"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.

 
 
 
 

What’s up with Wakanda’s trains? On public transport in Black Panther

The Black Panther promotional poster. Image: Marvel/Disney.

Black Panther is one of the best reviewed superhero films of all time. It’s instantly become a cultural touchstone for black representation in movies, while shining a positive light on a continent almost totally ignored by Hollywood. But never mind all that – what about the trains?

The film takes place in the fictional African country of Wakanda, a small, technologically advanced nation whose power comes from its main natural resource: huge supplies of a magical metal called vibranium. As is often the case in sci-fi, “technologically advanced” here means “full of skyscrapers and trains”. In other words, perfect Citymetric territory.

Here’s a mostly spoiler-free guide to Black Panther’s urbanism and transport.

City planning

It’s to the credit of Black Panther’s crew that there’s anything to talk about here at all. Fictional cities in previous Marvel films, such as Asgard from the Thor films or Xandar from Guardians of the Galaxy, don’t feel like real places at all, but collections of random monuments joined together by unwalkably-wide and sterile open spaces.

Wakanda’s capital, the Golden City, seems to have distinct districts and suburbs with a variety of traditional and modern styles, arranged roughly how you’d expect a capital to be – skyscrapers in the centre, high-rise apartments around it, and what look like industrial buildings on its waterfront. In other words, it’s a believable city.

It’s almost a real city. Image: Marvel/Disney

We only really see one area close-up: Steptown, which according to designer Ruth Carter is the city’s hipster district. How the Golden City ended up with a bohemian area is never explained. In many cities, these formed where immigrants, artists and students arrived to take advantage of lower rents, but this seems unlikely with Wakanda’s stable economy and zero migration. Did the Golden City gentrify?

Urban transport

When we get out and about, things get a bit weirder. The narrow pedestrianised sand-paved street is crowded and lined with market stalls on both sides, yet a futuristic tram runs right down the middle. The tram’s resemblance to the chunky San Francisco BART trains is not a coincidence – director Ryan Coogler is from Oakland.

Steptown Streetcar, with a hyperloop train passing overhead. Image: Marvel/Disney.

People have to dodge around the tram, and the street is far too narrow for a second tram to pass the other way. This could be a single-track shuttle (like the former Southport Pier Tram), a one-way loop (like the Detroit People Mover) or a diversion through narrow streets (like the Dublin Luas Cross City extension). But no matter what, it’s a slow and inefficient way to get people around a major city. Hopefully there’s an underground station lurking somewhere out of shot.


Over the street runs a *shudder* hyperloop. If you’re concerned that Elon Musk’s scheme has made its way to Wakanda, don’t worry – this train bears no resemblance to Musk’s design. Rather, it’s a flying train that levitates between hoops in the open air. It travels very fast – too fast for urban transport, since it crosses a whole neighbourhood in a couple of seconds – and it doesn’t seem to have many stops, even at logical interchange points where the lines cross. Its main purpose is probably to bring people from outlying suburbs into the centre quickly.

There’s one other urban transport system seen in the film: as befitting a major riverside city, it has a ferry or waterbus system. We get a good look at the barges carrying tribal leaders to the ceremonial waterfalls, but overhead shots show other boats on the more mundane business of shuttling people up and down the river.

Transport outside the city

Unfortunately there’s less to say here. Away from the city, we only see people riding horses, following cattle-drawn sleds, or simply walking long distances. This is understandable given Wakanda’s masquerading as a developing country, but it makes the country very urban centric. Perhaps that’s why the Jabari hate the other tribes so much – poor transport investment means the only way to reach them is a narrow, winding mountain pass.

The one exception is in freight transport. Wakanda has a ridiculously developed maglev network for transporting vibranium ore. This actually follows a pattern seen in a lot of real African countries: take a look at a map of the continent and you’ll see most railways run to the coast.

Image: Bucksy/Wikimedia Commons.

These are primarily freight railways built to transport resources from mines and plantations to ports, with passenger transport an afterthought.

A high-speed maglev seems like overkill for carrying ore, especially as the film goes out of its way to point out that vibranium is too unstable to take on high-speed trains without careful safety precautions. Nevertheless, the scene where Shuri and Ross geek out about these maglevs might just be the single most relatable in any Marvel movie.

A very extravagant freight line. Image: Marvel/Disney.

Perhaps this all makes sense though. Wakanda is still an absolute monarchy, and without democratic input its king is naturally going to choose exciting hyperloop and maglev projects over boring local and regional transport links.

Here’s hoping the next Black Panther film sees T’Challa reforming Wakanda’s government, and then getting really stuck into double-track improvements to the Steptown Streetcar.

Stephen Jorgenson-Murray tweets as @stejormur.

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