A problem, or an opportunity for a new landscape paradigm?
I was recently working on a tree project in Abu Dhabi when I came across a derelict site which intrigued me with it’s range of exotic self-seeded, non-native plants. The site was next to the Corniche and sandwiched between the Formal Park, my hotel and Capital Gardens. It struck me initially as the perfect basis of a xeriscape, as all the plants (mostly trees) were thriving without irrigation. On closer inspection and identification of the species involved, things got more complex and raised a lot of potentially conflicting thoughts and issues.
A natural Xeriscape
The site was clearly awaiting redevelopment and the plant invasion was opportunistic. Nothing that I could identify was native, yet all seemed happy there. When you see the list, you might understand why. Amongst the plastic and litter I identified:
- Prosopis juliflora
- Ficus benghalensis
- Eucalyptus glaucescens
- Conocarpus lancifolius
- Washingtonia robusta
Of those plants, the P. juliflora was the most robust and when you look at its reputation, that is of no surprise. It was of landscape scale, lush and greener than anything in the adjacent parks. It’s form, leaf, flowers and seeds are attractive from a landscape perspective. Yet this is undoubtedly the most controversial plant on this list – some would say alarming. A Native of arid zones in central and South America, this was, like so many others, introduced into the UAE in the 70’s as a forestry plant. Lauded as something of a super-crop tree, it is tenacious, vigorous, provids fuelwood and stock-feed in the form of abundant seeds. The latter, it turned out, were a problem in that they are spread by cattle and are extremely aggressive. Plants also regenerate rapidly from the roots when cut back and they reputedly produce biochemical inhibitors to suppress competition (allelopathy). With no natural competitors in the UAE and roots that can descend 50m in search of water, they out-compete native flora, even their cousin, Prosopis cineraria (ghaf tree).
Prosopis juliflora flowers
P. juliflora has a low, mounding habit, attractive from a landscape point of view.
Also on the site were a number of Banyan trees, Ficus benghalensis, which seemed to be growing happily. Another tough survivor, it should be borne in mind that the water table here is likely only a metre or so below ground, although it will have a high saline content.
Then there was Eucalyptus glaucescens, another forestry/amenity introduction of the 70’s, also known and now generally avoided for its aggressive roots, yet here looking beautiful with its grey, lanceolate foliage. This was the tallest tree on site.
Eucalyptus glaucescens, showing adult foliage
Of course, there was the ubiquitous Conocarpus lancifolius, widely planted still yet also recognised and a danger to any nearby drains, and on it’s way out in popular use. Except it does make such a good tall hedge, and it has a much nearer native origin, coming from Somalia, Djibouti and Yemen. I’m not sure that the UAE landscape industry is ready to ditch it just yet.
There was even a palm, Washingtonia robusta, self-seeded around the place. Much of it was to be found growing underneath the canopy of the P. juliflora, so that at least is not put off by any allelopathic biochemicals from the Prosopis.
There were also a few unidentified things, this shrub, for example. A legume of some kind, if anyone can ID it, please let me know.
Inhabiting, or at least visiting the site, was a Rose-winged Parakeet. Another exotic invasive with beautiful form but aggressive tendencies; it seemed appropriate to the moment, somehow.
What does this mean for future landscapes and ecology?
From a conventional ecology point of view, these plants are all threats, and the threats probably outweigh their usefulness. So why am I even talking about this? Clearly, the move towards more naturalistic landscapes draws heavily on native species and would shun all of these species.
Except we have climate change.
Climate change is the elephant in the room, when it comes to ecology, in fact when it comes to sustainability generally and a livable planet overall. That we have already moved beyond vital tipping points is highly likely; that climate zones are moving away from the equator at a rate too fast for nature to adapt is a fact. Flora and even some fauna just can’t move regions that quickly. They will adapt, eventually; but those that are rare, specialist and struggle with change, will die. The tougher generalists will adapt and survive. Nature will build a new ecology to reflect the new reality, and it doesn’t mind if it takes a few thousand years to do so. Only we humans mind and so, if we are to survive, we must adapt our environments to fit the new reality. It is a sad fact that many cherished plants will eventually die out or move zones. In the UK, I dread losing our native oaks (I view these as our ghaf tree equivalent), yet we may get Mediterranean species to replace them, such as holm and cork oak.
