March / April 2018 No. 82 R60-00
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CONTENTS Maintenance at Telkom Park................................................3
SA Sports and Play Industry...............................................11
Urban Trees - 2017 IERM Paper......................................13
Landscaping Feature Unisa E-Garden......................................................................15 South Hills Park......................................................................19
March / April 2018 No. 82 R60-00
How Landscape Architects Can Reduce Dependency on Potable Water.........................................22
ON THE WEB
ON THE COVER
This and previous issues of Landscape SA are available online at http:/www.landscape-sa.co.za
Telkom Park sponsored by Bidvest Top Turf. See article on page 3.
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Editor Karyn Richards Email: firstname.lastname@example.org Tel: 011 326 0303 Fax: 086 714 0448
Marketing Manager Helen Bennetts Email: email@example.com Tel: 011 326 0303
Publisher The Eagle Publishing Company Tel: 011 326 0303 Fax: 086 714 0448 Website: www.eaglepub.co.za P.O. Box 41928, Craighall, 2024 The Cottage, 47 Rothsay Avenue, Craighall Park, Johannesburg
Rob Furney Tel: 011 326 0303 Fax: 086 714 0448 Email: firstname.lastname@example.org
Design Jackie Nene Tel: 011 326 0303
Commitment and High Standards In March I attended the bi-annual SANA trade show in Gauteng, having been asked beforehand to act as one of the judges for the stands. It is one thing to just walk around the show as a visitor, which I normally do, but quite another to look at the stands more critically, and to judge them according to specific criteria. I was struck by the continuously high standards of the displays and their strong visual appeal, with many of them also showing artistic flair and creativity. As with any trade show or exhibition, setting up a stand, regardless of its size, is a mammoth task; it involves a lot of carrying, organising, to-ing, fro-ing, arranging and re-arranging in order to display the product in an appealing way. Although some are more eye-catching than others, it’s still a big undertaking. I think especially of one company based in Pretoria, displaying very large, heavy pots and containers.What a logistics nightmare that must have been, not to mention the careful loading and unloading required to avoid damage to the display goods. Packing and transporting of trees, shrubs and plant material also has to be done with care, and are equally fragile. I was hugely impressed by the high standards shown throughout, and commend everyone on their commitment and dedication. A newcomer to the green industry is SASPI, the South African Sports and Play Industry, whose first conference took place in April at the Wanderers Stadium in Johannesburg. Their mission is to improve the standing of sports surfaces in the country by encouraging training, higher standards, professionalism and ethical conduct. They are focussed on promoting quality workmanship for sports and play surfaces, as well as on the construction of artificial and natural pitches and athletics tracks.Take a look at their editorial in this issue and in forthcoming ones, look out for articles on some of the papers presented at the conference. We welcome them to the green industry – there is definitely a place for them within it.
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landscape sa - Mar/Apr 2018
MAINTENANCE AT TELKOM PARK The water feature is a focal point in the food court space
Telkom Park in Centurion, Gauteng, is Telkom’s flagship site and a national key point.The extensive landscaped grounds have been maintained by Bidvest Top Turf for the past six years.
ndries Nothnagel, Operations Manager at Top Turf, says their initial maintenance brief from the client was to ensure that the gardens contribute to the Telkom brand and complement the head office, while producing a “wow” effect for visitors and staff. Approximately 8 000 people make use of the facility on a daily basis. Although the site was originally 50% veld grass it is now only 10%, and there is a more manicured look with mainly indigenous plants and a few exotics. For security reasons, the client requested Top Turf to
trim tall veld grasses in favour of a neater appearance. Nothnagel says they attempt, on an ongoing basis, to sell more water wise practices to the client, as well as to propose removing some lawn areas. Large plant groupings are promoted to ensure that water requirements are as compatible as possible. With paving and the more manicured maintenance installed, scope and budget changes needed to be made. Composting and lawn dressing is budgeted for annually, with over 200m3 imported and spread each year. Mulching with bark chips is undertaken and fertilising is done annually. The site is divided into two irrigation sections – the old portion which was part of the initial installation over a decade ago, and a new irrigation system which was installed during the conversion from veld to manicured gardens three years ago. Top Turf and the client are working together to replace the old system to fall in line with the dolomite regulations applicable for the area; the new system complies with this. Drip irrigation has been installed in the courtyard next to the food court. Water meter readings are taken weekly for the system, and Top Turf is working on a case study of water usage with Leslie Hoy of Rand Water. The client, says Nothnagel, wants facts and figures to make calculated changes in an effort to save water. Bidvest Top Turf and Telkom are always looking for innovative ways to conserve water. Recently, water retention gel was introduced during the laying of new lawns to promote water saving by reducing watering frequencies. This has been a great success and will be introduced in other areas of the landscape as well. Maintenance is undertaken seasonally with mowing in summer using a ride-on mower, push mowers, brush cutters, blowers, hedge trimmers, pole pruners and various small tools. Mowers and brush cutters are used to maintain large lawn and veld grass areas, and the sloped angles of grassed mounds makes mowing challenging. All blowing takes place in the early mornings and on weekends before the influx of traffic and when there are fewer vehicles parked on site. Large, hard surface areas require a full time person for herbicide applications, with spraying of unwanted weeds taking place throughout the week and on weekends. Irrigating of gardens is set to take place at night and adjusted according to seasonal requirements.
Seasonal colour in the landscape
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Grassed natural area around the water feature
Nothnagel says that: • splitting and dividing takes place with Agapanthus, Dietes and Tulbaghia species and these are used as and when required on other parts of the site; • the landscape is intended to look natural and underplayed, with minimal colour; • crown lifting of trees is undertaken in April and August by a specialised team, however continual monitoring of trees takes place and remedial work is done as and when required; • Alfred Rapoo is the on-site contracts manager, assisted by supervisors and garden technicians. Continuous onsite training is
Covered walkway to the main entrance
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undertaken to multi-skill staff; • Top Turf is also responsible for maintaining the outdoor gym area, running track and five-a-side soccer field; • an on-site health and safety file is available and safety audits are conducted frequently to ensure that industry requirements are met and exceeded.
