"The urban ecosystem": How should we design cities to make the most of green space?

Lungs of New York: Central Park in 2010. Image: Gryffindor/Wikimedia Commons.

Back in 1839, public health expert J F Murray published his article The Lungs of London, in Blackwood’s Edinburgh Magazine. Even then, city dwellers appreciated the advantages of open, green spaces. Murray described the benefits of the parks of London as “great vehicles of exercise, fresh air, health, and life to the myriads that congregate in the great metropolis”.

Living in cities offers numerous advantages in terms of employment, education, healthcare and social communication, among others. But urban living also comes with its challenges: in particular, urban environments can put a strain on mental and physical health, because they tend to be noisy, polluted, overcrowded and hot.

Ecologists are increasingly turning their attention to urban areas, in an effort to find solutions to these problems. Their work is beginning to show us how cities can be designed to accommodate all the advantages – and minimise the disadvantages – of urban living.


Specifically, urban ecologists are considering how we can enhance “ecosystem services” for those living and working in cities. It is now widely recognised that ecosystems – including urban ecosystems such as parks, protected areas and waterways – provide essential services for people. Temperature regulation, air purification, noise reduction, human well-being, carbon storage (both above and below ground), water infiltration, agricultural production, pollination, and pest control – all of these are examples of the services that urban ecosystems can provide.

Of course, besides services there are also so-called disservices, such as noise pollution and high temperatures, that can be associated with open spaces. For instance, some people find that the dawn chorus of birds in spring affects their sleep patterns; or that they suffer from hayfever when there are high pollen counts.

But now, armed with an understanding of ecosystems and the services they provide, ecologists are able to shine some light on a central question in urban planning: should cities be designed so that intensive and extremely compact urbanisation sits alongside separate, large, continuous green spaces – an approach known as “land-sparing”? Or, is it better to adopt “land-sharing”, where compact green spaces are scattered throughout the urban sprawl?

Sharing or sparing?

A recent study by researchers from the University of Exeter and Hokkaido University, Japan, found that land-sparing is the most effective approach to maintain the majority of ecosystem services. But they also recognise that some degree of land-sharing is important, especially when it comes to the ecosystem services that benefit our well-being.

 

A bit of both. Image: Lawrence OP/Flickr, CC BY-NC-ND.

Being near high-quality green space can provide important health benefits, as well as “cultural ecosystem services”, such as places for recreation, spiritual and religious enrichment, education, cultural heritage, inspiration, social gatherings, and cultural diversity. If a city is to provide these services, it needs to be designed so that people can quickly and easily access green spaces as part of their everyday activities.

The authors of the study concluded that the best way to ensure the optimum distribution of development and green space is to take a top-down, policy-led approach. Changing the design of a city is no easy matter, but we know from experience that it can be done.

As far back as 1809, architect John Nash began work on Regent’s Park in London, where much of his input can still be seen today. In 1858, Frederick Olmsted won the competition to design Central Park in the heart of New York. And in the 1870s, Baron Haussmann – who was charged with redesigning Paris – wanted to join the Bois de Boulonge with the Bois de Vincennes to make a green belt around the city.

These are all perfect examples of land-sparing – but it is worth noting that these green spaces were established when the cities were already in the process of being redesigned.

Berlin's Tempelhof Park in May 2010. Image: Times/Wikimedia Commons, CC BY-NC-SA.

A more recent example of land-sparing is the 300 hectare Tempelhof Airport in Berlin. The site was earmarked for development, but the public voted to retain it as a large, open, green space in May 2014. Ingo Gräning, of the state-run Tempelhof Project stated: “No other city would treat itself to such a crown jewel [of open space]”.

Of course, not all cities have enough available land to “treat” themselves in this way. In densely-built cities like Hong Kong, the opportunity to create large open spaces may never arise. Berlin is an exception – many cities do not have the option of dropping a large park into a built-up area, and in most cases it is not feasible to combine lots of small parks and gardens into a large green area. A lot depends on the history of a city and its geography, and land-sparing is not an option for every location.


