Without forests, life on earth would be unthinkable and unlivable.
Urban forests are homes to a wealth of biodiversity and are an integral part of community ecosystems. They improve the livability of our cities and make all our lives better.
Even though their aesthetic value might be striking, the many critical services they provide tend to be overlooked. Urban trees can help alleviate some of the adverse effects and social costs of development and make cities more resilient to these changes.
The term, urban forest, refers to all public and privately owned trees within a metropolitan area.
For the most part, cities' rapid growth takes place without any land use planning strategies, and the subsequent human pressure has highly damaging effects on the forest, landscapes, and green areas in and around cities.
Further, climate changes often deepen the environmental impacts of urbanization, significantly increased pollution, reduced availability of food and resources, increased poverty levels, and can lead to extreme climate occurrences.
In fact, for many years, tree canopies in our urban centers have been declining. Large mature trees that reach their lives end are often substituted with smaller species – if at all. These replanted trees then struggle to establish and reach maturity due to the constraints of the pavement surrounding them.
Indeed, green spaces offer a myriad of essential ecological, economic, and social welfare services to more than 220 million people living in urban centers in the US (US Census). As the population of towns and cities continues to increase, sustainable urban and community forests are vital for their well-being. Furthermore, adding nature back into the hardscape and urban environment in which we live, work, and play reduces the number of issues that affect our quality of life. Truly, trees and green spaces help us connect with nature and restore our health, ability to learn, happiness, and spirit.
With this in mind, let's unpack how urban forests contribute to making cities more socio-economic and environmentally sustainable.
Trees play an essential role in increasing urban biodiversity, affording plants and animals a favorable habitat, food, and shelter and act as a reservoir for threatened species. Further, the urban forest offers many enjoyments to city dwellers and can serve as local environmental health indicators.
Undoubtedly, few things can parallel the aesthetic impact and seasonal interest that trees offer the urban setting. They provide a substantial visual to any area and can significantly enhance a streetscape design and promote tourism.
Again, a mature tree plays a vital role in climate change. Trees influence temperature levels, energy use, and air quality by providing shade, transpiring moisture, and reducing wind speed. Trees absorb high quantities of Co2 per year, especially in cities with high levels of pollution. According to research, the establishment of millions of trees around residences in the USA is said to save $2 billion annually in reduced energy costs.
Equally important, the strategic placement of trees in a city can improve air quality by cooling the air between 2 and 8 degrees, thereby reducing the “heat island” effect and assisting urban communities in adjusting to climate change. Trees can also reduce carbon emission from buildings' energy use and other sources by aiding to conserve energy and reduce air pollutants through their leaves.
Additionally, sizeable mature trees are excellent filters for urban pollutants and fine particulates. Tests conducted in streets lined with trees have shown a 60% reduction in particulates from car exhaust. Trees absorb pollutant gases and filter fine particles like dust, dirt, or smoke out of the air by catching them on leaves and bark and storing it as cellulose. This carbon reduction is known as sequestration.
For every 5% of tree cover in a community, storm run-off is reduced by 2%. Trees prevent rainwater run-off from reaching watercourses with the harmful chemicals it collects from urban roadways and sidewalk, while also decreasing topsoil erosion.
Likewise, a mature tree regulates water flow and plays an essential role in preventing floods and reducing the risk of natural disasters. Trees and soils increase water quality and reduce the need for costly stormwater treatments by diverting and holding or reducing the flow of precipitation reaching the ground.
Studies have shown that living nearby urban green spaces and having accessibility to these areas can improve physical and mental health. For example, trees have also proven to positively impact skin cancer, asthma, hypertension, and other stress-related illness by filtering out polluted air, reducing smog formation, and providing shade from solar radiation while providing an attractive, calming setting for recreation.
The relationship between urban forestry and urban greening with healthier social systems is remarkably direct. The existence of trees and well-maintained lower undergrowth vegetation can transform desolate spaces into pleasant, welcoming, well-used places. Such common areas serve to strengthen ties amount residences, increase informal surveillance, and deter crime, thereby creating healthier, safer communities. In housing developments with gardens and trees, crime rates drop. Places with high green space levels have less property crime and a reduction in both violent and petty crime, including domestic violence, through the therapeutic calming influences of mature tree planted in urban communities.
Trees neighboring roads help delay traffic by making the road seem like part of the community. Also, they make us feel at home and protected, promoting more time outside socializing, walking, exercising, and with more eyes on the street to help deter crime.
Moreover, trees-line streets help reduce noise. Excessive noise can be detrimental to community health; thus, trees act as a sound buffer to reduce noise pollution which can be especially helpful if our home is near busy thoroughfares.
Most importantly, trees also contribute to increased local food and nutrition security, providing food such as fruit, nuts, and leaves for human consumption and fodder. Their wood can be utilized in a variety of ways, like construction, cooking, and heating.
A well-planned urban landscape with trees can increase property values by up to 20 percent and attract tourism and business opportunities.
Urban Forest employs more than 62,000 people in California alone like arborists and entry-level nurseries and landscaping companies than add over $3.2 billion in value to the California economy. Also, it generates opportunities for businesses in all aspects of tree care, maintenance, and conservation. According to the U.S Forest Services, every $1 invested in trees brings a return of $2.75 in benefits. Thus, throughout their lifetime, trees can provide a beneficial package worth two to three times more than all the investments made in them.
In summary, a city, a town and a community with a well-planned and well-managed green infrastructure support a healthy environment, becomes a more resilient, sustainable, and regulated climate for everyone.
For more information, consult the links below:
http://sjmastergardeners.ucanr.edu/Landscape_Trees/
https://ucanr.edu/sites/sjcoeh/Trees/
https://www.fs.fed.us/psw/topics/urban_forestry/products/2/cufr_38.pdf
https://caufc.org/why-urban-forests/
https://www.fs.fed.us/psw/topics/urban_forestry/documents/20150422CAStreetTrees.pdf
http://www.calforestfoundation.org