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?
The beauty of native desert plants is often overlooked
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:
Soil scientist/microbiologist
Hydrologist
Botanist
Permaculturalist/regenerative agroforester
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:
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.
Sesbania sesban, a nitrogen-fixing shrub or small tree
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.
Eucalyptus street tree, Abu Dhabi. Note the epicormic growth from the base
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 saligna
Acacia (Senegalia) senegal
Acacia tortilis
Albizia lebbeck
Leucaena leucocephala
Pithocellobium dulce
Prosopis cineraria (possibly)
Prosopis juliflora
Sesbania sesban
Strong epicormic growth is ideal for coppice. Prosopis juliflora
Other species, coppicable but non-nitrogen fixing, would include:
Azadirachta indica (assumed from observed regrowth)
Conocarpus lancifolius (assumed from observed regrowth)
Eucalyptus sp.
Ficus sp.
Moringa oleifera
Tamarix sp.
Ziziphus spina-christi
Regrowth from cut branch of Tamarix aphyllaZiziphus spina-christi, showing classic epicormic growth
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.
Ziziphus stump, showing strong epicormic regrowth
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.