Design input Daniel Rebel and Tiaan Laker of Danie Rebel Landscape Architects (DRLA) designed the landscape almost three years ago. Laker says that DRLA wanted to retain the continuum of the original design in which they were involved, integrating it with the previous phases. Recreational amenities such as the jogging track, outdoor gym and five-a-side soccer pitch were integrated into the design in order to accommodate 2 000 more staff members who moved to the campus from other Telkom premises in order to accommodate the entire workforce in one place. Solar panels were provided to the new parking area. Laker’s design put into place a grass theme around the food court and brought natural slate to tie in with existing buildings, along with flowering material to the surrounds of the water feature. Timber decks and cladding were integrated into the landscape and together with the gabion walls around the water feature, contribute to this area’s very natural appearance. The rocks used in the gabion wall construction were obtained from the demolition of the previous gabion walls that had to make way for the upgrades to the
The five-a-side soccer pitch is maintained by Bidvest Top Turf The water feature is a focal point in the food court space
The landscaping is intended to look natural and underplayed
Gabion walls contribute to the areaâ€™s natural appearance
Mounds present a challenge for mowing
campus. A green roof was provided to the food court area. In his design, Laker focussed on sustainable practices, removing some Populus simonii trees and replacing them with Celtis and Combretum species. The former were used for mulching. Plant material in this latest phase is hardy and water wise, comprising Agapanthus, Crocosmia, Dietes, Freylinias, Aloe species, Aristida, Tulbaghia, Kniphofias and Chondropetalum.
Site challenges Nothnagel says that one of the biggest challenges of the site is the constant upgrading of buildings and infrastructure, leading to many external contractors damaging the gardens and irrigation. The number of people using the facility is also a challenge and Top Turf has to adapt to this on a daily basis. Nevertheless he states that there is a good working relationship between all the service companies on the site. lsa Food court colour
Photos by Karyn Richards and courtesy of Bidvest Top Turf landscape sa - Mar/Apr 2018 5
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MADIKWE BERRY Vic van Eck, formerly of Servest Landscaping and Turf, left the company in September 2017 and is now involved in blueberry farming. Madikwe Berry, a growing operation situated 15 km from the Botswana border, is located within the 17 000 hectare Madikwe Conservancy. There are presently 15 farms which make up the conservancy.
Lucerne fields which will be cleared to make way for the next 20 ha of berries
he growing operation works in conjunction with UK based Berryworld, which is responsible for the overseas marketing and distribution of Madikwe Berry’s fruit. The fruit is for export only and there is no local consumption. Van Eck says his syndicate joined forces with Berryworld and their business plan meets their criteria for growing conditions, finance, water supply, technical support and the right strains and cultivars.
Technically complicated Blueberry growing is a technically complex and precise science, according to Van Eck, a qualified chemical engineer. Due to his background, the engineering and scientific aspects of blueberry growing appealed to him and the “green factory” requirements are exacting in terms of irrigation, fertilising and pruning. “It’s a very carefully synchronised undertaking, and probably the reason for the high cost of blueberries to consumers. We adhere to Berryworld’s product specifications throughout the growing procedure,” says van Eck. Irrigation water is supplied from the Marico River which runs through the conservancy and water rights are in place for using the Molatedi Dam which provides good quality, low pH water. Blueberries are a high water consumption product, with 50 ha requiring two million litres of water per day. Only drip irrigation is used. Van Eck explains that the UK has a high demand for blueberries and Madikwe Berry’s production is timed to supply that market when its local production falls at the end of the growing season. “We’re competing against countries like Peru and Argentina but our quality is good and new varieties are very heat tolerant”, he says. Madikwe Berry is aiming to grow five varieties which van Eck says are the right size, taste and firm texture required for the UK’s discerning market. These five varieties are large, easy to pick and cultivated so that
harvesting occurs from September to November. Picking will be done manually by about 600 staff and the ripe fruit freighted to Cape Town or Johannesburg for export. An on-site pack house is maintained at just above 0⁰ C to store the berries prior to freighting. The berries are grown in coir bags, in a substrate comprising pine bark or coco peat. Good drainage is essential, as is the pH level of the water. Initial dosing of pH takes place as the water leaves the river and is fed to buffer tanks. Fertigation types include calcium nitrate, ammonium sulphate and mono ammonium phosphate. A combination of plastic and net tunnels are used and beehives (400 in total) are placed at the ends of each tunnel for pollination. Bee activity is vital for yield and fruit size. Risk factors include hail, frost and over watering. Spraying is done under strict conditions but not while pollination is underway or fruit is being harvested. Berryworld UK has its own nursery in Stellenbosch where mother stock tissue seedlings are propagated. These are sent to Madikwe Berry as plugs, where they are planted in the above-mentioned coir bags. Van Eck says that the precise nature of blueberry growing means that nothing is left to chance. “All procedures are carefully documented and whatever we do is in consultation with Berryworld”. He spends approximately ten days per month at the farm, where there is also a permanent project manager, production manager, 15 permanent staff and technicians who prune and scout for pest outbreaks, weeds and diseases. The number of staff permanently employed on site will eventually grow to 50 once the project is fully developed. Madikwe Berry is in the middle of the Madikwe Conservancy and is not only vulnerable to pests and diseases but also to large game such
Installation of Phase 1 polytunnels and storm water in progress.The entire area will be covered in weedmatt.
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River water storage tanks
Drinking water purification plant State of the art fertigation/irrigation installation
Tel: (+27) (0) 21 859 1026 Email: email@example.com Web: www.haygrove.co.za
as baboons, monkeys and porcupines. The area was previously used for growing lucerne to supplement the natural food source in times of drought and to feed animals. Being a remote site, Madikwe Berry was responsible for establishing all infrastructure which included building their own roads, bridges, guard houses, water purification plant and waste water treatment plant. The production of blueberries will be strictly monitored against European standards, namely GAP and GHP. Where possible, ecofriendly solutions will be sought, such as companion planting with Alyssum and lucerne which will draw thrips and other predators away from the berries. To enhance fruit size and maximise yield, approximately 400 beehives will be brought in annually when the plants start flowering, during which time no pesticides can be Irrigation/fertigation pumps sprayed that could influence pollination.
New adventure Van Eck says he had a good innings at Servest but felt ready for a new challenge. “The berry venture is quite daunting but at the same time invigorating. I’m in it for the long haul”. lsa Photos by Connall Oosterbroek 8
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Haygrove Tunnels for Crop Protection Haygrove is an international company doing business in over 57 countries worldwide. The Haygrove concept was originally developed by berry growers in the UK who were unable to find a cost effective solution to cover their crops and were dissatisfied with the structures currently available as they were both expensive and lacked design flexibility. Haygrove has been distributing and building greenhouse tunnel structures in Southern Africa for over 18 years.A range of structures has been developed to cater for growers across the spectrum, from the backyard enthusiast or subsistence farmer to the largest commercial growers. Haygrove greenhouse tunnel structures have been specifically designed to provide applicable greenhouse technology and use the natural environment optimally to get the best production from crops, ensuring quick payback and extended benefits. Haygroveâ€™s commercial tunnel structure series range from single stand-alone tunnels to multi-span tunnels covering hectares at a time. The structures are specified to suit individual grower needs with regards to crop requirements, climatic conditions and budget. Bay widths, leg heights, door types, length of bay, side skirts, top covers, guttering and trellising systems are all variables that can be manipulated to provide an optimal solution for growers. Haygrove consultants are available to visit growers on site to help design the best solution for each project. Haygroveâ€™s new shade net tree cover structures are designed to be erected over existing orchards; they are flexible and upgradeable. Innovative design and new steel profile hoops have resulted in a decrease in cost/m2 and offers growers the ability to completely remove and replace the net with ease. All of this while working from the ground! This allows optimum light penetration and better pollination. The arched structure allows more consistent light penetration through the net into the crop canopy and provides 35% more air volume than a flat top structure of the same leg height. Structures are designed to be moveable by using leg anchors augured into the ground.
Use is made of plate-anchors and cables to provide structural stability and superior wind resistance. Leg heights can vary from 1.25m to 4,5m, providing unmatched air volumes and the ability to cover larger tree crops. The maximum apex height is 7.5m. The growhouse and garden tunnels are DIY kits that can be couriered door to door and are designed to cater for rural subsistence growers and urban backyard garden enthusiasts. All Haygrove greenhouse tunnel structures are constructed using high tensile galvanised steel. Many of the components are manufactured locally in South Africa. Haygrove has covered over 650 hectares of crops in South Africa and neighbouring countries. Zimbabwe has recently experienced a surge in the high value berry industry, with several hectares being erected in the last year. Haygrove covers a vast array of crops including berries, tomatoes, peppers, cucumbers, flowers, nursery stock, salads, citrus, apple and cherry trees - all have responded well to being produced under protection. Haygrove structures effectively make use of natural ventilation. The polythene is held in place against the structure with a roping system which allows the plastic to be pushed up on the sides and down the full length of the tunnel in order to produce varying degrees of ventilation. This also eliminates the need for forced air movement and expensive fans and wet-walls. Steel gutters can be fitted on each leg row to harvest runoff during the rainy season which can be stored in a dam and recycled into the fertigation system. Another unique feature of Haygrove structures are the leg anchors with flights on the bottom that are augured into the ground hydraulically. This eliminates the need for concrete at each leg, which in turn means that not only is the tunnel construction easy, but the tunnels can also be relocated to different fields. For further information visit www.haygrove.co.za, phone +27 (0)21 859 1026 or email firstname.lastname@example.org
Spilo Technical textiles (since 1951) markets various woven fabrics for weed growth prevention and ground cover, thereby avoiding the use of harmful or noxious chemicals. The built-in strength and other properties of AGRI WEAVE also give it a high resistance to extreme weather conditions. , In particular the HDPE (high density polyethylene) is formulated for the extreme UV experienced in Southern Africa. Tried and tested under all conditions, AGRI WEAVE has performed well. It can be used as a ridge cover for crops in direct sunlight, or as a floor covering in shaded tunnel structures. Spilo Technical Textiles, Paarl, Cape Town, South Africa Tel: (021) 862-6100, eb: www.spilo.co.za Email: email@example.com
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SOUTH AFRICAN SPORTS AND PLAY INDUSTRY The South African Sports and Play Industry (SASPI) is a registered NPO (trade body) established in 2016 by six founding members. Its mission is to improve the standing of the sports surfaces industry in South Africa and to promote the participation of all role players in the industry by encouraging training, higher standards, professionalism, ethical conduct and social interaction through regular meetings, conferences and workshops. World Rugby Certified field at Windhoek Gymnasium
FIFA Certified football pitch in Kleinmond
FIH Global Certified hockey pitch at Ashton International College
SASPI will host its first conference on 25 April 2018 at the Wanderers Stadium in Johannesburg. This will include International speakers covering a range of topics which will aim to educate and inform municipalities, architects, consultants, specifiers, suppliers, contractors, installers, legal advisors and investors in sport and play facilities across Africa. For more infomation regarding the conference, or becoming a member of SASPI, please visit the SASPI website www.saspi.co.za
he six founding members include Belgotex Floors, Fintrex, Seamless Flooring, Servest, TurfTech as well as UJSportslabs. Hence, SASPI represents the sports and play industry as a whole and is concerned with the construction of artificial and natural pitches, athletics tracks, sports courts and play surfaces. The main aim of SASPI is to: • provide and maintain a central organisation for the promotion of efficiency, progress, welfare, knowledge, education and general development among persons engaged or employed in the sport and play industry; • act as a networking platform, support professional standards and pursue social issues in the sport and play industry; • encourage a high standard of quality and workmanship in the sports surfaces and play industry and to exercise control, supervision and guidance in respect of the conduct of its members; and • formulate and recommend contract procedures and standards for the guidance and common use of all SASPI members. To achieve this, SASPI has developed compliance standards to which members need to adhere; this assists with regulation. SASPI has three categories of membership including principal members, selected supplier members and associate members.
UJSportslabs is a multi-disciplinary consultancy practice and specialist sports surfaces testing laboratory. With broad-based experience in sports surfaces development, backed by UK based sports labs, it provides a blend of specialist services designed to meet the needs of clients. As consultants, it provides feasibility studies, site investigations, design/specification, contract administration and project management. The company is also equipped to provide a wide range of sports specific testing of all types of flooring, synthetic carpet systems and tracks, as well as the components which make up these products. Whether it is a health check on an existing sports surface to assess if there are any problems regarding the safety/performance of the surface, or checks to assess the end of life of a surface, its services are flexible and tailored to meet client’s needs. It also provides recommendations and budgets regarding replacement of the surface, options for the system and design input to ensure the facility meets current technical requirements. It conducts specific performance testing on completion of a surface to ensure compliance with specified standards for FIFA, FIH, IRB and IAAF. lsa For more information visit www.ujsportslabs.co.za, email firstname.lastname@example.org or phone +27 (011) 559 6602.
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Johannesburg City Parks and Zoo (JCPZ), together with religious representatives from various faiths, unveiled the 400 ha Olifantsvlei Cemetery in the south of Joburg in November 2017. The critical need for burial space, particularly in this part of the city, has intensified due to Avalon Cemetery reaching its full capacity for primary burials. The new cemetery will accommodate over 800 000 new burial spaces for the next 50-70 years. This is based on Joburg’s exponentially growing population and the projected mortality and burial trends in the city, which currently has 33 formal cemeteries, including 29 passive and four active ones. The active ones include Olifantsvlei, Westpark, Diepsloot and Waterval. The 29 passive or dormant cemeteries, including Avalon, Lenasia, Alexandra and Newclare cemeteries, are being used by families who are considering re-openings for second and third burials of family members, in the same grave. In recent months Avalon cemetery has seen a 25% increase in the number of families considering re-openings for second and third burials. JCPZ is encouraging families and funeral directors to explore the option of using existing cemetery space more effectively. This is part of the city’s efforts to alleviate the growing demand for new cemeteries Opening of the Olifantsvlei Cemetery
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The Association of Rotational Moulders UTH AFRIC AN E SO of Southern Africa (ARMSA) has TH NA H TI IT O W announced the publication of a South African National Standard, SANS 1731:2017 for polyethylene 1731:2017 chemical and water storage tanks, developed in conjunction with the South African Bureau of standards (SABS). This is proof that the tank purchased has been properly armsa.co.za designed and manufactured to be fit for purpose for the length of its warranty life. It compels tank manufacturers to conform to world best practice, according to ARMSA chairperson Wayne Wiid, and protects consumers as well as members of the construction, landscaping, architecture and plumbing industries against tanks of a lesser quality. The standard offers the following: • provides specific criteria in terms of the source of raw material, ultra violet protection, overall weight, wall thickness, light penetration, stress crack resistance and impact strength for a range of different sizes; • ensures that production methods used to manufacture the tanks comply with best practice; • requires that traceability is built into the manufacturer’s control systems; • includes an audit check for actual storage volumes vs stated volumes; • evaluates the overall appearance of the finished tanks; and • certifies the requisite number and type of fittings and the date of manufacture. Productivity Engineering and Services Consultants (PESC), an independent third party auditing company appointed by ARMSA, will regularly check audit tank manufacturers who choose to comply. If compliant, PESC will issue a certificate giving independent assurance of a manufacturer’s claim that their products meet the SANS criteria. Compliant tank manufacturers will be able to market their compliance with an ARMSA/SANS approved sticker on their tanks, as well as using the certificate and sticker in their general marketing programmes. Wiid says that any tank manufacturer can claim to meet the SANS standard but without formal certification, there is no guarantee. They therefore urge all stakeholders and home owners to request the PESC certificate from the manufacturer prior to purchase to ensure that tanks delivered to sites or homes have been thoroughly tested and certified. For further information email email@example.com or firstname.lastname@example.org
DARD STAN NK TA
New Cemetery in South of Joburg
Armsa Standard for Water and Chemical Storage Tanks
Corobrik’s newest range of face brick and pavers, which have yet to be launched nationally, were on display at the KZN Construction Expo in February. This is a multi-disciplinary show focussing on the building and construction needs in the province. It provides buyer and seller engagements with attendees comprising contractors, engineers, architects, designers, quantity surveyors, property developers, government and industry associations. The event featured all the latest products, tools, technologies and training programmes across the industry. This year Corobrik showcased the latest black Latest black face brick from Corobrick face brick as well as the Doppio, Cobble and Piazza pavers. Their sales team was available to discuss versatile ways to contrast and complement their current face brick and paver range, which are increasingly popular with developments. Corobrick’s Commercial Director. Musa Shangase, says there is a definite trend in the construction industry to incorporate black and grey colours, as well as a move towards exposed areas, revealing the raw brickwork. For further information contact Allin Dangers on 031 560 3111
CO MP LI ES
Corobrik’s Latest Product Range
and to ensure that dormant cemeteries remain active to avoid the urban decay that affects vast, under-utilised spaces. Olifantsvlei Cemetery is retained in a pristine condition throughout the year by a dedicated maintenance team and is fully fenced with two access points to alleviate traffic congestion. The cemetery will allow for headstones and not tombstones in its efforts to discourage communities from erecting tombstones that are impacting on the aesthetics and maintenance standards found in the city’ s resting spaces. The entrances to the cemetery are guarded by 24 hour security and random checks are undertaken to retain its sanctity. For further information contact Noeleen Mattera on 011 712 6722
URBAN TREES AS BRIDGEHEADS AND SENTINELS FOR INVASIVE FOREST PESTS AND DISEASES
The article below, by Trudy Paap1,2, Treena Burgess1,3 and Michael Wingfield1, was presented at the 2017 IERM Conference.
