Mangrove Reproduction

Certain mangrove species can propagate successfully in marine environment because of special adaptions. Embryo germination begins on the tree itself, a process called “viviparity”. The tree later drops its its developed embryos, called propagules, which may take root in the soil beneath. Viviparity may have evolved as an adaptive mechanism to prepare the propagules for long-distance dispersal, and survival and growth within a harsh saline environment. During this viviparous development, the propagules and nourished on the parent tree, thus accumulating the carbohydrates and other compounds required for later autonomous growth.

Propagules may float for extended periods (depenting on the species), up to a year, adn still remain viable. Viviparity and the long-lived propagules allow mangrove species to disperse over wide areas. 

Mangrove Habitat and Growth

Mangrove distribution is primarily determined by sea level and its fluctuations. Other secondary factors are: air temperature, salinity, ocean currents, storms, shore slope, and soul substrate. Most mangroves live on muddy soils, but they also can grow on sand, peat, and coral rock.

Zonation often characterizes mangrove forests. Certain species occupy particular areas, or niches, within the ecosystem. Some mangrove species occur close to shores, fringing islands, and sheltered bays; others are found further inland, in estuaries influenced by tidal action.

Mangroves vary in height according to species and environment, from mere shrubs to 40 meter (app, 131 feet) tall trees. The prop roots of some mangrove species, such as Rhizophora spp., or red mangrove, and the pneumataphores (unique breathing roots) of others, such as Avicennia spp., or black mangrove, contain many small “breathing” pores, called “lenticles”. These allow axygen to diffuse into the pland and down to the underground roots by means of air space tissue in the cortex, called “aerenchyma” The lenticels are inactive during high tide.

Lenticles in the exposed portions of mangrove roots are highly susceptible to clogging by crude oil and other pollutants, attacks by parasites, and prolonged flooding from artifacial dikes or causeways. Over time, environmental stress can kill large numbers of mangrove trees.

Evolutionary adjustments to varying coastal marine environments have produced some astounding biological characteristics within mangrove plant communities. Certain species of mangroves exclude salt from their systems, others actually excrete the salt they take in via their leaves, roots, or branches, In species that exclude salt, the mangrove root system is so effective in filtering out salt that a thirsty traveler could drink fresh water from a cut root, through the tree itself stands in saline soil.

Mangrove Ecology

Healthy mangrove forests are key to a healthy marine ecology. Fallen leaves and branches from mangroves contribute to the forest detritus, or forest floor made up of shed vegetable parts (or salty mangrove leafs) and provide nutrients for the marine environment. Intricate food webs of immense verities of sea life are directly supported through this detritus. Mangroves are a critical forest ecosystem, dominating coastlines in tropical and subtropical regions of the globe. There are 54- 75 species of true mangroves; not even counting mangrove associates. Which are found only in intertidal zones of coasts, and are taconomically isolated from terrestrial counterparts. They are highly adapted to their environment, apable of excluding and expelling salt, allowing mangroves to thribe in highly saline waters and soils. Sality can still however limit the distribution of mangroves, however, as can other environmental factors such as climate, tidal fluctuation, sediment, and wave energy. Mangroves are found worldwide, but the greatest species diversity is in Southeast Asia, with only twelve species inhabiting the New World countries, and only four of those are found in the US along the southern coast.

Species that rely on mangroves.

Due to mangroves being an inter-tidal species, many other species rely on them for survival. Due to their numbers dropping so low in the last decade there are over 30 endangered species directly related to mangroves. From vegetation to fish to mammals, mangroves still find a way to be hugely influential in their lives. Some aquatic life that rely on mangroves are manatees, fish, sting rays, sharks, and many other species. Due to the mangroves spider like roots, many small fish spend the entirety of their youth hiding in mangrove roots until they are big enough to go out into open water. Manatees main diet is sea grass, or sea weed that relies on the nutrients that mangroves release through their roots. Some mammals that rely on the mangroves are Tigers, monkeys, mice, wild cats, and other countless birds. Things like monkeys and mice all rely heavily on mangroves for a habitat. Due to their habitat heavily declining, so are the things that live there. Things like tigers and sharks also die when the prey they feed on do.  

About Mangroves

Although once thought of as useless wastelands, careful study and research has revealed that mangroves are among the most important ecosystems on this planet. Valued for anchoring coastal ecosystems as well as providing economic and ecosystem services to humans, mangrove forests are true treasures. The complexities of these systems are enormous, and there is still much to learn. Mangrove forests are highly interconnected within the ecosystem itself, but they also make up a transitional zone between land and ocean, connecting and supporting both. It is no surprise that mangroves are called “roots of the sea.” Some interesting facts about mangroves are their complex forests are found between the latitudes of 32º N and 38º S, along the tropical and subtropical coasts of Africa, Australia, Asia, and the Americas. They are the only vegetation to give live birth. Also because they dwell in inter tidal zones they are salt water tolerant and filter it out through their leaves.