Urban Tree Canopy, Native Plants, and Community Health
The City of South Bend is updating its climate action plan this year. New draft goals include increasing urban tree canopy and native plants. As a 2024 Climate Action Ambassador, I asked local experts and community members how these green initiatives may improve human health in our community.
Air, Soil, and Water Quality
Urban trees and native plants improve air, soil, and water quality. Plants clean our air by absorbing pollutants like carbon dioxide (CO2) and releasing oxygen. Reducing CO2 is more than just a way to fight climate change, it is also directly beneficial to improving environmental and human health. Additionally, native plants (especially those in wetlands) help improve soil and water quality by acting as the “kidneys” of the landscape and absorbing pollutants.
“Increasing tree canopy coverage… can also improve air quality which is critical for people with chronic diseases such as asthma and heart disease. Louisville, Kentucky is currently doing a study to see how much increasing canopy coverage improves air quality and reduces incidence of heart disease (Green Heart Louisville HEAL Study).”
- Professor Deborah Marr, Indiana University South Bend (IUSB)
Bo Foldesi, South Bend resident, has heard a lot about how keeping house plants is beneficial for cleaner indoor air and better mental health. Since it works so well for indoor areas they are very supportive of the idea of increasing tree coverage and native plant spaces within the community for similar benefits.
Urban Heat Island Effect
Extreme heat leading to deaths from heat stress is a major concern in our warming climate. The graph above shows how in the 2018–2022 there was a large increase in exposure deaths, including deaths from extreme heat. Dramatic climate disasters like hurricanes often get big headlines, but extreme heat is a “silent killer” that causes more deaths than all other weather disasters combined (Source).
“Trees are our natural air conditioners. You can really tell the difference standing under the shade of a tree on a hot sunny day.”
- Diana Zebroski, IUSB student
South Bend residents that are unhoused or take public transportation are more susceptible to the health impacts of extreme heat. Professor Monica Tetzlaff of IUSB says that she would love to see some trees around bus stops to give shade and relief from the heat for those waiting for the bus. Justin Nielson, a student at IUSB, says that he would love to see more trees around the O’Brien Skate Park to help skaters stay cool.
“Trees provide shade, reducing the amount of sunlight absorbed by buildings and pavement. This helps to lower surface temperatures and create cooler microclimates. They also release water vapor through leaves, which cools the surrounding air.”
- Professor Zachary Schrank, IUSB
Flooding
“In terms of climate change, we are already seeing in Indiana increased flooding risk, more extreme storms, and more hot days (Indiana Climate Change Impact Assessment). Increasing canopy coverage in South Bend can help address each of these problems.”
- Professor Deborah Marr, IUSB
Urban tree canopy helps mitigate flooding in multiple ways. Tree leaves and branches reduce the speed at which rain falls. Roots help the rainwater soak into the ground. Native plants tend to have long roots, making them more drought resistant and also better assistants in soaking up stormwater.
Biodiversity & Mosquitoes
“[When] folks tend to get a problematic number of any insect [it] tends to be corrected when the ecosystem becomes more balanced, which creates competition. For example, when folks see lots of aphids on their milkweed, it looks concerning. However, if the insects that eat aphids (lady bugs, parasitic wasps, hoverflies, etc.) are present in your habitat, they will be gone in no time. And the way to welcome those beneficial insects to your yard is to add native plants, trees, and shrubs! The birds and dragonflies that will visit also include mosquitoes in their diet.”
- Jodi Magalski, President of Wild Ones South Bend, a non-profit organization focused on native plant education
Biodiversity, or the diversity of life, has positive benefits to human health. Healthy wetlands, for example, encourage the development of mosquito predators like dragonflies. If your yard has mosquito problems, instead of spraying your whole yard which can be harmful to beneficial insects (and even your own health!) I encourage you to remove areas of stagnate water and/or use larvicides (Link to more info).
Mental and Physical Health
“Increasing the use of native plants and green spaces in cities can contribute to healthier immune systems and even mental health. For example, immune related diseases are more common in urban areas. A study in Finland showed that daycare centers where young children could play in green spaces with more trees and forest soils had healthier immune systems compared to children who played in standard daycare centers with minimal greenspace (Roslund et al. 2020).”
- Professor Deborah Marr, IUSB
Cassy White, Manager of Community Health Outcomes for Beacon Health System, mentioned the concept of “social determinants” in a 2024 City of South Bend panel on climate change. This means that where you live, work, or otherwise spend your time affects 80% of your health. Living near areas with vegetation and spending time in nature are consistently shown to help improve mental and physical health.
“Whenever you walk into a space with trees it just feels better: cooler, quieter, more relaxing, more beautiful, and more interesting.”
-Justin Nielson, IUSB student
Urban trees can even improve our communities by providing relief from noise pollution by absorbing sound waves. Green space is a great way to find some peace and quiet, even in a busy city.
“Dense vegetation creates a natural barrier between noise sources (like traffic or construction) and residential areas, providing a quieter environment.”
- Professor Zachary Schrank, IUSB
As a student at Indiana University South Bend studying the environment, I have learned that sustainability is about meeting present needs while also preserving the future. And as a 2024 Climate Action Ambassador, I am advocating for improving the environment in which we live because it will make our community healthier and safer for generations to come.
The final draft of South Bend’s updated Climate Action Plan will go to South Bend City Council this fall for voting and approval. Do you have your own feedback or would you like to offer support for existing climate strategies? Let us know by sending an email to CAP2024@southbendin.gov with any thoughts, questions, concerns, or groundbreaking ideas.
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