Why Our Cities Need More Trees: The Environmental and Social Benefits
Trees are an essential part of the natural world and play a vital role in our lives. They provide us with the oxygen we need to breathe and the wood we use for fuel and building materials. Trees also help to regulate the climate by absorbing carbon dioxide from the air and releasing oxygen. In addition, trees provide a habitat for a wide variety of wildlife and are an essential food source for many animals. Trees can also have some social and psychological benefits. They can provide a sense of beauty and tranquility and serve as a gathering place for communities. Finally, trees can have economic benefits, increasing property values and making neighborhoods more attractive. Trees are an essential part of our environment and lives, and we should do everything we can to protect and preserve them.
There are several reasons why many cities do not have enough trees. One reason is that as cities have grown and developed, many trees have been removed to make way for buildings, roads, and other infrastructure. In some cases, trees may also be removed for safety reasons if they are diseased, damaged, or pose a risk to people or property. Another reason is that cities may not have sufficient resources to plant and maintain new trees. This can be due to a lack of funding, manpower, or both.
Additionally, some cities may not have adequate policies to protect and preserve trees, which can result in a lack of trees over time. Finally, urban environments can be challenging for trees to survive in due to pollution, compacted soil, and limited access to water. All of these factors can contribute to a lack of trees in cities.
Urban environments can be challenging for trees to survive in for many reasons. One reason is that cities often have high levels of air pollution, which can harm trees. Trees can also be damaged by salt and other chemicals used to de-ice roads in the winter. Compact soil is another challenge for trees in urban areas, as it can limit the growth and development of their root systems. In addition, urban trees may have limited access to water, as they may not be able to absorb as much water as they need due to the presence of hard surfaces such as sidewalks and roads. Finally, urban trees may be subjected to physical damage from pedestrians, vehicles, and other sources. These factors can make it difficult for trees to survive and thrive in urban environments.
They Keep Us Cool
“The increased rates of urbanization and industrialization of the 20th and 21st centuries have dramatically changed the land use and cover of modern cities, affecting the citizens’ quality of life and lifestyle both in a positive and negative way.” (Tsoka et al., 2021)
Cities rely on trees for cooling because they provide shade and cool the air around them through a process called evapotranspiration, which is the process by which water is transferred from the Earth's surface to the atmosphere through evaporation from soil, water bodies, and plant surfaces and through transpiration from plant leaves.
Trees help clean the air and lessen the harmful effects of pollution by taking in carbon dioxide and giving off oxygen. Trees not only provide welcome shade, but they also block some of the sun's rays before they can warm the ground. “An analysis of 94 urban areas around the world indicates that trees have a significant impact on the temperature and are responsible for, on average, 1.9°C (SD 2.3) of cooling in a city. Trees incorporated into the built environment can reduce a city's temperature by 9°C. This reduction of temperature in major cities (Akbari, Pomerantz, & Taha, 2001; Loughner et al., 2012; McDonald et al., 2016) can ultimately help ameliorate the impact of climate change on human health.” (Turner‐Skoff & Cavender, 2019) Because they transpire water through their leaves, trees help cool the air and thus mitigate the urban heat island effect, which occurs when urban areas are several degrees warmer than the surrounding rural areas. In terms of the vegetation’s positive effect on the buildings’ energy needs, the results of a monitoring campaign by Parker et al. in Florida have suggested that planting trees and shrubs around a building can reduce the daily air-conditioning electricity use by 50% as a result of the solar radiation interception and the evapotranspiration effect (Parker, 1983). (Tsoka et al., 2021)
Management
“The remaining “natural” habitats in urban areas have been largely transformed through fragmentation, the introduction of non-native species, and alteration of natural forest structure and composition.” (Escobedo et al., 2011)
The management of urban ecosystems is fraught with difficulties. Urbanization significantly contributes to the loss of natural habitats, which can reduce biodiversity and the value of ecosystems. High pollution levels are another feature of many urban environments; this has consequences for plants and animals. Challenges to ecosystem management in urban areas arise from factors such as limited green space, rising temperatures, and shifting precipitation patterns brought on by climate change. The presence of many different actors, from government agencies and developers to residents and local businesses, adds another layer of complexity to managing urban ecosystems. In addition to figuring out how to keep urban greenery in check, planners also need to figure out which tree species are best suited to the area since it can be harmful to encourage the introduction of species that aren't native. This can cause unwarranted invasive species to flourish in environments they are not native to, which can spell ecological disaster.
There are drawbacks to using urban forest remnants as pollution abatement measures. One report claims that “using urban forests to mitigate pollution is likely to be suboptimal or even counterproductive if it does not account for the scale at which possible ecosystem disservices from urban forests affect people. Therefore, managing urban forest ecosystem services for pollution mitigation should consider possible effects across multiple temporal, political, social, economic, ecological, and spatial scales (Millennium Ecosystem Assessment, 2005; Kremen, 2005; Fisher et al., 2009). (Escobedo et al., 2011)” It's possible that these forests, while helpful in filtering out pollutants and improving air quality, won't be enough to solve the pollution problem in urban areas on their own. Due to their size and dispersion, remnant forests are not always effective at removing harmful chemicals from the air. Furthermore, these forests' presence in urban areas can lull policymakers into a false sense of security, diverting attention away from more substantive solutions to the problem of pollution, such as lowering emissions from vehicles and industry. Decomposing organic matter in urban forests can also contribute to air pollution if the forests are improperly maintained. Therefore, while remnant urban forests can help reduce pollution, they cannot be relied upon on their own.
