Scientists say country's homegrown vegetation uses far less water and chemicals
Going native: UAE urged to wean itself off thirsty imported flora
As anyone who has travelled in the UAE will know, much of the country is surprisingly green.
It is not just desert oases that account for the presence of tens of millions of trees in a part of the world where high temperatures and low rainfall seem to conspire against the natural world.
As has been well documented, the UAE has for the past half century made enormous efforts to green the desert, with hundreds of thousands of hectares of forest planted.
Indeed, thanks to these and other initiatives the country’s founder, Sheikh Zayed, was selected for a number of major environmental accolades, among them the World Wide Fund for Nature’s Golden Panda award, the organisation’s highest honour.
The abundance of vegetation seen today is not just found in the rural areas; it extends to the UAE’s towns and cities, where central reservations, roadside verges and parks and gardens offer an array of trees, shrubs and grass.
The country’s plantations offer a modern-day echo, albeit on a more modest scale, of the lush vegetation that existed here thousands of years ago during periods when climatic conditions were more benign.
The greenery seen today has not grown without significant amounts of help, especially as many of the trees and shrubs planted here are exotics – not native to the UAE – and require more water than native species.
As much as four-fifths of the country’s water consumption is reportedly accounted for by greening projects and it is perhaps no surprise that the country is one of the highest users of water in the world on a per-capita basis.
This leads to an environmental cost as it puts pressure on dwindling supplies from aquifers and requires carbon-intensive desalination.
There is, however, a way of ameliorating the problem.
“We have a very good list of native plants that can do the same job in landscaping, but have been here for hundreds of thousands of years,” said Dr Taoufik Ksiksi, a professor in the Department of Biology at UAE University in Al Ain.
Dr Ksiksi is the senior author of a scientific paper recently published in the Emirates Journal of Food and Agriculture, Landscaping with native plants in the UAE: A review. The paper is a rallying cry for the increased use of native plants in the Emirates.
Along with colleagues from UAE University, Dr Shaijal Ppoyil and Dr Shyam Kurup, and researchers at the International Islamic University in Islamabad, Pakistan, Dr Hasnain Alam and Dr Jabar Khattak, Dr Ksiksi has highlighted the many benefits of planting native species. He said part of the reason for writing the paper was to “raise awareness to the decision-makers” of the issue.
Native plants do not “bring any problems that we didn’t plan for”, in contrast to what is frequently the case with introduced plants.
As the recent paper details, native plants are better at offering shade for wildlife, are well adapted to the soil and climate (so require less water and fertilisers), offer food for herbivores and make parks and gardens look less artificial and reflect the country’s natural heritage. By contrast, non-native species need more water and other inputs and may be difficult to control once established.
A case in point concerns the tree Prosopis juliflora, known commonly as mesquite.
“It’s created a lot of havoc … this is a very nasty species,” said Dr Ksiksi.
Also called ghweif in the UAE, this native Central American species was planted in Abu Dhabi emirate three decades ago and, mirroring the situation with similar introductions in other countries, is unpalatable to native herbivores and has spread widely. To make matters worse, it stifles the growth of native plant species through chemicals in its leaves.
Considerable efforts have been made by the UAE authorities to control mesquite, but it has not proved easy to eliminate.
“It doesn’t have any use. The animals don’t want it; the insects don’t eat it,” said Dr Ksiksi. “It kills other species growing around it, so it lowers the biodiversity in the desert.”
“It’s only good for firewood. The problem is, if you try to kill it, it grows even stronger.”
Among the plants it has outcompeted is a related species, Prosopis cineraria, which has the common name of ghaaf. Dr Ksiksi indicated it was greatly preferable that this tree was planted instead of mesquite.
“It has a high level of water efficiency and it allows other species to grow – it doesn’t kill other species. It’s very good for the biodiversity,” he said.
The recent paper documents many of the ways in which the UAE authorities have tried to encourage the planting of native species.
The Abu Dhabi 2030 urban master plan encourages the planting of native, drought-tolerant and salt-tolerant species, while more than one third of the species in ornamental projects between 2010 and 2012 were native.
Setting ambitious targets, Abu Dhabi Public Realm Design Manual said drought-tolerant local species should make up at least four-fifths of landscaped areas.
Habiba Al Marashi, chairwoman of Emirates Environmental Group, is also keen to see “more focus” on the planting native species.
“There’s a lot more knowledge, more conscious decisions taking place and more planting of indigenous plants,” she said.
A full analysis of how many of the plants in landscaped areas in the UAE are native has yet to be completed.
A strategy favoured by Dr Ksiksi is planting cacti, which he says can compete with introduced species. He would also like to see efforts to remove non-native plants redoubled. One of his postgraduate students has identified “hotspots” where non-native species are concentrated. These could become target areas for removal, although completely eliminating them is impossible
“It’s not easy to get rid of them. So we have to live with them and manage them,” said Dr Ksiksi.
With a continued emphasis by the authorities on planting native species, improved methods of propagating such plants, and efforts to remove exotics, the hope is that the problems caused by non-native plants can be managed.