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119-696: Kota Kinabalu Wetland Centre is 24 hectares (59 acres) of the only remains of mangrove forest that once existed extensively along the coastal region of Kota Kinabalu , Malaysia . Previously known as Likas Swamp or Likas Mangrove and later Kota Kinabalu City Bird Sanctuary, the Centre came foremost out of 20 wetlands selected by the Sabah Wetlands Inventory Committee in 1986. The Centre is an important refuge and feeding ground for many species of resident birds, as well as several migratory bird species from Northern Asia. In addition, it

238-670: A potential evapotranspiration ratio (PET) value of <0.25. However, most lowland tropical forests can be classified as tropical moist or wet forests, which differ in regards to rainfall. Tropical forest ecology- dynamics, composition, and function- are sensitive to changes in climate especially changes in rainfall. Soil types are highly variable in the tropics and are the result of a combination of several variables such as climate, vegetation, topographic position, parent material, and soil age. Most tropical soils are characterized by significant leaching and poor nutrients, however there are some areas that contain fertile soils. Soils throughout

357-577: A sump to reduce nitrates and other nutrients in the water. Mangroves also appear in home aquariums , and as ornamental plants, such as in Japan . The Manzanar Mangrove Initiative is an ongoing experiment in Arkiko , Eritrea , part of the Manzanar Project founded by Gordon H. Sato , establishing new mangrove plantations on the coastal mudflats . Initial plantings failed, but observation of

476-556: A tropical rainforest biome may contain thousands of tree species, but this is not to say mangrove forests lack diversity. Though the trees are few in species, the ecosystem that these trees create provides a habitat for a great variety of other species, including as many as 174 species of marine megafauna . Mangrove plants require a number of physiological adaptations to overcome the problems of low environmental oxygen levels, high salinity , and frequent tidal flooding . Each species has its own solutions to these problems; this may be

595-603: A 2009 study by the World Resources Institute (WRI) indicates the ecosystems contribute US$ 174 to US$ 249 million per year to Belize's national economy. From 1990, in Tanzania, Adelaida K. Semesi led aresearch programme which resulted in Tanzania being one of the first countries to have an environmental management plan for mangroves. Nicknamed "mama mikoko" ("mama mangroves" in Swahili), Semesi also

714-668: A complex mosaic of adjacent vegetation types such as grasslands, saltmarshes, and woodlands, and this can mean that flexibility in foraging strategy and choice of foraging habitat may be advantageous for highly mobile forest birds. Relative to other forest types, mangroves support few bird species that are obligate habitat (mangrove) specialists and instead host many species with generalised foraging niches. Mangrove forests are home and sanctuaries for many of aquatic bird species, including: The intricate root system of mangrove forests makes them attractive to adult fish seeking food and juvenile fish seeking shelter. Mangrove forests are among

833-641: A drone in days, and at a fraction of the cost. Seventy percent of mangrove forests have been lost in Java , Indonesia . Mangroves formerly protected the island's coastal land from flooding and erosion. 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

952-538: 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). 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. However, the ecological interactions between fiddler crabs and bacteria, their regulation and significance as well as their implications at scales spanning from

1071-650: A half meters, or 59 inches, on average). Amongst this group are the Efe, Aka, Twa , Baka , and Mbuti people of Central Africa. However, the term pygmy is considered pejorative so many tribes prefer not to be labeled as such. Some notable indigenous peoples of the Americas , or Amerindians, include the Huaorani , Ya̧nomamö , and Kayapo people of the Amazon . The traditional agricultural system practiced by tribes in

1190-413: A higher concentration of white mangroves. Mangrove forests are an important part of the cycling and storage of carbon in tropical coastal ecosystems. Knowing this, scientists seek to reconstruct the environment and investigate changes to the coastal ecosystem over thousands of years using sediment cores. However, an additional complication is the imported marine organic matter that also gets deposited in

1309-576: A low-cost alternative to wood and charcoal stoves. These may help in reducing the demand for charcoal. 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. One village in Tamil Nadu was protected from tsunami destruction—the villagers in Naluvedapathy planted 80,244 saplings to get into

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1428-417: A maximum potential of 0.316996250 Gt (6.9885710 × 10  lb) of CO 2 emissions . Globally, mangroves have been shown to provide measurable economic protections to coastal communities affected by tropical storms. Heterogeneity in landscape ecology is a measure of how different parts of a landscape are from one another. It can manifest in an ecosystem from the abiotic or biotic characteristics of

1547-401: A new niche. Direct competition will often lead to one species dominating another by some advantage, ultimately driving it to extinction. Niche partitioning is the other option for a species. This is the separation and rationing of necessary resources by utilizing different habitats, food sources, cover or general behavioral differences. A species with similar food items but different feeding times

1666-595: A quarter of the destruction of mangrove forests. Likewise, the 2010 update of the World Mangrove Atlas indicated that approximately one fifth of the world's mangrove ecosystems have been lost since 1980, although this rapid loss rate appears to have decreased since 2000 with global losses estimated at between 0.16% and 0.39% annually between 2000 and 2012. Despite global loss rates decreasing since 2000, Southeast Asia remains an area of concern with loss rates between 3.6% and 8.1% between 2000 and 2012. By far

1785-465: A roof over the two remaining layers. It contains the majority of the largest trees, typically 30–45 m in height. Tall, broad-leaved evergreen trees are the dominant plants. The densest areas of biodiversity are found in the forest canopy, as it often supports a rich flora of epiphytes , including orchids, bromeliads, mosses and lichens. These epiphytic plants attach to trunks and branches and obtain water and minerals from rain and debris that collects on

1904-614: A seasonal basis but dwelt primarily in adjacent savanna and open forest environments where food is much more abundant. Other people described as rainforest dwellers are hunter-gatherers who subsist in large part by trading high value forest products such as hides, feathers, and honey with agricultural people living outside the forest. Many indigenous peoples around the world live within rainforests as hunter-gatherers, or subsist as part-time small scale farmers supplemented in large part by trading high-value forest products such as hides, feathers, and honey with agricultural people living outside