If you are already positioned in the arid equatorial zones then you have precious few plants that will form your new ecologies and landscapes. Perhaps the plants I have described above will be UAE naturalized-natives in 100 years’ time and the ghaf and sidr may be gone, or diminished, or moved north. I hope not, but before we spend vast fortunes on eradication and control of non-natives, we should look to the future. These aggressive invaders may just form the landscape of our children; I know I’d rather live with a landscape, than none at all. If there is no landscape, there is no life. They may, in fact, be here to save us.
Once we grasp this fact, we can look at building new landscapes to suit our changing environments. I’ve written about this before and you can read the articles listed below. We must be vastly more holistic in our thinking in order to do this and broaden our horizons to understand the new future. Technology will help us to monitor, collect data and produce working strategies. Robotics and drones will help manage and control plant communities. Alongside that, we need a vastly better understanding of soils, microflora and fauna, for the bit of nature that we see is just, literally, the tip of the iceberg. The selection of tree and shrub species for adaptation is easy, we get this wrong when we don’t deal in whole context thinking eg. only thinking of forestry or ornamental benefits.
The challenge ahead is huge but in a weird way, exciting; it will challenge the human race to grow. There’s a whole new science to develop and we’d best get on with it.
Other articles by ML that relate to this topic:
Posted in Arboriculture, Climate Change, Dubai, UAE, Ecosystem Services, Environment, landscapes, Middle-East, Natural Landscapes, Regenerative Planting, Sustainability, Trees Tagged with: Abu Dhabi, adaptive landscapes, biodiversity, climate change, Dubai, ecology, Invasive species, landscape, Middle-East, native plants, non-native, sustainability, trans-migrational landscapes, trees, wildlife
The way in which we design, create, maintain and use urban landscapes is likely to change radically in the next 15 years (in fact, modern society is in for overwhelming change). Urbanisation, climate change and the rapid rise of technology and artificial intelligence (AI) will see to that. Don’t think that the rate of change will be the same as has occurred in the previous 15 years, for technological growth is on an exponential growth curve, not a linear one. Cities and systems are becoming smart, connected to the Internet of Things and that is just for starters. So how will this change the way we design and use our urban landscapes?
Firstly, we know that there is huge movement of populations from rural to urban life, especially in the developing worlds and most markedly in Asia. This creates huge pressure for new urban infrastructure and this is not always well planned growth, especially in terms of forward thinking to account for future changes. Nonetheless, it is happening and happening fast. The UN expects 66% of the world’s population to be urban by 2050, by which time there will be 9bn of us – so 6bn in cities. Mega-cities have to grow in a way that sustains huge numbers of people.
Secondly, climate change is also occurring at exponential rates, raising the difficulties of living in any environment but with especial problems for mega cities, most of which are in coastal regions and subject to rising sea levels and worsening weather patterns. Cities are hotter than the surrounding land due to the nature of materials used, whilst heavy rainfall brings flash-flooding. In arid countries, built environments are in danger of becoming too hot for humans to inhabit. Cities will have to take on these challenges, generating micro-climate.
Thirdly, technological change is happening exponentially and this will impact what we do, how we live, how – if – we work and how we tackle the above problems. Some view the challenges and changes with fear, thinking they will only exacerbate problems. They could do, anything can be mismanaged (such as a planet) for example. I foresee that technology is actually the only way we are going to get ourselves out of the mess we have created, the only thing that can act on the vast scale needed to re-balance an out-of-kilter Gaia.
When we take these three factors into account, we can see that the future of urban landscapes has to be so much more than the addition of the odd pocket-park here and there. Landscapes have to mitigate the environmental factors, make huge mega-cities liveable for a population increasingly disconnected from nature and provide meaningful lives in an era when many of us may not work in the way we are used to.