Ebenezer Howard – the first modern urban planner theorist – recognised this, when he initiated the Garden City movement in 1898. His aim was to bring the advantages of nature to city dwellers, by introducing compact green areas and small parks into cities. The first examples of Howard’s organised land-sharing can still be seen today, in the UK towns of Letchworth and Welwyn.

So when asking ourselves which approach is best, there is no straightforward answer. Whether land-sparing or land-sharing is most effective will depend on the context; factors such as the shape of the land and the existing developments in the area will all play a part.

But there is no doubt that cities benefit from the services offered by urban ecosystems, and both land-sparing and land-sharing are important means of providing these advantages.The Conversation

Philip James is professor of ecology, University of Salford

This article was originally published on The Conversation. Read the original article.

 
 
 
 

Ottawa-Gatineau, the national capital which language differences nearly split into two countries

The Canadian parliament, Ottawa.

There are many single urban areas with multiple, competing local identities: from the rivalry of Newcastle and Sunderland in Tyne & Wear, to the Wolverhampton residents who resolutely deny that they are part of Birmingham, despite being in the same urban conurbation and sharing a mayor.

However, no division is quite as stark as that of the Ottawa-Gatineau metropolitan area in Canada. Often referred to as the National Capital Region, Ottawa and Gatineau lie directly opposite each other on either side of the Ottawa River, a hundred miles from Montreal, the nearest other significant population centre. Because the conurbation straddles a provincial boundary, the two cities literally speak a different language, with Ottawa in predominantly Anglophone Ontario and Gatineau in Francophone Quebec.

This is reflected in their populations. According to the 2011 census, French was the mother tongue of 77 per cent of those in Gatineau, a percentage maintained by policies intended to keep French as Quebec’s dominant language. Similarly, although Ottawa provides some bilingual services, 68 per cent of its residents are predominantly Anglophone; Franco-Ontarians frequently complain that the city is not officially bilingual.

Although there are similar divided cities, such as the Cypriot capital of Nicosia, Ottawa-Gatineau is unique in that the city was not divided by a war or major political event: its two halves have been part of the same political territory since the British defeated the French in the Battle of the Plains of Abraham in 1759, before either of the cities were even established. Indeed, the oldest part of Gatineau is actually an Anglophone settlement with the name of Hull (it was merged into the Gatineau municipality in 2002).


Today, the two cities facing each other across the Ottawa river have separate services, and elect difference mayors to run them: OC Transpo serves Ottawa, the Société de Transport de l’Outaouais (STO) serves  Gatineau, and few tickets are transferrable between the two systems.

OC Transpo is currently constructing a light rail system to many parts of Ottawa; but proposals to expand the route into Gatineau, or to merge the two transport systems have been fraught with obstacles. The City of Ottawa owns a disused railway bridge, connecting the two cities, but arguments about funding and political differences have so far prevented it from being used as part of the light rail extension project.

The divisions between Ottawa and Gatineau are made all the more unusual by the fact that Ottawa is the federal capital of Canada – a country where bilingualism is entrenched in the Charter of Rights & Freedom as a bedrock principle of the Canadian constitution. As a result, while all proceedings within the Canadian legislature are bilingual, this principle of bilingualism is not reflected on the streets surrounding the building.

The inevitable map. Image: Google.

These linguistic, as well as political, differences have been a long-running theme in Canadian politics. Quebec held independence referendums in both 1980 and 1995; in the latter, the separatists were defeated by a margin of less than 0.6 per cent. Quebecois independence would be made all the more humiliating for Canada by the fact it would be losing the Canadian Museum of History in Gatineau, while its parliament was forced to look out across the river at its new neighbours.

While Quebec as a whole only narrowly rejected independence in 1995, 72 per cent of Gatineau residents voted against the separatist proposal. The presence of many federal employees living in the city, who commute to Ottawa, meant that the city was rather unenthusiastic about the prospect of independence.

So, with Quebec nationalism currently at a low ebb, Gatineau seems set to remain a part of Canada – albeit while retaining its independent from the other half of its conurbation, across the river. While recent challenges such as flooding may have been better tackled by a unitary authority, the National Capital Region seems set to remain a tale of two cities.

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