2023-529: A small piece of iron and a pierced plastic bag with fertilizer containing nitrogen and phosphorus are buried with the propagule. As of 2007 , after six years of planting, 700,000 mangroves are growing; providing stock feed for sheep and habitat for oysters, crabs, other bivalves, and fish. Another method of restoring mangroves is by using quadcopters (which are able to carry and deposit seed pods). According to Irina Fedorenko, an amount of work equivalent to weeks of planting using traditional methods can be done by

2142-579: A study published in 2020 in the journal Nature. In 2019 they took up a third less carbon than they did in the 1990s, due to higher temperatures, droughts and deforestation. The typical tropical forest may become a carbon source by the 2060s. Despite the negative effects of tourism in the tropical rainforests, there are also several important positive effects. Deposits of precious metals ( gold , silver , coltan ) and fossil fuels ( oil and natural gas ) occur underneath rainforests globally. These resources are important to developing nations and their extraction

2261-725: A trend towards declining populations in rainforests, for example, reptiles that feed on amphibians and reptiles. This trend requires close monitoring. The seasonality of rainforests affects the reproductive patterns of amphibians, and this in turn can directly affect the species of reptiles that feed on these groups, particularly species with specialized feeding, since these are less likely to use alternative resources. Efforts to protect and conserve tropical rainforest habitats are diverse and widespread. Tropical rainforest conservation ranges from strict preservation of habitat to finding sustainable management techniques for people living in tropical rainforests. International policy has also introduced

2380-604: A tropical rainforest is stratified into layers, each hosting unique ecosystems . These include the emergent layer with towering trees, the densely populated canopy layer, the understory layer rich in wildlife, and the forest floor , which is sparse due to low light penetration. The soil is characteristically nutrient-poor and acidic. Tropical rainforests have a long history of ecological succession , influenced by natural events and human activities. They are crucial for global ecological functions, including carbon sequestration and climate regulation. Many indigenous peoples around

2499-440: A vast diversity in plant and animal species. The root for this remarkable speciation has been a query of scientists and ecologists for years. A number of theories have been developed for why and how the tropics can be so diverse. Interspecific competition results from a high density of species with similar niches in the tropics and limited resources available. Species which "lose" the competition may either become extinct or find

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2618-415: A widespread root network at the surface for more efficient uptake of nutrients in a very nutrient poor and competitive environment. Most of the nutrients within the soil of a tropical rainforest occur near the surface because of the rapid turnover time and decomposition of organisms and leaves. Because of this, the buttress roots occur at the surface so the trees can maximize uptake and actively compete with

2737-479: Is a breeding ground for marine life protected by the Fishery Department of Sabah. Apart from providing shelter and food for both resident and migratory species of wildlife, wetlands also prevent salt build-up in surrounding freshwater supplies, stabilising sedimentation, storing nutrients and removing toxins. Birds from around the globe, including non-breeding winter visitors, are commonly sighted at

2856-712: Is already occurring. The fine, anoxic sediments under mangroves act as sinks for a variety of heavy (trace) metals which colloidal particles in the sediments have concentrated from the water. Mangrove removal disturbs these underlying sediments, often creating problems of trace metal contamination of seawater and organisms of the area. Mangrove swamps protect coastal areas from erosion , storm surge (especially during tropical cyclones ), and tsunamis . They limit high-energy wave erosion mainly during events such as storm surges and tsunamis. The mangroves' massive root systems are efficient at dissipating wave energy. Likewise, they slow down tidal water enough so that its sediment

2975-458: Is an example of niche partitioning. The theory of Pleistocene refugia was developed by Jürgen Haffer in 1969 with his article Speciation of Amazonian Forest Birds . Haffer proposed the explanation for speciation was the product of rainforest patches being separated by stretches of non-forest vegetation during the last glacial period. He called these patches of rainforest areas refuges and within these patches allopatric speciation occurred. With

3094-497: Is deposited as the tide comes in, leaving all except fine particles when the tide ebbs. In this way, mangroves build their environments. Because of the uniqueness of mangrove ecosystems and the protection against erosion they provide, they are often the object of conservation programs, including national biodiversity action plans . Worldwide there are about 80 described species of mangroves that live along marine coasts. About 60 of these species are true mangroves which live only in

3213-603: Is generally between 1500 and 2500 m while the upper limit is usually from 2400 to 3300 m. Tropical freshwater swamp forests , or "flooded forests", are found in Amazon basin (the Várzea ) and elsewhere. Rainforests are divided into different strata, or layers, with vegetation organized into a vertical pattern from the top of the soil to the canopy. Each layer is a unique biotic community containing different plants and animals adapted for life in that particular strata. Only

3332-413: Is intersected by a complex network of tidal waterways, mudflats and small islands of salt-tolerant mangrove forests. The interconnected network of waterways makes almost every portion of the forest accessible by boat. 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. The fertile soils of

3451-407: Is more readily consumed in the interior of the mangrove forest. Anthropogenic inputs may push the limits of survival in many mangrove microhabitats. For example, shrimp ponds constructed in mangrove forests are considered the greatest anthropogenic threat to mangrove ecosystems. These shrimp ponds reduce estuary circulation and water quality which leads to the promotion of diel-cycling hypoxia. When

3570-418: Is not becoming more carbon dense, then carbon has to be lost at a rate equal to the amount of carbon fixed as NPP. Hence this productivity is either retained within the mangrove forest, as a standing stock of live material such as wood, buried in sediments , or exported to neighbouring habitats as litter, particulate and dissolved organic carbon (POC and DOC) and dissolved inorganic carbon (DIC), or lost to