Weedy and neglected landscape plantings are all too common. No-one wants to pay for maintenance
How will cities become smart and use this to better the environment? If we are looking to increase the amount of urban landscaping significantly, then the first issue to tackle is cost of maintenance. No one wants to pay for maintenance and often, no one does. How many planted landscapes do you see smothered in weeds, wrecking or negating the designed purpose? Or municipal plantings and car-parks where plants inevitably die and are never replaced, leaving huge gaps. Shrubs hedge trimmed into amorphous shapes because that’s the quickest way to “maintain” them. It’s a poor standard and it’s all we’re going to get – no-one is going to pay for trained horticulturalists to do something better.
Landscape lobotomy: maintenance is the quickest, cheapest possible
Yet there is an interesting possibility – automation is likely to remove nearly 50% of jobs in the next decade, especially low-skilled or repetitive ones. In the landscape trade, there are already semi-autonomous strimmers and grass-cutters on the market, how long before we have horticultural robots maintaining our landscapes? All the technology is already here, prices are falling and an uplink to an AI would identify every weed known, give the correct procedures, know how and when to prune every plant in common cultivation. Robots would work long hours without tea breaks! If basic maintenance getters a lot cheaper, we can have more landscape and such robots would be cheaper, eventually. Living walls would be a prime candidate, with a simple maintenance cradle (much like a 3D printer head) that crosses the wall with a maintenance bot on it. I’ve seen so many potential living wall projects fall at the maintenance-cost hurdle. In such a scenario, displaced maintenance crew can retrain as bot-supervisors or true horticulturalist for private clients.
Horticultural robots will make maintenance cheaper and more effective.
We’re going to have to do more than just make maintenance affordable; rather, that is the factor that releases the possibility to do more urban landscaping. Many of the elements we need to put in place are already in existence and being used, but we need to join the dots and think holistically. For example, green roofs are seen as a separate trade from green (I prefer living) walls. Instead, we need to be talking of biological membranes (biomembranes) for buildings, a whole-system concept, where the living skin regulates the internal environment, filters pollution in both directions, dealing with generation of energy, cooling, clean air and water. Living walls that currently use potable water for irrigation when they could be cleaning up the used greywater that all buildings generate is another example.
Building Biomembranes regulate building ecology and create vertical landscapes
Systems that provide services that are of consequence to the functioning of a building, street, or neighbourhood need careful management and control, much of which will become automated. In just the last year, for example, new irrigation controllers have come on the market which not only are connected to you via internet, they also connect to the nearest weather station and adjust their regime according to the conditions. I use these for living walls; I do not advocate any irrigation for horizontal landscapes in temperate climates. But things will move beyond this, with AI monitoring ground moisture levels and moving harvested rainwater from one holding system out to another part of the city where it is needed. And urban farming – especially vertical – will be a large part of mega-city greening, although it might not be on display. Sophisticated hydroponic systems are springing up in warehouses and roof-top polytunnels all over. Such food can and should be organic, local, healthy, nutritious.
A smartly connected landscape means we can maximize the benefit it gives to the people who live, work or pass through it. With the majority of people living in urban mega cities, we have to create an environment that is fit for ultra-dense urban living. As these metropolis’ grow, people will have less and less daily contact with Nature, which is not good for our deeper wellbeing. Biophilia is our innate need for contact with the natural world: plants, trees, flowers, insects, sunlight, water, earth. A concrete jungle is not a substitute for the real thing but we mostly won’t have time to “get out there” and experience wild Nature.
I think inner city pollution will blow over – excuse the pun- in the next 5-10 years as we start a massive switch over to electric transport, most of it driverless. In fact, drone taxis are already under development and as buildings and living habitats reach skyward we can expect the landscape to move with them. It will become commonplace to have high-level dronepads – even private ones. Some people might not even go down to the ground much! So landscapes and biophilia must come to them. Fortunately, there is a rash of building-integrated vegetation going on and I see this trend increasing. Incidentally, if you wanted more good reasons for using bots to maintain planting, imagine working on living walls or trees that are 50 stories up!
