This is last in a four-part series of articles on this subject, somewhat separated from the other three by time, because of COVID. Links to the first parts are at the bottom.
In searching for a new way of creating natural, non-irrigated landscapes in the Middle East, I have already shared how certain species, often non-native, will regenerate on abandoned brown-field sites across the Middle East; my personal experience is from observations in the UAE but I suspect this holds true across most of the region. I have suggested that to recreate such unirrigated landscapes (xeriscapes), designed with conscious intent, we must seed them, rather than plant. That sounds simple, but is actually quite complex and reveals yawning gaps in design and horticultural knowledge, as well as seed supply. So how could we rectify that?
I think the UAE in particular needs a place of horticultural learning, but I don’t mean just a conventional horticultural college (though it needs that too), but a place to test and learn new things. Perhaps that would be a botanic garden, but one focused on future adaptation rather than what is or was; seed collection is generally part of the remit of such places. There was one being designed in Sharjah, but I understand that is not going ahead, which is a great shame. Such knowledge is desperately lacking in the region. It is also true that the UAE needs much greater horticultural and arboricultural knowledge and practice, to advance all standards and methods of care. However, to achieve what I propose, such a place would have to first study, trial and learn, then disseminate new techniques.
There is a huge volume of knowledge needed, of soils, species, of seed gathering and storage, seeding trials and combinations and of how to design, create and then manage such landscapes. The one thing we have to realise, is that this approach is contrary to pretty much all conventional landscape and horticulture conventions and practice. In fact, the best place we can look for inspiration and instruction is in permaculture (see Greening the Desert) and regenerative agroforestry. Such practices are gradually moving from the fringe into mainstream thinking, for one simple reason: they deliver results with relatively low inputs. The principle difference here is that we are focussed upon novel ecology building, rather than food production. That doesn’t mean there wouldn’t be food produced, or other useful products.
The “dream team” that might be assembled to carry out such work, might include:
Ecological landscape designer
To me this is exciting and a combination all these elements would emerge as a new land-management practice that could be utilised in many parts of the world. It is the Middle East and other arid regions who need this the most; if through the effects of climate change the native flora should fail as the environment becomes ever more hostile, what will replace them? We need to tip the balance towards resilience first, then regenerative ecosystems. As wet-bulb temperatures threaten to reach the 35°C and make the Middle east uninhabitable, we need to employ the benefits of evaporative cooling on a massive scale.
So how do we design such landscapes? First, we should see this as the creation of novel ecosystems: new, functioning ecologies that serve the needs of the moment and are adapted and will continue to adapt, to changing climatic conditions. As such, they will be a mix of natives and non-natives, even some plants labelled “invasive”. The key to this system is long-term development and management as a resource. In my last article (third in this series) I looked at the effects and benefits of coppicing as a system of management, a source of mulch materials and so the generation of fertile and water-retentive soils. Such landscapes, created en masse (think of green corridors surrounding cites for hundreds of miles) would have a major beneficial effect in mitigating the heating effects of climate change, moderating dust storms and absorbing the occasional but problematic flooding from rainstorms.
Next, we have to understand the nature and habit of the particular piece of land we are dealing with. Key to success is the capturing of whatever rainfall there is (as mentioned above, even Dubai has rain – and occasional floods). We need to encourage and enhance the capture and retention of this rainfall with the use of contoured swales, heavily mulched. Even small changes in elevation create micro-climate and a plant’s success may be favoured by a few inches of contour. We also need to maximise the soil’s ability to retain that water with the addition of soil ameliorants and organic matter (the aforementioned mulch). We might band the planting into ribbons that follow these swale contours, and choose different plants in different bands. It is at the transition between different eco-zones that we get the greatest diversity of species, both flora and fauna. It is possible that if carried out on a large enough scale, such landscapes might have a benign effect on the local hydrology, even inducing rainfall. Whatever the potential, this needs serious effort and resources to implement and that implies government backing. Pilot schemes could be carried out though, on a small scale, with the backing of ecologically aware business and/or philanthropists. I’d love to have some conversations!
This concludes my series and my thoughts so far. As an observer and some-time participant in aspects of landscapes of the Middle East (particularly trees). I may be very wide of the mark here, or I may just have spotted something that hasn’t yet been thought about. What I do know is that the ME region will desperately need to create ecological resilience and buffers if it is to remain habitable over the next 100 years.
The first three articles in this series are below:
A tide of change is sweeping the world, changing all before it. Where we will end up, no-one knows, but things will not be the same again, nor will Coronavirus – COVID 19 – go away in a few short weeks. Yet amidst all the fear lies a golden opportunity to reset the way we live, change the world economy and mitigate the worst of climate change. The outcome could be a better society and quality of life, but there are no certainties it will happen.
Fifteen or so years ago, I thought the world crisis would be about energy as we hit “peak oil” and supplies started to become more expensive. In July 2008 oil costs hit an all-time high of $147/barrel and was part of the cause of the recession of that time. Energy demand appeared to outstrip supply, although the surge may also have been brought about by speculative trading. According to the IEA, peak conventional oil production occurred in 2006; if so, this has since been masked by the production of unconventional oils and the rapid rise of solar and wind, which are now cheaper than coal. The crisis was postponed, then forgotten by the majority. Right now, in the midst of this C19 crisis, crude oil prices have fallen, in some cases to unparalleled lows. This will price fracking and shale oils out of the picture, but will damage the renewables market too.