3689-521: Is often given priority to encourage economic growth. Mining and drilling can require large amounts of land development , directly causing deforestation . In Ghana , a West African nation, deforestation from decades of mining activity left about 12% of the country's original rainforest intact. With the invention of agriculture , humans were able to clear sections of rainforest to produce crops, converting it to open farmland . Such people, however, obtain their food primarily from farm plots cleared from

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3808-463: Is only available for about half of the global area of mangroves. However, of those areas for which data has been collected, it appears that 35% of the mangroves have been destroyed. Since the 1980s, around 2% of mangrove area is estimated to be lost each year. Assessments of global variation in mangrove loss indicates that national regulatory quality mediates how different drivers and pressures influence loss rates. Shrimp farming causes approximately

3927-450: Is the result of heavy heat and moisture forming oxides of iron and aluminium, which are insoluble in water and not taken up readily by plants. Soil chemical and physical characteristics are strongly related to above ground productivity and forest structure and dynamics. The physical properties of soil control the tree turnover rates whereas chemical properties such as available nitrogen and phosphorus control forest growth rates. The soils of

4046-534: Is the result of phosphorus levels in the soils, precipitation, high temperatures and the extensive microorganism communities. In addition to the bacteria and other microorganisms, there are an abundance of other decomposers such as fungi and termites that aid in the process as well. Nutrient recycling is important because below ground resource availability controls the above ground biomass and community structure of tropical rainforests. These soils are typically phosphorus limited, which inhibits net primary productivity or

4165-416: Is used, as this is connected to the sea and subjected to the tides, and less diseases occur, and as far less mangrove is destroyed for it. Grassroots efforts to protect mangroves from development and from citizens cutting down the mangroves for charcoal production , cooking, heating and as a building material are becoming more popular. Solar cookers are distributed by many non-government organizations as

4284-545: The Amazon rainforest ) are called carbon sinks . As major carbon reducers and carbon and soil methane storages, their destruction contributes to increasing global energy trapping , atmospheric gases. Climate change has been significantly contributed to by the destruction of the rainforests. A simulation was performed in which all rainforest in Africa were removed. The simulation showed an increase in atmospheric temperature by 2.5 to 5 degrees Celsius. Some species of fauna show

4403-689: The Guinness Book of World Records . This created a kilometre-wide belt of trees of various varieties. When the 2004 tsunami struck, much of the land around the village was flooded, but the village suffered minimal damage. 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. Like seagrass, mangrove trees transport oxygen to roots of rhizomes , reduce sulfide concentrations, and alter microbial communities. Dissolved oxygen

4522-841: The Indigenous peoples of the Americas , the Congo Pygmies in Central Africa, and several tribes in Southeast Asia, like the Dayak people and the Penan people in Borneo . Food resources within the forest are extremely dispersed due to the high biological diversity and what food does exist is largely restricted to the canopy and requires considerable energy to obtain. Some groups of hunter-gatherers have exploited rainforest on

4641-522: The Mesozoic era supercontinent of Gondwana . The separation of the landmass resulted in a great loss of amphibian diversity while at the same time the drier climate spurred the diversification of reptiles. The division left tropical rainforests located in five major regions of the world: tropical America, Africa, Southeast Asia, Madagascar, and New Guinea, with smaller outliers in Australia. However,

4760-749: The genetic variation used in evading the damage caused by new pests is still derived from resistant wild stock. Tropical forests have supplied 250 cultivated kinds of fruit , compared to only 20 for temperate forests . Forests in New Guinea alone contain 251 tree species with edible fruits, of which only 43 had been established as cultivated crops by 1985. In addition to extractive human uses, rain forests also have non-extractive uses that are frequently summarized as ecosystem services . Rain forests play an important role in maintaining biological diversity , sequestering and storing carbon , global climate regulation, disease control, and pollination . Half of

4879-400: The red , white , and black mangroves occupy different ecological niches and have slightly different chemical compositions, so the carbon content varies between the species, as well between the different tissues of the plant (e.g., leaf matter versus roots). There is a clear succession of these three trees from the lower elevations, which are dominated by red mangroves, to farther inland with

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4998-671: The spider monkey ( Ateles sp.), African giant swallowtail ( Papilio antimachus ), three-toed sloth ( Bradypus tridactylus ), kinkajou ( Potos flavus ), and tamandua ( Tamandua tetradactyla ). The emergent layer contains a small number of very large trees , called emergents , which grow above the general canopy , reaching heights of 45–55 m, although on occasion a few species will grow to 70–80 m tall. Some examples of emergents include: Hydrochorea elegans , Dipteryx panamensis , Hieronyma alchorneoides , Hymenolobium mesoamericanum , Lecythis ampla and Terminalia oblonga . These trees need to be able to withstand

5117-498: The " world's largest pharmacy ", because over one quarter of natural medicines have been discovered within them. It is likely that there may be many millions of species of plants, insects and microorganisms still undiscovered in tropical rainforests. Tropical rainforests are among the most threatened ecosystems globally due to large-scale fragmentation as a result of human activity. Habitat fragmentation caused by geological processes such as volcanism and climate change occurred in

5236-557: The 28° latitudes (in the torrid zone between the Tropic of Cancer and Tropic of Capricorn ). Tropical rainforests are a type of tropical moist broadleaf forest , that includes the more extensive seasonal tropical forests . True rainforests usually occur in tropical rainforest climates where no dry season occurs; all months have an average precipitation of at least 60 mm (2.4 in). Seasonal tropical forests with tropical monsoon or savanna climates are sometimes included in

5355-519: The 5° N and 5° S latitudes. Approximately 75% of world's mangroves are found in just 15 countries. Estimates of mangrove area based on remote sensing and global data tend to be lower than estimates based on literature and surveys for comparable periods. In 2018, the Global Mangrove Watch Initiative released a global baseline based on remote sensing and global data for 2010. They estimated the total mangrove forest area of

