Residents moving to the Emirates and attempting to recreate their gardens from back home with non-UAE native plant varieties are increasing the likelihood of more alien species being introduced to the environment.
While most foreign plant species cannot survive in the UAE's particularly hot climate, a recent study discovered about 360 alien plants growing across the country.
The scientists behind the research indicated that foreign residents planting flora more familiar with their home countries may be behind the rise in alien species.
The researchers, Dr Viacheslav Byalt, of the Komarov Botanical Institute in St Petersburg, Russia, and Mikhail Korshunov, of the Russian State Agrarian University in Moscow, identified at least 357 alien plant species in the Emirates.
“This is a very large number of those species for an area that size, even without taking into account the arid desert climate,” Mr Korshunov told The National.
He said there was "an active increase in the share of alien plants in the UAE" because of the country's economic success. "This trend is typical for all countries and regions of the Earth,” he added. “Most of the plants come through nurseries and retail outlets selling planting material, but we cannot blame them for this – such is the market demand.”
Mr Korshunov suggested residents from other countries may also be bringing plants with them, as has been seen in New Zealand and Hawaii. The analysis did not consider how many introductions may have been caused by foreign residents.
Warnings
UAE residents have been strongly advised by authorities to stick to growing plants that are native to the region, amid demand for more exotic species from overseas.
EAD told The National that it was regularly monitoring threats from alien plants, and had implemented a monitoring programme to document ecosystems and their plant species, both native and alien. It emphasised the importance of planting native species in landscaping projects to minimise the need for non-native varieties.
The agency's instruction to residents came after the study, which focused on Fujairah but highlighting a nationwide issue, found “a clear” relationship between growth in economic activity and an increase in the number of non-native plants being found in the UAE.
Risks
If non-native plants establish wild populations, they could pose a danger to local flora. While the agency said the UAE's "harsh environmental conditions” made it difficult for alien plants to establish themselves, there are exceptions, such as Mesquite.
The plant, which is native to Mexico, South America and the Caribbean, has become established as an invasive weed around the world. “Since this species has an expansive nature, it can also spread over a large area and may outcompete the native species in such habitats,” EAD said.
Research on alien plants in Fujairah, published late last year in the botanical journal Turczaninowia, identified 14 species from the Fabaceae plant family that were not previously recorded in the UAE. They added to others identified in previous research.
Growing in numbers
Aliens among us
The UAE National Invasive Species Strategy and Action Plan 2022 – 2026, published by the Ministry of Climate Change and Environment, states there are 52 alien vascular plant species and more than 598 native plant species in the UAE.
Of the alien species, five, including mesquite, have been identified as invasive. All have “well-established populations in the country” and are subject to work to “contain and manage them”. UAE laws prevent the introduction of invasive alien species.
In a separate study published recently in the Journal of Arid Environments, researchers at institutions including the University of Sharjah identified how mesquite gains the upper hand over native plants.
Mr Korshunov, who is completing a doctorate based on his work in the UAE, said the hot and dry climate “protects very well from invaders”.
“The few species that can compete with native species in an arid climate require close attention in order to preserve biodiversity and the appearance of ecosystems," he said.
He added that, when areas were being planted, local flora – which requires less water and care, and supports biodiversity – should be used instead of non-native species. He said there had been positive results from planting native sidr, oleander, elephant grass and tephrosia in the breeding centre for the Arabian tahr at Wadi Wurayah, in Fujairah.
“The number of native insects and birds has increased, and even native partridges have returned and are breeding successfully,” Mr Korshunov said.
Saif Pasha, a spokesman for Tanseeq Investment, the owner of a landscaping company, Tanseeq, and Acacia Garden Centre in Dubai said "it was not necessarily the case" that consumers preferred non-native plants, "but there is a demand for them".
He said all plants were acclimatised to the UAE, so they are sold on to customers "only after they get used to the weather". He indicated that plants used in landscaping projects were "mostly from the outside", but needed to be looked after.
"Anything that cannot survive, there's no point in planting. We only sell the trees that make sense," he said, adding that the olive was popular.
An invasion
According to estimates published last year by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, about six per cent of alien plant species, or 1,061 species globally, have become invasive.
“There are thousands of species of alien populations,” said Tim Blackburn, professor of invasion biology at University College London. "Most of these don’t have much impact, some have quite large impacts. The trouble is that it’s quite difficult to predict from first principles which species they are going to be. Generally, we don’t know they’re going [to become invasive] until they’re so widespread there’s not a lot you can do about it."