Sustainable Landscapes - Sustainable Communities, Australia
sustainable communities 32 2.4 SUSTAINABLE LANDSCAPESSustainable Landscapesthe great thing about sustainable do many things including providing practical to replace the productive capacity of the landlandscapes is that they can simultaneously solutions to reducing water use through water taken up by a new building.address aesthetics and amenity, water sensitive design and as part of a wastewater Sustainable landscape may be used tomanagement, air quality, passive design, treatment system. control salination, help take up carbon dioxideclimate modification, biodiversity habitat Sustainable landscape design is an approach and contribute to restoring and maintainingcreation and local food production. to designing and constructing the artificial biodiversity. The location of vegetation canThere are literally hundreds of definitions landscapes that surround our buildings. Ideally influence choices about building orientation:for ‘sustainable’ but the basic idea is that if these landscapes should maintain themselves a tree may shade part of a site and limit solarsomething is sustainable it can keep going and survive by being part of the natural cycles access but be an essential part of retaining soil,indefinitely. Natural systems have been of the local environment. providing habitat and creating shelter.operating successfully for millions of years. In many cases this means finding out what theNothing made by humans can do that. original local environment was like. This is often When choosing a site,Sustainable landscapes are concerned with difficult, as in our cities and even in rural areas take account of existingthe planning and design of outdoor space. It the landscape was significantly changed after vegetation for windbreaks,is important to consider the landscape as an European settlement.integral part of your home’s sustainable designs. shading and views. Sustainable landscape means putting backThe scope of design of outdoor space may much of what was in place before development.range from revegetation of a large bush block It may also mean introducing things that were Design landscaping to be experienced insideto the detailed design of small courtyard spaces not there before. and out. Sustainable landscaping can beintimately linked to a sustainable home. The employed to create shade, or to enhance orextent and type of vegetation is obviously frame views. It can be attractive to look at andimportant but sustainable landscape design can site also provide privacy from surrounding buildings. It can also supply food and help create pleasant Sustainable landscaping is about more than areas for recreation. [See: 2.2 Choosing a Site; planting Australian natives, it is about designing 2.5 Biodiversity On-site] landscapes to fit the new ecology created when buildings are constructed. It can include In recent years the definition of a sustainable food producing gardens irrigated by captured landscape has evolved to include landscape stormwater and landscaping practices like elements that are literally part of a building. Edwina Richardson Edwina Robinson permaculture. Many extensive green roofs are constructed specifically to support native and indigenous Sustainable landscaping includes such vegetation as part of a wider strategy for diverse approaches as restoring creeks where enhancing or replacing the natural biodiversityThis garden has been planted with local wetland plants development has trammeled or annihilated of a place or region. Often this kind of roofand attracts frogs, dragon flies and local birds. their previous course, or creating roof gardensThis street needs ... A pump to take An airconditioner to A device to capture A dust catcher and air filter up stormwater improve the climate carbon dioxideShade from ultraviolet radiation Wildlife habitat Something decorative? And low maintenance! This street needs trees!