5474-405: The Amazon is based on swidden cultivation (also known as slash-and-burn or shifting cultivation) and is considered a relatively benign disturbance. In fact, when looking at the level of individual swidden plots a number of traditional farming practices are considered beneficial. For example, the use of shade trees and fallowing all help preserve soil organic matter , which is a critical factor in

5593-612: The Andean foothills, and volcanic areas of Southeast Asia, Africa, and Central America. Oxisols, infertile, deeply weathered and severely leached, have developed on the ancient Gondwanan shields . Rapid bacterial decay prevents the accumulation of humus. The concentration of iron and aluminium oxides by the laterization process gives the oxisols a bright red color and sometimes produces minable deposits (e.g., bauxite ). On younger substrates, especially of volcanic origin, tropical soils may be quite fertile. This high rate of decomposition

5712-667: The Iban "kenyalang" and the Kenyah "mamat". Pygmies who live in Southeast Asia are, amongst others, referred to as " Negrito ". Yam , coffee , chocolate , banana , mango , papaya , macadamia , avocado , and sugarcane all originally came from tropical rainforest and are still mostly grown on plantations in regions that were formerly primary forest. In the mid-1980s and 1990s, 40 million tons of bananas were consumed worldwide each year, along with 13 million tons of mango. Central American coffee exports were worth US$ 3 billion in 1970. Much of

5831-537: The Indian Sundarbans were assessed as endangered in 2020 under the IUCN Red List of Ecosystems framework. There is a consistent pattern of depleted biodiversity or loss of species and the ecological quality of the forest is declining. The unique ecosystem found in the intricate mesh of mangrove roots offers a quiet marine habitat for young organisms. In areas where roots are permanently submerged,

5950-476: The abundance of rainfall changes throughout the year creating distinct moist and dry seasons. Tropical forests are classified by the amount of rainfall received each year, which has allowed ecologists to define differences in these forests that look so similar in structure. According to Holdridge's classification of tropical ecosystems, true tropical rainforests have an annual rainfall greater than 2 m and annual temperature greater than 24 degrees Celsius, with

6069-479: The abundant Ocipodid crabs, mainly represented by fiddler crabs, do not permanently ventilate their burrows. These crabs may temporarily leave their burrows for surface activities, or otherwise plug their burrow entrance during tidal inundation in order to trap air. A recent study showed that these crabs can be associated with a diverse microbial community, either on their carapace or in their gut. The exoskeleton of living animals, such as shells or carapaces, offers

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6188-425: The amount of carbon fixed by mangroves normally greatly exceeds the amount stored within the forest, although the scale of outwelling varies considerably between forests, due to differences in coastal geomorphology , tidal regimes, freshwater flow and productivity. In the 1990s, global estimates could account for 48% of the total global mangrove primary production of 218 ± 72 million tons C yr (see diagram on

6307-523: The animal and plant waste. The understory layer lies between the canopy and the forest floor. The understory is home to a number of birds, small mammals, insects, reptiles, and predators. Examples include leopard ( Panthera pardus ), poison dart frogs ( Dendrobates sp.), ring-tailed coati ( Nasua nasua ), boa constrictor ( Boa constrictor ), and many species of Coleoptera . The vegetation at this layer generally consists of shade-tolerant shrubs, herbs, small trees, and large woody vines which climb into

6426-487: The areas where mangroves did survive by themselves led to the conclusion that nutrients in water flow from inland were important to the health of the mangroves. Trials with the Eritrean Ministry of Fisheries followed, and a planting system was designed to provide the nitrogen, phosphorus, and iron missing from seawater. The propagules are planted inside a reused galvanized steel can with the bottom knocked out;

6545-473: The atmosphere into long-term storage" in greater quantities than other forests, making them "among the planet's best carbon scrubbers " according to a NASA-led study. Tropical rainforest Tropical rainforests are dense and warm rainforests with high rainfall typically found between 10° north and south of the Equator . They are a subset of the tropical forest biome that occurs roughly within

6664-410: The atmosphere. 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. Export of mangrove carbon has been estimated to make a significant trophic contribution to adjacent ecosystems. The theory of outwelling is supported by mass balance evaluations that show

6783-1102: The availability of energy-yielding electron acceptors and increase nitrogen turnover via direct excretion. Thus, macrofauna may alleviate nitrogen limitation by priming the remineralisation of refractory nitrogen (that is, the nitrogen that can't be biologically decomposed), reducing plant-microbe competition. Such activity ultimately promotes nitrogen recycling, plant assimilation and high nitrogen retention, as well as favours its loss by stimulating coupled nitrification and denitrification . Mangrove sediments are highly bioturbated by decapods such as crabs. Crab populations continuously rework sediment by constructing burrows, creating new niches, transporting or selectively grazing on sediment microbial communities. In addition, crabs can affect organic matter turnover by assimilating leaves and producing finely fragmented faeces, or by carrying them into their burrows. Therefore, crabs are considered important ecosystem engineers shaping biogeochemical processes in intertidal muddy banks of mangroves. In contrast to burrowing polychaetes or amphipods,

6902-463: The broader definition. Tropical rainforests ecosystems are distinguished by their consistent, high temperatures, exceeding 18 °C (64 °F) monthly, and substantial annual rainfall. The abundant rainfall results in nutrient-poor, leached soils, which profoundly affect the flora and fauna adapted to these conditions. These rainforests are renowned for their significant biodiversity . They are home to 40–75% of all species globally, including half of

7021-451: The brushwood, it serves to catch floating mangrove seeds and provide them with a stable base to germinate, take root and regrow. This creates a green belt of protection around the islands. As the mangroves mature, more sediment is held in the catchment area; the process is repeated until a mangrove forest has been restored. Eventually the protective structures will not be needed. By late 2018, 16 km (9.9 mi) of brushwood barriers along

