Working with nature can help us build greener cities instead of urban slums



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Garden roofs (like these in Chengdu, in China’s Sichuan province) need maintenance and community involvement.
from shutterstock.com

Paul Osmond, UNSW

As Australian cities grow and transform, we need to ensure we are not building the slums of the future by making buildings so tall and tight they turn our streets into stark canyons. Sydney’s Wolli Creek, where buildings dominate and tower over a transport hub, is an example of where this is happening. It is now considered one of the city’s densest areas.

Dense, high buildings limit the space available for urban greenery and, unfortunately, the current development boom privileges concrete and glass over vegetation. A more strategic approach to urban growth can ensure our cities maintain adequate green space and become low-carbon, efficient and affordable.

It’s also vital the community and individuals are enthusiastic drivers of such change, with shared ownership of it. Imaginative projects – at times described as urban acupuncture – can all play a role. This is where small-scale interventions (like green balconies) are applied to transform the larger urban context, improve the environment and make the city liveable.




Read more:
Higher-density cities need greening to stay healthy and liveable


Going up or out

Whether you go up (higher) or out (more), or both, there are always challenges and opportunities.

The drawback in going out is that we start creeping into our remaining open space, including important biodiversity hotspots.

Sydney’s Wolli Creek is considered one of the city’s densest areas.
from shutterstock.com

Going out can also encroach on agricultural land. Farmers around the Sydney basin produced up to 20% of the area’s fresh food needs in 2011. But researchers have predicted urban sprawl and rising land prices will lead this to drop to 6% by 2031, losing both produce and jobs.

Going up is an approach driven by proximity to transport, utilities and employment, particularly in Sydney and Melbourne. Major upward developments, like Wolli Creek, are logically being located around transport nodes. But these then become dense and concentrated areas, putting growing pressure on open space and community facilities.

Community projects

Community consultation is key before any major project and redevelopment, as genuine dialogue supports shared ownership of the outcomes. Existing community projects must be celebrated. Having an engaged and empowered community leads to a healthier, happier population.




Read more:
No garden? Five creative ways city dwellers can still grow their own


In Sydney, new precincts like Waterloo are ambitious and have good intentions. These areas aim to deliver new homes, shops, major transport services, community facilities, parks and open spaces over the next 20 years – and they’re located close to the urban centre.

Waterloo already has three community gardens, which bring together public housing residents through growing and sharing fresh produce. This approach is important to continue and initiate new projects.

Green roofs can become community gardens.
from shutterstock.com

Around the world there have also been successes with city farming where the community grows and sells agricultural produce locally. In skyscraper Singapore, they are farming vertically at Sky Greens, providing an alternative to importing food for this densely peopled city-state.

Green roofs are another alternative where communities can grow flowers and vegetables while providing training and jobs. A good example is the Uncommon Ground rooftop farm in Chicago.




Read more:
Australian cities are lagging behind in greening up their buildings


In Australia, the Grounds is a former pie factory in the industrial heart of Sydney’s Alexandria. In 2012, the site began to metamorphose into a cafe, restaurant, bakery, organic mini-farm and more. This is a successful example of how a little greenery has turned a bleak post-industrial site into an enjoyable destination, where young and old from far and wide come to enjoy the plants, animals and coffee.

The Grounds in Sydney’s Alexandria was transformed from an industrial site into an enjoyable destination.
Herry Lawford/Flickr, CC BY

A domestic garden, a green balcony or a green wall can all play a role – but these need ongoing care and attention, which means individuals and engaged communities must drive the enthusiasm.

Nature in the city

So, for a start, let’s not build fast and furiously without grasping the place as a whole and making the most of what is already there. This means preserving mature trees and shrubs, leaving open space unpaved and protecting areas of deep soil for future planting.

Maintaining, enhancing and creating urban green space not only fulfils the requirements for urban acupuncture, but – to mix medical metaphors – provides a kind of urban vaccination against the emergence of slums, where nothing can grow and depression sets in.

The ConversationWe can combine building development with what Stefan Boeri Architects have described as “vertical densification of nature within the city” to achieve a new kind of urban nature – nature in the city to transform the nature of the city.

