Globally, native biodiversity in cities is decreasing. When species go locally extinct in an area, it will disrupt the local environment. According to Maria Schewenius who has a PhD in environmental studies, “Urbanization is an important driver of land-use and land-cover change […] which in turn alters biodiversity and the delivery of critical ecosystem services of importance for urban resident health and well-being” (Schewenius et al., 2014). Building off of Schewenius an increase in nature in cities, possibly through urban green spots would be beneficial to the mental wellness of humans. Biodiversity can also help decrease the effect urban sprawl has on the environment, such as pollution and the urban heat island effect – when an area has a higher temperature than its surrounding areas due to buildings releasing the suns temperature more than the surrounding natural areas (United States Environmental Protection Agency, 2014). “In the past decade, the creation and growth of cities and towns have been identified as major threats to global biodiversity” (McDonnell & Hahs, 2015). To feed off of what McDonnell and Hahs said, since the number of cities is increasing, the threats they have identified to biodiversity will continue to grow. Eric Bender (2022), a science writer, provided, some animals are adapting successfully in urban areas, but others are not, so if wildlife conservation planners observe how species are adapting in urban areas it “may help to improve conservation management” which could be helpful for planning urban green spots, along with planning cities with better ecosystems that are “better places for people to live.” Additionally, in the TED Talk, Julia Watson: How to build a resilient future using ancient wisdom published by TED Industries, there are many examples of the ways third world countries are using ancient techniques to help the environment while also helping themselves (Watson, 2020). Together these two sources show a common theme of adapting to the environment and how populations learn to use it to their advantage. Animals are adapting to live in cities and finding ways to help them is critical as there are an increased number of cities.
When city planners are constructing green spots, ensuring that the species they use are native instead of nonnative is important. Additionally, it is important to think about the effects increasing the number of urban green spots will have on the environment outside of flora and fauna, because it could help decrease urban pollution, and the urban heat island effect. Finally, it is important to consider the effects it will have on humans, because not only will well-being be affected, but the economic value of some neighborhoods may change, which could affect the affordability for some people. Protecting and creating biodiversity within urban areas can help decrease pollution and decrease mental illnesses in humans. Lauren O’Brien (2022) and Rachael Urbanek from University of North Carolina Wilmington, Department of Environmental Sciences and their colleague James Gregory from North Carolina State University, Department of Forestry, Forest Soils, Watershed, and Wetlands Hydrology, provide, “at the urban level, a reduction in noise pollution can be achieved with a higher extent of porosity and green space coverage.” The question arises: to what extent should the US use urban green spots to protect native biodiversity in urban areas? Based upon looking at how native species interact with the environment, how green spots effect the environment, and how humans can benefit from green spots, it can be concluded that urban green spots are important and should be maintained.
One thing to ensure is that the species in urban green spots are native species. “The replacement of native plants with non-native ornamentals has the capacity to disrupt urban food webs, and [urban green spots] with native plants support a greater diversity of insects and, hence, insectivorous birds” (Aronson et al., 2017). Native species foster more biodiversity within a city because they do not change the food web. In fact, increasing native species could help increase the complexity of a food web. According to Caragh Threlfall from the School of Ecosystem and Forest Sciences, The University of Melbourne, and their associates, primary and secondary consumers are positively impacted by native vegetation in urban green spots, which could possibly influence the way urban food webs are made (Threlfall et al., 2017). Many species benefit from native species. Not only are they better because they do not disrupt the native food web, they also do not run the risk of being an invasive species which wreak havoc on environments.
Even though some animals can successfully adapt in cities, other species have trouble (Bender, 2022), which is why ensuring all species are native could help this. Some non-native species end up being invasive which can be detrimental to an ecosystem (Alvey, 2006). Non-native species can lead to invasive species or to a monoculture resulting in an immense decrease in biodiversity in an area. According to Sonja Knapp, a research scientist and their associates, “The aim is to prevent the planting of invasive plants and alien species and to avoid mono-cultures of plants” (Knapp et al., 2019). A monoculture of plants would be harmful to an environment because it would simplify a food web rather than complexify it, leading to a further decrease of urban biodiversity.
Some researchers have stated using non-native species in urban green spots would prove easier and more beneficial because they are cheaper, can be better suited for the urban landscape, and can provide a wider range of services for humans. According to Dearborn and Kark (2010) from the Department of Biology, Bucknell University and The Biodiversity Research Group, The Hebrew University of Jerusalem, respectively, non-native, and exotic species, may be better for urban areas because they are better suited for urban landscapes and the cheapest option for an area. For cities that do not have the budget for a lot of native plants, which tend to cost more money, non-native species might be a more cost-effective option. A city could avoid this by using an idea from Great Britain where cities hold wilderness competitions to see which has more biodiversity (Conniff, 2014). According to Spotswood, some animals may be better suited for urban environments (Spotswood et al., 2021). So, non-native species may be able to adapt better to living in cities. They can be grown with specific thoughts in mind, like reducing pollution, and increasing wellness of humans. They can better adapt to urban areas or are just generally better suited for it. However, as previously stated they harm the food web, and environment more, due to an increase in habitat homogeneity, which decreases biodiversity, and creates non-native food sources for surrounding plants and animals. Also, according to Threlfall, exotic and non-native species are causing biodiversity to decrease in many areas, within the city and in rural areas (Threlfall et al., 2017). Using non-native species should be avoided whenever possible.