7140-429: The chemistry of this peat and represent approximately 2% of above ground carbon storage in mangroves. As the nests are buried over time this carbon is stored in the sediment, and the carbon cycle continues. Mangroves are an important source of blue carbon . Globally, mangroves stored 4.19 Gt (9.2 × 10  lb) of carbon in 2012. Two percent of global mangrove carbon was lost between 2000 and 2012, equivalent to

7259-410: The coastline had been completed. A concern over reforestation is that although it supports increases in mangrove area it may actually result in a decrease in global mangrove functionality and poor restoration processes may result in longer term depletion of the mangrove resource. In terms of local and national studies of mangrove loss, the case of Belize's mangroves is illustrative in its contrast to

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7378-764: The community. The initial disturbance is often a natural phenomenon or human caused event. Natural disturbances include hurricanes, volcanic eruptions, river movements or an event as small as a fallen tree that creates gaps in the forest. In tropical rainforests, these same natural disturbances have been well documented in the fossil record, and are credited with encouraging speciation and endemism. Human land use practices have led to large-scale deforestation. In many tropical countries such as Costa Rica these deforested lands have been abandoned and forests have been allowed to regenerate through ecological succession. These regenerating young successional forests are called secondary forests or second-growth forests. Tropical rainforests exhibit

7497-500: The delta have been subject to intensive human use for centuries, and the ecoregion has been mostly converted to intensive agriculture, with few enclaves of forest remaining. Additionally, the Sundarbans serves a crucial function as a protective barrier for millions of inhabitants against floods that result from cyclones . Four protected areas in the Sundarbans are listed as UNESCO World Heritage Sites . Despite these protections,

7616-442: The driving force moving the decomposable carbon from the litter to the soil. Respiration rates are highest early in the wet season because the recent dry season results in a large percentage of leaf litter and thus a higher percentage of organic matter being leached into the soil. A common feature of many tropical rainforests is the distinct buttress roots of trees. Instead of penetrating to deeper soil layers, buttress roots create

7735-755: The eastern and central Amazon as well as the Southeast Asian Rainforest are old and mineral poor whereas the soils of the western Amazon (Ecuador and Peru) and volcanic areas of Costa Rica are young and mineral rich. Primary productivity or wood production is highest in western Amazon and lowest in eastern Amazon which contains heavily weathered soils classified as oxisols. Additionally, Amazonian soils are greatly weathered, making them devoid of minerals like phosphorus, potassium, calcium, and magnesium, which come from rock sources. However, not all tropical rainforests occur on nutrient poor soils, but on nutrient rich floodplains and volcanic soils located in

7854-492: The easy movement of larger animals such as: ungulates like the okapi ( Okapia johnstoni ), tapir ( Tapirus sp.), Sumatran rhinoceros ( Dicerorhinus sumatrensis ), and apes like the western lowland gorilla ( Gorilla gorilla ), as well as many species of reptiles, amphibians, and insects. The forest floor also contains decaying plant and animal matter, which disappears quickly, because the warm, humid conditions promote rapid decay. Many forms of fungi growing here help decay

7973-454: The emergent layer is unique to tropical rainforests, while the others are also found in temperate rainforests . The forest floor , the bottom-most layer, receives only 2% of the sunlight. Only plants adapted to low light can grow in this region. Away from riverbanks, swamps and clearings, where dense undergrowth is found, the forest floor is relatively clear of vegetation because of the low sunlight penetration. This more open quality permits

8092-615: The end of the glacial period and increase in atmospheric humidity, rainforest began to expand and the refuges reconnected. This theory has been the subject of debate. Scientists are still skeptical of whether or not this theory is legitimate. Genetic evidence suggests speciation had occurred in certain taxa 1–2 million years ago, preceding the Pleistocene . Tropical rainforests have harboured human life for many millennia, with many Indigenous people in South and Central America, who belong to

8211-582: The environment. For example, coastal mangrove forests are located at the land-sea interface, so their functioning is influenced by abiotic factors such as tides, as well as biotic factors such as the extent and configuration of adjacent vegetation. For forest birds, tidal inundation means that the availability of many mangrove resources fluctuates daily, suggesting foraging flexibility is likely to be important. Mangroves also offer estuarine prey items, such as mudskippers and crabs, that are not found in terrestrial forest types. Further, mangroves are often situated in

8330-444: The equator because they cannot withstand freezing temperatures. 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. This tangle of roots allows the trees to handle the daily rise and fall of tides, which means that most mangroves get flooded at least twice per day. The roots slow the movement of tidal waters , causing sediments to settle out of

8449-437: The forest and hunt and forage within the forest to supplement this. The issue arising is between the independent farmer providing for his family and the needs and wants of the globe as a whole. This issue has seen little improvement because no plan has been established for all parties to be aided. Agriculture on formerly forested land is not without difficulties. Rainforest soils are often thin and leached of many minerals, and

8568-745: The forest canopy are widely recognized as important for the establishment and growth of rainforest trees. It is estimated that perhaps 75% of the tree species at La Selva Biological Station, Costa Rica are dependent on canopy opening for seed germination or for growth beyond sapling size, for example. Tropical rainforests are located around and near the equator, therefore having what is called an equatorial climate characterized by three major climatic parameters: temperature, rainfall, and dry season intensity. Other parameters that affect tropical rainforests are carbon dioxide concentrations, solar radiation, and nitrogen availability. In general, climatic patterns consist of warm temperatures and high annual rainfall. However,

8687-555: The forests. Peoples have inhabited the rainforests for tens of thousands of years and have remained so elusive that only recently have some tribes been discovered. These indigenous peoples are greatly threatened by loggers in search for old-growth tropical hardwoods like Ipe, Cumaru and Wenge, and by farmers who are looking to expand their land, for cattle(meat), and soybeans, which are used to feed cattle in Europe and China. On 18 January 2007, FUNAI reported also that it had confirmed

