[3] Many mangrove forests can be recognised by their dense tangle of prop roots that make the trees appear to be standing on stilts above the water.
The intricate root system of mangroves also makes these forests attractive to fish and other organisms seeking food and shelter from predators.
They have attracted much research interest because of the various ecological functions of the mangrove ecosystems, including runoff and flood prevention, storage and recycling of nutrients and wastes, cultivation and energy conversion.
[7] Many mangrove forests can be recognised by their dense tangle of prop roots that make the trees appear to be standing on stilts above the water.
The intricate root system of mangroves makes these forests attractive to fishes and other organisms seeking food and shelter from predators.
Bacteria and protozoans colonise the plant litter and break it down chemically into organic compounds, minerals, carbon dioxide, and nitrogenous wastes.
Thus, for a plant to survive in this environment, it must tolerate broad ranges of salinity, temperature, and moisture, as well as several other key environmental factors—thus only a select few species make up the mangrove tree community.
[11] Mangrove plants require a number of physiological adaptations to overcome the problems of low environmental oxygen levels, high salinity, and frequent tidal flooding.
[13] Once established, mangrove roots provide an oyster habitat and slow water flow, thereby enhancing sediment deposition in areas where it is already occurring.
[15] Because of the uniqueness of mangrove ecosystems and the protection against erosion they provide, they are often the object of conservation programs,[10] including national biodiversity action plans.
The Sundarban forest lies in the vast delta on the Bay of Bengal formed by the super confluence of the Brahmaputra and Meghna rivers with distributaries of the Ganges.
The area is known as an important habitat for the endangered Bengal tiger, as well as numerous fauna including species of birds, spotted deer, crocodiles and snakes.
[30] In areas where roots are permanently submerged, the organisms they host include algae, barnacles, oysters, sponges, and bryozoa, which all require a hard surface for anchoring while they filter-feed.
[40] For forest birds, tidal inundation means that the availability of many mangrove resources fluctuates daily, suggesting foraging flexibility is likely to be important.
[43][44] Mangrove ecosystems generally act as a net sink of carbon, although they release organic matter to the sea in the form of dissolved refractory macromolecules, leaves, branches and other debris.
[59][60][61][62] In addition, crabs can affect organic matter turnover by assimilating leaves and producing finely fragmented faeces, or by carrying them into their burrows.
[61][42] The exoskeleton of living animals, such as shells or carapaces, offers a habitat for microbial biofilms which are actively involved in different N-cycling pathways such as nitrification, denitrification and dissimilatory nitrate reduction to ammonium (DNRA).
[68][69][70][71][72][73] Colonizing the carapace of crabs may be advantageous for specific bacteria, because of host activities such as respiration, excretion, feeding and horizontal and vertical migrations.
[74] However, the ecological interactions between fiddler crabs and bacteria, their regulation and significance as well as their implications at scales spanning from the single individual to the ecosystem are not well understood.
[78][81][79][77] The outwelling hypothesis argues that export of locally derived POC and DOC is an important ecosystem function of mangroves, which drives detrital based food webs in adjacent coastal habitats.
Mangroves have been reported to be able to help buffer against tsunami, cyclones, and other storms, and as such may be considered a flagship system for ecosystem-based adaptation to the impacts of climate change.
[118] Compared to seagrass meadows and coral reefs, hypoxia is more common on a regular basis in mangrove ecosystems, through ocean deoxygenation is compounding the negative effects by anthropogenic nutrient inputs and land use modification.
As of 2007[update], after six years of planting, 700,000 mangroves are growing; providing stock feed for sheep and habitat for oysters, crabs, other bivalves, and fish.
According to Irina Fedorenko, an amount of work equivalent to weeks of planting using traditional methods can be done by a drone in days, and at a fraction of the cost.
[124] Wetlands International, an NGC based in the Netherlands, in collaboration with nine villages in Demak where lands and homes had been flooded, began reviving mangrove forests in Java.
Wetlands International introduced the idea of developing tropical versions of techniques traditionally used by the Dutch to catch sediment in North Sea coastal salt marshes.
[124] Originally, the villagers constructed a sea barrier by hammering two rows of vertical bamboo poles into the seabed and filling the gaps with brushwood held in place with netting.
As sediment gets deposited around the brushwood, it serves to catch floating mangrove seeds and provide them with a stable base to germinate, take root and regrow.
A recent, satellite-based study[126]—funded by the World Wildlife Fund and conducted by the Water Center for the Humid Tropics of Latin America and the Caribbean (CATHALAC)—indicates Belize's mangrove cover declined by a mere 2% over a 30-year period.
[134] In May 2019, ORNL DAAC News announced that NASA's Carbon Monitoring System (CMS), using new satellite-based maps of global mangrove forests across 116 countries, had created a new dataset to characterize the "distribution, biomass, and canopy height of mangrove-forested wetlands".