Biodiversity in cities is important because it can help decrease the effects urbanization has on the environment. Urbanization results in deforestation and habitat loss and, an increase in chemicals contaminants, noise pollution, air pollution, and water pollution. Increasing biodiversity would help reverse these effects. Between storm water runoff and pesticides, many water sources are areas of pollution. When the water is polluted, it affects which animals and plants can live there, however, plants can help the decomposition of certain pollutants. (Knapp et al., 2019). If plants in polluted waters can decrease water pollution, there would be more clean water in an environment, providing clean drinking water sources for animals, and decreasing overall pollution in urban areas. Additionally, since many rivers and lakes feed into reservoirs that humans use for drinking water, there would less pollution in the water they drink. Urbanization leads to deforestation which leads to, increased air pollution, impermeable surfaces, rising surface temperatures, and a social disconnect from nature. By creating urban forests, or urban green spots with adequate trees, it can reduce, local air pollution, surface heating, thermal discomfort, help urban wildlife, increase property values, and help reconnect with nature, while simultaneously providing a sense of space. (O’Brien et al., 2022). Through increasing nature in cities through urban green spots, pollution and surface heating would decrease so it would help decrease climate change as well.
Being in nature can have a major impact on the physical and mental health of humans. According to Kuras, having nature in cities has positive impacts on the wellbeing of humans, especially since nature within cities is the only nature that over half of the world’s population experiences every day (Kuras et al., 2022). Having nature can lead to a decrease of mental and physical illnesses in humans. Most people dwell in cities and do not have time to go to rural areas to be truly in nature often so, by building cities with green spots within them it will increase the amount of nature people interact with daily. It is important to know how to ensure that the green spots will better mental health (Schewenius et al., 2014). Population increases lead to an increased number of urban areas. This means that finding ways to incorporate nature into cities is important, especially because each city will be different. Since different cities have different layouts, price ranges, and climate, varied species will thrive while others do not, ensuring all species are native is important.
As city planners are considering ways to incorporate nature it is important to pay attention to the socioeconomic status of a neighborhood. According to Uchida certain biodiversity management techniques that focus on land-sparing rather than land-sharing could lead to an increase in the unequal distribution of urban green spots (Uchida et al., 2022). When cities focus on biodiversity they need to focus on the entire city and not just the sectors where wealthy people dwell because many poorer neighborhoods lack biodiversity and urban green spots, which leads to an increase in redlining and racism. So, city planners should consider this when they are planning the way they lay out urban green spots within urban areas. Though, increasing biodiversity in impoverished areas could raise land values and lead to gentrification (Kuras, et al. 2020). When an area undergoes urbanization, some spaces will inevitably be less appealing than others so they will have a lower land value meaning that under class people with less wealth live there. However, increasing the nature and green spots and biodiversity of this area could lead to an increase in land value which would lead to gentrification meaning that those people would either have to move or become homeless because they can no longer afford to live there.
Some researchers claim there is no need to focus on the addition of nature within urban environments because they already contain so much. According to Sarkar & Bhadra (2022), many species are capable of adapting and surviving within old buildings, roof openings, and pylons. Also, the warmer weather is better for some species, and provides improved foraging conditions, meaning that the urban heat island effect could potentially increase biodiversity, However, species thriving in warmer conditions, are most likely not native, which as stated previously is harmful for biodiversity. Furthermore, according to Aronson it might not be necessary to add new urban green spots but, preserving current ones are because they “are vital for supporting urban biodiversity” (Aronson et al., 2017). According to Fidino adding green space within the city could lead to decreased housing density, and increase urban sprawl, leading to increased commute times and housing prices for people (Fidino et al., 2020). However, this does not mean urban green spots should not be increased in cities, it just means these facts need to be taken into the consideration of city planners. For example, most of these can be avoided by adding urban green spots to places not commonly used, such as, vacant lots, or brown fields.
Over 50% of the human population lives in cities (Bender, 2022). The amount of natural land proposed to be converted to urban land is expected to triple the amount of 2000 by 2030, and it is already halfway there (Conniff, 2014). So, how, and why should the US prioritize protecting biodiversity in cities? Green spots in urban areas would help increase and protect biodiversity and provide many additional benefits such as, reducing pollution, reducing the urban heat island effect, and improving human health, both mental and physical. However, urban green spots are not a one size fits all but rather a rough draft to adapt to many places. Additionally, plants cost money to plant so depending on the budget a city has, it could be difficult to create green spots with native species. In conclusion, if cities prioritize biodiversity by increasing urban green spots, there would be many benefits, both for the environment, and humans.
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