In recent years, the climate has come into focus and a global outcry arisen at the lack of concerted government action. This outcry was 20 or 30 years too late, although it may have needed a generation who would actually look at the issue. The high level of action demanded to counter the climate catastrophe never materialised, instead it took a microscopic virus to galvanise the world into drastic action. The action, of course, was for self preservation against C19, yet has the (temporary) effect of being action against the world’s level of carbon emissions. Why we couldn’t see the need for such self preservation against an uninhabitable planet, I don’t know; a matter of scale, perhaps. If we live just nine meals from anarchy, then it implies we also don’t look much further ahead than that. At least governments can no longer argue that we can’t put in place climate solutions quickly; Coronavirus has blown that myth out of the water.
So the question is, what happens next, once C19 is “under control”? I believe that governments and business the world over, will try to kick-start the same old system, get the economy going again, and resume business as usual. Or try to. I don’t think that the C19 story will be over that easily; I’ve heard from people that know better than me that it likely to return in waves, or cycles, perhaps as often as three-monthly. Even if this only happened every few years, the economy would get hit and stall again, start up again, stall again. Governments will respond in one of two ways: totalitarianism, like China and populist regimes, or co-operation and people-centred policy like some more enlightened countries. Certainly, those with populist leaders appear to be heading into deep sh*t, like Brazil and the USA. Time will tell, we can but watch.
This on-going wave of multiple crisis will eventually cause a global rethink and a difficult switch to a circular economy. Resilience and just-in-time linear supply are not really compatible, as has been shown by recent events. So far we have been lucky in that the shortages on the shelves have not actually been production shortages but those caused by excessive demand, but the next wave of them may be as companies struggle to fulfill orders and deal with near-bankruptcy, staff and material shortages and transport problems. God only knows how this will play out in third-world countries.
We may never be able to travel the world again in the way we did before and that will be a good thing overall. Travel has become easy, cheap and taken for granted. As a result, I don’t think people actually appreciate the value of the experience and the environmental costs are high, not just in terms of aviation. Global hotel chains and the hospitality industry now sway on the brink. I speak here as one who loves travel, and I have often worked in the Middle-East. I was in Dubai in February, which seems surreal now; it may prove to be my last visit.
I read of the intentions of huge mega-projects in Saudi (for example), aiming to get right back on track as soon as possible, to build vast new resorts, even cities. Even if such things can now be afforded, I just cannot see tourism ever being quite the same again; the blind insistence in business-as-usual worries me a lot.
On the positive side, we may come to see travel as more of a land-based adventure. When I was twenty, I traveled (hitch-hiking) over land and sea from the UK to Tunisia; it took 16 days and was an amazing experience, better than the actual arrival at my destination and the short flight home was an anticlimax. Travel broadens the mind, but that cannot be said for a lot of tourism, where there is minimal contact with cultures and holidays become a voyeuristic selfie-fest.
Business will travel less and go virtual, both nationally and especially, internationally. A lot of meetings that I used to travel to London for are now virtual and will probably remain so afterwards; as with many conferences and seminars.
One good thing that has been emerging over the last few weeks has been the reprieve of nature from the effects of pollution. Images of murky waters turning clear, wild animals wandering empty streets, clear air over smog-riddled urban centres, empty roads, quiet skies. It’s as if the world was acting in concert to mitigate climate change. Again, it’s showing up the lie that we can’t act faster to bring carbon under control; which is the larger threat to our survival? We act from a place of fear to an imminent medical emergency, whilst barely moving on the slow-motion tsunami that is on the horizon.
If we take the principles of Gaia, or just think in terms of natural systems, C19 could be the planet – Nature – giving us a really big shake up. It seems that these viruses (there are many, many more) are emerging from an over-intensive contact and abuse of nature, specifically in the harvesting of wild animals for meat. Gaian principles might well expect to re-balance an out-of-kilter system, for we humans have become a cancer in our destructive habits and for all our consciousness, we act without thought or regard to the consequences. Nature would do far better without us, something we should keep in mind.
On the positive side, there is much effort to bring about the emergence of regenerative agriculture, socially responsible business, environmentally beneficial ways of living and reduced consumption and pollution. These are nice – and essential – ideas but you only have to look at how Trump is wiping out environmental protections, how big business is maneuvering for the come-back and how China is commissioning vast new coal-powered energy capacity to see this is not likely to go well.
What MAY force through the necessary changes of behavior, is going through the cycle of pandemic-recovery-pandemic that I outlined at the beginning; the old system needs to be shaken and broken up thoroughly before the new can emerge. Unfortunately, we are in for a pretty rough ride.
Better buckle up, and see how we can all adapt and prepare.
This is the third in a four-part series. In previous articles (links at bottom) I talked about the spontaneous regeneration on brownfield sites in the UAE and the utilisation of seeded landscapes to create semi-natural ecosystems without irrigation. Another factor of these landscapes would be to make them productive in a way that would enrich the soils of not just that landscape but, by the production of useful products, returning fertility to the soil for both the site concerned and also urban landscapes and gardens elsewhere.
Coppice woodland is not a term that you normally associate with the Middle East, yet there are many trees, both native and introduced, that would work in this manner. So what would be the point? Well, we have become used to landscapes being either for agriculture, or for ornament, yet this simplification overlooks the fact that we can have landscapes that are multi-functional and that they can also be productive in other ways.