8806-975: The global picture. A recent, satellite-based study —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. The study was born out of the need to verify the popular conception that mangrove clearing in Belize was rampant. Instead, the assessment showed, between 1980 and 2010, under 16 km (6.2 sq mi) of mangroves had been cleared, although clearing of mangroves near Belize's main coastal settlements (e.g. Belize City and San Pedro)

8925-489: The ground. Tropical rainforests exhibit high levels of biodiversity. Around 40% to 75% of all biotic species are indigenous to the rainforests. Rainforests are home to half of all the living animal and plant species on the planet. Two-thirds of all flowering plants can be found in rainforests. A single hectare of rainforest may contain 42,000 different species of insect, up to 807 trees of 313 species and 1,500 species of higher plants. Tropical rainforests have been called

9044-472: The heavy rainfall can quickly leach nutrients from area cleared for cultivation. People such as the Yanomamo of the Amazon , utilize slash-and-burn agriculture to overcome these limitations and enable them to push deep into what were previously rainforest environments. However, these are not rainforest dwellers, rather they are dwellers in cleared farmland that make forays into the rainforest. Up to 90% of

9163-487: The hot temperatures and strong winds that occur above the canopy in some areas. Several unique faunal species inhabit this layer such as the crowned eagle ( Stephanoaetus coronatus ), the king colobus ( Colobus polykomos ), and the large flying fox ( Pteropus vampyrus ). However, stratification is not always clear. Rainforests are dynamic and many changes affect the structure of the forest. Emergent or canopy trees collapse, for example, causing gaps to form. Openings in

9282-527: The idea of developing tropical versions of techniques traditionally used by the Dutch to catch sediment in North Sea coastal salt marshes. 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. Later the bamboo was replaced by PVC pipes filled with concrete. As sediment gets deposited around

9401-998: The interface between the land, the ocean, and the atmosphere, and are centres for the flow of energy and matter between these systems. 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. The forests are major blue carbon systems, storing considerable amounts of carbon in marine sediments , thus becoming important regulators of climate change . Marine microorganisms are key parts of these mangrove ecosystems. However, much remains to be discovered about how mangrove microbiomes contribute to high ecosystem productivity and efficient cycling of elements. There are about 80 different species of mangrove trees. All of these trees grow in areas with low-oxygen soil, where slow-moving waters allow fine sediments to accumulate. Mangrove forests grow only at tropical and subtropical latitudes near

9520-470: The intertidal zone between high and low tides. "Mangroves once covered three-quarters of the world's tropical coastlines, with Southeast Asia hosting the greatest diversity. Only 12 species live in the Americas. Mangroves range in size from small bushes to the 60-meter giants found in Ecuador. Within a given mangrove forest, different species occupy distinct niches. Those that can handle tidal soakings grow in

9639-445: The large surface areas these roots create provide support and stability to rainforests trees, which commonly grow to significant heights. This added stability allows these trees to withstand the impacts of severe storms, thus reducing the occurrence of fallen trees. Succession is an ecological process that changes the biotic community structure over time towards a more stable, diverse community structure after an initial disturbance to

9758-475: The local fish populations, which are an essential food source. The environmental costs of shrimp farms in the mangrove forests grossly outweigh the economic benefits of them. Cessation of shrimp production and restoration of these areas reduce eutrophication and anthropogenic hypoxia. In some areas, mangrove reforestation and mangrove restoration is also underway. Red mangroves are the most common choice for cultivation, used particularly in marine aquariums in

9877-582: The maintenance of soil fertility in the deeply weathered and leached soils common in the Amazon. There is a diversity of forest people in Asia, including the Lumad peoples of the Philippines and the Penan and Dayak people of Borneo. The Dayaks are a particularly interesting group as they are noted for their traditional headhunting culture. Fresh human heads were required to perform certain rituals such as

9996-511: The more productive and diverse ecosystems on the planet, despite limited nitrogen availability. Under such conditions, animal-microbe associations ( holobionts ) are often key to ecosystem functioning. An example is the role of fiddler crabs and their carapace -associated microbial biofilm as hotspots of microbial nitrogen transformations and sources of nitrogen within the mangrove ecosystem. Among coastal ecosystems, mangrove forests are of great importance as they account for three quarters of

10115-398: The most damaging form of shrimp farming is when a closed ponds system (non- integrated multi-trophic aquaculture ) is used, as these require destruction of a large part of the mangrove, and use antibiotics and disinfectants to suppress diseases that occur in this system, and which may also leak into the surrounding environment. Far less damage occurs when integrated mangrove-shrimp aquaculture

10234-405: The nitrogen supply was unlimited. In addition to species variation, different environmental conditions can also affect the nitrogen assimilation rates in mangrove plants. Because Cl ions can reduce protein synthesis and nitrogen assimilation , soil pore water salinity appears to be a negative factor that significantly alters the nitrogen uptake rates of mangrove plants. Adequate data

10353-515: The ongoing challenge of balancing conservation with human development needs. Tropical rainforests are hot and wet. Mean monthly temperatures exceed 18 °C (64 °F) during all months of the year. Average annual rainfall is no less than 1,680 mm (66 in) and can exceed 10 m (390 in) although it typically lies between 1,750 mm (69 in) and 3,000 mm (120 in). This high level of precipitation often results in poor soils due to leaching of soluble nutrients in

10472-415: The open sea, in sheltered bays, and on fringe islands. Trees adapted to drier, less salty soil can be found farther from the shoreline. Some mangroves flourish along riverbanks far inland, as long as the freshwater current is met by ocean tides." Mangroves can be found in 118 countries and territories in the tropical and subtropical regions of the world. The largest percentage of mangroves is found between

