Mangroves

Mangroves forests info A mangrove forest is a general term known to describe a variety of species of trees or shrubs that grow in salt water. Mangroves consist of about 55 species, 20 genera, and it belongs to 16 families. Mangrove forests are found on 60-75% of the tropical coastlines. In Curacao and Venezuela the family that we can find is Rhizophoaceae. The Rhizophora mangle is also know as the Red mangrove. This is the mangrove that is dominant in Curacao, followed by the Black mangrove, and then a few White mangroves. Mangroves provide different functions to wildlife benefits since it is a feeding, breeding, and nursery grown for many fish, shellfish, birds, and other wildlife species. Mangrove trees grow in soil that is more or less permanently waterlogged and in water whose salinity fluctuates. **Structures and adaptations** __Respiration:__ Instead of obtaining direct oxygen, they use anaerobic activity that causes soil in mangrove to be anoxic. Rhizophora has two types of roots. Aerial roots also known as prop roots that stem from the trunk and drop roots that sprout from the branches and grow downward. The function of the prop roots is to support the tree and penetrate the soil some distance away from the main stem. The roots have tiny pores called Lenticels, which allow air to pass into the root. The lenticels have a honeycomb shape. Their structure allows them to exchange gases between internal tissues and the atmosphere. These roots are hydrophobic, so when they are in water they do not function and neither air nor water can enter. __Salinity__ Mangroves grow in waters where the salinity is between that of fresh water and seawater. This ecosystem handles the salt by secretion, by the rejection of the roots and by the tolerance of high tissue salt concentration. The Rhizophora are excluders so they have mechanism in their roots that absorb the fresh water and reject the salt water. __Photosynthesis__ Photosynthesis will occur more efficiently at temperatures of 25°C to temperatures of 35°C. To maximize the photosynthesis the leaf must be in a position that exposes them directly to sunlight. The smaller leaves are exposed more to the sun because they lose more heat than the larger ones due to convection. They become so exposed because the sunlight can give 10°C of more heat. __Reproductive__ The Rhizophora’s produce pollen since bees are attracted to the mangroves and to its flowers. The mangroves are wind-pollinated and they must produce some nectar. There are two steps in which the mangroves reproduce which are vivipary and by the dispersal of water. (Vivipary is the uninterrupted stage where the embryo is developed and then fertilized.) Mangroves also reproduce by proagules. This is basically that the “child” mangrove will be attached to the “parent” mangrove until it can become self-supplied. As long as they are attached the “child” mangrove will be receiving water and nutrients and they become photosynthesizes active. The proagules are generally floating in a vertical position until they detach from their parent mangrove. Some proagules can root in 30 days but others can last up to a year. __Physical conditions__ In mangrove ecosystems water motion must be minimal since slow water allows fine particles of sediment to settle down and accumulate on the bottom. This accumulation of sediments creates a muddy substrate. The prop roots of mangroves are so numerous that they from an impenetrable tangle these root systems decrease water movement letting the sediment or particles to settle down giving mangroves the name “land builders”. __Associated Organisms__ Dominant marine animals in mangroves include: mollusks, crustaceans, sponges, sea squirts and other peculiar fish, which can either harm or benefit mangroves. Mollusks found in mangroves include generally: snails and bivalves mainly oysters. They attach and live on the roots and trunks of the mangrove trees. For crustaceans in mangroves they are represented mainly by various species of crabs. Sponges attach to the roots, but they help fix nitrogen levels which in turn allows mangroves to obtain nitrogen which would be unavailable to them otherwise. Mangroves also help serve as a nursery ecosystem for many shrimp, spiny lobsters, and many other species.






 * Bibliography: **
 * <span style="font-family: 'Times New Roman',Times,serif; font-size: 16px; line-height: 23px;">Hogarth, Peter J. //The Biology of Mangroves and Seagrasses//. Oxford: Oxford UP, 2007. Print