Health & Wellness
“The presence of trees provides additional direct and indirect benefits to human health and wellness.” (Turner‐Skoff & Cavender, 2019)
A city's tree population has been shown to improve residents' health in several ways. Trees help to purify the air we breathe because they consume harmful gases and release beneficial oxygen. This can potentially lessen the likelihood of developing respiratory and other health problems. Spending time in natural settings, especially those with trees, has improved mental health and reduced stress. People are more likely to go for walks or rides in tree-lined areas, and these activities are suitable for their health in many ways. As remarked by Turner-Scoff & Cavender “Residents of tree‐lined communities feel healthier and have fewer cardio‐metabolic conditions than their counterparts (Turner‐Skoff & Cavender, 2019)”. The detrimental effects of noise pollution on human health can be mitigated by planting trees, which act as sound barriers and absorbers. “Trees and greener environments are strongly linked to reduced negative thoughts, reduced symptoms of depression, better-reported moods, and increased life satisfaction (Turner‐Skoff & Cavender, 2019)”. People's mental and physical health can benefit from increased opportunities to relax, socialize, and connect with nature. People's health and well-being can be significantly improved by the presence of trees in urban areas. As further remarked by Turner-Skoff & Cavender, “trees not only make people happier and healthier, but they make communities more livable.”
Green for All?
“Well‐maintained trees are associated with improving the social capital and ecology of a community.” (Turner‐Skoff & Cavender, 2019)
To enhance urban dwellers' quality of life, "green infrastructure," or the interconnected system of parks, plazas, and other green spaces, is crucial. The urban heat island effect can be mitigated, air quality improved, flood risk decreased, and biodiversity increased thanks to green infrastructure. Green infrastructure has many benefits, but one of its main drawbacks is that it is typically only easily accessible to those with greater financial means.
We call this problem "environmental injustice," which stems from unequal access to green infrastructure. Poorer people and people of color are disproportionately represented in neighborhoods with fewer parks and green spaces than their more affluent counterparts. If people don't have access to green infrastructure, it can harm their health and quality of life.
The inequitable distribution of green infrastructure can be attributed, in part, to the high costs associated with its creation and upkeep. Parks, gardens, and street trees all need consistent funding for things like staff, equipment, and maintenance to flourish as public green spaces in a city. In addition, land in urban areas is frequently at a premium, which means that developers may put building construction ahead of preserving green spaces.
One more consideration is the typical pattern of distribution for green infrastructure. Instead of prioritizing neighborhoods in dire need of parks, developers and city planners may prioritize those already prosperously or well-served by existing infrastructure. As a result, the gap between haves and have-nots can widen, as those with more money have a greater chance of having their voices heard. Several options exist for resolving the issue of unequal access to green infrastructure. One strategy involves giving underdeveloped areas top priority for new park construction. This category includes community-led initiatives to transform underutilized spaces into gardens and parks. Incentives from the government can also encourage builders to prioritize green infrastructure.
Another option is to increase funding for the upkeep and management of green infrastructure. This can aid in keeping existing parks in good condition and making them available to the public. Promoting equitable access to green spaces and raising public understanding of the benefits of green infrastructure are two additional goals.
Even though green infrastructure has the potential to enhance the lives of city dwellers, limited access to such areas is a significant issue. Building public awareness of the importance of equitable access to green spaces, increasing funding for maintenance and management, and prioritizing green infrastructure development in underserved areas are all potential solutions to this problem.
“We have entered a new era in which humans are the dominant species and the main influencer of the planet. The built environment as it currently exists is not conducive to most trees.” (Turner‐Skoff & Cavender, 2019)
A Greener Future
The presence of trees in a cityscape is crucial. They offer a variety of advantages that enhance urban living conditions. Trees help clean the air by taking in harmful gasses like carbon dioxide and giving off healthy oxygen. They are also helpful in preventing flooding and erosion by cutting down on the amount of stormwater runoff in urban areas. The "urban heat island" effect, in which cities are typically much hotter than surrounding rural areas, can be mitigated by trees that provide shade and shelter. Wildlife, such as birds, insects, and small mammals, can find refuge in the shadow of trees.
Last but not least, trees can raise property values, improve an area's visual appeal, foster a sense of community, and give residents a place to unwind and get to know their neighbors. Trees are a must for a flourishing city. To reap the benefits of urban trees in the future, we must view our urban forests as investments. However, with proper planning and maintenance, urban forests can produce multiplicative effects that improve lives at all levels of society.
Works Cited
Akbari, H., Pomerantz, M., & Taha, H. (2001). Cool surfaces and shade trees to reduce energy use and improve air quality in urban areas. Solar Energy, 70(3), 295–310. https://doi.org/10.1016/s0038-092x(00)00089-x
Escobedo, F. J., Kroeger, T., & Wagner, J. E. (2011, August). Urban forests and pollution mitigation: Analyzing ecosystem services and disservices. Environmental Pollution, 159(8–9), 2078–2087. https://doi.org/10.1016/j.envpol.2011.01.010
Tsoka, S., Leduc, T., & Rodler, A. (2021, February). Assessing the effects of urban street trees on building cooling energy needs: The role of foliage density and planting pattern. Sustainable Cities and Society, 65, 102633. https://doi.org/10.1016/j.scs.2020.102633
Turner‐Skoff, J. B., & Cavender, N. (2019, July 8). The benefits of trees for livable and sustainable communities. PLANTS, PEOPLE, PLANET, 1(4), 323–335. https://doi.org/10.1002/ppp3.39
