Urbanization is the increasing pattern over time of people moving from rural towards urban areas. It involves the development and growth of towns and cities, in response to the population growth that reside and accumulate within such areas. Studies show that urbanization will increase by 64% in the developing nations and 86% in the developed nations by 2050. United Nations says that much of this will happen in Africa and Asia, largely transforming the society, economy and the environment. If this is the case, we need to focus our attention on urbanization, biodiversity and conservation.
In Japan, the most populated area is Tokyo. Consequently, it’s also the most populated city around the world, having 37.8 million residents within its 13,500 km2 land area. It also has the largest urban economy of US$1.9 trillion.
Metro Manila, Philippines ranks fourth as the world’s most urbanized area. About 24 million Filipinos compete in the 1,580 km2 land area of the city. It has a Gross Domestic Product of US$3,791, being the highest in the country.
New York City, USA is the 9th largest city around the world. There are 8.6 million people living in its 790 km2 land area. Its Gross Metropolitan Product ranks first in the country, having reached US$1.39 trillion.
Pros and Cons of Urbanization
Economic growth, as a result of productivity of the working population, accelerates urbanization. As this population also increases in number, they occupy more space, requiring the expansion of land area in the city. Sometimes it’s a reverse process. Nevertheless, such need demands more land conversions and, disturbance of natural habitats.
Here’s an infographic that simplifies this complex process.
Land conversions and constructions of urban infrastructures all have their own ways of altering the environment and the natural state of biodiversity. Correspondingly, they also cause most pollution around us, be it air, water, noise, land, etc. They also radiate heat from all the lights, electricity, buildings, asphalt roads used as urban structures. It’s where “heat islands” came into the concept.
1) Paucity of aquatic invertebrates
Researchers explored on the impacts of artificial seawall in Sydney Harbour in Australia to the intertidal inhabitants such as gastropods (snails), bivalves, ascidians (sea squirts), sea anemones, algae, whelks, starfish, platyhelminths (flatworms), sea urchins and many more. They took samplings at 4 different locations with sandstone rocky shore that were relatively undisturbed and found adjacent to the seawall made of quarried sandstone blocks. They studied the animal assemblages distinct of low-shore and mid-shore and, established 100 quadrats in each area.
There was a high diversity of species found. However, distribution patterns of species were obvious. Across habitats, it was typical to find algae and sessile (non-moving) animals. However, 50% of mobile animals, like grazing gastropods, opisthobranchs (sea slugs), sea urchins, limpets were not found on seawalls. Rare species were only found on rocky shores. It was typical that species are fewer in seawalls than the rocky shores.
It was suggested that the lack of microhabitats in the seawalls, such as rock pools, deep crevices, thick algal cover, caused the decrease in the number of the animals. The study concludes that the features of the seawall structure itself don’t support the habitat requirements of the mobile intertidal species. However, since a myriad of intertidal seawalls are being constructed, it is suggested that they be built similar to the natural intertidal habitats that support the lives of invertebrate assemblages. The structures could be added with cavities so they can retain water and constructed with gentler slopes.
2) Vanishing birds and plants
Organisms’ response to urbanization was investigated in Swiss Plateau, Switzerland by looking at the specific characteristics of birds and plant species assemblages such as the degree of specialization they have in use of resources, mobility and abundance. They observed these attributes in various spatial scales.
The results clearly showed that urbanization influences species’ responses. And those species that are more mobile and have very specific requirements (called “highly mobile specialist”) are the ones that were negatively impacted the most. They are endangered by urbanization based on how much specialized these living things are, their mobility and interaction.
Scientist have observed 2 kinds of trends: 1) Plants demonstrated the effects of urbanization through their divergence response. Species that were highly mobile and have narrow habitat range survived. 2) Birds and butterflies showed decline of the number of highly mobile specialist species. Their response was trait convergence.
Overall, it was found out that the organisms that tend to be affected to a higher degree by urbanization are the mobile species. Those that have wider spatial distribution are the most threatened. It is recommended to take into consideration the ecological aspects and wide range of spatial scales in assessments of urbanization’s impact on biodiversity.
3) Increasing human pressure induces biodiversity loss in marine intertidal reefs
Coast of Brazil
Different anthropogenic (human-related) pressures were taken into account and related to a marine intertidal community in tropical South Atlantic coast.
A negative trend of increasing anthropogenic pressure and decreasing species richness was found. This is because of the myriad of human activities done within the area. Examples are the many jetties built to control erosion, building constructions, commercialization of beachfronts, ongoing fish markets and establishments of storm sewers that have illegal sewage attachments.
