Plant diversity in UAE comes under twin threat

Invasive plant species and overgrazing are the most serious threats to plant diversity in the UAE, according to research by the UAE University (UAEU).

The study also found the potential of exotic trees for affecting wild plants in the country, saying exotic species adversely affect the ecosystem.

"Some alien tree species used in afforestation cause major problems as invaders of natural and semi-natural ecosystems. The magnitude of the problem has increased significantly over the past few decades, with the rapid increase in afforestation and changes inland use," said the study.

The research has been conducted Ali El Keblawy of the Department of Biology of the College of Sciences at the UAEU. The Research Affairs Unit of the UAEU financially supported the project.

The aim was to evaluate the potentiality of different kinds of forests in the country in protecting the floral diversity and to evaluate the most suitable conditions that could enhance the biodiversity of the forests.

It was also aimed at evaluating the impact of artificial forests on physical and chemical characters of the soil. El Keblawy said the biological diversity is in crisis globally.

Human activities are destroying the natural world and its biota at an ever-increasing rate. Species extinction and gene erosion are still widespread in spite of numerous national and international efforts.

The UAE, like other oil producing countries in the Middle East, is developing rapidly. As a result of the extensive development, human population expanded in different habitats of the country. Such expansions threaten wildlife.

The research indicated that the most important threats to biodiversity and to its habitats in the Arab countries are urban expansion, overgrazing, desertification, agricultural expansion, and drought.

"One of the most serious threats to plant diversity in the UAE and Oman is the great expansion of the invasive plant species. Overgrazing, which has resulted from an increase in stocking goats, camels and cattle throughout the UAU, has been recognised as another major threat," said the report.

Artificial forests are covering an area of 300,000 hectares in the country. One of the important exotic trees planted in the UAE is Prosopis Juliflora. This tree has invasive ability and serious impact on native plants. "In the highly invaded areas, Prosopis Juliflora has completely replaced native species, resulting in a complete destruction of the most perennial species."

The research acknowledged that artificial forests have enriched vegetation and soil amelioration in the UAE. It however highlighted the need for the replacement of exotic tree with native trees as they are compatible with the environment and use comparatively less water.

The result of the research also indicated that medium and small trees encouraged greater diversity and abundance of plants than larger trees.

"This suggests the importance of reducing the crown of the forests in the UAE. Such reduction, in addition to increasing species abundance and diversity, will also reduce the amount of water consumed by trees and provide dry forage for animals."

The research also found 'great increase' in soil salinity. This is an indicator of the high salinity in irrigation water and emphases the importance of having a proper management for the forests to ensure their sustainability, it said.