Global distribution of botanical gardens (www.bgci.org/map.php)
rban forests are important suppliers of ecosystem services and as the world becomes increasingly globalised, will likely play important roles in preserving biodiversity. Urbanisation results in an urban heat island effect and as such, the mitigating effect of trees is important under climate change scenarios. Urban trees can reduce airborne particulates and other pollutants, are beneficial to human health and well-being, and generally enhance urban environments. An important and commonly overlooked negative factor is that the urban landscape is frequently the first point of contact with exotic forest pests, including insects and plant pathogens. Movement of humans and international trade are frequently more concentrated in urban centres, consequently, urban trees can be vulnerable to accidentally introduced pests. Urban trees often exist as single species plantings and may occur on unfavourable sites. Low diversity and the potential for stressful conditions arising from anthropogenic disturbances can predispose trees to pest attack, enhancing the likelihood of exotic forest pests becoming established and increasing in density. Once established in urban environments, dispersal of introduced pests can proceed to natural forest landscapes or planted forests. In addition to permanent damage to ecosystems, the consequences of these invasions include costly management strategies and eradication attempts. This paper highlights the importance of urban trees in terms of their vulnerability to invasive pests. Examples are taken from past accidental introductions to discuss impacts arising from these incursions, and the importance of global biosecurity is highlighted as a crucially important barrier to pest invasions. Finally, we suggest that urban trees may be viewed as â€˜sentinel plantingsâ€™ to help predict and prevent the invasion of new pests, and where introduced pests with the capacity to cause
Strelitzia reginae in the Karoo Desert National Botanical Garden
serious impacts could potentially be detected during the initial stages of establishment.
Pathways With few exceptions, invasions by exotic insect pests and pathogens of trees are the result of unintentional introductions, largely the byproduct of economic activity.The two most important pathways are the movement of live plants and wood packing materials. Other pathways include trade in logs, lumber, fuelwood and manufactured wood articles, and baggage carried by travellers.
Importance of managing urban invasions The invasion process is traditionally recognised as consisting of three phases: arrival, establishment and spread. Managing invasive pests in urban areas is important to ensure preservation of the many values trees bring to the urban environment, but is also important due to the close link urban trees have with the phases of invasion. landscape sa - Mar/Apr 2018 13
Urban street tree in Cape Town
Damage to Emerald Ash Borer tree (Agrilus planipennis). Photo by Troy Kimoto, Canadian Food Inspection Agency, Bugwood.org
Loss of trees from urban areas affects aesthetics, property values, shading, storm water runoff, ecosystem services and human health. There are costs associated with tree felling, removal and disposal, as well as treatment and eradication efforts. As hubs of trade and human movement, many initial establishments occur in urban areas. Once established on suitable hosts, populations of pests can be amplified in urban environments. These form so-called â€˜bridgeheadsâ€™ that facilitate movement into natural and planted forests. Populations can continue to grow and spread to the point where they become pervasive. By this stage the damage moves beyond an effect on an individual host species, potentially destabilising entire ecosystems. As invasive species advance through these stages, eradication attempts become increasingly costly and challenging and the likelihood of achieving control decreases. Worldwide, there is a growing list of damaging invasive forest pests and in many cases there is clear evidence of the arrival of these pests into urban areas and their subsequent spread into forest landscapes. Two examples are presented here to illustrate this trend. In South Africa, the root pathogen Armillaria mellea was shown to have been introduced into the Companyâ€™s Garden in Cape Town by the early Dutch settlers. Recent evidence has shown that this pathogen has moved into Kirstenbosch Botanical Gardens at the foot of Table Mountain, where it now threatens sensitive natural ecosystems. The arrival of Emerald Ash Borer (EAB) in the United States may well represent a worst-case scenario, with it having become the most destructive and economically costly forest insect to ever invade North America. Using dendrochronological reconstruction, Siegert et al. (2014) reconstructed the historical establishment and spread dynamics of EAB, documenting its arrival and establishment in urban environments and subsequent spread. There is concern that the entire Fraxinus genus may be functionally lost from forests across the continent as a consequence of this invasion.
Current regulation and its limits Current measures for protection against invasive pests are provided by the International Plant Protection Convention (IPPC) through the establishment of International Standards for Phytosanitary Measures (ISPM).These are acknowledged by the Agreement on the Application of Sanitary and Phytosanitary Measures of the World Trade Organisation (WTO). Under current protocols, Pest Risk Analysis (PRA) is the mechanism by which organisms can be recognised as potential threats requiring regulation. While current regulatory efforts are having positive effects, in the face of surging global trade they are inadequate.Thus damaging invasive pests continue to become established in new environments. One of the challenges faced is that for an organism to be regulated against, it must be named and known to be harmful. Unfortunately there are many cases where damaging forest pests were unknown to science prior 14
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to their arrival in a new environment, or were known but not problematic in their native range. Consequently, they could not have been detected and stopped at checkpoints. Given the failings of biosecurity regulations, early detection can be considered the second line of defence. Targeted surveys focusing on the areas at highest risk of invasion can strongly increase the probability of intercepting invasive species, providing substantial net economic benefits. Urban trees, including those present in botanical gardens, can be used as traps to lure pests from surrounding areas, and when adjacent to high-risk sites such as ports, can provide early warnings of potential pest invasions.
Botanical gardens as sentinel plantings
Botanical gardens and arboreta worldwide offer a unique opportunity for sentinel research. These plant collections often host a large range of exotic tree species (sentinels), thus presenting an opportunity to determine susceptibility to potential pests that have not yet been introduced to their native range. The International Plant Sentinel Network (IPSN) was launched in 2013 as a platform to coordinate information exchange and provide support for sentinel plant research within botanical gardens and arboreta. The network develops and coordinates global surveys and facilitates the collection and sharing of information, with the ultimate aim being to provide early warnings and information on new and emerging pests.
