Invasive mesquite

Muscat: Mesquite, an invasive, thorny tree is threatening the ecology of the Sultanate of Oman as it spreads like wildfire. The Prosopis juliflora or mesquite was once used as a fodder for livestock. And by holding the sands at bay with its deep, cloying roots, it was envisaged as a much-needed weapon against desertification. Initially, at least, it proved its worth. Some farmers credit their fields’ continued existence to its sand-stopping properties; others value the mesquite as a ready source of charcoal at a time when there are curbs on tree cutting.

Soon the perils of this invasive species became evident. It colonised huge tracts of land and displaced other native trees and poisoned livestock that consumed its pods. Its tentacle-like roots have sponged up water in dry areas. Such is the mesquite’s capacity for wreaking havoc that it seemingly even contributed to the spread of malaria as the tree’s flowers provide plenty of nectar for mosquitoes.

The tree’s roots, which can reach up to 50 metres to suck water in drylands, and its ability to withstand extreme temperatures have allowed it to prosper where other plants wither. With no natural predators outside of its native habitats, the mesquite has expanded across several million hectares in the last few years alone, according to the International Union for Conservation of Nature.

It has obstructed water flow in aflaj and contributed to soil degradation by absorbing nutrients. Mesquite pollen can trigger allergy symptoms such as nasal congestion, sneezing, itchy throat, contact dermatitis, and even asthma flare-ups.

Mohammed al Hinai, a plant expert, said that one mesquite tree can carry approximately 3,000 seeds, and capable of covering large areas in short time.

Burning is the best option to stop the spread of these trees. However, this is not possible when these shrubs grow near electricity poles and farms.

Efforts to eradicate these shrubs are hampered as some people still plant mesquite. Al Hinai said there is a need to spread awareness about the harmful impact of mesquite.

Al Hinai proposed forming field teams in each governorate comprising experts from the public and private sectors to develop a plan to stop the proliferation of this tree.

Suhail bin Salem bin Saeed Bait Saeed said mesquite is one of the invasive species that threatens Oman’s environment. He pointed out that volunteers in the Governorate of Dhofar have tried to uproot these trees to prevent its spread, especially at the foot of the mountains and in places where there is a density of rare and perennial trees.

He suggested that the authorities intensify awareness in social media about the dangers of mesquite and address the local community to fight mesquite in neighbourhoods, farms and abandoned places.

In Jaalan Bani Bu Ali, Abdullah al Araimi said mesquite destroyed many wild trees, pastures and wells. The volunteers are trying various means such as burning and uprooting to prevent the spread.