Expanding the tree canopy and green spaces in San Diego can be an impactful club service project that encompasses all of Rotary's areas of focus while leaving a significant and lasting legacy. Read more to understand why and how.
The Importance of Urban Forests
When considering the benefits of trees and green spaces, large rainforests and redwood forests often come to mind. While these are important to the planet, the trees in urban areas also provide significant benefits for our health, our communities, and the environment. Expanding the tree canopy in San Diego can be an impactful club service project that encompasses all of Rotary's areas of focus while leaving a significant and lasting legacy. Read more to understand why and how.
Urban trees improve our health in several interconnected ways.
- Trees cool our city by 10-20 degrees in the summer. Heat can be deadly and exacerbate health issues like lung and heart disease. Extreme heat is the leading cause of climate-related deaths.
- Trees and urban green spaces offer calming space. Studies show that when we are surrounded by greenery, our stress hormones, blood pressure and heart rate all decrease.
- Green spaces and areas with leafy tree canopies promote outdoor activities, which may help mitigate obesity associated with various chronic illnesses.
- Urban forests help reduce lung diseases and cancers by effectively cleaning the air we breathe. Studies show that asthma and COPD symptoms are significantly decreased in areas where there are more green spaces and rates of cancer (especially lung and bladder) are reduced.
- People in areas with more trees have lower rates of coronary artery disease, hypertension, and stroke, likely due to reduced stress, lower blood pressure, and the calming effect of trees. Exercise encouragement, pollution reduction, and cooler temperatures in summer also contribute.
Trees benefit our communities and improve the comfort and livability of our city.
- Trees offer some significant economic benefits to communities.
- Tree lined streets are valued by about 5-20% more than similar housing without trees depending on the maturity of the trees. Adding trees to a low-income area increases property values while cooling the community.
- In San Diego, the right tree in the right location of your front yard will increase your property value by about 10K. That’s a nice investment.
- Shade slows down the deterioration of roads so more street trees mean more time between repair and paving.
- Consumers spend more time and money around businesses that have a healthy urban forest around them.
- Apartments and offices in wooded areas rent more quickly, have higher occupancy rates, and tenants stay longer
- There is a correlation between tree canopy and crime rates. Research indicates that a 1% increase in tree canopy can lead to a 1% decrease in crime, specifically violent crime and vandalism, in urban areas. A study reviewed low-income housing in America and observed that communities with access to green spaces experienced a 20-50% reduction in domestic violence calls to police. The researchers suggest that having green areas for relaxation might reduce violence.
- Urban forests aid concentration. Students with classroom views of trees perform better on standardized tests when compared with students with parking lot or building views. Students with ADHD improve focus and reduce medication when regularly exposed to green spaces.
Finally, urban forests make our environment healthy.
- Urban forests fight air, water and noise pollution.
- Trees vacuum up CO2 and store carbon. They are one of the biggest carbon sinks in the city.
- Tree canopies can also reduce the demand for energy on our electrical grid by cooling our cities.
- Trees help with water runoff and soil retention during heavy rains – preventing flooding and landslides. Trees absorb an amazing amount of water, clean it and can help recharge our ground water. A large native oak is drought tolerant but can drink in about 100gallons of water per day. The shade and leaf debris of trees also helps reduce evaporative water loss from soils.
- Trees mitigate biodiversity loss in the city by providing clean air, food, shelter, and habitat for wildlife – from earthworms and pollinators to birds and mammals. Urban forests often contain a greater diversity of species than rural forests and are a haven for migratory wildlife.
San Diego needs more trees for resiliency. A survey revealed that San Diego’s tree canopy is less than a third of what's needed and unevenly distributed, with wealthier areas being greener. Tree inequity relates to social inequity. While local organizations plant thousands of trees yearly, many are lost due to development, disease, drought or aging. Therefore, it's crucial to plant new trees and maintain existing ones. Finding space in established neighborhoods is a challenge for these reasons.
- Most of the property is private and unavailable. City of San Diego is responsible for most sidewalk trees and goes door to door to talk to owners about placing trees in their front yard easements when possible – not an easy task.
- Trees should not be under power lines or over water and sewer pipes.
- Trees should be planted no closer than 5 feet from buildings and regularly irrigated within a 50-foot area around structures to minimize wildfire risk, according to CalFire. Eucalyptus and other trees that are highly flammable are not recommended.
- New trees need to be suited to and resilient in our changing climate.
- Once you have planted the right tree in the right space, the right way, you cannot just walk away in San Diego because the tree might still not survive. Those new trees need water and maintenance for at least three years to thrive.
There are numerous ways that your club can contribute to expanding San Diego's tree canopy by collaborating with established local organizations that work closely with the Urban Forestry Council and excel in community planting initiatives. Consider undertaking a multi-year project in a preferred park or organizing your own event. The optimal time for planting is late fall, allowing trees to benefit from the winter rains for establishment. Green Friday (the day after Thanksgiving) or Dia De Los Muertos plantings (to honor a deceased loved one) are commonly held in November. Early Spring, particularly around St Patrick’s Day, is another favorable time for planting as the soil remains cool and moist, and the days begin to warm. Arbor Day, celebrated on April 25, features several planting events throughout the county. Additionally, cleanup activities around newly planted trees can be conducted year-round to help young trees thrive.
Here are some great partners for tree planting and maintenance events:
- The County of San Diego (https://www.sdparks.org/volunteer/#UpcomingEvents) has over 56,000 acres of property open to the public from large tracts of open space to small neighborhood pocket parks all over the county. They plan on planting at least 10K trees each year. They also water, monitor and maintain the trees, clear out invasive plants and do park cleanups so that the chance of success of new trees is very high. They also provide educational opportunities at these events for all volunteers.
- The City of San Diego (trees@sandiego.gov) also has about 42,000 acres of land and similar opportunities from Cabrillo National Monument to Mission Trails Park. The city is also responsible for planting street trees in neighborhoods and community centers, schools and along roads. Lately they are focusing on those parts of the city that have the fewest trees and are at greatest risk from heat and rain events. A new grant allows for 3 years of watering and maintenance.
- Tree San Diego (treesandiego.org) is an amazing non-profit that has grown in San Diego County for the last 10 years. TSD offers free trees to anyone in San Diego with monthly tree giveaways if you would like to organize your own event. They also offer regular tree plantings and maintenance events, educational events for homeowners and a tree stewardship certification training program.
- Forever Balboa Park (https://foreverbalboapark.org/volunteer/tree-stewards/) is a park non-profit that plants new trees and maintains the extraordinary tree collection with dedicated support from volunteers. Tree stewards are trained to plant, monitor and maintain the park’s 15,000 trees.
- Other cities around San Diego that have occasional tree planting events: