Posts Tagged ‘ living roofs ’

Issue 112: Pandering to Nature

May/June – 2010
Author: Christine Paul

The much-anticipated arrival of Giant Pandas at Adelaide Zoo in South Australia called for the creation of a special eco environment, including a Giant Panda Forest. Also recently unveiled were ‘living roofs’ as well as vertical gardens adjoining the panda enclosure, which require the use of specialised hydroponic systems.

South Australia’s Adelaide Zoo is home to more than 1,800 animals and almost 300 species of exotic and native mammals, birds, reptiles and fish exhibited in over 8 hectares of magnificent botanic surroundings, the result of more than 125 years of care and attention.

The zoo is also now home to Wang Wang and Funi, two Giant Pandas, recently sent from the People’s Republic of China as part of an exchange program, whereby several zoos around the world have been selected to breed panda pairs. It is envisaged that any resulting offspring will eventually be returned to China and released back into the wild.

The arrival on 13 December 2009 of Wang Wang and Funi at Adelaide Zoo – officially welcomed by Australia’s Governor General Quentin Bryce – was the first time that pandas have been loaned to an Australian Zoo for any significant period of time.

Following a quarantine period during which they were seen behind plate-glass windows, the pandas were confined to day rooms and off-limit areas within the zoo before being introduced to their current home.

Today, Wang Wang and Funi enjoy naturally landscaped outdoor areas – each 600sqm – equipped with misting systems, mature and new trees, chilled rocks and waterfalls to ensure the pandas are content and cool over South Australia’s summer months.

Pre-panda preparation
In late 2007, the zoo launched an ambitious modernisation program, based around three major projects: a new panda enclosure, a new Entrance Precinct and a new perimeter security strategy.

In the same year, the Royal Zoological Society of South Australia appointed respected architectural group HASSELL to develop a series of comprehensive design solutions destined to service a long-term plan to establish Adelaide Zoo as a major centre of excellence for conservation and husbandry.

“The project was guided by collaboration with stakeholders and a study tour in the US to understand the specific requirements of the brief,” says HASSELL’S Senior Associate, Timothy Horton.

“It was important to create an immersive landscape experience for the pandas with a stimulating environment, including streams, trees, caves and rocks with built-in refrigeration that can be chilled to 12 degrees on hot days.

“We have placed the pandas in an Australian context, however, both the climate and enclosure reinterprets Chinese architecture and landscape design through a modern idiom,” he says.

According to a zoo spokesperson, the three projects, totalling a cost of AU$33m, represent, “a major opportunity to enhance a much-loved South Australian institution and to provide a new and significant civic space for Adelaide that both embodies the aspirations of the Royal Zoological Society of South Australia to engage with the community, and communicates the zoo’s objectives to visitors.

“The panda exhibit’s aims were to convey an understanding of both the natural habitat of the Giant Panda and the current context of research and conservation efforts, which are strongly associated with the Wolong sanctuary, a protected area located in Wenchuan County, Sichuan Province, People’s Republic of China,” he says.

Design for the Giant Panda bamboo forest incorporates best practice husbandry and a “unique visitor experience that is fully integrated with the existing exhibits and enclosures as well as the new Entrance Precinct.”

An 8-acre bamboo plantation based at a SA Water treatment plant at Bolivar provides an ongoing supply of bamboos for the Giant and Red Pandas. The plantation utilises the services of SA Water land and water as well as Work for the Dole / Volunteer groups.

The Entrance Precinct and Envirodome
To coincide with the arrival of the pandas at the zoo, upgrades to existing infrastructure elsewhere were also completed, including the Entrance Precinct, which houses a range of administrative and public functions.

Officially opened on 14 February 2010 by South Australia’s Premier, Mike Rann, the zoo’s Entrance Precinct comprises three key areas, including the entrance building, the ‘Santos’ Conservation Centre (a 110-seat theatrette with audio visual projection), and public forecourts.

“The design principles that underpin the Entrance Precinct reflect those of Zoos South Australia (ZoosSA), that is, the four key areas of conservation, education, research and environment. The entrance building is a concrete structure providing high thermal mass to reduce heat gain in summer, and to capture, store and return heat in winter. In-slab heating provides warmth in winter. Water is warmed using heat rejected from plants, and circulated through pipe-work embedded in the slab,” says Timothy Horton.

“Materials have been selected for their durability, recyclability and amount of energy used to manufacture. Australian hardwood timber has been used extensively, and has been selected from sustainable managed sources. The use of timber has minimised the use of materials with high embodied energy such as aluminium to areas such as window framing and doors. Australian Spotted Gum timber is termite-resistant, and appropriate for external use.

“In areas like the cafe and the shop, evaporative air-conditioning is used. This is a more efficient cooling system to operate than conventional refrigerated air-conditioning. In enclosed spaces, a ‘mixed mode’ air-conditioning system has been used. This allows spaces to be ventilated naturally during normal use. During days of extreme heat or peak usage, sensors regulate the windows and air-conditioning systems to adapt to the change in internal comfort. A central computer further regulates night-time natural ventilation to purge daytime heat gain,” he says.

Timothy says that one interesting aspect to HASSELL’S design for the zoo was its extensive use of green walling to showcase plant species that are indigenous to the Adelaide Plains.

“There was a need to demonstrate the zoo’s place as a significant horticultural park as well as a zoological organisation,” he says.

“A green wall, or ‘living’ wall, is a wall that is covered with vegetation, which is grown in either soil or an inorganic growing medium supported in a specially designed supporting structure.

“The green wall plantings help to reduce overall temperatures of the building, which in turn reduces energy consumption. Green walls are also a means for water reuse, with the plants purifying slightly polluted water from the underground tank by absorbing the dissolved nutrients,” Timothy says.

“Underground water tanks irrigate the green walls and green roof using water captured from the ‘Level 1’ and Conservation Centre roofs. This avoids the need for potable drinking water to be used. Collectively, the zoo project includes around 10,000 new plants, including 200 trees.”

On Level 1 of the entrance building, a dramatic sculptural stair is cantilevered from a central green wall while the ‘Long Gallery’ offers a break-out space with bar, and full height glazing overlooking the landscape forecourts, green roof planting, Botanic Park, and with distant views to the Adelaide CBD.

Housed in the old Ape Block along with the Education Centre is the Westpac Envirodome. Providing an interactive visitor experience where non-animal exhibits aim to educate visitors on conservation of the environment, the Envirodome itself has been largely recycled and has a green roof, rainwater-fed toilets, hay-bale walls and solar-panels.

Horticultural issues and challenges
During design stages of the Entrance Precinct and in other areas of the zoo, HASSELL worked closely with Curator of Horticulture for ZoosSA, Jeff Lugg.

Responsible for overseeing the design and landscaping of all exhibits and grounds, including green walls and green roofs at both Adelaide and Monarto Zoos, Jeff has been with ZoosSA for the past 21 years. He has also worked as a consultant for the past 3 years in the Middle East on exhibit design for a large UAE zoo.

Together with Allys Richardson, Jeff is also author of Botanical Guide to the Adelaide Zoo – Bush Food (2004).

In 2006 the South East Asian exhibits, housing Sumatran Tigers and Orangutans and landscaped by Jeff and his team, won state and national awards for excellence in landscaping.

“At the new Giant Panda exhibit and zoo entrance, we worked in conjunction with Amy Reed of HASSELL Architecture and Brenton Pike, Assistant Curator Horticulture, Adelaide Zoo,” says Jeff who heads a full-time horticultural staff of 12.

“Essentially, our brief for the project involved input into the exhibit and public space design and maintenance; landscaping of exhibits to create/replicate habitat; choice of vegetation, structures, water features as well as the design surrounding the gardens and grounds.

“Our role in a sense is both to enhance visitor experience and recreate a comfortable habitat for our animals,” he says.

“Adelaide Zoo is fast becoming a leader in green walls and green roofs in South Australia with a total of three green walls and five green roofs onsite. We have extensive and intensive roofs and our green walls are both internal and external.

“The decision to use green walls and roofs at Adelaide Zoo had a lot to do with the changing nature of zoos in Australia where we are seeing a trend for them to become more conservation based/orientated. We are definitely moving away from the old Victorian period style of zoos with concrete, cages and bars towards more immersive, naturalistic habitats,” Jeff notes.

“During the planning phase of the Envirodome there was a strong focus on sustainable building process and outcomes. There was also the opportunity to introduce green roof/wall technology into the zoo and to experiment with different styles to suit the many different applications.

“Our current green walls/roofs are considered fairly unique in SA. We understand that we hold 80-90% of green roofs and 100% of green walls constructed in SA at this point in time,” he says.

Inside the Envirodome is a living green wall, exhibits (including tree frogs, pythons and chameleons), a running creek bed and a marginal aquatic bog.

“Horticulturist Mark Paul and his company Ex-Parrot were contracted to do the entire installation of the green wall inside the Envirodome,” Jeff says.

“This entailed the sourcing, supplying, growing on plants, irrigation design and installation using approximately 30sqm of Australian rainforest themed vegetation.

“In our designs we have used a broad spectrum of plants ranging from tropical to arid native plants,” he says.

Total plant numbers are estimated to be about 10,000 for both walls. The plant mix used in the internal front entrance of the Envirodome includes Plectranthus aleopectus, Asplenium australasicum (Birds Nest Fern), Platycerium bifercatum (Elkhorn), Microsorium diversifolium and Microsorium scandens (Kangaroo Fern and Fragrant fern), Adiantum aethiopicum and fragrans (Maidenhair ferns).

“The trick was to get the mix right so that they could successfully co-exist,” Jeff explains.

In terms of nutrients, the spot fertiliser method was used extensively.

“We use slow release fertiliser behind the plants as well as fertigating the system through the whole wall,” he says.

An Integrated Pest Management approach
A major issue encountered in the first year of the green wall was insect attack.

“We suffered from several different species of scale and mealy bug. Traditionally, routine applications of a systemic pesticide such as Confidor (Imidacloprid) would be utilised, however, due to the wall being a habitat for several chemically sensitive reptile species, this was not an option,” Jeff says.

“Instead we were able to work with ‘Bugs for Bugs’- an Integrated Pest Management company – to identify different types of scale and provide appropriate insect predators; two different types of ladybird, lacewings and parasitic wasps.

“In conjunction with improving air circulation/ventilation we have been able to reduce infestation to an acceptable level,” he says.

Other challenges have included the issue of lighting.

“Getting a uniform degree of lux across the plants was certainly difficult as we are dealing with a curved wall so readings varied not only from the top to the base but also from the beginning, externally exposed section of the wall to those areas deeper inside,” Jeff explains.

“Prior to installation of the green wall, the lighting was installed too close to the existing wall. Thus, it is very difficult to achieve even coverage of light levels over the entire wall. Whilst the upper sections of the wall are quite lush, their growth compounds inadequate light levels towards the bottom of the wall. We hope to rectify this problem by mounting additional lighting as funding becomes available.

“Humidity was another problem as there was insufficient ventilation in some areas of the wall so we were finding increasing problems with fungus attacking the plants,” he says.

“One solution was to install louvred windows into the new entrance screen so as to achieve better airflow.”

With a bi-weekly maintenance regime for the green walls, Jeff intends that they remain healthy and attractive for visitors and residents alike.

“Initially, we had consultants in to look after the health of the plants on the walls, prune too vigorous growth and control pests and diseases, but now we have trained up our own member of staff to take over these tasks,” he says.

“It has now been 16 months since the installation of the green wall in the Envirodome and we are pleased to say that the plants are still looking healthy.

“All in all, I would say we are very pleased with the successful outcome to date with the green walls/roof project in Adelaide Zoo. It’s a fantastic outcome that the zoo is embracing technology by employing a full-time staff member, supporting trial modules and assisting with experimental design so that we are able to collect baseline data for green roofs in SA,” he says.

“It’s given us the potential to expand – now we want to strap a wall or roof to anything not moving!”

Fytogreen
Working in conjunction with Jeff Lugg and his team to create two vertical gardens and green roofs at Adelaide Zoo were Fytogreen Australia.

Established in 2002 by Managing Director Geoff Heard, Fytogreen was originally a daughter company of the Dutch parent Fytogreen BV, a subsidiary of Verheijen Resins. Today, it is 100% Australian owned.

Fytogreen manufactures a urea melamine formaldehyde resin that is blown into a hard foam substrate to suit specific uses, including Fytocell (neutralised foam flakes and solid foam slabs for specialised hydroponic culture) and Fytowall (neutralised, biodegradable foam slabs, wrapped and placed in frames for vertical gardens and modular turf).

Supported by a hydroponic watering system, the Fytowall garden panels are attached to a vertical surface such as a wall, fence or balcony.

At the time of installation the plants are already pre-grown and trained for vertical growing, creating an instant established visual display.

“Fytogreen has installed over 900sqm of vertical gardens in Australia”, says Fytogreen’s Stuart Tyler.

Installations have been in both private and public spaces, including The Marriott Hotel Sydney, Miele Showroom, Eaglefarm Qld, Vic Harbour’s-ANZ Docklands building, and Assumption College at Kilmore in Victoria.

“Fytowall is designed to be sustainable, water-efficient and robust in all growing conditions,” Stuart says.

“For the Adelaide Zoo project, which is 97sqm outdoor and 110sqm indoor Fytowalls, we worked with the main contractor and builder, Hindmarsh. The plants were selected and the array designed by HASSELL Architecture SA. The Fytowall was pre-grown off site at our nursery for 20 weeks prior to installation.

“Many different species create an ecosystem of large biodiversity. Some of the species of outdoor plants chosen were Lomandra Savanna Blue, Lomandra Wingarra, Enchlaena tomentosa and Dianella Tas Red. The indoor wall has a mixture of about 15 species of ferns, ground covers and flowering, low light species.”

Stuart says that Fytogreen was originally favoured for the zoo project because of the biodegradability of their product.

“Before we got into doing vertical gardens we talked with many owners to see what issues were involved and what they really wanted to see being offered. What we learned was that two key issues of concern for them were water and sustainability,” he says.

“Fytowall offers unique advantages in that it is a lightweight, environmentally friendly hydroponic growing media that has the unique ability to ‘wick’ water upwards. The foam has a balanced water- and air-holding ratio and saturation is reached when water is at 63% of its volume, leaving 37% air available.

“At the vertical gardens in the zoo, generally, irrigation is on for about 10 minutes per day and is not recycled as only a small amount is leaked below,” he says.

Another interesting feature of the hydroponic system is that it is automated with sensors and alarms that send alerts to maintenance crew mobiles for any system failure.

“All vertical gardens require maintenance with regular inspections and monitoring. Pruning, weeding and pest control are all managed in a maintenance program,” Stuart adds.

“We started our training for the Adelaide Zoo’s vertical garden before installation with maintenance specialist, Danni Shallow. Danni, who has an excellent understanding of vertical gardens, will then take over.”

Studies show that efficient green walls or vertical gardens can provide a 3° to 5°C insulating factor, which can assist in reducing the urban heat island effect common in built-up areas.

Additionally, research has found plants and their growing medium have removed significant amounts of VOCs (Volatile Organic Compounds) from indoor air.

“The environmental benefits of vertical gardens are many,” agrees Stuart Tyler.

”Vertical gardens, while being environmentally friendly, also create a wow factor.”

The new vertical gardens at Adelaide Zoo are clearly helping to blur the line between garden and building. The environmental benefit of more green space is also a prized bonus.

For more information about Adelaide Zoo, go to:
www.adelaidezoo.com.au

For more information about Fytogreen Australia, go to: www.fytogreen.com.au

About the author
Christine Paul is a Sydney-based journalist with a special interest in the environment and sustainable technology.
Email:
scribes_inc@hotmail.com

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