ctbuh.org/papers Title: A “Flight Manual” for Air Plants Authors: Stuart Jones, Technical Director, Hyder Consulting Grant Harris, Principal, Ironbark Environmental Arboriculture Subject: Sustainability/Green/Energy Keywords: Green Roofs Green Walls Publication Date: 2015 Original Publication: CTBUH Journal, 2015 Issue III Paper Type: 1. Book chapter/Part chapter 2. Journal paper 3. Conference proceeding 4. Unpublished conference paper 5. Magazine article 6. Unpublished © Council on Tall Buildings and Urban Habitat / Lloyd Godman; Stuart Jones; Grant Harris Sustainability/Green/Energy A “Flight Manual” for Air Plants The green fabric that clothes the earth is fraying. Sadly, through overuse, the garment we depend upon is wearing out. The construction of buildings and urban infrastructure like roads and car parks become “dead pixels” in the living image of the planet. Repairing the old garment by stitching plants into the structures of our cities is a vital option. Incorporating plants into tall building design is an important aspect of this restoration project. This paper describes Lloyd Godman Stuart Jones the successful installation of plants on the exterior of Melbourne’s iconic Eureka Tower (see Figure 1) and provides an example of a selective vertical gardening system with a high Environmentally Sustainable Development (ESD) factor, which eliminates the requirement for plant growth substrate. The Importance of Vertical Gardens years. The urbane tall buildings we now see may quickly become historic symbols of a past From simple organisms, evolving through age, when architecture was less connected to Grant Harris millions of years to complex biological systems, nature. vegetation has obeyed its innate compulsion Authors to cover the planet with a living green Lloyd Godman, Ecological Artist membrane that supports all other life. Plants Vertical Garden Systems 90 Shaftesbury Ave., St. Andrews VIC 3761, Australia have waxed and waned in their fight to cover t: +61 44818 8899 geological surface since the Ordovician period Utilizing living plants as an effective façade e: [email protected] www.lloydgodman.net (495 million years ago), and as we progress poses many problems. Unlike metals, glass and through our current era, the Anthropocene, it is concrete, which are inert, plants require Stuart Jones, Technical Director Hyder Consulting evident that human actions are the primary nurturing. Concerns over increased Level 16, 31 Queen St., Melbourne determinant for the survival or extinction of maintenance costs (Zhang et al. 2012), damage VIC 3000, Australia t: +61 3 8623 4000 species. The exponential rate at which our cities to façades, and increased loading on structural e: [email protected] have expanded demands that we now plan systems (Wood et al. 2014) are barriers to the www.hyderconsulting.com and act to integrate our urban centers into the implementation of green roofs and walls. Grant Harris, Principal biosphere of the planet. The combined surface Zhang et al. provide a succinct definition of Ironbark Environmental Arboriculture 3/11 Coate Avenue, Alphington of high-rise buildings and other urban “intensive” and “extensive” green roof systems. VIC 3078, Australia infrastructure can provide significant areas to t: + 61 41560 7375 e: [email protected] support plants, and weave back the threads of Intensive green roof systems are characterized green fabric. by deep (greater than 15 centimeters) growing Lloyd Godman is an ecological artist and has an media, opportunities for a diverse plant palate MFA from RMIT University, Melbourne. He has had more than 45 solo exhibitions and been included in Integrating plants into the built environment on the rooftop, and high maintenance more than 250 group exhibitions. His current work improves air quality, moderates temperatures requirements. In many cases, intensive green explores living plant works and “super-sustainable” art. In 2011, he began creating suspended rotating plant (Saadatian et al. 2013), improves human roofs are being replaced by extensive green sculptures and since then has worked with plants on well-being, lifts the spirit (Townsend & roofs, which have a much thinner, lighter media tall buildings, including Eureka Tower, Melbourne. Weerasuriya 2010), and can provide habitat for (thus fewer structural requirements), and offer Stuart Jones has recently been appointed Technical other species (Oberndorfer et al. 2007). In fewer, but potentially more practical plant Director for Hyder Consulting in Melbourne. Previous to this he was the Owner/Director of Point March 2015, it was promising to see a law choices. 