Urban Forest Plans in the Spotlight

Citygreen - Urban forest plans in the spotlight

Urban Forest Plans in the Spotlight:

The City of Perth in Western Australia is developing an Urban Forest Plan to answer the continued threat of climate change.

Perth Lord Mayor Lisa Scaffidi told PSnews Online that trees in the CBD provide shade and beauty as well as important environmental benefits. Perth’s urban forest includes trees and vegetation in public and private areas.

“Cities are particularly vulnerable to increased temperatures because of solar radiation from impervious surfaces such as buildings, roads and footpaths which can create urban heat islands in some areas,” Scaffidi told PSnews Online.

“These increased temperatures have the potential to effect adversely the liveability of our city. It is important to mitigate the urban heath island effect by cooling our public spaces.”

The plan will focus on increasing canopy cover in public areas, replacing old trees, and protecting the existing trees and landscapes. So far, there are 6,900 street trees in the city, excluding the ones on Kings Park and the city’s 26 parks and reserves.

“Perth is regarded as a ‘green city’ but we are also a growing city, so it’s vital that we grow even greener,” Scaffidi told PSnews Online.

Meanwhile, in San Francisco, the city’s efficiency in maintaining its urban forest has been questioned after a fallen branch recently injured a pedestrian. Rachel Gordon, director of communications and policy at San Francisco Public Works, told The San Francisco Appeal that with only 10 full time arborists, it is hard to maintain the thousands of trees that are overdue for pruning.

The budget cuts to the urban forestry staff means that trees are being pruned once every 10 to 12 years instead of one to five years. The San Francisco Public Works have been trying to offload the maintenance responsibility of most of the 105,000 street trees to private property owners in the last couple of years.

However, Gordon says that there are property owners who refuse to care for the trees because of the cost. Public Works needs around $20 million annually to maintain a better pruning cycle.

Dan Flanagan, executive director of Friends of the Urban Forest, said in a statement that there should be a dedicated funding stream for street tree maintenance like in other cities.

Gordon agrees saying that the trees need to be professionally pruned, not by property owners, especially those that are 60 feet tall or are very old. At the moment, the funding for an arborist apprenticeship program at Public Works has bee approved. This will allow eight full time paid apprentices to join the current team.

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Green Spaces not Enough for Biodiversity

Citygreen - Green Spaces not Enough for Biodiversity

As much as green spaces in urban areas are important, this may not be enough to ensure biodiversity in cities, according to a study by the University of Iowa.


The Future of Urban Water

Citygreen - The Future of Urban Water

The Future of Urban Water:

What would the state of urban water be in the next couple of years?

Well, the report The Future of Urban Water: Scenarios for Urban Water Utilities in 2040 by ARUP explores trends and future scenarios for the future of urban water utilities in 2040. It is the result of a jointly funded collaboration between Arup and Sydney Water.

“The programme has helped us gain a better understanding of possible pathways into the future, including implications for future infrastructure, governance and customer experiences.”

It depicts four plausible scenarios for the future of urban water utilities in 2040, using Sydney as a reference city. The report explores how a wide range of social, technological, economic, environmental and political trends could shape the urban water future.

The World Economic Forum’s Global Risks 2014 report said water crises is one of the top five global risks posing the highest concern. “Despite this, water issues are often overlooked or misunderstood, and there is a need for better awareness of their social, economic and environmental impacts.”

The Arup report said aside from the increasing water scarcity and pollution, rapid population growth and urbanisation are “major factors posing fundamental challenges to the global water cycle, with a particular pressure on the urban water supply”.

Australia utilises over 50 percent of its water consumption for agricultural purposes. The rest is for household, industrial and commercial use. But in urban areas, “the main driver for demand remains the population, and thus population growth”.

One of the key drivers for water conservation is smart infrastructure. It responds intelligently to changes in its environment to improve performance. “It is estimated that the market size for smart grid technologies will almost triple by 2030. Smart water networks could save the industry US$12.5 billion a year.”

Another is the change to a more digital lifestyle where people will be able to monitor the consumption and cost of water in real time. “More awareness of the issues could lead to increased scrutiny of water utilities and pricing of services. The availability of data provides an opportunity to educate customers about consumption and managing resource use.”

The report also mentioned new solutions for water supply such as the extensive use of desalination. About 96 percent of the earth’s total water supply is found in oceans. “Worldwide, desalination plants are producing over 32 million cubic metres of fresh water per day. However, energy costs are currently the principal barrier to its greater use.”

Finally, the report also said green infrastructure is part of the plan. “Benefits of increased green infrastructure include the reduction of flood risk, improved health and wellbeing as well as providing a habitat for wildlife. Extensive green networks can be formed over time to create an encompassing city ecosystem that can support the sustainable movement of people, rebuild biodiversity and provide substantial climate change adaptation.”

For more of the report, you can check this out.

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The Economic Benefits of Green Buildings

Citygreen - The Economic Benefits of Green Buildings

The Economic Benefits of Green Buildings:

The World Green Building Council has released a report reviewing the costs and benefits for developers, investors and occupants for turning buildings green.

The report called “The Business Case for Green Building” provides insight into different case studies of green buildings around the world. It said that there is an increasingly compelling business case for green buildings.

“The evidence presented highlights that sustainable buildings make clear business sense – it’s not just about saving the planet. These benefits range from risk mitigation across a building portfolio and a citywide economic benefits, to the improved health and well-being of individual building occupants,” the report said.

Also, green buildings nowadays can now be delivered at a price that’s comparable to those for conventional buildings. “These costs can be recouped through operational costs savings and, with the right design features, through a more productive workplace. Design decisions made at the start of a project will impact the long-term value of the building and its return on investment.”

Aside from that, studies around the world show that green buildings attract tenants more easily and command higher sale and rent prices.

“In markets where green has become more mainstream, there are indications of emerging ‘brown discounts’ where buildings that are not green may rent or sell for less.”

However, the report said that in order to effectively transform the global marketplace, there is a need for more data and for even more case studies from all over the world.

Businesses can partner with each other or with academia and government to better understand the financial implications of a green building.

“What is clear is that there is a mounting evidence that in many markets across the world, part of being a better quality building means being a green building. In premium markets in particular, green is increasingly expected by tenants and owners – it is just part of what good ‘quality’ means,” the report said.

Rick Fedrizzi, Chairman of World GBC, said that the report “confirms yet again that when environmental strategies – along with program management – are integrated into the development process from the beginning of a building’s life cycle, green buildings save energy, save water, save precious resources and most importantly save money”.

The report highlights the best business case evidence available today for green buildings. It also shows how governments can leverage green building policies to support local economies and meet their long-term goals.

“With this foundation, we call on the private and public sectors to use their collective knowledge and strength to move the green building agenda forward, knowing that it benefits people and the environment – and their bottom lines.”

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Poorer Urban Areas Suffer Worse Heat

Citygreen - Poorer urban areas suffer worse heat

Poorer Urban Areas Suffer Worse Heat:

A recent study in New York community districts and United Hospital Fund neighbourhoods shows that there is a higher rate of heat-related mortality in poorer areas.

According to an article in the Harvard Gazette, there were higher heat related deaths in southern and western Bronx, central Brooklyn, northern Manhattan, and the eastern side of midtown.

The poorer residents mainly occupy these smaller heat islands. The study showed a strong correlation between excess deaths and poverty, poor housing quality, hypertension, and impervious land cover.

“It is known that there is an unequal distribution of risk from climate change around the world,” Joyce Klein Rosenthal, an assistance professor of urban design, told the Gazette. “What’s less known is that there is a significant variability of risks from climate change and extreme events within American cities, related to poverty and conditions in the built environment.”