To understand this concept, we should look to agroforestry, or forest gardens, where multi-functionalism is the order of the day. We think of these systems as being in tropical or temperate regions, yet there are many plants that can be organised and used in this fashion in arid lands. I want to focus this article on one aspect only, the production of biomass. Biomass has multiple functions: the production of poles for building and firewood, compost, and when shredded, mulch. We can produce biochar, which is seen as an increasingly important part of long-term soil enrichment and carbon sequestration. There are also food and fodder crops which would be a valuable product, dependent upon species. And of course, verdant biomass supports verdant wildlife.
Many of these plants are also nitrogen-fixers and these are especially valuable for building fertility and assisting the development of other species. Whilst some may have allelopathic properties, which inhibit the germination of other seedlings within the root zone, my general observation is that this is not particularly effective, nor a problem.
So a list of trees that would grow in the Middle East unirrigated, can be coppiced and are nitrogen fixers, would include:
Acacia (Senegalia) senegal
Prosopis cineraria (possibly)
Other species, coppicable but non-nitrogen fixing, would include:
Azadirachta indica (assumed from observed regrowth)
Conocarpus lancifolius (assumed from observed regrowth)
There will be many other species that could fit these lists, but it’s a start. Many ornamental trees, such as Millingtonia and even Delonix show tendencies to throw up epicormic growth from wounds and therefore, in theory might coppice, but I am concentrating on trees which can do this without irrigation.
It’s important to say right here that this shouldn’t ever be designed as a monoculture; there is sound ecological reasons to to maximise the diversity of a planting. Naturally, you wouldn’t use everything, for conditions will suit some better than others for any given site. Nor would you coppice everything all at the same time. Staggering the harvest evens out the work-flow but more importantly, creates communities of plants at different stages of growth. The “edge zones” are always where the greatest biodiversity occurs, for you get the overlap of differing ecologies. Whilst each species will have it’s own regrowth rate and optimum cutting cycle, this can also be varied, according to the use of the product.
Of course, there is a problem, for many of these species are incredibly thorny, which is a real issue for those carrying out the coppice-work. Young vigorous growth also tends to have the most vicious thorns! On a larger scale, it may be possible to use forestry-style Forwarder tractor-trailer units to collect the brush and load it directly into the chipping machine hopper, without human intervention. Someone’s still got to cut it and do initial handling though.
So how do we express this idea, of coppiced woodlands, arid-land style? it would depend on context but there are several approaches we could take. On a large scale, machine operated (as mentioned above), we would have to do traditional layouts with alleys or rows, firebreaks etc. Mixed planting though, would be preferable although strips of one species are possible. If kept narrow, with different species to either side, the effect ecologically would be similar to mixed planting.
In smaller areas, or where human interaction is intended, then these could take the form of the mixed, seeded landscapes that I discussed in my previous article. In other words, we can combine the function with the elements of aesthetics and ecological diversity. Not to mention desert reclamation. Remember, all this is proposed as unirrigated land. The verges along main roads are a prime candidate, instead of over-manicured lawns and hedges that you see at many junctions.
My next article will discuss design, the knowledge and training needed for the creation of such landscapes. I believe we could transform the landscapes of the Middle East, without the intensive irrigation that is required by conventional approach.
In part one of this four-part series, I discussed the colonization of brownfield sites in the UAE’s cities with a range of trees and shrubs – almost all of them “exotic invasive” species. I argued that these could be forming the basis of new, adapted ecologies. To revise those arguments, please the link at the end of this article. The next question is, once we accept this premise, how do we create these new ecologies as a conscious expression of our own adaptation to climate change?
First, let’s understand that we need these landscapes to be unirrigated. Why? Well, in the Middle East especially, water is a precious resource and expensive; the UAE is particularly bad, with a per capita use of 550 litres/day. So with landscaping, let’s keep the irrigation for the urban centres, parks and gardens. If we just focused, for example, on all the miles of roads and interchanges between Dubai, Abu Dhabi and Al Ain that are irrigated, and imagine these replaced with unirrigated greenery, the water saving from this alone would be massive. Yet that is an immense challenge, for as soon as you plant something in a desert, you must water it.
If we want a vibrant plant ecology, then we also need a vibrant soil ecology, something that conventional landscaping ignores completely
I think this is the key, that planting in such a climate rarely establishes without help, whereas seeds can. What we need therefore, is a methodology of establishing and maintaining, seeded landscapes.
It is true that in a scenario where we are consciously creating an unirrigated landscape, we would want to greatly increase the odds of establishment. In this respect, much detailed assessment would need to be given to soil amelioration. If we want a vibrant plant ecology, then we also need a vibrant soil ecology; this is crucial and something that conventional landscaping ignores completely. A large part of this would be creating contour swales across the site to capture whatever rain falls and to ensure it soaks into the soil. Even a small change of elevation can change the conditions and so the ecology that can grow there.
Once we’ve created swales, can we build a healthy soil, rich with microbial activity and naturally water retentive in such an arid climate? I think we can, but we must first change our thinking from one of assisting landscapes with external inputs (irrigation) to that of creating self-sufficient ones, with cyclical, living, self-sustaining ecologies. Soil becomes the vital kingpin in all this, not just an anchorage medium for plants.