As for the wider environment and the looming crisis of climate change, I can only hope that emerging nanotechnologies give us the tools to clean up our act and neutralise the positive feedback loops we are creating. Scientists are already working on nanotechnologies which capture and convert carbon into useful materials and one day such microscopic machines may roam our land and seas, removing plastics and other dangerous waste. If this is done at a molecular level, we turn problems into resources. We’ll be printing our houses (already being tested) compounds made from waste materials but without the current worries of using say, bricks made from recycled plastic which off-gas VOCs. We can only hope these technologies emerge before it’s too late to save the climate in a state that we can survive in.
So the next 10-15 years are going to see change at an unprecedented rate and it may not all be a smooth ride. I am excited by it however and think that there is much to be done to ensure that we create new urban environments worthy of habitation and that we take care of all environments and indeed the whole planet. Smart cities are coming and at their best they could loosen our imaginations and liberate us from a monotonous life of work and stress. Let’s make that the scenario that happens…
Posted in Biophilia, Climate Change, Design, Ecosystem Services, Environment, Landscape Futurism, landscapes, living walls, Smart Cities, Sustainability, Urban Landscapes, Vertical Greening Tagged with: adaptive landscapes, artificial intelligence, bio-systems, biophilia, climate change, eco-system services, ecology, futurism, green walls, landscape, living walls, robots, smart cities, sustainability, urban landscapes, Vertical Landscapes
We are now a decade into the explosion of living or green walls. There have been many successes and some notable failures along the way, some of of which may be system-induced and some caused by inadequate or inappropriate maintenance regimes. Assuming we now have systems that work at least reasonably well, what is required by way of maintenance to keep walls looking good?
First of all, we have to acknowledge it is the large, commercial projects which get the attention and sit within the public eye. If anything goes wrong with these, it is noticed, big time. Commercial walls, I have found, are governed by financial pressures and that can sometimes mean that over time, budgets are cut and maintenance regimes compromised. When maintenance goes out to commercial tender, it is usually the cheapest price that wins.
Secondly, we have to understand that there is a profound difference in the way we perceive vertical landscapes from horizontal ones. With ordinary planting beds, we would plant probably between five and nine groundcover plants per m². Living walls are planted at between 30 and 100 plants per m², a highly artificial and crowded environment. Yes, we are treating these as groundcover which knits together, but unlike horizontal beds, gaps between plants are not deemed acceptable. It is also harder for plants to spread or fill in laterally, depending upon the system they are planted into. Visually, when you look at a living wall, you look straight on at eye-level, then upwards. So the lower sections of walls can come under intense scrutiny. Any failures have to be replaced and the rate is higher than that of horizontal planting, for the aesthetic reasons just stated.
Thirdly, living walls depend upon the right plants being chosen; they have to have the right characteristics of habit, growth and longevity. Some common garden plants are notoriously temperamental, short-lived or subject to pests such as the notorious Vine Weevil (which seems to attack an ever-increasing variety of plants). As a designer, I have previously used many plants that I don’t use now, and I find the list is shrinking, as you learn about a plant’s ruggedness over time. We are still pioneering a new methodology and now I’d rather use a smaller palette and feel more confident about it’s long-term success.
Fourthly, finally and perhaps of greatest importance, is the maintenance given to a living wall. I prefer the term living wall to green wall, because it reminds us that they are just that, living. They are also put into an extremely hostile and unnatural location and aspect. Sometimes those who look after them don’t do a good enough job. Many commercial landscapers are not horticulturalists and don’t really know that much about plants. That may sound shocking (and I’m pointing fingers at no-one, for this is just they way things are) but a Kew or RHS trained gardener is unlikely to be employed in a commercial company. Even knowing what to do for the best health of a plant on the ground could be inappropriate if done to the same plant on the vertical.
The pics above show living walls in three different systems, all in poor condition (including one using my older system); I’m not saying where or who because blaming is not appropriate nor my intention; rather, awareness raising is. The fact is that each and every system out there has good and bad examples to show. It is interesting to note that training efforts have been begun in at least one university, but this type of knowledge is a hands-on, college affair. Right now, it is only learnt on the job and this is art of the problem; many operatives simply don’t know their plants. If you don’t know the name, you’re not going to know anything about how it grows or when and how you should prune it.