Paul Osmond, Senior Lecturer and Director, Sustainable Built Environment program, UNSW

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

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How tree bonds can help preserve the urban forest



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City trees don’t just look after themselves.

Joe Hurley, RMIT University; Dave Kendal, University of Tasmania; Judy Bush, University of Melbourne, and Stephen Rowley, RMIT University

Great cities need trees to be great places, but urban changes put pressure on the existing trees as cities develop. As a result, our rapidly growing cities are losing trees at a worrying rate. So how can we grow our cities and save our city trees?

Tree bonds have recently been proposed by Stonnington City Council as a way to stop trees being destroyed in Melbourne’s affluent southeastern suburbs.

Tree bonds are a common mechanism for protecting trees on public land, but have so far had limited use on private land. A tree bond requires a land developer to deposit a certain amount of money with the local authority during development. If the identified tree or trees are not present and healthy after the development, the funds are forfeited.

The size of the bond can be established based on estimated tree replacement costs, and/or set at a level that is likely to achieve compliance (likely to be thousands or tens of thousands of dollars).

Why are trees important in cities?

The concept of an “urban forest” includes all the trees and plants in cities. This includes tree-lined city streets as well as parks, waterways and private gardens. The urban forest contributes substantially to the quality of life of all urban dwellers, both human and non-human, and is increasingly used to adapt cities to climate change.




Read more:
Does higher-density city development leave urban forests out on a limb?


Trees cool the streets, filter the air and stormwater, and create a sense of place and character. They provide food and shelter for insects, birds and animals.

There is growing research evidence for the physical, mental and social health benefits of urban trees and green spaces. Many local councils such as Brimbank and Melbourne are investing substantially in tree planting to increase these benefits.

However, despite new tree planting on public land, tree canopy on private land is declining.

What can we do to protect trees?

There are a range of existing policy and land use planning measures focused on landscaping requirements for new development. Recently, the Victorian government introduced minimum mandatory garden area requirements. Some Melbourne councils, including Brimbank and Moreland, have also included planning scheme requirements for tree planting for multi-dwelling developments.

Other mechanisms for protecting urban trees on private land include heritage and environmental overlays within local planning schemes, and listings of significant trees and heritage trees.

However, penalties, monitoring and enforcement of tree protection bylaws have not kept pace with the pressures of urban change.

If penalties are insignificant relative to development profits, developers can easily absorb the costs. If monitoring is weak and removal has a good chance of going undetected, tree protection is more likely to be ignored. And if enforcement is weak, or there is a history of successful appeal or defeat of enforcement, many trees may be at risk of removal.

Even when it is successfully pursued, after-the-fact planning enforcement action is a particularly unsatisfactory recourse for tree removal. Replacement trees may take decades to match the quality of mature trees that were removed. What is needed, then, are mechanisms that prevent tree removal in the first place.

Increasing use of tree bonds

The advantage of tree bonds is that they place the onus of proof of retention on developers, rather than the onus of proof of removal on local councils. If a tree is removed, the mechanism is already in place to monitor (the developer needs to demonstrate the tree is still there) and penalise (the financial penalty is already with the enforcing body).




Read more:
Concrete jungle? We’ll have to do more than plant trees to bring wildlife back to our cities


However, tree bonds still do not guarantee tree protection. Some mechanisms used to impose tree bonds may be vulnerable to challenge. For example, historically in Victoria, the planning appeals body VCAT has struck out conditions imposing tree bonds, arguing that punitive planning enforcement measures should be used where trees are removed.

Even where bonds can be imposed and enforced, developers may still be able to demonstrate that trees are unsafe or causing infrastructure damage, and thus need to be removed. In these circumstances, it is often hard to prove otherwise once the tree has been removed.

Nurturing an urban forest

Ultimately, if a landowner is hostile to a tree on their land, that tree’s health and survival can be imperilled, whether through illegal removal, neglect, or applications for removal based on health and safety grounds. It is therefore important that building layout and design realistically allow space for trees to flourish and be valued by landowners.