10591-596: The organic matter produced and retained in mangroves can slow the recycling of nutrients, particularly of nitrogen. Nitrogen limitation in such systems may be overcome by microbial nitrogen fixation when combined with high rates of bioturbation by macrofauna , such as crabs and lobsters. Bioturbation by macrofauna affect nitrogen availability and multiple nitrogen related microbial processes through sediment reworking, burrow construction and bioirrigation , feeding and excretion. Macrofauna mix old and fresh organic matter, extend oxic–anoxic sediment interfaces, increase

10710-542: The organisms they host include algae , barnacles , oysters , sponges , and bryozoa , which all require a hard surface for anchoring while they filter-feed. Shrimp and mud lobsters use the muddy bottoms as their home. Mangrove crabs eat the mangrove leaves, adding nutrients to the mangal mud for other bottom feeders. In at least some cases, the export of carbon fixed in mangroves is important in coastal food webs. Mangrove plantations host several commercially important species of fish and crustaceans. In Puerto Rico ,

10829-514: The past, and have been identified as important drivers of speciation. However, fast human driven habitat destruction is suspected to be one of the major causes of species extinction. Tropical rain forests have been subjected to heavy logging and agricultural clearance throughout the 20th century, and the area covered by rainforests around the world is rapidly shrinking. Tropical rainforests have existed on earth for hundreds of millions of years. Most tropical rainforests today are on fragments of

10948-661: The plant litter and break it down chemically into organic compounds , minerals, carbon dioxide, and nitrogenous wastes . The intertidal existence to which these trees are adapted represents the major limitation to the number of species able to thrive in their habitat. High tide brings in salt water, and when the tide recedes, solar evaporation of the seawater in the soil leads to further increases in salinity. The return of tide can flush out these soils, bringing them back to salinity levels comparable to that of seawater. At low tide, organisms are exposed to increases in temperature and reduced moisture before being then cooled and flooded by

11067-529: The presence of 67 different uncontacted tribes in Brazil, up from 40 in 2005. With this addition, Brazil has now overtaken the island of New Guinea as the country having the largest number of uncontacted tribes. The province of Irian Jaya or West Papua in the island of New Guinea is home to an estimated 44 uncontacted tribal groups. The pygmy peoples are hunter-gatherer groups living in equatorial rainforests characterized by their short height (below one and

11186-587: The primary reason why, on some shorelines, mangrove tree species show distinct zonation. Small environmental variations within a mangal may lead to greatly differing methods for coping with the environment. Therefore, the mix of species is partly determined by the tolerances of individual species to physical conditions, such as tidal flooding and salinity, but may also be influenced by other factors, such as crabs preying on plant seedlings. Once established, mangrove roots provide an oyster habitat and slow water flow, thereby enhancing sediment deposition in areas where it

11305-416: The quality of the water degrades, the shrimp ponds are quickly abandoned leaving massive amounts of wastewater. This is a major source of water pollution that promotes ocean deoxygenation in the adjacent habitats. Due to these frequent hypoxic conditions, the water does not provide habitats to fish. When exposed to extreme hypoxia, ecosystem function can completely collapse. Extreme deoxygenation will affect

11424-524: The rainfall in the Amazon area is produced by the forests. The moisture from the forests is important to the rainfall in Brazil , Paraguay , Argentina Deforestation in the Amazon rainforest region was one of the main reason that cause the severe Drought of 2014–2015 in Brazil For the last three decades, the amount of carbon absorbed by the world's intact tropical forests has fallen, according to

11543-403: The rapid uptake of other trees. These roots also aid in water uptake and storage, increase surface area for gas exchange, and collect leaf litter for added nutrition. Additionally, these roots reduce soil erosion and maximize nutrient acquisition during heavy rains by diverting nutrient rich water flowing down the trunk into several smaller flows while also acting as a barrier to ground flow. Also,

11662-472: The right). By incorporating information on carbon burial, CO 2 efflux and carbon outwelled as leaf litter , POC and DOC, the remaining 52% was thought outwelled as DIC, though there was insufficient data to confirm this. More recent assessments of DIC export at two sites in Australia ; supported the estimates of Bouillon et al. in 2008, although in 2014 Alongi suggested that only 40% of NPP

11781-427: The sanctuary, especially during migratory season of Asian birds (i.e. Sept-April). Other mangrove wildlife includes monitor lizards , fiddler crabs , mudskippers , weaver ants , butterflies and other insects, jellyfish , water snakes and mud lobsters . Mangrove forest Many mangrove forests can be recognised by their dense tangle of prop roots that make the trees appear to be standing on stilts above

11900-495: The sediment through the tidal flushing of mangrove forests. Mangrove forests can decay into peat deposits because of fungal and bacterial processes as well as by the action of termites . It becomes peat in good geochemical , sedimentary, and tectonic conditions. The nature of these deposits depends on the environment and the types of mangroves involved. Termites process fallen leaf litter , root systems and wood from mangroves into peat to build their nests. Termites stabilise

12019-406: The single individual to the ecosystem are not well understood. Mangrove forests are amongst the world's most productive marine ecosystems, with net primary productivity (NPP) in the order of 208 Tg C yr . Mangrove forests achieve a steady state once the forest reaches maximum biomass at around 20–30 years through a constant process of mortality and renewal  so, assuming the living biomass

12138-466: The specifics of the origin of rainforests remain uncertain due to an incomplete fossil record. Several biomes may appear similar-to, or merge via ecotones with, tropical rainforest: Moist seasonal tropical forests receive high overall rainfall with a warm summer wet season and a cooler winter dry season. These forests usually fall under tropical monsoon or tropical savanna climates. Some trees in these forests drop some or all of their leaves during

12257-534: The supporting plants. The fauna is similar to that found in the emergent layer, but more diverse. It is suggested that the total arthropod species richness of the tropical canopy might be as high as 20 million. Other species inhabiting this layer include many avian species such as the yellow-casqued wattled hornbill ( Ceratogymna elata ), collared sunbird ( Anthreptes collaris ), grey parrot ( Psitacus erithacus ), keel-billed toucan ( Ramphastos sulfuratus ), scarlet macaw ( Ara macao ) as well as other animals like