My answer (and this goes much against my designer instincts) is to restrict the planting palette to those most able to survive. I always want to use more varieties, but it is sobering when you see them dying because they can’t cope with the conditions, or falling off the wall because the roots have been eaten by Vine weevil or millipedes. Beautiful grasses that have high levels of old, straw-like debris among the new healthy leaves are a no-no and geraniums may or may not look good in the winter months; such plants must be used with care. Patterned designs seem to fall by the wayside too; bold swathes are fine until one species fails and dies back, then you are left with a gaping wound.
So you may be thinking, should we do this at all? My answer is an emphatic yes, we should and must. We need to green the vertical in cities, for it is often the only space left available. We have all the needs of biodiversity, pollution mitigation and biophilia to account for and living walls provide those where no other greening method can – not even trees. We still have much to learn however, and the skill of maintenance has to be appreciated more by all involved. In fact it needs to be venerated and it’s practitioners respected and paid more.
Systems, at best second or third generation, need to evolve and be better understood. Or rather, plants need to be understood more, and their optimal needs met. We have, as I keep saying, hardly scratched the surface of what is possible and of what needs yet to be done. We need to learn more, try more and expect more.
Let’s get to it.
Posted in Biophilia, Climate Change, Design, Ecosystem Services, Environment, Green walls, landscapes, living walls, Sustainability, Vertical Greening Tagged with: biodiversity, biophilia, green infrastructure, green walls, living walls, maintenance, sustainability, urban greening, Vertical Landscapes
I launched my newsletter this week on vertical greening, sending it out to clients and those who’d signed up here or on the website. From the number of views and feedback, (considerably higher than industry standards) I’d say it was a success! The aim is to inform interested parties of news and developments in the field of vertical greening.
Don’t miss the next issue – sign up using the form on the right!
Posted in Arboriculture, Biophilia, Design, Dubai, UAE, Environment, Indoor Plants, living walls, Retail, Sustainability, Vertical Greening Tagged with: green walls, living walls, newsletter, sustainability
Reporters always have to grab a headline, so I shouldn’t have been surprised when the new green wall near Victoria station started grabbing headlines such as “London’s largest living wall prevents flooding”. It’s a misleading headline to say the least: A, it’s not the largest wall, that “accolade” (if size is all that counts) belongs to Patrick Blanc for his wall at Leamouth Peninsular, constructed by Biotecture in 2009 and B, it doesn’t prevent flooding. How could it? Striding about, with a big umbrella? No, it has rainwater harvesting – as can any building, regardless of whether or not they have green walls (although they then have to have some use for it, such as flushing toilets), and that helps absorb water and delay rainfall from contributing to stormwater runoff. It may directly capture a small amount on the surface of the wall, but not much.
Rubens Hotel greenwall by Gary Grant and Treebox
Now don’t get me wrong; this is a lovely green wall and most welcome. I know all the guys involved and they’re all genuine people. The wall will have many environmental benefits. No, what bothers me is the way the press grab shallow headlines that reduce the very real benefits to glib catchphrases, often completely divorced from meaningful context . Of course rainwater harvesting reduces the risk of flooding, but one small scheme in a large area will have negligible benefit (just as the Edgware Road wall I designed for TfL will, on it’s own, have a negligible effect on air pollution); unless many buildings in that area follow suit and harvest rainwater, the impact will not be felt.
What walls such as this do, is pioneer and display the possibilities of what we may do and the potential outcome if we do enough of it. But the current attitude is, right, we’ve put up a green wall/green roof/planted trees, so job done, environment’s sorted… it’s just so NOT.
Right now i’m frustrated by this attitude. For example, it seems that government, having done their bit (on air pollution, mentioned above), now have no monies in the “clean air fund” to take things to the next level; where we so urgently need to be going. The simple reality is that a lot more testing is needed, more system trials; ways need to be found to effect a large-scale roll out of affordable greening (a major criticism is that the technology is too expensive). If the government won’t make funds available to do this, even in the face of massive EU fines for breaching air quality standards, then who will? So the Edgware Road green wall becomes just another political chess piece, used then forgotten once it’s done it’s short-term bit of marketing.