Native soils need to be worked with, not replaced. They can be moderated, made more moisture retaining, but basics like salinity and pH will always dictate plant choice. First and most important, is to increase the soil’s water retention capacity. There are a number of ways to do this, involving additives which may incorporate clays, granules or other water-holding mediums and we know that when used in irrigated landscapes, they can reduce water demand by up to 50%. Given that an unirrigated landscape might have periods of time when it is extremely dry, we need a medium that doesn’t become hydrophobic if it does dry out and that will react swiftly to absorb water when it does arrive.
We can also inoculate the soil with mycorrhizal fungi cultured from local, healthy environments to enhance soil micro-ecology; there is little point in importing this from another part of the world, as the relevant strains of microbes are likely absent. Microbes and bacteria are the essence of good soil. Many of the plants used will be nitrogen-fixers, and so live in a symbiosis with certain bacteria. They also make nitrogen available to other species, as cycles of life and decay build up.
Organic matter is essential and the best innoculator of bacteria and fungi, but it can be the most problematic element as it is in short supply. One aspect of the practical usage of such landscapes, and a part of the long-term management, can be the coppicing of trees and shrubs for biomass to make compost. Organic matter tends to oxidise if conditions are not conducive, so we need to get things right, but I’m sure that even desert soils can sequester carbon, given the right conditions.
We would need to mix these various elements into the soil to the appropriate depth, perhaps a metre, probably by air injection, and possibly to different depths for the different mediums. Soil preparation becomes the most major, one-time investment in the land but will pay back endlessly over the lifetime of the landscape.
Once the preparation is done we have to seed the land, when conditions are optimal (not when contract deadlines require); this would have to be timed after rain, if possible. Otherwise, I would give the land a soaking, with our soil amendments helping to retain the moisture, then apply seed, in a variety of ways, possibly by hydra-seeding. Finally, a locally-sourced stone mulch should be placed over all, to again help retain moisture, but not too thick to inhibit germination. This would be the entirety of the preparation and installation work.
Next is the nurturing stage, followed by on-going management and maintenance; this will be very different from a conventional landscape, but no less intensive, at least for the first few years. It may be beneficial to give additional watering to aid plants as they germinate and establish, but this must be done with care, or seedlings could be washed away. We would need to give enough to ensure success, but no more.
Once established, these plants would grow at whatever speed the conditions allowed and a new landscape would emerge over time. Thinning out and reseeding of failed areas would be the main work, acts of stewardship rather than maintenance. Prunings shredded and spread as mulch, soils fit to support life, insects, animals and birds would soon make this place their home. The result would be a slow and genuine landscape uplift into the realms of a new and adapted ecology.
How we design such landscapes, choose which plants to use, obtain the seed and know how to maintain them, is the subject of the next article.
This is the first of a four-part article, links to the others are at the end.
These articles are all a part of the same thought progress, which has been brewing for some time and started with an article I wrote two years ago, in March 2018. I think this is an important subject, and hope that you’ll agree and read them…
Whenever I am in the UAE, I find time to visit various parks and gardens; on my latest trip to Dubai (February 2020), I went to see Al Ittihad park, a well-kept secret in the spine of the Palm Jumeirah, underneath the monorail, which was designed using native and naturalized plants of the UAE. It also, the blurb said, promised everything was labeled, so ideal for a crash course in local flora. The park was interesting but unfortunately all the labels had gone, and it was being maintained in the manner of all landscapes; incorrectly, especially so for native planting.
Of equal or greater value, however, are
simple walks around the back-streets and suburbs of a city and I find empty
brownfield sites, awaiting development, often offer the best insights as to
what will actually grow in an arid region, if things are left to their own
devices. It’s more than you’d think, and
it’s not all native. I’ve written about
this before, in this article and I’m building here on my earlier observations.
The world is gripped in fear of biological invasion, currently of Coronovirus but I’m talking here of the floral kind. Globally, there is a growing passion for conservation, restoration of what was, of what we think of as native and right. We seem to think that in taking this approach, we are setting right the wrongs we have done; nothing could be further from the truth. Fortunately, Nature doesn’t share that passion and is busy dispersing its flora and fauna around the place, wherever and however it can. That it uses humans as vectors for that dispersal, is obvious, if you just look upon it from a wider perspective. Perhaps Nature knows something that we humans are trying hard to ignore; that the climate is changing, the rules of life are shifting, that ecologies need to adapt to the new conditions.
I think we humans are both arrogant and ignorant when we say, “that plant doesn’t belong here, we must get rid of it”. Plants that arrive and succeed are the pioneers of a new, adapting ecology; yes, they are aggressive, yes, they grow without restraint and colonize -usually – disturbed ground, yes, some make monocultures. Like all pioneer species they are fast, competitive and relatively short-lived. But they establish life and the conditions for the next species of successional plants to come along. All parts of the world are, or soon will be, under such huge environmental stress that we must actively embrace change and nurture these new ecologies. We cannot live in a world without complex ecology, nor can we hold back the change, so we have to go with it.
To come back to my brownfield sites, on
my previous article, linked above, I encountered the following trees growing on
a brownfield site in Abu Dhabi:
From recent observations in Dubai I can
add the following trees:
Plus the Prosopis and Ficus from the above list.
From the looks of it, this site was
more recently cleared than the Abu Dhabi one, and trees appeared to be no more
than 2-3 years old.