Conclusion As hubs of human-mediated movement and areas of anthropogenic disturbance, trees in urban environments are vulnerable to exotic pests and pathogens. It is vital that we manage invasive pests on urban trees to preserve the important ecological, environmental and social services these trees provide, but also to prevent the build-up of invasive populations to the point where they then have the capacity to spread to surrounding forest. In light of increasing globalisation and in the face of climate change, these threats are only set to worsen. A global commitment to strengthening phytosanitary regulations, rigorous surveillance and increasing funding for research and public outreach are essential if we are to reduce the frequency of invasions by damaging exotic pests. In the event that these do occur, early detection and rapid response through programmes such as the IPSN may provide the only opportunity for eradication. Urban trees, including those present in botanical gardens, provide a unique opportunity to fill gaps in PRA and provide opportunities to detect invasive forest pests during the initial stages of establishment. Such early detection offers the only realistic prospect of eradication and can substantially reduce long term management costs.
Acknowledgement This work was funded by the South African National Department of Environment Affairs. References have been omitted due to space limitations but may be obtained from Trudy Paap on email@example.com 1. Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa 2. South African National Biodiversity Institute, Kirstenbosch Research Centre, Cape Town, South Africa 3. Centre for Phytophthora Science and Management, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia lsa
UNISA E-GARDEN Project Team Client: University of South Africa (UNISA) Landscape Architects: kwpCREATE Landscape Contractors: Bidvest Top Turf and Life Landscapes
The new amphitheatre where debates, events and speeches take place accommodates Unisa’s ethics aspect
The Unisa E-garden at the Muckleneuk campus in Pretoria arose from the need to provide an audio visual platform there. E refers to ethics, energy and environment and the existing garden, together with a new amphitheatre, is used for informal discussions and different types of events and functions.
t was felt that the campus lacked a ‘heart’ where social interaction could take place and that the change should be characterised by the African cultural values of openness, warmth and inclusion. It should also promote awareness of everyone’s environmental responsibilities and of sustainability issues. From an ethics point of view, the E-garden is intended to uphold the institution’s core values of respect, integrity, accountability and excellence.
Design considerations Landscape architects Tobias Mahne and Piet Vosloo of kwpCREATE identified the following issues to guide the design: • the site’s slope was ideal for the building of an amphitheatre and also had beautiful views towards Freedom Park and Fountains Valley. An existing pond and water feature could also be incorporated; • although traditionally a distance learning institution, it was becoming apparent that more students needed to visit the campus and there was therefore a need to establish a pedestrian link across the site, as well as to ensure that this was accessible for wheelchairbound people. A ramp has been provided and is integrated with the stepped terrace seating of the amphitheatre, allowing everyone to access the higher level of the campus’ buildings; • the water feature, previously considered unsafe, now has a semisecluded seating area; • the design complements the design strategies and material selection of other projects on the campus, in particular the Miriam Makeba terrace and Kgorong building. It is now robust, multi-functional and able to cater for heavy foot traffic. Design concepts implemented by kwpCREATE tie in with the client’s requirement of displaying an African spirit. This was achieved by: • the amphitheatre’s seating arrangement which symbolises
Amphitheatre seating with walkway paving showing a basket weave pattern to represent unity
openness and inclusion by means of its curved lines denoting African gatherings; • the metaphor of weaving different aspects into one strong unit by means of materials that show both unity and diversity. A basket weave pattern in the paving represents the creation of a unified and ethical Unisa staff; and • grasses and plant material that symbolise movement through the campus. KwpCREATE was appointed for the project after winning a competition which was open to all landscape architects registered with SACLAP. Five companies participated and made presentations to Unisa.After their appointment, the project was divided into two phases, phase one being the amphitheatre and water feature and phase two the landscape sa - Mar/Apr 2018 15
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Existing pond with raised seating wall and new planting
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Existing cycads near the pond, with newly installed artificial turf
landscaped link to the Miriam Makeba terrace on the north of the site. Landscape architect Charl Louw then took over and was responsible for the detail design, construction drawings and site supervision.
Off the grid In keeping with Unisa’s environmental responsibility requirement, the facility operates by means of off-grid solar energy to power outlets for cell phones, laptops, lighting, water pumps and plugs. An audio loop, buried in the lawn in front of the amphitheatre’s stage, enables hearing impaired people to listen to events and proceedings with the help of
wi-fi type earphones. Unisa’s Sustainability Framework Guiding Statement relates to the theme and principle of energy and the abundant supply of renewable natural resources, and states as follows: “Unisa embraces the use of renewable energy and employs clean, advanced technology and the appropriate management practices in its continued efforts to improve energy efficiency.” The solar PV plant was constructed with state of the art panels that were placed on the roof section of the OR Tambo Building. This ensures that the e-garden and amphitheatre are sufficiently lit to make
Existing retaining wall and planting forms a framework to the space
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Landscaping Feature the garden and gathering spaces usable in the evenings for graduation shoots, concerts and events.
Landscape installation For procurement reasons, the project was implemented by two contractors: construction and hard landscaping was undertaken by Life Landscapes, whilst planting, irrigation and paving were installed by Bidvest Top Turf. This necessitated extensive project management by Louw, who was on site regularly and very “hands-on”. Jonathan Ferguson of Top Turf explains that they worked in collaboration with Life Landscapes. The paving, he said, was a difficult pattern to lay and every brick had to be adjusted to ensure a correct and solid fit. An African feel was required for the paving and changes in patterns and colours indicate different areas and uses. For visually impaired people, there are changes in brick texture to indicate where one is standing or walking. Existing planting was retained and Top Turf planted new material in the form of Scadoxus multiflorus, Haemanthus albiflos, Crinum bulbispermum, Falkia repens, Plectranthus ecklonii, P. verticillatus, Asystasia gangetica, Portulacaria afra, Aristida junciformis and Cyperus albostriatus. New planting was focussed around the water feature and artificial lawn has been planted in a dark unused space underneath a concrete pillar. Ferguson says the biggest site problem was that of minimal storage space but that the collaborative effort with Life Landscapes worked effectively, with weekly meetings to co-ordinate installation. He says that Christine Meyer, manager of Unisa’s Horticultural Services Department, united the two companies well. Louw, he said, also assisted with his regular site visits, hands-on approach and snagging that was done as work progressed to ensure that quality issues were dealt with as they occurred.