5 Consulting in Melbourne for 14 years. Stuart has passed in France, which mandates that over 25 years’ professional experience in all phases of project delivery and specializes in creative structural rooftops on new buildings built in commercial Building on Zhang’s categorization of green design, with extensive experience in Australia and zones must either be partially covered in plants roofs, the authors propose that incorporating throughout Asia. or solar panels. This mandate draws a line, vertical gardens into a building’s design can Grant Harris is the principal of Ironbark Environmental whereby inspiring contemporary architecture employ two systems, which are adaptive or Arboriculture, with more than 12 years’ experience in the arboricultural sector. He also holds a degree will be measured by the successful integration selective. in Environmental Science (Wildlife and Conservation of living green texture into the fabric and form Biology). His particular areas of interest are the use of green infrastructure to mitigate urban heat island of the structure. Imagination and Adaptive systems effects and urban ecology. experimentation have driven a welcome Analogous to intensive green roofs, adaptive expansion of roof and vertical gardens in recent vertical gardens require the environment to be 38 | Sustainability/Green/Energy CTBUH Journal | 2015 Issue III adapted to support the plants’ biological have no requirement for soil and tolerance of demands, which will vary depending on the extremes in moisture availability. Both of these ecophysiological characteristics of the selected are attractive characteristics when choosing species. This condition is met by mesh- plants for utilization in a selective vertical mounted plant growth substrate, irrigation and garden system. fertilization. The benefit of adaptive systems is that they allow a greater selection of species; Tall buildings present an extremely however, they have limitations, including the challenging environment for plant growth, cost of installing and maintaining structures to where consistently high wind speeds increase support plant growth substrates (Pérez et al. transpirational losses and thereby increase 2011). water stress on plants growing in these Figure 1. Eureka Tower, Melbourne. © John Gollings environments. Tillandsia bereri and a hybrid, Selective systems Houston, were selected to test the concept of leading to the colloquial name of “air plant.” Akin to extensive green roofs, selective systems a selective vertical garden system because This adaptation removes the requirement for use critical species selection to identify plants they have the following characteristics: a plant growth substrate to be installed on the that naturally grow in environments similar to building façade. The lack of water-seeking those encompassing an existing building’s Drought tolerance roots also negates building managers’ façade. They have the advantage of reducing or Bromeliads minimize transpirational water concerns about potential damage and eliminating the requirement for plant growth losses by utilizing the crassulucean acid maintenance costs. substrate and associated installation and metabolism (CAM) cycle, in which the maintenance costs. The limitation of selective stomata are closed in the heat of the day and Absorption of airborne pollutants systems is a reduced plant palette. open to uptake CO2 at night, releasing oxygen The trichomes of Tillandsia have a high during darkness (Benzing 1990). Moisture and absorptive capacity, which allows them to nutrient uptake occur through specialized absorb air pollutants rapidly (Li et al. 2015). Plant Selection trichome cells, further reducing transpirational The installation of large Tillandsia screens on water losses; these adaptations make tall buildings has the potential to act as an air Epiphytic plants are those that use other plants Tillandsia very drought-tolerant. filter for the building and surroundings. for mechanical support; a diversity of plant groups has evolved to fill this environmental No requirement for soil Minimal weight niche. Life as an epiphyte, high in the forest One adaptation of Tillandsias to the epiphytic Based on previous installations, the weight of canopy, exposes the plant to greater life-mode is the modification of the role of the a Tillandsia screen is estimated to be 3 kg/m2, fluctuations in moisture availability in roots from that of moisture and nutrient which is minimal in comparison to adaptive comparison to their terrestrial cousins, nestled absorption to that of “hold-fasts” that function systems that require plant growth substrates comfortably in the soil below. Tillandsia (see only to attach the plant to the substrate and supporting structures. The light weight of Figure 2), which is a genus of the Bromeliad (Benzing 1990). The leaves of the plant replace Tillandsia means they are perfectly