There were also a range of groundcovers
and grasses growing; I haven’t been able to ID them all, but some I saw
Such plants are equally important in
building new ecologies, and a big part of the whole. There are of course, a huge range of native
or adaptive plants not represented here, which would nonetheless grow, given
These observations might be interesting, but how useful are they? If we think of conventional, irrigated landscapes, perhaps not very useful at all; we know and use many of the trees already. Where this becomes interesting, is in that they self-seed and establish without any human intervention. If we could master the art of this, then such landscapes we would nurture and manage, with occasional thinning, removals, perhaps some sucessional seeding or planting. Imagine this on a large scale, in peri-urban locations, alongside roads, at intersections, instead of the over-watered ornamentation we see now throughout the UAE. We then save the ornate for the urban parks, streets and gardens.
Could this be the basis for a new approach to creating landscapes and if so, how would we do it?
Gravel gardens have been around a long time yet with a few well-known exceptions (Denmans, Beth Chatto and more recently, Olivier Filippi), never really make it into the mainstream of garden design. I suspect that for some designers, there is insufficient structure to satisfy, yet that is actually one of the main benefits. This makes them low-impact, from a carbon perspective, and naturally adaptive, with the kind of planting they use.
I have been designing such gardens for the past twenty plus years, and a part of my own garden is gravel, on the area of an old driveway; it’s the part I enjoy the most. Unlike perennial borders, there is structure all year round and I often wander around in the depths of winter, enjoying the shapes and forms, or the scent of rosemary (sorry to say, now officially Salvia). It’s like you’ve brought a little bit of the Mediterranean into the garden. Plants self-seed around and it’s always a bit different every year. It’s a style also eminently suitable for the arid regions of the Middle-East, whether xeriscaped, or not.
Not everywhere is suitable for a gravel garden and the obvious criteria of sun exposure and poor(ish), free-draining soil are a must. Whilst drainage and soil structure can be altered, aspect cannot. The other factor, frost/cold exposure is actually not such a barrier, although it will limit the plant choice a bit.
Some years ago I was tasked with turning an old farmyard on the South coast of England into such a garden. The compacted rubble base was on average 50cm deep, so we loosened and/or removed about 400 tons and replaced a similar amount of topsoil into slightly contoured mounds. As it was a farm, the soil was already available stacked on site and there was somewhere to remove the rubble to. We then rotovated 50cm of gravel into the mounded soil to improve drainage and planted with a range of “Mediterranean” plants. Most were from this region, with some Australian/New Zealand species, most notably Phormium (which I probably wouldn’t use today). We also built a stream and water feature, using 30 tons of boulders (glacial, so not strictly true to theme).
If I were doing this today, I’d leave even more of the rubble in place and blind the soil in over it. Over time I have come to realise that such conditions are an advantage, and expected by many Mediterranean plants.
We used a drip irrigation system for the first year of establishment, which was then switched off in the second year. A 50mm deep dressing of 20mm diameter marine shingle covered everything, including the paths, which were left from the original, compacted sub-base.
I tracked this garden for a few years until the property changed hands and learnt some valuable lessons (as you always do), such as don’t put too many larger growing shrubs in, as the openness of the spatial structure becomes compromised. Whilst they are good at establishing initial structure, be prepared to remove some of them as the garden matures. Some, like the Cotinus and Tamarix, were meant to be coppiced every few years, but didn’t have this done. Some perennials work better than others and low mounding shrubs are what make the predominant visual structure of the site.
This last two pictures, plus the header, are a part of my own gravel garden, created over an old driveway, where I constantly experiment with new plants and slowly expand it all.
Gravel gardening has much to offer and is an appropriate approach for our time, being of low carbon footprint and using plants that are adaptive and generally tough. Have a go, or get me to help…!
Landscapes are all about creating micro-climate, or would be, if designed for that goal. Why is this important and what do I mean?
Almost all life is contained in a thin crust of soil, a wedge of atmospheric gases, and water. Plants are the principal medium that interacts with and regulates all three. Absolutely nothing else does this as well, or at all; think about it.
The way we organise our plants in our urban landscape will determine how well this interaction occurs, how successful it is. Yet I have never heard of a single project that has been developed with this understanding and this goal in mind. With climate change, we urgently need to re-think the way we design our landscapes, and why we design them. Whilst all the human-centric design reasons will always hold true, we need to layer into our thinking this new understanding of how plants interact. To build new ecologies, new ecosystems, we have to design for plants to actually function, rather than just look nice. For when they do this, our environment literally comes alive. More importantly, they might just, if done on sufficient scale, save us from ourselves.
When I use the word treescapes, I don’t just mean trees and grass; we’ve had that for years in the form of parks, and in their traditional form, they’ve done little for us. No, our designs need to build up layers of living material – biomass, for with biomass comes moisture entrapment, shade, food for insects, etc. Think of it in terms of height and depth of microclimate. How much depth is there in a stretch of irrigated grass, maybe 50mm above ground, 200mm below? No species variation, so what we have is little more than a green desert, albeit one that can hold bit a of moisture.
Trees in paved streets are also less able to generate micro-climate, but they are a bit of an exception, as they provide shade for people to walk under. Where width allows, even here we should layer our planting.
If we replace that grass with a range of groundcover plants – not a monoculture – you begin to get a little more variation; different root structures and depth, different foliage shapes, height, form and flower. More variety, more microclimate, more food source, more ecology. Looks good too.