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Life Landscapes was responsible for the bulk earthworks, raising the pond level to accommodate a seating wall around it, copings, artificial turf installation and construction of the amphitheatre, its seating walls, steps and ramps. Wheelchair access was very important for the amphitheatre, as well as landing areas for the disabled to stop and rest, if necessary. Ida-Marie Strydom said they commenced with the amphitheatre, adding the ramps afterwards. “It was a complicated issue to get all the levels right and in general, this was a difficult specialised construction project. For example, the lower wall of the amphitheatre required railings and steel reinforcements to support the roof structure and we also had to ensure that the drainage worked according to Charl’s master plan. Storage space was another challenging issue and we had to move soil around the site all the time,” she said. In addition, Unisa’s health and safety regulations were very strict, she said, and the site had to be fenced off when heavy machinery was in use. Demolition work could only take place over weekends. “With all the challenges on this site, the hardworks needed to be right, and Charl’s supervision was strict but essential. Despite everything though, it was really enjoyable to work in collaboration with Top Turf,” she says.
Team effort Meyer says the situation was also challenging for her from the point of view of project management, as there were several specialists in different fields of expertise working together. “Despite this, Unisa is very satisfied with the end result and acknowledges the input of everyone in the successful outcome of the project.” lsa Text and photos by Karyn Richards
SOUTH HILLS PARK Project Team Client: Calgro M3 Landscape Design and Installation: FSG Landscaping
South Hills is an integrated residential development situated five kilometres south of the Johannesburg CBD.The project comprises various types of residential units and will have a positive impact on the local community due to various upliftment initiatives. One aspect of its ‘green’ component has been the creation of a park with facilities for passive and active recreation.
Boundary fence and view of the Johannesburg skyline
he client’s brief to FSG Landscaping was to convert a 14 000 m 2 barren area into a safe haven for families to enjoy. The approach was to be environmentally friendly, recycling and re-using as much as possible.The brief was also to encourage insects and wildlife back to the site with the appropriate use of plant material. FSG implemented the “reduce, re-use, recycle” philosophy in the following practical ways: • grassy berms and slides have been created from broken and disused water pipes; • concrete circles made from old drainage pipes have been planted with grass and can be used as informal seating;
Storm water swale constructed of dump rock and recycled bricks from the construction site
• a sand pit area contains second-hand tyres salvaged from the site and its surrounds. They have been painted in bright colours, adding an element of fun and additional play pieces for children; • tree trunks serve as seating around the netball and soccer fields; • bricks from the site’s rubble piles were recycled and used to construct the storm water swales; • edging for garden beds comprises natural rock found on site as well as old wooden pallets.
Sand pit and play area.The grassy berms and slides were created from broken and unused water pipes, and the tyres were salvaged from the site and surrounding area.Their bright colours add an element of fun to the play space.
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The curved cycle track adds interest to the linear shape of the park
Rocks found in the area were used to create a natural and visually appealing edging for the garden beds
Childrenâ€™s play equipment
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Outdoor gym equipment
Tree trunk used as informal seating around the soccer field
The basket ball court
The numerous rocks in the area were incorporated into FSGâ€™s plan to create visually appealing edging for the garden beds. The shallow rock bed where the soccer and netball fields are located made it difficult for the ground to be levelled and this challenge was addressed by importing soil and establishing an even layer of ground over the rock bed. An indigenous planting plan was drawn up, comprising water wise material offering summer colour from Gaura lindheimeri, Limonium perezii, Strelitzia reginae and Carpobrotus edulis groundcover. Winter colours will also be vibrant, arising from Crassula â€˜Campfireâ€™ and the soft pink plumes of Melinis nerviglumis.
Passive and active recreation Soccer field
Design influenced by site challenges Anika Erasmus of FSG Landscaping says that the steep incline and gradient of the site necessitated the creation of four storm water channels to direct runoff. These have been turned into aesthetic features rather than just functional ones, and comprise a combination of dump rock and discarded bricks in colours of grey and earthy brown. The space allocated to the park is also fairly narrow and a curved, winding cycle path, one of the recreation features for children, has been introduced to create interest and counteract the linear shape of the park. The cycle path is constructed of a concrete slurry, with a fairly rough surface finish.
The park caters for adults and children alike so that everyone can benefit from a healthier lifestyle. In addition to the cycle path, there are sand pits and play pieces for children, outdoor gym equipment for adults and soccer, netball and basket ball fields for all ages. Benches, braai facilities and informal seating accommodate passive recreation. Although the housing units of the development are not yet complete, the park is ready for use, with well established lawn areas to accommodate picnics and relaxation. FSG Landscaping believes the park will greatly uplift the local community and enhance their quality of life. lsa Text and photos by Karyn Richards
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HOW LANDSCAPE ARCHITECTS CAN REDUCE DEPENDENCY ON POTABLE WATER The City of Cape Town is facing an unprecedented water crisis, with water restrictions and penalties for exceeding the set usage limits being imposed.The trend to install boreholes has far-reaching implications for future generations.
A collection/ infiltration trench adjacent to paved parking. Rainwater from the parking area flows into the trench, where it is pre-filtered by plants and gravel.The raised catch basins allow for water from only substantial rainfalls to be removed from the site and collected in a retention pond. Runoff from light rains infiltrates the sub-grades, recharging the groundwater.
