Outdoor design: Going green in gardens is the UAE’s future

Green buildings and technology are given great priority in the UAE, and rightly so. However, we must not ignore the benefits of actual greenery.

Dubai Marina from Fairmont The Palm in Dubai. Sarah Dea / The National

Green buildings and technology are given great priority in the UAE, and rightly so, as they result in a cleaner environment. However, we must not ignore the benefits of actual greenery. The value of real estate is on the rise, and in the hurry to build, not much space is left for gardens, as every inch of land has a price on it. The UAE has plenty of green public spaces, but the contribution at an individual level could have an immense impact on creating a fresher environment.

How many trees do we need to maintain a supply of oxygen for the ever-growing human population? Scientific research from several countries around the world has shown that two mature trees can produce sufficient oxygen for a family of four. But this depends on the species, age, amount of foliage and health of those trees.

A tree can produce approximately 118 kilograms of oxygen per year; a 15-square-metre lawn can release enough oxygen for four people. The Arbor Day Foundation in the United States observes that “a single mature tree can absorb carbon dioxide at a rate of 48 pounds [22kg] per year and release oxygen to support two human beings”. It also absorbs 54 to 110 kilograms of particles and gases related to air pollution. In a year, an acre of trees can absorb the amount of carbon dioxide produced by a car driven 42,000km (just over once around the world).

Dubai is emerging as a fully urbanised society, with wider roads, more cars and taller buildings. With limited trees and open spaces, this produces what are popularly termed “urban heat islands”. Trees provide shade and limit solar radiation on a building or pavement, thus reducing heat generation. Trees can reduce temperatures by 7 to 10°C through shade and releasing vapour via their leaves.

Thoughtfully done, the designed landscape can reduce energy consumption related to cooling, which is essential for the UAE. Planting shade trees around buildings can reduce costs in energy usage by 20 to 25 per cent.

There are also economic benefits of incorporating greenery into urban spaces, particularly in terms of tourism. Surveys suggest that visiting a ­garden-themed attraction is the 10th most popular entertainment activity for tourists worldwide. The Miracle Garden in Dubai has set the bar, winning the Moselle Award at the International Tourism Network Awards.

Furthermore, recent observations in several countries have linked the increased values of certain properties to their surrounding landscaping. Good landscaping can add 10 to 20 per cent to the value of a property. A cost-benefit analysis showed that the greater the extent of canopy cover by trees, the higher the resale value of that property. Having street trees was found equivalent to the value of providing an additional 13 square metres of finished space.

Mechanisms have been developed to determine the beneficial effects of trees. I-Tree from the USDA Forest Service is a software suite that assesses the beneficial contribution of street trees to the atmosphere. A Tree Benefit Calculator is also available, which makes a simple estimation of the benefits of individual street-side trees. These simple tools can be accessed by the wider community. Just as drops of water make an ocean, carefully selected plants can create a healthier environment for all.

Usha Rani has a master's in landscape architecture and teaches in the department of architectural engineering at the University of Sharjah.