12376-443: The tide. 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. A mangrove swamp typically features only a small number of tree species. It is not uncommon for a mangrove forest in the Caribbean to feature only three or four tree species. For comparison,

12495-404: The trees to capture sunlight. Only about 5% of sunlight breaches the canopy to arrive at the understory causing true understory plants to seldom grow to 3 m (10 feet). As an adaptation to these low light levels, understory plants have often evolved much larger leaves. Many seedlings that will grow to the canopy level are in the understory. The canopy is the primary layer of the forest, forming

12614-449: The tropical coastline and provide different ecosystem services. 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. In pristine environments, mangroves are among the most productive ecosystems on the planet, despite growing in tropical waters that are often nutrient depleted. The refractory nature of

12733-482: The tropical rainforests fall into two classifications which include the ultisols and oxisols . Ultisols are known as well weathered, acidic red clay soils, deficient in major nutrients such as calcium and potassium. Similarly, oxisols are acidic, old, typically reddish, highly weathered and leached, however are well drained compared to ultisols. The clay content of ultisols is high, making it difficult for water to penetrate and flow through. The reddish color of both soils

12852-426: The typical Yanamomo diet comes from farmed plants. Some action has been taken by suggesting fallow periods of the land allowing secondary forest to grow and replenish the soil. Beneficial practices like soil restoration and conservation can benefit the small farmer and allow better production on smaller parcels of land. The tropics take a major role in reducing atmospheric carbon dioxide . The tropics (most notably

12971-728: The uptake of carbon. The soil contains microbial organisms such as bacteria, which break down leaf litter and other organic matter into inorganic forms of carbon usable by plants through a process called decomposition. During the decomposition process the microbial community is respiring, taking up oxygen and releasing carbon dioxide. The decomposition rate can be evaluated by measuring the uptake of oxygen. High temperatures and precipitation increase decomposition rate, which allows plant litter to rapidly decay in tropical regions, releasing nutrients that are immediately taken up by plants through surface or ground waters. The seasonal patterns in respiration are controlled by leaf litter fall and precipitation,

13090-472: The water and build up the muddy bottom. Mangrove forests stabilise the coastline, reducing erosion from storm surges, currents, waves, and tides. The intricate root system of mangroves makes these forests attractive to fishes and other organisms seeking food and shelter from predators. The main contribution of mangroves to the larger ecosystem comes from litter fall from the trees, which is then decomposed by primary consumers . Bacteria and protozoans colonise

13209-547: The water. This tangle of roots allows the trees to handle the daily rise and fall of tides, as most mangroves get flooded at least twice per day. The roots slow the movement of tidal waters, causing sediments to settle out of the water and build up the muddy bottom. Mangrove forests stabilise the coastline, reducing erosion from storm surges , currents, waves, and tides. The intricate root system of mangroves also makes these forests attractive to fish and other organisms seeking food and shelter from predators. Mangrove forests live at

13328-627: The winter dry season, thus they are sometimes called "tropical mixed forest". They are found in parts of South America, in Central America and around the Caribbean , in coastal West Africa , parts of the Indian subcontinent , and across much of Indochina . These are found in cooler-climate mountainous areas, becoming known as cloud forests at higher elevations. Depending on latitude, the lower limit of montane rainforests on large mountains

13447-516: The world as of 2010 at 137,600 km (53,100 sq mi), spanning 118 countries and territories. Following the conventions for identifying geographic regions from the Ramsar Convention on Wetlands, researchers reported that Asia has the largest share (38.7%) of the world's mangroves, followed by Latin America and the Caribbean (20.3%), Africa (20.0%), Oceania (11.9%), and Northern America (8.4%). The largest mangrove forest in

13566-626: The world have inhabited rainforests for millennia, relying on them for sustenance and shelter, but face challenges from modern economic activities. Conservation efforts are diverse, focusing on both preservation and sustainable management. International policies, such as the Reducing Emissions from Deforestation and Forest Degradation ( REDD and REDD+ ) programs, aim to curb deforestation and forest degradation. Despite these efforts, tropical rainforests continue to face significant threats from deforestation and climate change , highlighting

13685-755: The world is in the Sundarbans . 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 seasonally flooded Sundarbans freshwater swamp forests lie inland from the mangrove forests on the coastal fringe. The forest covers 10,000 km (3,900 sq mi) of which about 6,000 km (2,300 sq mi) are in Bangladesh. The Sundarbans

13804-457: The world's animal and plant species, and two-thirds of all flowering plant species. Their dense insect population and variety of trees and higher plants are notable. Described as the "world's largest pharmacy", over a quarter of natural medicines have been discovered in them. However, tropical rainforests are threatened by human activities, such as logging and agricultural expansion, leading to habitat fragmentation and loss . The structure of

13923-483: Was a Council Member for the International Society for Mangrove Ecosystems . 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". Mangrove forests move carbon dioxide "from

14042-610: Was exported as DIC. Mangrove forests and coastal marshes are typically considered N-limited ecosystems because of their high primary production. Therefore, mangrove plants are highly efficient at utilising soil nitrogen, making them an important sink for excess nitrogen from upstream. However, different mangrove species may still utilise nitrogen at different efficiencies, even though they share similar nitrogen pathways (see diagram on right). Reported nitrogen assimilation rates in mangrove plants ranged from 2 to 8 μmol g h under ambient nitrogen conditions, and 19 to 251 μmol g h when

14161-400: Was relatively high. The rate of loss of Belize's mangroves—at 0.07% per year between 1980 and 2010—was much lower than Belize's overall rate of forest clearing (0.6% per year in the same period). These findings can also be interpreted to indicate Belize's mangrove regulations (under the nation's) have largely been effective. Nevertheless, the need to protect Belize's mangroves is imperative, as

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