Public Health & The 3–30–300 Rule
An interview with Professor Konijnendijk on trees and the urban ecosystem.
Much has been written about the ideas of Professor Cecil Konijnendijk, of the University of British Columbia’s Forestry School. He is best known for the 3–30–300 rule as a goal for urban planning.
He believes that trees impact health and urban climate adaptation. His rule: In a healthy, urban environment, everyone should be able to see 3 trees from their window, the tree canopy should cover 30% of the urban area and people should live within 300 meters (3 football fields) of a park area.
I recently caught up with Professor Konijnendijk, and gained further insights into his work.
What do you think is the most important benefits of communities implementing the 3–30–300 rule?
The primary benefits fall into several areas: Public Health, Climate Action, and the shift to thinking about cities as ecological systems. There are tremendous benefits to any community when the begin to focus of working with natural processes.
As you know, we are in a public health crisis. Trees can cool the cities and tempers, while cleaning the air and increasing a community’s resilience. Covid highlighted both a human desire to be outside and the need many people had for a bit of encouragement to get up and move around outdoors.
Parks provide that encouragement. Trees provide resilience for cities, buffering heavy rains and providing a sponge structure in the ground. And seeing trees from a window impacts mental health. The key is the importance of all part of the 3–30–300 rule.
Vivek Shandas, another urban planning professor with a focus on trees, has said that for several millennia, we have built towns and cities to protect ourselves from danger. We need to think of increasing urban trees in the context of the next stage of protecting cities.
Yes. Weather volatility is creating urgency around this. The lessons of the recent hurricanes and fires are that nature-based thinking can and should be part of disaster preparedness. In Haiti, in earthquakes people flocked to parks and community gardens as “safe places”.
Trees are more powerful in this regard than most people realize. In addition to reducing wind strength, and the power of raindrops falling, communities look to parks and green spaces as social meeting places.
In addition, part of our public health crisis is mental health. The social aspect parks, and impact of the vegetation on our brains, cannot be overstated. We are at the point where urban dwellers are rethinking how they want to live and connect with their neighbors.
On behalf of SymSoil, I often write about food security. As a fan of Ron Finley, whose TED talk A guerrilla gardener in South Central LA inspired the planting of many vegetables, I often wonder why fruit and nut trees are usually not used in urban tree plans.
I think there are many misconceptions, which discourage the use of fruit and nut trees by cities. Municipalities often are concerned that these trees will be messy, dropping fruits or nuts on the ground. People fear an increase in insects or other pests and these trees may grow more slowly than more ornamental trees.
There is often a lack of awareness of the benefits of fruit trees, which is unfortunate. There are always nuisances, which need to be managed. But often urban forestry plans seek trees that will not grow too large, so in that respect fruit trees may be ideal. Here in Valencia, Spain, the fruit of urban trees is harvested and distributed through neighborhoods.
Interesting. In Rancho Mirage, homeowners are encouraged to take their extra citrus fruits to City Hall, where there are bins for grapefruit, oranges, and lemons, which are distributed through foodbanks throughout Southern California. Yet, here in Northern California, commercial landscapers often cull fruit before it ripens.
How are you seeing the 3–30–300 rule being implemented in other parts of the world?
I have been consulting in the Middle East, which has increased my awareness that 3–30–300 is aspirational. There are areas where there are not enough species of trees that can survive, or the local vegetation cannot support large number of trees. In those locations, there is more focus on shrubs and working with the native ecosystem.
In Saudi Arabia, there is an awareness of the need for creativity in addressing these ideas. For example, using water that condenses from air conditioners to water plants, and rethinking plumbing to use shower and other grey water in landscaping. The key is finding vegetation which is locally appropriate and will survive and reducing the waste of water. From the Saudi’s perspective, reducing the urban ambient temperature by 1° or 2° C is a meaningful impact.
That is a reminder that Nature-based Thinking requires flexibility.
Exactly! The designers of these systems need to be mindful of natural processes.
Cities are part of an ecological system and healthy soil is a key component of that system that we can influence. Trees survive in dirt, but without healthy soil they can’t thrive. Soil with a healthy microbiome impacts water absorption, the breakdown of toxins often found in cities and, of course, the fungal components which trees need to flourish and grow.
More information about Professor Cecil Konijnendijk can be found below.
Soil provides a bottom-up approach to building better urban canopies. Trees are key to a complex, interdependent circle of life with cooperative creatures, like insects and birds, underground networks of roots and microbes, and for humans — cooling shade, clean air, water filtration, community gathering spaces and public health. Bottom line: Humans need to live near trees.
We encourage you participate in Fridays for the Future (FFF) and The Tree Plan by going outside and planting or protect one more tree today.
Why does SymSoil care? We focus on solutions to environmental issues, with a focus on soil biology. Trees and plants feed, and are fed by, the soil microbiome. Healthy soil influences water, carbon sequestration and human health. SymSoil holds a patent on the first scalable approach to manufacturing Soil Food Web products as an alternative to agrochemicals. SymSoil is a supporter of 100KTrees4Humanity, an urban tree planting project focused on action that moves us towards solutions to climate change with equity and inclusion.
More on the 3–30–300 Rule:
Urban Alliance: Promoting health and wellbeing through urban forests — Introducing the 3–30–300 rule
Nature Based Solutions Institute: The 3–30–300 Rule for Healthier and Greener Cities
BIOPHILIC CITIES JOURNAL — The 3–30–300 Rule for Urban Forestry and Greener Cities
