Very few ecosystems have attracted ecologists, environmentalists and nature lovers as much as mangroves have. With their rich salt-prone flora and an undeniably rich make up of fauna, mangroves have and still continue to be the best life-guard against calamities from the sea for humans. What then, are mangroves?
Mangroves are halophytic plants which are an ecosystem by themselves. They do not belong to any particular plant family but are a diverse group; a collection of herbs, shrubs,vines and trees from unrelated classes, orders and families. The most distinguishing characteristic feature of these land plants is their ability to grow and thrive well in salt saturated water conditions with specially modified plant organs for the same. While most mangroves are centered around salt water, there are those that also thrive well in fresh water too. Coastlines and inland waterway routes give rise to suitable habitats for the existence of mangroves.
• Adaptations of mangroves
In order for a plant to adapt and live in a mangrove ecosystem, its metabolic and physiological functioning modifies with the need. Since salt and water and the two main elements that make these land plants differ from the rest of the land-plant world, the modifications are in relation to these. There are basically four main ways in which these plants adapt to the salt intake.
1. Some plants filter salt at the root level
2. Some plants, though they take in the salt with the water, exudes this salt back into the water through their physiological processes
3. Some plants exude salt via the stomata of the leaves which can be noticed as salt deposits
4. Some plants collect salt in the older leaves only, which fall off as the leaves mature.
While these are the main adaptations for the release of salt, mangrove plant roots are specially adapted for water too. For these, while most of the roots are in water, special aerial roots with pheumatophores (roots with the modification to breathe in air) can be observed. Plants closest to the waterfront may possess strong prop roots too.
• Examples of Mangroves
The Sunderbans (which mean Beautiful Forests) in West Bengal of India are home to the Royal Bengal Tiger which incidentally are on the verge of extinction due to the tearing down of the mangrove forests for human habitation and for wood.
The mangroves of Florida are the largest in the United States of America, with three main species of mangrove trees found here apart form other families of plants co-habiting. They are the Red Mangroves (Rhizophora mangle) which is at the water front and takes the most amount of weather battering, the White Mangrove (Laguncularia racemosa) which is the next row of plants to canopy the middle region of the mangrove stretch, and lastly the Black Mangrove (Avicennia germinas) which is the row furthest away from the water. Differences in leaf and root adaptations between the first and third rows can be seen as mentioned in the adaptations above.
• Flora and Fauna:
Mangroves are home to thousands of species of plants and animals, especially those that are on the brink of extinction due to their habitat under threat. Mangroves are noted for their collection of medicinal plants. It is home to fish that breed between its roots; where the removal of the trees make these fish easy prey to predators. Birds like the gulls, hawks, storks and eagles build their nests in these trees and use these forests as their breeding grounds in specific seasons. Crocodiles love the swampy, mangroves of Australia in the Kimberly Region. These same mangroves are also home to the nocturnal flying fox which is the prime agent in the dispersal of seeds from the mangroves.
Uses of mangroves:
While mangroves are a major supplier of wood and medicinal compounds, they also act as a barrier against strong storms, winds, cyclones / hurricanes and also major disasters such as flooding, tidal waves and tsunamis. Mangroves are closely knit together that it becomes very difficult for strong currents of water to make its way through the heart of it. Likewise, in return, it also protects the weathering of soil and prevents soil erosion.
Mangroves are waterlogged areas, a world of its own, with an ecosystem totally different from the rest of the world. While it is a unique place for specific types of plants and animals to co-exist as one, it nonetheless is important to man. However, there should be a balance between the human world and mangroves for the best results to be obtained. If mangroves are lost, so also would a world of potential, life and human safety be lost. We would be exposed to the mercies of natural calamities.