Next we add shrubs and suddenly we are into an new realm, that of woody plants (I’m being simplistic here, many groundcovers are of course woody). Shrubs create three-dimensional space with their frameworks, within which micro-worlds reside. Deciduous plants shed their leaves, as do evergreens, and this begins to build leaf litter – mulch. Don’t tidy it up! We need ecologies in that soil, and microbes need food. Our obsession with tidyness has a lot to answer for. Suddenly, we have height in our micro-climate, three-dimensional form. We humans (for we scale everything according to our own height and perception) can walk amongst these plants, take part, interact. Our microclimate is now two metres high, maybe more. But something is missing and it’s still too hot…
Trees! Now we have a game changer and our micro-environment just became vast, in relative terms, maybe up to 30 metres, though 10-20m may be more average. We now have true diversity of shape, height, leaf, flower and roots. We have shade! Under trees it may be 10°C cooler and we love it. Plants love it too. Moisture now gets retained within the human habitable zone, fungi and microbes thrive in soils, insects and birds abound. This is our urban jungle and we need it. The planet needs it. This tiny sliver of crust we live on can be rich, abundant, in every climate and every place, if we put our minds to it, if we have the will. And when the planet becomes searing, creating livable environments with trees of any type, may be the only thing that keeps us alive, unless we become troglodytes.
This is the next level of landscape design, the new challenge; creating future ecologies and environments that matter, that keep us cool, that give us resources and soothe our souls. We will create new (novel) ecologies that fit the changing environment, trans-migrating parts of ecologies that once lived elswhere. In that place they may be dying out, as might your local ecology. If they now fit where you live, that’s where they need to be. In turn, that place of origin may itself need to adapt and change. In all things and all places, we need microclimate, shade and soil.
The other side of work I undertake in the Middle-East region (other than tree consultancy) is planting design, for creating new landscapes always brings me a special joy. When they are in public spaces, I love the chance it gives to interact (albeit remotely) with many people in place, over time and hopefully, enhance their enjoyment of that place. In the public realm, what that place is, is being questioned and challenged in the light of urbanisation and climate change. Ecology and environment are driving design as never before.
I am about to start working on a collaborative project in Saudi Arabia. It will involve the specification of many trees, shrubs and groundcovers and I get to find out just how many locally-sourced big specimens I can find that are of acceptable quality. Much of this will come down to the application of formative pruning in the nursery and I’ll be on the lookout for the best available in the region. I suspect I’ll be sourcing a lot from neigbouring UAE, simply because of familiarity of sources. Quality remains a challenge, though.
My most pressing concern I have is how to improve on irrigation techniques, which are traditionally massed surface drip lines onto marginally improved sand. This is inefficient and wasteful and I shall be looking at the use of moisture retention mediums and sub-surface irrigation. I believe most watering of landscapes in arid climates could be cut by half, just by more efficient application and retention, in the right place. The picture above shows typical wastage in a Dubai suburban landscape.
Whilst urban planting requires urban plants, I will also be looking at the use of more climate-adaptive species, which I think is important in an era of climate crisis; the Middle-East is going to struggle to cope with every degree of temperature increase. The use of more desert-adapted planting is not new, and not applicable everywhere but I believe there is much scope for experimentation and new thinking.
For me, planting design is about building communities, layering types of plants together in harmonious associations that fit. I don’t mind grouping plants together that come from different geographical regions, but they have to come from a similar ecological niche. Such design is so much more than just nice foliage contrasts and I believe the results can be subtle, but profound.
Landscape must, of course, fit our purpose but I believe we tend to pursue this end to the exclusion of everything else. Nature is the basis of landscape, and so too is ecology, ecosystem and planet. We should not divorce our landscapes from this reality; rather, they should always seek to remind us of these connections. So yes, in town centres and urban streets, we have our eco-bling landscapes; vibrant places, exotic, heady, purfumed, exciting. Nature at it’s most unbelievably flamboyant (cue pic: delonix, the flamboyant tree). Elsewhere, we need more grounded landscapes, more real, more connected to place.
I love this tree, it is everything I have described above, pure eco-bling. Yet it is not appropriate everywhere and because it has become a part of the standard landscape palette, I belive it is overused, and used in places where other species would be more appropriate. I think there are many trees and shrubs that could be used in the region that haven’t been tried yet, from East Africa, for example. The climate there may be more equatorial and more varied but it is not so remote or different as that of some exotics imported from sub-tropical climates (the Delonix mentioned above is from Madagascar, again not too dissimilar).
I think planting design in the Middle-East faces a whole new range of
challenges and opportunities. The changing climate will force new
thinking, to match the new development and the new understanding that is
emerging of our intimate relationship with nature. I’m hoping to
contribute towards that new expression and understanding.
The world is finally, at the last minute, waking up to the impending effects and consequences of climate change. In the scramble to work out what we must do (apart from the obvious cessation of burning fossil fuels), one thing, one factor is looming large: we need to put carbon back into the soil, where it can be stored indefinitely, and we need to reforest the Earth. Much of this is in the agricultural realm but there is a huge amount that can – and must – be done within the landscape and horticultural sectors.
Horticulture has a MISSION, it just doesn’t realise it yet
At the centre of this is good soil husbandry, something that we have largely forgotten about. Modern agriculture bypasses all need of soil health by chemically feeding crops; no need for microbes, nutrients, humus, mycelium or earthworms. Chemical fertilisers and herbicides bypass the lot. Most of our soils now are depleted to the point of useless by chemical farming, exacerbated by the tradition of ploughing, which causes erosion from rain and enables much of the soil carbon to move back into the atmosphere.