f borehole water extraction exceeds the speed of its natural recharging process, these underground aquifers can dry out over time. The problem is further compounded in urban areas, where traditional approaches to storm water management have significantly slowed down the recharging process. Shortage of ground water further increases the landscape’s dependency on irrigation systems for survival. Resolving the water crisis requires a multi-disciplinary approach to find sustainable alternatives to decrease our dependency on potable water. As ‘stewards of the land’, landscape architects have a critical role to play as they have the necessary skills and insight to assist city officials and end users in implementing technologies and design ideas that can significantly reduce consumption. It is the profession’s responsibility to rise to the occasion and effectively contribute to resolving the water crisis. By working closely with urban planners and civil engineers, we should promote and facilitate cost-effective and sustainable solutions. Harvesting rain water, recycling grey-water, installing water efficient irrigation systems, reducing loss of water due to evaporation or leaks from water features and improving water infiltration into the soil to recharge ground water are some of the more obvious initiatives that can help in effectively reducing the consumption of water supplied through municipal systems and private boreholes. Landscape architects need to: • influence the current practice of removing bulk storm water from urban environments; • promote a well-balanced ecosystem that allows for storm water infiltration; and • facilitate substituting a portion of potable water with recycled grey water or harvested rain. Investing in rainwater harvesting systems, temporary detention 22
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ponds, water recycling systems, bio-filtration and infiltration trenches within urban landscapes will maximise the long-term benefits of these initiatives and simultaneously reduce our dependency on the city’s potable water supply. Using harvested rain or recycled grey water is a perfect replacement for irrigation, various construction and maintenance procedures, topping up ponds and swimming pools, flushing toilets or other daily activities that require water.
Environmental narrow gaps along the curb, allows storm water from the road to be cleaned and Runoff from the roofs and paving of this sports infiltrated into the ground or stored for complex moves through a bio-filtration trench future use. A series of small detention and that removes pollutants from the water. This process also slows down the peak runoff, retention ponds combined with infiltration allowing for a more effective filtration process. trenches can also slow down a turbulent Rainwater that falls within this site runs runoff, while helping to replenish local through this natural cleansing process and is aquifers. later collected for future irrigation needs or recharges the local aquifers. Rainwater harvesting: Non-potable water stored in surface ponds or a system of above or underground tanks can be collected from roofs, paved areas and even from soft landscapes. Calculating the optimal size of the collection tank is based on estimating the volume of water that can be harvested from the selected area and comparing it to the pre-calculated water demand based on the desired water use e.g. irrigation. A large volume of stagnant water in a tank may easily become polluted without regular monitoring and maintenance. In order to reduce pollution in stored water, any new water added to the tank should be pre-filtered from debris such as leaves, sticks, trash, etc. by running it through various strainers or sumps. In addition, a second stage of filtration, completed after the water is collected, is necessary to remove all small particles or even invisible pollutants and organisms that may quickly make the collected water unusable for its intended purpose or may damage the plumbing system. A small water feature incorporated into a rainwater harvesting system may be the best mechanism to monitor the filtration process and the desired purity of the stored water. This drainage section was specially designed for maximising water infiltration into the sandy subgrades.The natural grass sports complex equipped with this simple drainage solution does Grey water recycling: A good example not require a large and costly system to remove runoff from the 12 playing fields, and more of recycling grey water is recovering the importantly allows for maintaining pre-construction water quality and levels at the natural backwash from sand filters of a pool wetland adjacent to the site. system or from a playground splash pad for an irrigation system. Water collected from showers or the laundry may Saving initiatives require only minor processing before it can be re-used. A simple bioThe following are some of the most significant fresh filtration pond or trench may be sufficient to remove pollutants from water saving initiatives that grey water, making it suitable for non-potable consumption. Water efficient irrigation systems: Plants that have no access to landscape architects should ground water (e.g. those on green roofs) require an irrigation system. promote: The raised catch basins Rainwater infiltration:This A drip irrigation system installed entirely below the surface of the integrated into the rain gardens can be done via a number ground allows for minimising water waste through eliminating splash, within this residential community of simple and cost effective and providing water directly to the plantâ€™s root zone. Other water allow for collecting a portion of techniques that facilitate saving technologies (i.e. a weather station) allow for controlling the the runoff from soft landscape areas into the community water infiltration. For watering cycles based on the local weather conditions. retention ponds. Rainwater that Efficient water features: Wind, sun exposure and high water example, a PVC drain line is not removed from the site temperature increase evaporation from water surface; therefore, in a gravel-filled trench may recharges the ground water. location of the pool affects its water efficiency. Other water saving be installed Âą 10 cm above The collected water is used for landscape irrigation only during the bottom of the trench. techniques include selecting appropriate waterproofing systems, periods of drought. This allows rainwater from reducing the splash from water jets by installing a wind detector, small rain events to sink reducing a pool surface area or installing a pool cover, ensuring proper into the subgrades instead filtration and treatment of water that minimises the need for replacing of being removed by the water in the system. Use of indigenous plant material: Plants that grow naturally in a pipe. In another example, a shallow bio-filtration trench specific region are adapted to surviving local climatic conditions. together with a series of Therefore, indigenous plants may not require additional watering via an landscape sa - Mar/Apr 2018 23
This graph represents the complexity of the rainwater harvesting calculations aimed at designing the optimal size for a water collection cistern. It incorporates the monthly runoff supplies from rain, water demands for the selected water needs, collected water level at the beginning of each month and the potential water collection surplus or additional water top-ups, if needed.
irrigation system unless they grow within uniquely harsh environments such as under a roof or with no access to ground water. Eliminating access to water from even the most drought-tolerant plants will always result in their deterioration.
Finding creative solutions Professional landscape architects with multi-disciplinary skills are experienced in finding creative solutions to even the most complex multi-lateral problems. Solving some of these problems requires
complicated analyses of site specific conditions, calculations based on data collected from multiple sources and modelling of various design options. Ultimately, regardless of the project limitations, landscape architects strive to find the best possible design solutions that meet the needs of the project, protect the environment and deliver healthy and attractive landscapes. lsa Text and photos supplied by Pawel Gradowski, Managing Director, LASquare Landscape and Aquatic Architecture. Tel 072 655 0911
INDEX TO ADVERTISERS Bidvest Top Turf............................................................................................. 18
Multi Power Imports.............................................................................. OBC
Evergreen Turf............................................................................................... 10
Life Landscapes............................................................................................. 16
Wilson Stone................................................................................................ 10
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When you want the best, you go with the most experienced. After more than 50 years, we naturally know what weâ€™re doing, seeing we invented the zero-turn mower back in 1964. There can only be one original, and we have one for any task.
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