Relationship of biotic and abiotic factors in a mangrove forest

List of Biotic and Abiotic Factors in a Forest Ecosystem | Sciencing

relationship of biotic and abiotic factors in a mangrove forest

The major factors, governing the mangrove ecosystem dynamic ecosystem, and are dependent on the following inter-related, environmental both, biotic and abiotic factors: . Productivity, energy flow, trophic relationship, nutrient cycling. Where are Mangrove swamps found? > . Biotic and Abiotic Factors. Biotic Factos. Animals- such as the mangrove crab, Saltwater Crocodile, Jabiru, Sea Snake. As you can see, mangroves are a very important and significant part of not only the environment, but to human communities as well. Without.

The often-acclaimed functions and values of tropical mangals also have to be critically assessed in the light of existing and future data. It is proposed that research effort should also be targeted towards the assessment and mitigation of the predicted impacts of urgent problems faced by tropical mangals e.

More than half of the ha opment in research on the structure and function of of mangroves present in Thailand in has already tropical mangrove ecosystems. Many of these studies been converted to prawn farms or various other uses not only help provide a more comprehensive picture by Aksornkoae Mangals in many other of global mangrove ecology but also challenge earlier tropical countries also face the same rate of destruc- models largely based on systems in Florida Golley et tion, e. Indonesia NaaminMalaysia Gong al.

Also obvious during the last decade was Philippines Calumpong While recognizing the the continued and dramatic destruction of natural often disastrous outcomes of large-scale conversion of tropical mangrove resources. The naturally high pro- natural mangals, ecologists have nevertheless yet to ductivity of tropical mangroves has traditionally been present sound and unequivocal data to support their exploited for a wide variety of purposes, both as sources traditional claims on mangrove ecological values and of forestry or fisheries products and for human settle- functions, such as the often-assumed linkage between ment Hatcher et al.

More recently, tropical mangroves are being mangrove forests as nursery sites. Moreover, the long- extensively cleared for the construction of aquaculture term impact and the ramifications of anthropogenic ponds for prawn production Primavera School of Environmental and Applied Sci- tion. I will also argue that the interaction between the ence, Faculty of Environmental Sciences, Griffith University Gold two sets of forces i.

The role of tropical mangals as a S. I will also explain why flow regime is stressed in recent ecosystem models research on mangrove ecology should be targeted attempting to explain and predict aquatic ecosystem towards real-world management problems and propose behaviour Junk et al. There are, however, problems of directly applying this classification scheme to other systems. This argument is not fundamentally different mangrove ecology built on findings from Florida from that of Lugo and Snedakeras the major systems has been strongly influenced by salt-marsh influence on ecosystem function, such as material research along the Atlantic coast of North America.

The Lugo and parts of the world. Snedaker model of mangrove ecosystem function has Odum summarized and evaluated the been influential in the interpretation of data collected status of three ecosystem-level hypotheses concerning throughout the world.

Thus Pool et al. The origins of these three of water turnover within the forests. Boto and Bunt hypotheses can be traced back to the earlier works by assumed that all litter represented by the dif- Odum, his co-workers and others who studied the salt- ference between litter production and standing crop in marshes of the Atlantic coast of North America e. This emphasis on the production and fate e. Davis ; Chapman depicted mangroves of organic detritus strongly influenced mangrove as successional systems: In the Florida themselves had a significant impact on the physical model, the production of organic detritus from man- environment and such impact culminated in an alter- groves was considered to be little affected by biotic ation of growth conditions favoured by different species processes such as herbivory Heald or other in time.

Subsequently much discussion has occurred forms of in situ processing in the mangrove forest: Models of mangrove ecosystem physical forces, such as hurricanes, as opposed to the function were constructed employing the mass balance earlier idea of an internal, biologically-fuelled process.

Biotic and Abiotic Factors - The MANgrove Swamps

In these models, physical forces such as solar Lugo later argued that most mangroves are non- and tidal energy input acted as the only significant successional and instead represent the steady-state forcing functions driving the dynamics of organic community on little-disturbed depositing coasts in the matter production and export Odum ; Twilley tropics. The idea of biologically driven, autogenic suc- Subsequent studies on litter dynamics of cession was further challenged by Thomwho Florida mangroves maintained this view Twilley ; opined that mangrove growth was primarily determined Twilley et al.

He also sug- tems. Recent findings in other parts of the Americas gested that mangrove distribution was the result of the suggest, however, that ecological processes, such as opportunistic response of species to fluctuating en- crab consumption, could be important even at high vironmental conditions largely locally controlled by the geophysical energies Twilley et al.