So whilst we need current global models of food production to transform into regenerative agriculture and agroforestry, we also need to look at our urban landscapes and gardens, and create a new design ethic, a new paradigm, even. I can’t deal here with agriculture but I have been thinking long and hard on what the landscape and horticulture trades need to do; fortunately, I believe there is a lot that we can do.
We need to envelope our existing horticulture trade within ecology, to create an “environmental horticulture” You could also call it ecological, resilience or regenerative horticulture. We (those of us in the trade) know that as a profession, the training of both horticulture (growing) and landscape (doing) are in decline. Horticultural colleges have shrinking budgets and often get the less ambitious or capable students; after all, who is inspired by the prospect of strimming verges or hedge-trimming another unloved carparking lot? Yet last year’s report by the Ornamental Horticulture Roundtable Group valued horticulture at £24.2 billion in GDP in 2017. That’s not inconsequential, yet it goes unrecognised. Fortunately, there is a way to make it much more enticing to prospective students.
Horticulture has a MISSION, it just doesn’t realise it yet. That mission is to adapt our urban landscapes and gardens to cope with climate change, to mitigate temperatures, water flows, to grow biomass and regenerate soils back to health. Healthy soil is the foundation of life, of all life, including our own. Good soil holds fertility, water and carbon. Yet who amongst us now knows much of soil science? Who designs landscapes as ecologies, as “novel ecosystems”, who chooses plants because they have these abilities, not just for pretty flowers? Who designs plantings for their biomass harvest, for creating mulches to feed the soil?
In this respect, I don’t believe it’s necessary – or right, in fact – to work with native plants only. What is native? What was native? What was here 11,700 years ago when the last glacial period ended and the glaciers retreated? Flora and fauna move around the globe all the time, they are opportunistic, not fixed permanently into some tightly integrated ecosystem. We know there is no “ecological climax”, no ultimate ecosystem for any given place. As temperatures rise, climate zones are now shifting away from the equator quicker than Nature can keep up, although it’ll get there eventually. Maybe we help nature, rather than interfere when we bring in exotic plants that naturalise. Maybe those plants are the start of new ecologies that will adapt to the rapid changes that this climate emergency is bringing us. If plants do well, we need to understand how to enhance and build new ecologies with them. This is how we adapt, how we survive and how we rectify the damage we have done as a species; not by returning to some pristine “before” (which doesn’t exist) but by assisting Nature to heal and adapt. The Earth will do this all by itself, and has done so many times. It doesn’t mind if it takes thousands, or even hundreds of thousands of years to adapt. But we do; we can’t wait that long.
So horticulture needs to stop growing pansies in peat with unrecyclable plastic trays and start sorting out which plants really matter for our future; which ones contribute to new and existing ecologies, which ones are good for biomass, which ones contribute to soil health, which ones give us ecosystem services. We should not enhance one environment at the expense of another.
What’s needed is a very-near future profession of trained eco-warriors, soil saviours, tree patriots and landscape lovers. It needs people who understand soil, who know how to design and use sensors, data and the internet of things, people who see what’s coming and how to mitigate and reverse negative effects, people who really know how to design and install green infrastructure and future automated robotic maintenance systems. Our landscapes can grow food in amongst all the beauty, with urban food forests. We need new knowledge built on old and we need passion, commitment. A wise government would fund this for the returns will be numerous.
This is the enlightenment, that out of dire stress and trouble, we could really learn how to value, connect with and protect this crazy, beautiful world within which we live. Or we can do nothing and watch it all go to hell. I know which I’ll be doing.
Concrete is a wonderfully versatile material, which has been in use since Roman times and with it we can build amazing structures that would otherwise be impossible. Unfortunately it also carries a huge environmental cost, caused mostly in the cement binding used. Whilst gravel extraction is also an issue, for that there are some alternatives such as recycled, crushed concrete.
The production of modern cement (OPC – ordinary portland cement) is a hugely polluting process and produces around 8% of the world’s carbon emissions – at least twice that of the aviation industry. Whilst the Romans used a volcanic dust called pozzolona as their binding agent, until the invention of OPC, we used lime, in various forms. Lime too has to be processed by heat and so is not without it’s environmental cost, but it uses less energy to produce than cement and lime concrete/mortar reabsorbs carbon over its lifetime (if exposed to the air), offsetting some of the initial pollution. Moreover, because it is softer, materials can be disassembled easily, for re-use.
In a landscape, there is ubiquitous use of concrete in a range of structures – walls, paving, sub-bases, ponds etc. some of which could be reduced or avoided altogether. Whilst landscaping will always use an insignificant amount of concrete compared to urban development and infrastructure, there are good reasons to minimise the volume of cement and other hard landscape materials used.
Some of these reasons are for obviously sustainable goals: reducing material/resource input and carbon and other wastes. Equally important in my view, is to increase the soft elements exposed in a garden – soils – and to increase the levels of planting and foliage biomass/diversity. This thinking is about the increase of biophilic benefits.
However, if sustainability is to be given top priority – as it must – then the use of cement has to be reduced as much as possible. This is quite a challenge to us all, as it is not always easy to find an alternative and I don’t suggest for one minute that it should never be used, but it should be reserved for essential structural use only. Even then there may be alternatives. Recycled concrete can make a suitable aggregate (or part of) and low cement alternatives such as CEM 1 reduce the energy and carbon emissions tally.