It seems that the solution for all these problems that were perpetrated by urbanization is, a more effective monitoring and implementation of conservation-related policies in coastal areas and, having robust plans for infrastructure. The coast of Brazil is known to provide good resources that help the economic needs of the locals. However, it is also a vulnerable marine habitat that may respond to unwanted biodiversity loss in the long run. Scientists say that major biodiversity changes have already begun in the Western Mediterranean coast. While there’s still time, the human pressure in this area must be addressed immediately.
Waitemata Harbour, Auckland, New Zealand
In another study in the Waitemata Harbour in Auckland, a similar trend was observed. There is a decreasing number of species in sites that have an increasing number of disturbances. Anthropogenic disturbance was represented by the number of resource consents issued within the inner harbour. These resource consents refer to the discharges released to the harbour. Using data collected from a comprehensive biodiversity survey conducted in Auckland, intertidal species were identified from hard shores that were nearby sites where resource consents were approved. Results were consistent to the species decline trend with urbanization.
Urban Trends, a.k.a. Impacts of Urbanization
Elmqvist, T. et al. discuss the five trends that affect biodiversity and ecosystem services in a recent publication about urbanization. Five major trends were described. Here are the details.
5 Major Urban Trends of Urbanization
1. The physical space occupied by urban areas tends to expand faster than urban populations. As both increase, more land where cities will be built, must be secured to prepare for supply of urban consumption. Those in urban areas that show a decline in population and economic activities, can be viewed as opportunities for vegetation and demands for rebuilding of urban space.
2. It is recognized that urban areas create heat islands that change local and regional climate and, affects net primary production, ecosystem and biodiversity.
3. Water, timber and energy will be consumed as urban areas expand. In addition, agricultural lands will be used up and will affect habitats, biodiversity and ecosystem.
4. The expansion of urban areas occurs rapidly at locations adjacent to biodiversity hotspots. This is even faster in low elevated areas like the coastal zones that have high biodiversity.
5. Most urban expansions in the near future are directed towards areas that have low economic development and less institutional capacity. This implies that there will be limited efforts on biodiversity protection and conservation.
Importance of Biodiversity Conservation
We now face the days where we need to accept the fact that urbanization is happening in a faster rate and causing global ecological change. We have to admit that our ecological studies must be paired synchronous to urbanization. We are in a dire need of addressing them together, if we want to move towards biodiversity conservation. The urban population still rely heavily on our natural resources for water, food and ecosystem services. This should drive most urban dwellers to be more active and responsible in biodiversity conservation and protection. If all else fail in biodiversity, the urban areas won’t be able to maintain sustainability, and it will cause disruptive maintenance of the urban lifestyle.
Perhaps we need to remind ourselves and go back to reconnecting our modern lives to the simplicity that nature provides. We need to understand that ecological sustainability is a critical foundation of urbanization. We may have reached good progress in urban ecosystem studies over the last years. However, there’s still much to work on our understanding of urban dynamics. Specifically, we need to know more about interactions in multiple scales, feedbacks, tradeoffs and synergies between specific and general resilience (Cumming et al. 2013 in Elmqvist T. et al. 2014).
It is recognized that we need to put our minds on urban sustainability and resilience, and policies that support them. We must be engaged in collaborating with a global system of cities. We need to adopt such type of system that will enable us to manage our resources, for sustainability and resilience. Being resilient-minded will equip us to overcome challenges akin to rapid urbanization and climate change
The Truth About Urbanization
The increasing human population, the daily endeavor for economic development and technological advancements, the striving for global competitiveness have caused negative impacts on biodiversity. They have altered the habitats that support biodiversity ultimately perpetrating the extinction of many species. It has done greater damages in a more rapid rate compared with any other causes of biodiversity disturbances in the last 50 years.
The Hope of Positive Change
How do we respond to our crisis? Let’s help in minimizing the negative impacts to biodiversity by doing our part. Urbanization, biodiversity and conservation may sound conflicting. But in times like this, we need to think differently and be solution-oriented. In our own small ways, we can be responsible with our garbage disposal, recycling, doing our best to not add up more carbon to the atmosphere by using clean energy sources, not advocating products related to illegal wildlife trade, plant more trees, live simple as much as possible, use LED bulbs, conserve water, renew our appreciation of nature by going outdoors and visiting natural parks and much more. As a parting suggestion, but certainly not the last and least, we need to be involved and actively participate about how we can help, within our communities and social reach. Biodiversity protection is a “group work”. Let’s join the group.