The urban forest needs protecting and enhancing. This calls for a range of policy mechanisms that work together to retain mature trees, maintain adequate spacing around them, and encourage residents to value and protect the trees around their homes.

The ConversationTree bonds provide an attractive solution for local governments in the absence of a strong land use policy framework for protecting trees.

Joe Hurley, Senior Lecturer, Sustainability and Urban Planning, RMIT University; Dave Kendal, Senior Lecturer in Environmental Management, University of Tasmania; Judy Bush, Postdoctoral Research Fellow, Clean Air and Urban Landscapes Hub, University of Melbourne, and Stephen Rowley, Lecturer in Urban Planning, RMIT University

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

How urban bushland improves our health and why planners need to listen



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Diverse bushland and wetlands in urban areas contribute to the health and wellbeing of all residents.
Author provided, Author provided

Pierre Horwitz, Edith Cowan University

Urban bushland has health benefits beyond being a great place to go for a walk. It filters our air and water, helps cities avoid extremes in temperatures, and is linked to lower rates of chronic disease. The Conversation

But these and other health benefits are virtually never accounted for in local and state land development processes.

Urban planners need to consider these health benefits when making decisions about the future of our cities.

What do we mean by urban bushland?

Urban bushland ranges from a bush park of native trees, to wetlands – in fact any native vegetation characteristic of the local region. With its undisturbed soils and associated wildlife, urban bushland is more diverse than other types of green spaces in our cities, like parks. So it adds significantly to neighbourhood biodiversity.

The more unfragmented the landscape, or unaltered the bushland, the more likely it will be to retain its biodiversity. Hills, watercourses and gullies, or a mixed forest, have greater biodiversity than flat land or a plantation of trees. Landscapes that change by the season add to that diversity.

The health benefits of green spaces (and urban bushland) partly comes from this biodiversity.

In cities, health benefits work at two levels. Not only do local residents receive health benefits when they use urban green spaces, the wider urban population also feels the health effects.

Healthy locals

The closer residents live to green space, particularly if it is accessible or usable, the better they report their health.

For an individual, access to green spaces contributes in multiple ways: it reduces stress, it helps us recover from illness or injury, and our thinking abilities improve when we are more contemplative and mindful of our green surroundings.

Our health improves when we use green spaces for physical exercise. And we benefit from the social engagement involved in caring for them.

The quality of green spaces plays a role in the health benefits for locals. For example, views of diverse vegetation more effectively lowers stress compared with less-diverse vegetation.

Exposure to biodiversity from the air, water, soils, vegetation, wildlife and landscape, and all the microbes associated with them (the sort retained in uncleared bushland and wetlands) enhances our immunity. This is thought to be the key to the health benefits of nature.

Wealth and health

The relationship between health benefits and living close to urban green spaces, including urban bushland, might be interpreted as being an effect of wealth. We know wealthier people tend to live in greener suburbs and wealthier people tend to be healthier.

But many studies take wealth into account, with the weight of evidence suggesting a direct health benefit from exposure to biodiversity.

So if the health benefits are due to the urban green spaces itself (and not related to wealth), they should be spread more evenly across the population.

Perhaps the health of poorer city dwellers will improve by living near to diverse green spaces, like bushland. Failing to provide access to nature entrenches health inequalities.

Healthy city

Urban bushland provides health benefits not just for local residents but for the whole city.

Forests and woodlands clean our urban air by removing particles and absorbing carbon dioxide. This reduces premature death, acute respiratory symptoms and asthma exacerbation across the city.

A recent review highlights the host of physical health problems that are reduced in urban areas with more nature, including less heart disease, obesity and diabetes. Mental health is also improved in urban areas where people are living with more green space.

Urban bushland, like this in the Western Australian city of Joondalup, provides health benefits to locals who access it and the wider population.
Author provided

Urban bushland improves city water. Wetlands and the vegetation around them clean our water by filtering, reducing exposure to pollutants carried in groundwater or surface water run-off.

Vegetation also moderates extremes of temperature providing shade when it is hot and less exposure when it’s cold and so reduces heat- or cold-related illnesses.

