Urban sprawl produces some of the greatest local extinction rates, frequently eliminates a significant portion of native species, and causes severe habitat loss. Several studies confirm that population numbers and genetic diversity of native species of plants, animals, and insects drop with greater urbanization [1,2,3].
One of the major causes of biodiversity decline in cities is the land-use change and, what is very closely connected, loss of habitat. As traditional ecosystems are altered to support complex urban infrastructure, the original wildlife is often not able to keep up with those sudden changes in available resources and begins to strive.
Another significant detriment caused by urbanization is that native species which are lost as a result of urban growth are frequently replaced with nonnative species. The introduction of such nonnative species threatens the biological uniqueness of local ecosystems.
Urban impacts on biodiversity reach their most devastating effects in developing countries. For example, less than 2% of the Atlantic forests of coastal Brazil within the urban reach of Sao Paulo remain, and it has been estimated that thousands of species from this region of high endemism have been driven to extinction, most never having been described by taxonomists.— Dennis D. Murphy
We all would like to see some more greenery in our cities. It is for this reason that we often wish that developers and local councils would make more space for green oases in city centers or incorporate some principles of green infrastructure in the future development plans. But you do not have to wait for the authorities to take action. You can actively participate as well.
There are some effective ways to green up your city and incorporate native ecosystems into the urban environment! Here are five ideas to go about harmonizing the local native flora and fauna with the surrounding urban development:
Easy steps to help you make your city greener
#1 Set up an allotment or a community garden
Creating a community garden not only gives the community a place to congregate and become more educated about where their food comes from, but it also gives insects a source of food!
By utilizing available community spaces and creating city gardens where different fruit, vegetables, flowers and herbs are grown you will be giving pollinators a much-needed source of food and shelter. Bees and spiders, for example, both essential to an ecosystem yet rarely thought about, are given the opportunity to thrive in a safe environment.
You will also be generating some source of food which can go a long way to supporting poorer communities in your area. Growing food and taking care of plants is also a pleasant and rewarding pastime for people of all ages!
#2 Green your building
A building made out of brick or concrete is not only unattractive, but it also does nothing for the environment. And guess what, our buildings don’t need to be just made of concrete. We can add some green to attract wildlife, such as birds, and at the same time support the process of emitting a little oxygen back into the city air.
The process of “greening” a building simply means that the roof or wall of the building is covered by vegetation. The outer part of the building is protected by a membrane between the structure and the growth, so it would not corrode the building in any way.
“Greening” a building provides an environmental benefit, but also a psychological benefit to the people working or living in the building by creating a sense of calm and peacefulness. A green roof not only looks appealing from afar but it can also be a quiet and restful place to escape to in the middle of the day. Similarly, green walls use the same principles are green roofs so that buildings can have green walls on their exterior.
A much simpler approach particularly for the outer wall of a yard for example can involve the use densely planted bushes and trees to form an outer wall rather than using a fence or other structure. If you cannot change your building’s wall or roof, you can always try and green your balcony by adding different plants and flowers there.
#3 Create isles of native environments for urban wildlife
There are many great ways in which you can attract small wildlife to your yard or balcony. If you have a small garden, different species will feel more welcomed if you choose to plant native plants, flowers and trees to support local biodiversity.
Native plants are better suited to create a natural habitat for local wildlife. Birds and insects are already adapted to eat and use native species of flora, so it is logical to incorporate these species into the urban landscape.
Of course, the more native species of plants are incorporated into the environment, the better. However, keep in mind that different plants cultivate and attract different creatures. You should do a little research prior planting to figure out what plants would be most beneficial and in what areas.
The same can be done in other urban areas. For example, school gardens or playgrounds are often barren or very monotonous. By liaising with the appropriate people, you can make these spaces greener which is both better for biodiversity as well as the children who will come to meet a lot of it in their place of play.
#4 Don’t use pesticides or fertilizers and rethink lawns
In order to increase biodiversity in an urban landscape with the natural ecosystem of the surrounding area, it is important to avoid using chemical fertilizers and pesticides.
The reason is that chemical fertilizers and pesticides have a “scorched-earth” policy when it comes to killing off bugs. They don’t discriminate when it comes to the good bugs and bad bugs, they kill ALL the bugs.
Why does this matter? Well, bees, for instance, are very sensitive to both organic and chemical pesticides. Yet, bees are a very important part of a functioning ecosystem.
And what about lawn maintenance? Well, a close-cut lawn means that it will provide animals with little to no source of food or shelter. Therefore, the lawn will be effectively useless to reinstating a rich and diverse ecosystem. It would be much better to incorporate lush, diverse, and native plants to your garden.
#5 Encourage wildlife corridors for connecting habitats
Connectivity refers to providing wildlife with corridors and connections between habitats. It allows for the free and safe movement of species from one area to another.
Providing options for wildlife to travel and find new food sources, water sources, and mates are extremely important to urban biodiversity. It allows for animals to maintain their populations, migrate, etc. The idea is to allow native animals to live as unimpeded as possible within the urban environment.
Remember to use all potential options, be creative and innovative in figuring out ways to develop new opportunities to create a green space, think of ways to make something multi-functional, and don’t be scared to try to make something green that hasn’t originally been considered!
Why does biodiversity decline in urban areas?
The loss of habitat is not the only adverse effect of urbanization. The impacts of human activity when altering land cover also introduce the phenomenon of habitat fragmentation. Original ecosystems are split into small fragments when buildings and related infrastructure are built progressively over them.
For example, think of a moss on the forest floor when a road is built directly in the middle of its natural habitat. What impact does that have on its living conditions? Temperature increases due to the direct exposure to sunlight, the soil gets drier and different species take over, stealing necessary nutrition from its poor existence.
Consequently, fragmentation comes with another toll for native species, the edge effect. The edge effect means that there are different conditions on the edges of a habitat than in the middle, which further decreases the inhabitable range for some species. The genetic diversity of populations declines as well, since small islands of habitats cannot possibly provide enough nutrients or space for large families to flourish.
Along with the negative impacts of fragmentation, city centers and suburbs usually struggle with the spread of nonnative species. Overall, the percentage of nonnative species rises up to more than 50 percent in urban areas . The cause of this trend is simple – human intervention. It is our intervention, such as planting exotic trees in city parks for aesthetic purposes, that dramatically affects delicate balance of native populations. Often, the urban ecosystem consists of significantly different species than surrounding natural areas.
Higher occurrence of nonnative species in the urban ecosystem is especially risky for native populations. Nonnative species easily get out of control in conditions where their natural enemy is missing, and can therefore outcompete native species.
Furthermore, nonnative species also increase the threat of disease outbreak with destructive consequences for native populations with low or no resistance to such diseases. To protect the health of original ecosystems, it is important to promote the diversity of native species over the introduction of nonnative species in urban areas.
Can be urban biodiversity protected?
With the growth of urbanization globally, cities are becoming the main force driving trends in environmental protection. Future development planners should prioritize biodiversity protection within the city as one of the most important aspects of landscape planning. This includes techniques that cherish the natural elements of an area and allow sustainable co-existence of people with native species .
In areas where original ecosystems have been nearly wiped out, biodiversity can be restored by cultivating diverse native species. Their re-introduction in an area offers multiple benefits, such as reduction of the spread of invasive species, improved resistance to diseases of an ecosystem, and increase of local biodiversity naturally and over the time.
Our endeavors to include biodiversity preservation on the list of future urban planning is the first step in tackling the problem of globally disappearing ecosystems. It is time to set our focus on our closest neighborhoods and begin their transformation into biodiversity guardians because our survival is ultimately dependent on it.