February 7th, 2017 by Mark Laurence

On my most recent trip to Dubai, I enjoyed walking through some of the new landscapes that emerge as projects are completed.  The UAE, along with most regions of the Middle-east has a rather limited palette of plants to work with (although that is growing as new plants are tried). What stuck me, however, was how poor the quality of nursery stock was in some cases and what problems are being created for later, especially with regards trees.

This is not new, nor confined to this part of the world but it bothers me that new areas of urban green are sometimes given a poor start with sub-standard nursery stock, often flown in from other parts of the world.

Simple pruning at an early stage would have improved this tree’s framework, removing crossing and rubbing branches.

Wandering around a residential area in Jumeirah, I came across some newly planted Delonix regia, one of my favourite exotic trees.  At first glance it looked nice, a simple planting of trees and groundcover but on closer inspection I was somewhat dismayed at the condition of the them.  The problems of poor framework were caused by their time in the nursery, not due to planting, although some of them could have been rectified by a vigilant planting crew.

This tree tie – complete with post – must have been like this from the nursery. The post did not reach the ground.

Many of the dozen or so trees had ties left on which the tree had grown around completely, making them impossible to remove.  As the planting is only around two years old (by my estimation), these may have been on the trees from their time in the nursery.  Possibly the planting was older and pre-dated the building they were attached to and the trees then grew around the ties after planting.  Either way, it’s a strong indication of neglect or lack of care. In the picture below, all the bark ridge above the tie may indicate “included bark” – bark sandwiched against bark, preventing live tissue growth and a strong branch collar formation.

The tree tie is trapped with “included bark” at the branch collar, which indicates a potentially weak branch join.

Several problems are arising here: pre-planting care in the form of correct formative pruning (five minutes with a pair of secateurs) and Post-planting care in terms of releasing planting ties – if they were not simply left over from the nursery days.  If there is no way to go back and release the ties, a bio-degradable tie should have been used.

This Ficus nigra was most likely damaged long before it was planted in this location.

Damage to the main trunk or structural framework of a tree might go unnoticed when the trees are small but cause major problems as the tree gets older and puts on size and weight.  This can range from the cosmetic to the potentially dangerous in a large tree and at this stage the remedy is costly and the expertise hard to find.

 

As fast-growing cities like Dubai mature, the needs of landscape shift from creation (in a hurry) to maintenance (at a constant pace).  Skills, awareness of the need for – and absence  – of skills, will become more and more urgent.  If Dubai wants to keep it’s beautiful, green mantle, then there is a whole new phase of arboricultural care awaiting to be discovered and initiated. I have carried out trees assesments and given basic training of correct pruning methods in the UAE, but that has hardly scratched the surface; there is a lot more to be done.

Trees are the urban, biophilic, blanket that clothe and surround the concrete mountains we build.  Trees make hot places not just bearable, but unbelievably beautiful.  Trees absorb dust, cool the air, add moisture and oxygen and enrich our Souls.  We need to honour and look after them, so that they can look after us.

Posted in Arboriculture, Biophilia, Climate Change, Dubai, UAE, Environment, landscapes, Middle-East, Trees, Urban Landscapes Tagged with: , , , , , , ,

regenerative tree planting methodology
December 29th, 2015 by Mark Laurence

Almost all urban landscapes are contrived and designed, due to their artificial nature and short timescales of development and use.  We see increasing use of mature rootballed trees and extensive hard landscape and this is normal for intense inner urban areas; I do get concerned that the increasing complexity of urban planting systems divorce trees particularly from their natural functions and prevent the occurrence of the biological interactions/communities that go to make up an ecosystem.  For example, I have seen trees planted whose surface levels are around a metre below the surrounding paving level.  No matter how well designed, this seems fundamentally wrong to me.

So I’m thinking that there must be a way of dealing with the majority of less intense landscape zones (especially where there isn’t the financial budget that a high-end development attracts) to provide urban regeneration, ecological restoration and biophilic connection, all on a modest budget.  This would create a new method to allow for wide-spread adoption in urban and suburban zones.  I think the solution comes from Nature’s own process of natural regeneration and a developed philosophy of minimal (but specific) preparation.

silver birch regeneration

silver birch are pioneering species for natural regeneration

Starting from the observation that Nature is very efficient at regenerating itself, what can we do?  Too often, I have seen unnecessary interference in this process.  I still recall that a few years after the great storm of 1987, I walked through some nearby National Trust woodland of pines and birch.  A great deal of damage had been done with many trees blown over.  Birch had however, regrown abundantly from dormant seed and was already three or four foot tall.  The NT then sent in the bulldozers to clear out the fallen wood so the area could be – replanted.  I watched them tracking over all the natural regeneration.  Why didn’t they just leave well alone?  The restoration of the woodland was only slowed down by such clumsy interference and this was not even a productive forest.

If we simply broke up paving in our urban centres and loosened up the sub-base, what would happen?  Nature would soon find a footing and things would start to grow; however, that process would be too slow and unpredictable for human sensibilities.  So what if we did a little more, adding a small amount of topsoil to the rubble, planting small (1+1 year transplants) bare root trees and shrubs,  with plugs of understory forbs, ferns and grasses. Starting so young, we’d generate a successful community in no time.  These could be designed as narrow ribbons – two to four metres wide, inserted into suitable wider areas of paving.

An urban area suitable for natural regeneration

An urban area suitable for natural regeneration

The above area was one I thought would be suitable for such an approach; there are many such areas throughout all urban spaces.  They cry out for regeneration, yet seldom can this be done for lack of adequate finance.  Below is a quick sketch showing how it might look.

Sketch showing regenerative planting

Sketch showing regenerative planting

The benefits of such an approach would be huge.  It would cost far less than using a traditional approach to landscaping such an area, maybe half (I haven’t costed it!).  The care would move from maintenance to management, using a rotational coppice methodology, rather than trim and tidy (which always ruins a plants natural habit. Biodiversity would be hugely enhanced, air pollution mitigation would increase, wind buffering, urban heat island reduction, stormwater runoff (they would act as rain gardens) and of course, our biophilic needs, our connection to nature.

Someone needs to be bold and try it; talk to me…

Posted in Arboriculture, Biophilia, Climate Change, Design, Ecosystem Services, Environment, landscapes, Regenerative Planting, Trees Tagged with: , , , , , , , , , , , , , , , , , ,

July 26th, 2013 by Mark Laurence

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: , ,