She added that it is very important to recognise that “designers, architects, and urban planners have the capacity and agency to improve urban conditions”. Rosenthal said that by understanding vulnerability within cities, there is a better chance to implement more “effective adaptive strategies with communities”.

Several cities have already started ways to ease the heat for the most vulnerable of residents through “longstanding programs to distribute fans and air-conditioners and open cooling centres on the hottest days”.

“Studies like this provide health outcome-related evidence supporting adaptive interventions. We have health disparities in the spatial distribution of excess mortality of seniors during heat events. The types of characteristics we found to be associated [with that mortality] are within the collective ability of municipalities to intervene,” Rosenthal told the Gazette.

She said that heat, like ground-level ozone, is an environmental stressor, “unevenly distributed in places where there are less trees, less green space, and associated with poorer housing quality”.

According to the study, income levels are associated with surface temperatures. It showed that poorer neighbourhoods are hotter while wealthier neighbourhoods are cooler.

“Urban design strategies can make a difference in reducing urban micro-heat islands,” Rosenthal said.

She added that if the aging population, hotter climate, and lack of affordable housing are not addressed, it may constitute a “perfect storm for future heat wave deaths”.

Rosenthal said the study proves that greening a neighbourhood should be taken seriously. “The disciplines of the built environment – urban planning, architecture, landscape architecture, and urban design – have the knowledge and responsibility to make a difference.”

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Nature Trails Detrimental to Urban Forests

Citygreen - Nature Trails Detrimental to Urban Forests

Nature Trails Detrimental to Urban Forests:

Being close to nature has its downside that is detrimental to the environment, according to a latest study by scientists from Curtin University and Griffith University.

Remnant urban forests are popular sites for recreational activities like hiking, biking, and motorised recreation. However, the study said this could result in the “formation of extensive trail networks, fragmenting vegetation into patches separated by modified edge effects and ultimately contributing to the degradation of the ecosystem as a whole”.

The study used a Geographic Information System (GIS) approach to assess the extent and diversity of trail-based fragmentation across 17 remnants of endangered urban forest in southeast Queensland, Australia (a total area of 829 hectares).

The study mapped out 14 different trail types totaling 46.1km of informal biking and hiking. More than 47 hectares or 5.7 percent of forest have been lost to trails and their edge effect, nearly equal to the area recently cleared for urban development.

“The degree of fragmentation in some remnants was in the same order of magnitude as found for some of the most popular nature-based recreation sites in the world. In localised areas, the fragmentation was particularly severe as a result of wide trails used by motorised recreation, but these trails were generally uncommon across the landscape (five percent). Spatial regression revealed that the number of access points per remnant was positively correlated with the degree of fragmentation,” the study said.

An article by Science Network Western Australia said experts from both universities and co-authors, Mark Ballantyne, Dr Ori Gudes and Professor Catherine Pickering, found these forest area trails result in changes to soil microbiology, compaction, erosion, the introduction of weeds and pathogens and wildlife disturbance.

“[All trail types] have an environmental impact. Each one has its own communities of animals and plants that rely on that area to live in. However, overall I fell the largest loss would be stress as they have a very limited trunk area and a large canopy, so for every tiny bit of trunk removed a large canopy [is also removed] so they’re not proportional,” Ballantyne told Science Network.

He added that the lack of planning plus the informal trails coming from tourists and park-goers leads to “networks of damaging trails that need to be structured and maintained for effectiveness”.

“We encourage more landscape-scale research into trail-based fragmentation due to its capacity to impact extensive areas of endangered ecosystems. Management should seek to minimise the creation of informal trails by hardening popular routes, instigating stakeholder collaboration and centralising visitor flow,” the study said.

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Helping Trees by Drinking Beer

Image from Friends of Grand Rapids Parks.


Tech Companies Help with Greening San Francisco

Citygreen - Tech Companies Help with Greening San Francisco

Image from UberConference.


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