It’s time that as a society, we grew up, stopped living off of vacuous soundbites and got to grips with our environmental issues. One headline I got from a talk I gave last year, was “designer calls for environmental efforts to be put on a war footing”. Another bit of melodrama, but I did use the phrase, and meant it. Only with that level of serious intent and commitment can we get to make meaningful progress on adapting our societies to the incoming effects of now unstoppable climate change.
Time to get real…
Posted in Climate Change, Ecosystem Services, Environment, living walls, Sustainability Tagged with: climate change, eco-system services, flood mitigation, green walls, living walls, Rubens Hotel
I came across some interesting vertical greening at Borough Market recently, in a glazed atrium/entrance space called the Market Hall which served as a place for people to relax, sit and eat.
Hop Plants in containers
The plants were obviously chosen for their connections with food, so the climbers were hops (used mostly for beer making) and there were an array of edibles in pots which spiraled up around metal columns; mind you, I wouldn’t like the job of watering, as there did not appear to be any automatic irrigation fitted. Olive trees were fitted into various seating units.
It made for a lively space and was an created in conjunction with Natural England and Bankside Urban Forest. I will be interested to see how the hops will do over time, not being in a fully outdoor environment, and I imagine they will still lose their leaves during winter, as it is (I presume) an unheated space. It always has to be accepted that plants used in close urban environments might be shorter-lived and require more care than in more natural circumstance, but I think that just goes with urban living.
A great initiative, let’s see more such spaces where people get close contact and interaction with plants.
Posted in Biophilia, Edible Planting, Indoor Plants, Sustainability Tagged with: Borough Market, Edible planting, Herbs, Indoor Planting, Natural England
I’ve written before on the subject of adaptive landscapes and trans-migrational landscapes but I’ve been reading recently of a real-life ecology that was created by man in the last 200 years, and is thriving. This is on Ascension Island in the South Atlantic Ocean, a once barren volcanic rock, which is now a thriving cloud forest, created in a somewhat uncoordinated way by successive generations of British sailors and governors bringing plants from all over the world. Where there were once just 25 species, there are now over 200, as this article tells.
Non-native bamboo and moss create homes for native ferns. photo Fred Pearce.
Whilst this example may be a one-off, it is nonetheless a hopeful sign. If new and thriving ecologies can be created with little real thought and science, it gives hope for what we can do if we put our minds to it.
In my previous articles mentioned above, I outlined the reasons why this is necessary. To recap, it is due to the planetary changes that are now occurring, whose effects we have yet to fully experience, which is going to change this planet for millennia to come, even if we get a grip on carbon emissions, which we must of course do. If we don’t, runaway climate change could make this planet largely uninhabitable (at least to higher life forms). Ecologist have to radically re-think what they consider to be ecology, for Nature cannot adapt the landscape at the rate of our man-induced changes. That means that species cannot adapt and move with the shifting geological region of the climate zone they are used to. Zones are moving North and South, away from the equator at a rate which may change 20% of the world’s climate zones by the end of the century.
Of course, Nature will correct things given time, but mankind cannot afford to wait, if it wants a planet worth living on – and the ability to live on it. That’s why the Ascension Island story is such good news. I would dare bet that we could extensively re-vegetate (or terraform, to use a word found in science fiction stories) areas within a 50 year period if we turned our minds to it, and our political will.
Ironically, I can see some of the stiffest opposition to this coming from conservationists. Much is made of the negative effects of the global migration of plants and insects, but we have to balance that with the positive gains, which are seldom mentioned, yet so taken for granted. And the planet is going to change now, whether we want it to or not. I’d rather the UK (for example) had a Mediterranean flora and fauna than none at all. We may one day grieve the loss of our native oaks, finally unable to cope with the higher temperatures, but we would surely welcome the holm oak (already naturalising in the South coast area), cork oak and olive here. Having an ecology of beauty and abundance is what counts now, not preserving what we are used to having. Get used to that; it’s already too late.