2.4 SUSTAINABLE LANDSCAPES 33 sustainable communitiesgreening strategy is also geared towards Native birds and reptiles can be protected from waterproviding habitat for threatened or endangered cats by keeping the cats indoors or in purpose A house covers ground that was oncespecies. Depending on their context, function, built enclosures. productive natural landscape where rain soakedvegetation types and watering regimes, green Growing fruit and vegetables is a way of into the soil to support vegetation. Its roof canwalls can be seen as legitimate contributions reducing our ecological footprint. Most be used to capture rainwater that can then beto the creation of a sustainable landscape vegetables and fruit require fertile soils with used to irrigate new vegetation, perhaps evenand may even be integrated into wastewater good drainage, regular watering and moderate on a roof garden or balcony. Capturing watertreatment systems. [See: 5.13 Green Roofs and amounts of sunlight depending upon the this way also reduces the release of stormwaterWalls] climatic zone. Vegetable gardens can generally to the street. [See: 5.13 Green Roofs and Walls; be provided in raised garden beds with the 7.3 Rainwater]GrowinG plants addition of home made compost and well Low water-use vegetation or ‘xeriscape’ can rotted animal manures. Fruit and vegetablesSustainable landscapes use plants which greatly reduce the need for supplementary generally require regular drip irrigation.perform well in the local area. Avoid native garden watering. Indigenous species are usuallyor exotic plants that are weedy in your Lawn is a common feature in Australian the best for the low rainfall conditions found inregion. Suitable plants may include native landscapes but it generally requires high much of Australia. [See: 7.6 Outdoor Water Use]and indigenous plants, as well as exotics levels of water, fertilisers and energy to Vegetation can even take up effluent via sub-(non-Australian plants) from similar climatic maintain its appearance. These impacts can surface irrigation, especially in outer urban andzones. Plants should ideally perform well be minimised by: rural sites. [See: 7.4 Wastewater Re-use]once established on existing soils and existing > Removing lawn and replacing it with a mixrainfall patterns without the need for excessive The use of water bodies like ponds and water of groundcovers and non-woody plants andwatering, soil modification and intensive features can be integrated into a sustainable permeable surfaces such as gravel.maintenance regimes. landscape solution as part of an overall water > Reducing the extent of lawn and increasing management system and as part of the passiveWhat is the difference between ‘native’ and the area of hardy garden beds. climate response strategy for your home.‘indigenous’? In general terms, native plants areall plants from Australia. Indigenous plants are > Substituting exotic grass species with drought tolerant low maintenance nativethose specific to a particular place. lanDscape materials grasses that retain the appearance of aA sustainable garden uses a wide range of conventional lawn. Landscape materials account for much ofplants from different structural categories, such the embodied energy in a landscape project.as trees, screening shrubs, medium shrubs, Synthetic grass products are an inappropriate Consider reusing existing site materials suchlow shrubs, groundcovers, strappy plants choice for sustainable landscapes. Non-living, as pavers and excavated rocks. Employand grasses, climbers, perennials and bulbs. synthetic plant substitutes diminish, rather than recycled materials wherever possible such asStructural diversity will encourage wildlife into add to biodiversity. They are products of mining crushed brick/ concrete, recycled timber andthe landscape and prickly plants will provide and a great deal of water and energy are used products like recycled glass. Where recycledshelter for small birds. Ensure wildlife are not in their manufacture. timber is unavailable use sustainably managedcompromised by domestic pets. plantation timber or timber composite products in preference to imported rainforest timbers. Avoid excessive amounts of paving which can contribute to microclimate heating and reduced site permeability. Following the saying “only pave where you sit, stand and walk!” air In a healthy house the inside and outside are designed to work together. Sustainable landscaping helps to maintain a healthy internal and external environment. Vegetation can be used to filter air from outside whilst indoor air quality is improved by selection of appropriate plants – some are able to take toxins like formaldehyde out of the air. [See: 3.3 The Healthy Home] Vegetation can create buffers and filters for wind and dust control. Edwina Richardson Edwina RobinsonA mix of native and exotic hardy plants replace lawn at this Canberra display home.