Shrinking urban bushland

Where new suburbs are developed on the outskirts of cities, the end result is usually near-complete clearing. Urban bushland is replaced with smaller, fragmented, more sanitised, open and neat spaces.

These are designed for a narrower (but still important) set of usable attributes, like a bike path, lawns and a playground. But the original values of the bushland are lost. This pattern is repeated in the expanding suburbs of cities across Australia.

If some urban bushland, wetlands or other landscape assets have been retained, the pressure on them from development is relentless, as seen recently in Western Australia where a highway is due to be extended through the Beeliar Wetlands.

Planning for better planning

Planning processes need to use ways to assess what we might lose and what we might gain from clearing bushland.

This could involve asking what types of services existing bushland provide for local residents and the city in general. These will include their role in providing clean air and water, controlling floods, cycling nutrients, as well as their recreational or spiritual services.

These could be compared with services the proposed development offers. The comparison should make decision makers, and more importantly the public, better able to judge the true worth or cost of a development.

Such cost-benefit analyses are usually used somewhere in planning processes but rarely, if ever, are the values of biodiversity and ecosystem services considered, or the cost savings from health benefits of bushland.

These sorts of cost-benefit analyses can also be used to account for the health effects associated with local bushland. Such health assessments (or health impact assessments) need to be more widely used. And where land subdivision, road building and suburban housing developments are planned, health assessments may need to be compulsory to better account for the contribution of urban bushland to health.


See also tomorrow’s article on green spaces in our cities

Pierre Horwitz, Professor, School of Science, Edith Cowan University

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

Not in my backyard? How to live alongside flying-foxes in urban Australia


Justin Welbergen, Western Sydney University and Peggy Eby, UNSW Australia

The conflict between urbanites and wildlife recently developed a new battleground: the small coastal New South Wales town of Batemans Bay, where the exceptional flowering of spotted gums has attracted a huge influx of grey-headed flying-foxes from across Australia’s southeast.

In response to intense and highly publicised community concern, federal Environment Minister Greg Hunt has announced he will seek an immediate National Interest Exemption to facilitate dispersal of these bats – a move that risks undermining legal protections afforded to this and other threatened species.

Similar conflicts are occurring elsewhere in NSW, such as the Hunter region, where some unscrupulous members of the public lit a fire in a flying-fox roost at Cessnock.

With the ongoing expansion of the human urban footprint, animals are increasingly confronted with urban environments. Human encroachment into natural habitats generally negatively affects biodiversity. However, urban landscapes can present wildlife with an irresistible lure of reliable food supplies and other resources. While urban wildlife can provide a range of benefits to health and wellbeing, it can also be cause for frustration and conflict.

Urban human-wildlife conflict is a growing area of management concern and scientific research. But the research suggests that the current strategies for addressing NSW’s conflicts between humans and flying-foxes might not have the intended results.

Flying-foxes increasingly find themselves in urban areas.
Justin Welbergen

Ruling the urban roost

Australian flying-foxes are becoming more urbanised, and the noise, smell and droppings from their roosts can have huge impacts on local residents.

A fundamental problem underlying current approaches to urban roosts is a lack of understanding of the extraordinary mobility of flying-foxes. They are some of the most mobile animals in Australia, with movements that range from foraging trips of up to 120 km in a single night to long-distance nomadism covering thousands of kilometres in a single year.

Nomadic movements of an adult female grey-headed flying-fox, tracked over a period of four years and currently at Batemans Bay.
John Martin & Justin Welbergen, unpublished

While roosts can remain active for decades, they are more like backpacker hostels than stable households, housing a constantly changing clientele that comes to visit local attractions. Roosts are connected into large networks through which flying-foxes move in response to changes in local food resources.

This explains the sudden influx in places such as Batemans Bay where preferred food suddenly becomes abundant. But it also highlights the importance of a national approach to flying-fox management and conservation.

Intense local flowerings of Eucalypts, such as spotted gums, produce copious amounts of nectar and pollen, which attract large numbers of flying-foxes and other species for several weeks. When a relatively small local flying-fox population that is tolerated by its human neighbours suddenly increases tenfold, it can place severe pressure on the local community.