But new adaptive ecologies, created by transferring plants, insects and microbes from other similar zones in the world, would give us a new practice, that of trans-migrating landscapes, and a new science, a new understanding. In this we must learn not to manipulate, but to understand Nature, to assist in what she would herself do, but over millennea. And we must do it within a lifetime.
Best get started…
Posted in Climate Change, Environment, landscapes, Sustainability Tagged with: adaptive landscapes, climate change, ecology, sustainability, trans-migrational landscapes
This ASLA (American Society of Landscape Architects) animation does a great job of explaining the need for trees. One minor criticism: the part which shows the trees’ underground root structure shows it way too small; should be at least twice the radius, if not three times. Never mind, worth a watch:
Posted in Arboriculture, Environment, landscapes, Sustainability Tagged with: climate change, trees, urban heat island
I’ve been reading several websites by visionary developers in Azerbaijan, who are proposing some massive Dubai-style developments to the Bay area of Baku, the country’s capital. One, the http://khazarislands.com/ seems like an ambitious Dubai-competitor, an ultra-sleek development on up to 30 artificial islands (think the Palm Jumeirah), the other is based on an existing island and whilst just as pretentious, http://www.ziraisland.com/ at least aims to generate all its own energy from renewables, and to be carbon-neutral.
The buildings are all based on the forms of nine iconic mountains in the Caucasus Range. Actually, not a bad idea from the point of view of seismic safety and thermal efficiency etc. Serious plans to make a huge modern metropolis that is self-sufficient are rare, with perhaps only the Chinese actually trying this with some of their Eco-Cities.
What is needed is to develop a coherent urban greening policy to integrate technologies like living walls and urban tree planting and care, with a carefully thought out irrigation policy. People still don’t see how essential green walls will be in integrating ecosystem services into a buildings basic functionality, but it will come. Let’s watch with interest.
Posted in Arboriculture, Biophilia, Climate Change, Dubai, UAE, Economic Issues, Ecosystem Services, Environment, Green walls, living walls, Middle-East, Sustainability, Trees, Vertical Greening Tagged with: arboriculture, Azerbaijan, bio-systems, biophilia, Dubai, green walls, living walls, Middle-East, sustainability, sustainable, Vertical Landscapes
Last year some interesting work emerged over the use of green walls for mitigation of air pollution; in particular the ability (or otherwise) of plants to remove particulate matter from the air, with pm10 being the size range focussed upon. This is the particle size most emitted from diesel exhaust, and this does a lot of damage when breathed in.
Like many cities, London is constantly breaching WHO and EU pollution limits and has the threat of a 300m euro fine being levied. Of course, the pollution is nothing like that in the news recently from Beijing, which is largely caused by the low quality coal that fires their electricity generation plants, coupled with cold winter air, which traps pollution in.
So the Mayor’s office set up the Clean Air Fund, and put £5m into research – a tiny amount compared to the fines, but better than nothing. A tiny amount of that was used to put up initially one, then two green walls, which were to be monitored by Imperial College London to see what types of plants trapped the most particulate. Biotecture put the first (and principle test wall) up for transport for London on the side of Edgware Road tube station, right by the Marylebone flyover, one of London’s worst pollution hotspots. The second one was added rather later at the Mermaid Theatre and was done by ANS.
The Green Wall (designed by me) at Edgware Road
I chose 15 species of plants which I knew would take the South facing aspect of our wall and which had smaller leaves – research told me that smaller, hairy leaves were the most effective at trapping particulates, and made sure the species were present across the whole height of the wall. Past research in Germany on Climbers had shown that plants trap more particulates at height, around the 4-5m mark. As it turned out, UCL only collected leaf samples from the pavement level, despite there being roof access where some sampling could be taken, and they only did this for about nine months, so I feel sure that the sample results are insufficient. Nonetheless, they showed a definite ability to capture particulate.
We have barely scratched the surface and what’s needed now are sustained and serious trials to gather more comprehensive results under widely varying conditions and climates… sponsors anyone?
Posted in Design, Environment, living walls, Sustainability Tagged with: Edgware Road, green walls, pm10, pollution entrapment, TfL