Again, the dominance of physical forces in shap- ralia. One good example illustrating this changing crabs in the mangrove forest prior to export. The value paradigm is the litter dynamics of mangals in north- of fresh or little-decomposed mangrove detritus to the eastern Australia.

Australian mangrove from mass balance calculations Analysis of the abundance of large epibenthos associ- based on the difference between the rate of litter pro- ated with mangroves concluded that mangrove litter duction and the amount remaining on the forest floor probably provided spatial refuges rather than food after high tide. Field sampling as well as have been exported by tidal flow. Later investigations laboratory experiments also demonstrated that the on the same systems discovered that biotic processes soluble tannins associated with mangrove leaf litter may account for a significant fraction of the missing bio- deposits can inhibit population growth of meiofauna mass.

Robertson recorded that sesarmine crabs Alongia, A laboratory study con- Sesarma spp. Malleyand was adversely affected by tannins released from high stand- later backed by similar findings from southeast Asia ing crop of detritus Lee in press. In contrast, bio- e. LeeAfrica e. N ratio of crab Recent evidence also points to the importance of faecal material decreases linearly with time after dep- biotic processes in determining not only the quantity osition Lee and may contribute significantly to but also the quality of the organic matter exported from the fraction of POM with low C: N ratios in the wide mangrove environments.

Lee investigated the spectrum from 20 to recorded by Boto and Bunt value of crab-consumed and processed mangrove The actual significance of this secondary material to coprophagous macrofauna in a tropical export of biologically processed mangrove-derived mangal and found that crab faecal material supported organic matter has not yet been estimated. These recent faster growth and lower mortality in the amphipod findings have significantly refined the picture painted Parhyallela sp.

This organic matter of form a significant component of the diet of predators mangrove origin, now finely fragmented and low in such as fish.

This trophic link is, however, thought to deterrent chemicals such as tannins, is ideal for colon- be of minor significance in view of the general lack of isation by microbes. It can form the basis of a copro- agreement in the stable isotope signatures of offshore phagous food chain both in the mangrove benthos and consumers and mangroves Rodelli et al. LEE and may consequently improve productivity.

As pointed out by Twilleyincreas- compact mangrove sediments Wolanski et al. Macrophyte productivity viously neglected by the geophysical forcing-function may consequently increase as a result of increased tidal premise. The effect tance of crab Ucides occidentalis processing in the of such tidal subsidies in coastal wetlands is obviously litter dynamics of high energy neotropical mangroves.

Recent findings in Indo-Pacific trop- elements that are important may themselves and thus ical mangroves have, however, shown that mangrove their impact on mangroves be subject to physical zonation is probably a result of joint actions by bio- forces. Since any effect of the physical forces on the logical e. Smitha; biotic agents may not be in the same direction as on competition: Smith b and physical processes the mangroves, the overall impact of combinations of Smith ; McGuinness a.

For example, sesarmine crab assemblages ecosystems have also revealed complex interactions have strikingly different levels of diversity and abun- between mangrove trees and their associated fauna. These differ- Ellison et al. Sharing of nitro- propagule consumption Smith et al. There is probably a strong evolutionary fouling sponges apparently resulted in increased growth and historical element in the difference in the abun- and production of both parties. With more attention dance and diversity of crabs in the different geograph- paid to biotic processes in mangrove ecosystems, such ical regions, but a positive relationship seems to exist intricate relationships will probably be increasingly between mangrove and crab species richness Lee recognized as important elements in the structure and This may not necessarily reflect a causal rela- function of such systems.

Smith recognized by a proponent of the Florida mangrove et al.

relationship of biotic and abiotic factors in a mangrove forest

Grapsid crabs themselves are, however, subject to Twilley pointed out that there are areas of abiotic influences e. Such control may processes that may together determine the overall pat- then result in different impacts of the crabs on man- tern of mangal structure and function. He further sug- grove ecosystem function, such as propagule con- gested that the relative importance given to these sumption rate McKee Davie compared categories of influence often depends on the perspec- grapsid crab species richness in various northeastern tive and the background of the researcher.

Tangible abiotic factors include soil, minerals, rocks and water. But abiotic factors can be intangible, such as temperature, other types of radiation and the chemistry of soil and water. Sciencing Video Vault Biotic Factors by Function Ecologists frequently group an ecosystem's factors by what role they play in the system, rather than by what particular species they are. This is known as functional classification. These functions relate to the movement of energy through an ecosystem, and trees — along with other photosynthetic plants — are the chief primary producers.