Despite their transient nature, these influxes are often wrongly interpreted as population explosions, leading to calls for culling. In comparison, more humane tactics – such as using loud noise or vegetation removal to disperse the flying-foxes – can seem like a more balanced response. But does dispersal actually work?

Council workers in Charters Towers, Queensland, using ‘foggers’ to disperse flying-foxes from a local roost.
Australasian Bats Society

Shifting the problem elsewhere

There is now ample evidence to show that dispersals are extremely costly and can exacerbate the very human-wildlife conflict that they aim to resolve.

Most dispersals result in the flying-foxes returning the original roost as soon as the dispersal program ends, because naïve new individuals continue to arrive from elsewhere. Overcoming this can take months or years of repeated daily dispersal.

Other dispersals result in flying-foxes establishing new roosts a few hundred metres away, typically within the same urban environment in locations that we cannot control. This risks shifting the problem to previously unaffected members of a community and to other communities nearby.

Former flying-fox roost at Boonah, Queensland, that contained thousands of flying-foxes before it was destroyed in June 2014.
Justin Welbergen

While flying-foxes are often portrayed as noisy pests, they serve our economic interest by providing irreplaceable pollination and seed-dispersal services for free. What’s more, those same bats that annoy people during the day work tirelessly at night to maintain the health of our fragmented forests and natural ecosystems.

So it is in our national interest to manage conflict at urban roosts, by using approaches that balance community concerns with environmental considerations.

Flying-foxes perform irreplaceable ecological roles in our natural environment.
Steve Parish

To be considered “successful”, a dispersal should permanently reduce conflict to a level that is acceptable to the community without causing significant harm to the animals. However, dispersals are currently implemented at the local council level with little or no monitoring of the impacts in or outside the immediately affected area. This makes it hard to assess whether they have been successful.

For example, it is not uncommon for flowering to cease and flying-fox numbers to decline naturally during the period of active dispersal. This gives the community a false sense that a permanent solution has been achieved, when in fact the issues will recur the next time the trees blossom. There is thus an urgent need for urban roosts to be managed with properly defined and applied criteria for success.

Evidence-based management

Unfortunately, lack of research effort directed at “ugly” and “less popular” Australian animals means that very few evidence-based management tools are available to deal with contentious roosts.

Research targeting a few key areas would greatly help efforts to improve urban roost management. For instance, we do not know how flying-foxes choose their roost sites, which leaves us unable to design “carrot solutions” by creating more attractive roost sites elsewhere.

Intensive tree-flowering events are relatively infrequent and hard to predict. This means that it is difficult to prepare communities for a sudden influx of flying-foxes.

Furthermore, the acceptability of various flying-fox management options differs between sections of the community, so it is difficult to find optimal solutions. Social scientists are currently trying to help identify priority areas that promote long-term viability of flying-foxes while also easing conflict with humans.

The extreme mobility of flying-foxes means that a uniform federal approach for management is needed.
Justin Welbergen/WildPhotos.org

Local, state and federal governments continue to allocate considerable funds for dispersal responses, even though such actions are high-risk activities for local communities and are unlikely to provide long-term solutions. We argue strongly that targeted research is needed to better inform land managers and affected communities of flying-fox ecology and provide them with low-cost, low-risk, evidence-based tools for dealing with urban roosts.

Flying-foxes don’t care about legislative borders, and state-based responsibility for wildlife management leads to discontinuity in approaches between jurisdictions. While flying-foxes are being monitored at the national scale, this initiative needs to be combined with a uniform federal approach for managing flying-foxes in our human landscapes. Otherwise, conflicts such as those faced by the residents of Batemans Bay will continue unabated.

The Conversation

Justin Welbergen, Senior Lecturer in Animal Ecology, Western Sydney University and Peggy Eby, Adjunct Senior Lecturer, Centre for Ecosystem Science, UNSW Australia

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

USA: Climate Change Rooftop Farmers


The link below is to an article on climate change in the USA and how urban dwellers are planting rooftop gardens in response.

For more visit:
http://tv.msnbc.com/2013/02/23/urbanites-combat-climate-change-with-rooftop-farms/