sustainable communities 34 2.4 SUSTAINABLE LANDSCAPES restoration ecoloGY only healthy food but reduce your household’s ecological footprint. Particularly challenging sites occur where there is little ecological value or pre-existing ecology In dry regions consider creating a small mini- has been destroyed. In such cases a substantial oasis which can provide passive cooling to the contribution to creating a sustainable landscape house. Locate this area on the cooler side of can be made by restoring as much as possible the building which receives evening breezes. of the original ecosystem and increasing Incorporate moisture loving plants, a water the ecological value of the site. [See: 2.9 feature, permeable paving and water harvesting Challenging Sites] methods in this space. Such strategies are particularly pertinent to urban sites where, very often, all the indigenous MAINTENANCE vegetation has been removed for development. The movement to replace elements of original Sustainable landscapes have much smaller living landscapes now extends to the public energy and water use impacts than traditional realm. In choosing a site, consider the wider landscape designs but they still require landscape and neighbourhood environment. management. Native gardens and the use of Paul Downton Paul Downton [See: 2.2 Choosing a Site] hardy plants can create environments that consume little water other than that provided If you don’t have a large garden space or by rainfall. Even then, there is no such thing want to contribute to restoring the landscapeLook for a neighbourhood where sustainable as a maintenance-free landscape. Anythinglandscape approaches are encouraged. as part of compensating for off-site impacts, that has been artificially created for human consider participating in native landscape and purposes requires on-going maintenance and ecosystem restoration projects run by not-for- this should be factored into the overall pictureA new science of ‘biophilia’ profit organisations like Trees For Life in SA and of any home design. Men of the Trees in WA. Many tree planting and(love of nature) is developing revegetation programs are also intended tofrom the recognition that compensate for carbon emissions. [See: 1.4vegetation and natural Carbon Neutral; 5.4 Biodiversity Off-site] ADDITIONAL reADINgenvironments have a Byrne, J (2006), The Green Gardener: sustainablemeasurable impact on our gardening in your own backyard, Viking Press, Newpsychological health. York. Chadwick, D (1999), Australian Native Gardening Made Easy, Little Hills Press, Adelaide.enerGY Men of the Trees www.menofthetrees.com.auAppropriate landscaping can enhance passive Mollison, B (1988), Permaculture – A Designersheating and cooling. Used as an integral part Manual, Tagari, Sisters Creek, Tasmania.of passive design strategies, windbreaks can Edwina Richardson Edwina Robinsonreduce wind chill or the impact of hot winds. Mollison, B (1991), Introduction to Permaculture, Tagari, Sisters Creek, Tasmania.Vegetation can cool and filter air as part of apassive cooling strategy. [See: 4.2 Design for Sullivan, C (2002), Garden and Climate, McGraw-Hill,Climate; 4.4 Shading; 4.6 Passive Cooling] New York. This dry creek bed is composed of waste rockShading needs to be seasonal and is best excavated from a building site and obtained from a Sustainable Gardening Australiaprovided by deciduous plants. Australia has few local landscape supplier. www.sgaonline.org.audeciduous native trees (the Toona australis or Thompson, J and Sorvig K (2000), Sustainableso called Red Cedar is one). Other ‘deciduous’ Landscape Construction: A Guide to Green Building CLIMATE CHANGE Outdoors, Island Press, Washington DC.natives such as Brachychiton lose their leavesin summer and therefore can not moderate Consider the predicted changes for your region Thompson, P (2002), Australian Planting Design,solar penetration to suit passive design. It is and adapt your landscape accordingly. To cope Lothian Books, Port Melbourne, Victoria.best to assume that most native vegetation with increased temperatures increase shade protection to homes using trees, large shrubs Trees for Lifewill give permanent or semi-permanent shade. www.treesforlife.org.au[See: 2.5 Biodiversity On-site; 7.6 Outdoor to shade walls and climbers. Where space isWater Use] limited use shade structures with climbers to Wolverton, B (1996), Ecofriendly House Plants – 50 reduce outdoor and building temperatures. indoor plants that purify the air in homes and offices,Captured rainwater or treated wastewater Weidenfeld and Nicolson, UK. Ensure the landscape has sufficient permeablecan be used to irrigate deciduous plants that surfaces to cope with increased rainfall events. Principal Author:contribute directly to a building’s passive solar Capturing water in rainwater tanks and through Paul Downtonperformance. greywater recycling will ensure water is available Contributing Author: to sustain plants during drought periods. Edwina Robinson Edwina Richardson Organic vegetable gardens will provide not