This means that trees convert the sun's energy into food energy, which is then used by other members of the ecosystem.

These other members of the ecosystem can also be categorized. Fauna There are different type of faunal communities in mangrove waters which are dependent on the water component in one way or the other.

The planktonic and benthic animal communities also play a very important role in the mangrove ecosystem just like the terrestrial animals. There are different species of crustaceans like Penaeus indicus, P.

Scylla serrata, Thalassina, etc. The fishes are represented by several species like the mud skippers, carangids, clupeids, serranids, mullets, hilsa, seabass, milkfish etc. The wildlife of Indian mangrove forests is quite diverse and interesting. Apart from the famous Royal Bengal tiger and estuarine crocodile Crocodilus porosusthere are different kinds of monkeys, otters, deer's, fishing cats, snakes and wild pigs.

The mangrove swamps of India are favoured by a variety of birds, both migratory and resident. Microorganisms Microbial organisms like yeast, bacteria and fungi play a very important and dominant role in the decomposition of mangrove foliage, regeneration of nutrients and mineralization Community stability properties Zonation On the basis of salinity, five zones of mangrove distribution are considered. These are the euhaline, polyhaline, mesohaline, oligohaline and limnatic zones.

The west coast is characterized by the rocky substratum and hence absence of mangroves in the mouth region. On the other hand, the same euhaline zone along the estuaries of the east coast, which is a delta region, shows the presence of luxuriant mangrove forests as observed in the Gangetic, Mahanadi and Godavari deltas. Wave action is maximum and the gradient is not steep; thus sediment accertion will take place in the region of confluence which is known as delta.

Otherwise, the entire sediment load will be washed into the sea. Its substratum is silty. The salinity in this area is less than 0. Different mangrove species, according to their salt tolerant ability and substratum preference occupy different zones along the estuaries. The accretion of sediment at the mouth of the major estuaries like Ganga, Mahanadi, Godavari, etc. During this process, the fine alluvial silt is deposited in the form of shallow islands in the mouth region.

Slowly the new mangrove formation develop following a typical succession pattern. After the growth of pioneer species, the dominant or climax vegetation of mangrove species takes over and flourish. These new mangrove formations are very sensitive to the flood waters during rainy season. Depending upon the flood, the rate of erosion in the mangrove soil varies. During heavy to very heavy floods, these new mangrove formation may be completely washed out. During the rainy season, the rate of erosion is higher while during non monsoon season the accretion is higher.

The effect of accretion and erosion seem to be more prominent along the east coast than on the west coast of India. Succession The succession of mangrove is dependent on the available seeds or propagules, their size or length and the tidal fluctuation. Seeds of grass, sedge or Excoecaria agallocha, which are minute in size, will always establish themselves at the uppermost limit of the intertidal region. At the same time, seedlings of taxa like, Rhizophora, Kandelia, Ceriops or Bruguiera will be established according to their floating height.

Productivity, energy flow, trophic relationship, nutrient cycling Detritus decomposition The major ecological role of mangroves is the stabilization of the shoreline and prevention of shore erosion.

relationship of biotic and abiotic factors in a mangrove forest

The dense network of prop roots, pneumatophores and stilt roots not only give mechanical support to the plant, but also trap the sediments.

The rate of sedimentation or accretion is generally much higher in these estuaries lined with mangroves. The second important ecological role of the mangroves is the detritus, which help in feeding and provides breeding and nursery grounds for the juveniles of many commercially important shrimps and fishes.

Major primary production in the mangrove ecosystem is from the trees. However, only a fraction of this production is consumed by herbivores. The remainder enters the mangrove water as litter fall. The decomposition of this litter fall produces detritus, which in turn is colonized by heterotrophic microorganisms, thus enhancing its nutritive value. The detritus, besides forming a food source for suspension and deposit feeders, is also consumed by the juveniles of a variety of bivalves, shrimps and fishes, which migrate into the mangrove environments in their life cycle for better feeding and protection.

There is a direct correlation between the extent of mangrove forests along a coastline and the fishery as well as shrimp catches from the coastal waters adjoining the mangroves, thus demonstrating the importance of mangroves for sustaining coastal fisheries. In mangrove forests, the floral elements responsible for the photosynthesis under brackichwater condition are of different types ie.

Angiospermic flora, phytoplankton and marine algae. These elements contribute mainly to the primary productivity. Apart from this, faunal elements like zooplankton are responsible for secondary productivity and benthic animals for tertiary productivity. The primary productivity of phytoplankton: Plankton production in mangrove environment represent only that of surrounding waters i.