much as 11–25°C cooler than peak temperatures of unshaded surfaces around them, which significantly impacts the liveability of local environments^[2].

Trees not only cool by providing shade; they also cool the air through evapotranspiration. They are essentially water pumps, drawing water up from the ground and releasing it into the atmosphere through the stomata on their leaves. As air temperatures go up, transpiration also increases.

Native trees planted in urban areas provide a range of benefits including:
• Cooling impervious surfaces through shading;
• Cooling air temperatures through transpiration;
• Providing habitat for animals, birds and insects;
• Shading footpaths and bikeways making summer activity bearable;
• Beautifying our suburbs;
• Reducing stormwater runoff;
• Drawing down carbon dioxide from the atmosphere;
• Contributing to noise reduction by acting as buffers;
• Filtration of air pollutants.

They also offer additional benefits such as:
• A reduction in energy use and bills where shade reduces the need for intensive air conditioning;
• Contributing to the reduction in heat-related deaths;
• Improving our mental and physical health by encouraging our connection to nature and outdoor activity;
• Fostering community cohesion by enhancing public spaces where the community can gather and build social connections;
• Boosting equity in communities by increasing local environmental quality.

The Miyawaki method of planting has some incredible advantages over traditional planting methods because the trees and shrubs are densely planted (up to 5 plants per m2 as compared to one tree every 1.5m2 to 2m2 in standard reforestation), and grow fast because of both soil remediation methods and density:
• The forest floor is rapidly shaded, so loses less water through evaporation, resulting in healthier soil;
• The trees and shrubs are quickly connected via mycorrhizal networks in the soil, allowing the sharing of nutrients and rapid growth (forest maturing up to 10 times faster than traditional techniques);
• Canopy cover is reached fast – in Far North Queensland, for example, it may only take 18 months;  
• Little to no maintenance is required after two to three years;
• Biodiversity levels in Miyawaki forests are up to 18 times greater than traditionally planted forests.  

Planting a Miyawaki forest is a community endeavour, not a landscaping exercise. It’s an opportunity for local communities to come together, learn about the benefits of trees and forests, take local practical action on climate change, and feel connected to the well-being of the environment they live and work in. This is why, at Carbon Positive Australia, we call these Community Pocket Forests.

Watch our Tiny Forest Webinar and discover the wonderful world of tiny forests in Australia

At Carbon Positive Australia, we want maximum positive impact created for every dollar donated to community planting. This means that we are looking for community planting projects that have benefits beyond just planting trees. Community pocket forests offer just that – a fast-growing, nature-based solution that offers a quick pathway to mitigating the impacts of extreme heat on communities whilst enhancing community cohesion and resilience in the face of climate change.

If you’d like to support projects like these, please donate here. 
If you have a Miyawaki pocket forest project proposal and would like to discuss funding and planting options with us, please email [email protected]

1. https://iceds.anu.edu.au/research/research-stories/we-know-heat-kills-accurately-measuring-these-deaths-will-help-us-assess 
2  Akbari, H., D. Kurn, et al. 1997. Peak power and cooling energy savings of shade trees. Energy and Buildings 25:139–148