I have used – and continue to use – concrete in many of my own designs and so this challenge is personal – but then aren’t all sustainability issues.
Let’s look at the different areas of the garden where cement is used:
Many walls use cement, either in mortar or in concrete blocks as well as in cement renders. In this garden (left) we built retaining walls using hollow concrete block construction on concrete footings with cement render and mineral pigments for the final colouring, with concrete paving slabs as coping. As the site was on a chalk hillside, it may have been possible to construct this using rammed chalk or earth. Indeed, we had a surplus of chalk on the site from the house construction and it would have made perfect eco-sense to have used this to build the walls. The walls could have been rendered using lime based mix, and the coping could have been stone. As the chalk hillside is inherently quite stable, rammed chalk could possibly have been used for the footings too. However, there are so many unknowns, and so few UK examples that it is a risk to do this, especially on such structurally critical terracing. Long-term effects of damp creeping into the walls would have been my main concern.
The cost of rammed earth construction may have been cheaper than conventional construction , both in time to do and in material purchase, especially when the removal off site of subsoil is taken into account.
The picture at right shows rammed earth walls in a sustainable landscape I designed for Grand Designs Live, ExCel, 2006. Rammed earth walls are made by compacting subsoil inside timber or metal formwork. The soil must be kept dry so it needs some kind of footing and capping, here provided by cast copings made with recycled aggregates and partial cement substitute (CEM 2 furnace slag). The gravel to the main paving area is a recycled brick/concrete mix, laid through a geo-grid membrane made from recycled plastic. The aim here is to be as carbon neutral as possible. Planting aspired to be edible (you can eat daylily flowers).
Walling alternatives to concrete include:
Cement alternatives/recycled aggregates
Timber walling (railway sleepers etc)
Round pole walling (preferably coppiced hardwood)
Fences & crib-type embankment walls
Brick/stone with lime mortar (brick also has high energy input)
Dry Stone walling
Modern paving is often made from concrete and in some instances it is quite hard to find realistic substitutes. Stone paving is the obvious one but can be expensive. There are many cheaper stone imports available these days, such as Indian Sandstone, which are cost-effective but which carry a high transport and pollution price tag. Reclaimed York paving is highly desirable and of course, reused, so environment friendly but will cost 2-3 times that of cast concrete or Indian Sandstone. Brick is also traditional as paviors but as for walling, still carries a high energy/pollution cost in production, plus is expensive to lay.
For larger areas and drives, self-binding gravels may be one of the better answers, as these form a firm surface, once compacted, without the use of cement. Recycled or local gravels are also acceptable and can be held in place using recycled plastic grids/membranes.
Paving is one of those areas which highlights the question of just what is sustainable. Is it better to use imported sandstone with its high transport miles but relatively low energy production, or locally made concrete paving with cement and aggregate use, but low transport miles? In either case, the (financial) costs may be similar. There are also ethical and human welfare considerations for stone imported from third world countries, especially in terms of working conditions, health & safety and child labour.
Timber decking can be a viable alternative, especially on sites with changes of levels. Local timbers of the more durable softwoods (like Douglas fir or larch), green oak, Sweet chestnut or recycled tropical hardwoods. All new timbers should be FSC (Forest Stewardship Council) certified. New hardwoods should be avoided even if the have an FSC certificate as there is much illegal timber that still gets sold and even managed plantations may still involves some environmental degradation. They certainly have high transport emissions.
Possible paving alternatives:
Recycled stone, brick, cobbles – and concrete slabs
Self binding aggregates don’t need cement
Fired paviors and tile look beautiful, but are still energy intensive
local or recycled aggregates and gravels
Decking can be used where appropriate
Locally produced concrete slabs minimise transport and can have lower carbon footprint than imported stone
Third-world stone may be low energy, but high transport emissions
Even natural looking ponds may use concrete in their construction and formal ponds may be dominated by it. Again choice of alternatives is limited.
Concrete is often used to retain rocks and place protective pads over liners, etc. In many places it may be possible to do without concrete pads, which are often used in a “belt-and-braces” approach to protecting a liner. Felt geomembranes are used as standard as a layer underneath and often inside the liner (this may in fact be degraded by contact with concrete) and in many cases, use of additional layers of felt may eliminate the need for concrete. Felt is usually a synthetic, petroleum based product, so also has its environmental considerations (as do liners!). I have successfully used old carpet as replacement for felt, under the pond (I wouldn’t recommend it inside) but be VERY wary of tacks that may have been used. Non-synthetic carpet will degrade over time, which must be born in mind. Of course, before the advent of felt, liners were simply bedded on a layer of sand.
Where rocks and stones create waterfalls, they are used to form spillways and to prevent stones moving when climbed over or stepped upon (an important safety consideration). It may be possible to use hydraulic lime based concretes for this, although I haven’t tried this out. Perhaps well laid rocks, without the use of cement are the key, which would require a careful re-thinking of the construction method. Nature doesn’t use concrete, but then natural streams don’t retain water within an artificial environment (liner). A more holistic approach to water features, where the roof water and household grey water are recycled and the pond design doesn’t hold a fixed level or amount of water, may be the long term answer.
So looking at alternatives to cement raise as many questions as answers and in the 12 or so years since this article was first written, there has been some progress, but not much. Best advice is to minimise the use wherever possible, recognising the long-term durability and benefits of strength that concrete possesses.