Mangroves are trees and shrubs that have adapted to life in a saltwater environment, usually found in the intertidal zone of a coastal or estuarine area. The halophyte characteristics of a mangrove tree allows it to grow in saline environments where no other tree can, thereby making significant contributions to the local ecosystem. Yet these reservoirs of “blue carbon” are seriously threatened. Across the globe, coastal ecosystems are currently being lost at a rate of about 2% a year – a staggering number when the carbon storage potential is considered.
In a harsh desert environment such as Qatar, mangroves are one of the few ecosystems able to sustain life during the hot summer months. In recent years, Qatar government has been more focused on protecting these areas than the past, however 70% of the country’s mangroves have already been lost.
Introduction to Mangroves
Being at the beginning of the marine food chain, mangroves are therefore instrumental to a thriving marine habitat. The mangroves extensive root system provides an area of natural protection for fish and other marine nurseries and play an important role in protecting the coastline from the erosive effects of waves and storms. By filtering sediments, the forests also protect coral reefs and seagrass from being flooded by sediment.
Mangroves can store 5 times more carbon per square metre than tropical or boreal forests and when these areas are destroyed, the carbon is released back into the atmosphere where it contributes to global climate change.
Mangroves in Qatar
Qatar is home to the Avicennia marina species; it is known as the grey or white mangrove trees, with the largest eight forests located in the east coast of the country. The oldest and largest mangroves can be found at Al Thakira and Al Khor. Although the government have starting a replanting project around the country, the mangrove lake at Al Wakra was recently uprooted for development. In a country where the harsh desert conditions limit the vegetation growth, mangroves in Qatar provide a haven for birds, fish and mammals.
Recent studies have shown that Avicennia Marina populations have the ability to adapt to the varying weather along the Qatar coastline through the evolution of genetic variations in the different mangrove forests.
Carbon Sequestration
The coastal ecosystems of mangroves mitigate climate change by sequestering carbon dioxide from the atmosphere and storing it within the biomass of the plant and roots, and in the soils below. This ability to predominantly store carbon in the soils of coastal ecosystems, ensures the carbon is stored for a very long time, up to millennia.
It is estimated that mangroves sequester up to 25.5 million tonnes of carbon per year and provide 10% of the essential dissolved carbon supplied into the world’s oceans.
Mangrove Depletion
Despite increasing awareness regarding the benefits and carbon storing potential of mangroves, their destruction continues globally due to both economic and political motives. Even in countries like Qatar, where mangroves forests are protected by law, a lack of enforcement coupled with an incentive to reclaim land can result in forest destruction. Another cause of mangrove destruction is pollution by solid waste such as plastics and glass.
When these mangrove forests are degraded, lost or converted to other land uses, the stored carbon in the soils are exposed and released into the atmosphere or ocean as CO2. On a global scale, this is currently resulting as 0.15 – 1.02 billion tons of CO2 released annually. The combined global area of mangroves, tidal marshes and seagrass meadows equates to only 2-6% of the total forest area. However, degradation of these systems can account for 3-19% of the global carbon emissions from deforestation.
Conservation of Mangroves
Legislation needs to be enacted on a global scale to protect mangroves from direct human damage. Such legislation must be enforced by local government to ensure mangroves are not removed, and the use of herbicides or other chemicals near mangrove forests are banned. Local communities need to be educated to understand the importance of these costal ecosystems, and the effects of their degradation.
The rapid development in Qatar has been encroaching on the mangrove populations along the coastline. Qatar is gradually increasing the level of protection of the country’s mangroves, with 40% of the country’s coastline now protected. Organisations such as Conservation International have begun mapping out the mangroves locations and data in Qatar and around the globe in order to assess the population distribution and threatened areas. With further enforcement and data tools, the mangrove forests of Qatar can be restored, and continue to provide immense benefits to this harsh desert environment.