RAJESH NAYAK

IMPORTANT ENVIRONMENT NOTES FROM WIKIPEDIA

ECOSYSTEM SERVICES

Humankind benefits in a multitude of ways from ecosystems.

Collectively, these benefits are becoming known as ecosystem services.

Ecosystem services are regularly involved in the provisioning of clean drinking water and the decomposition of wastes.

the ecosystem services concept itself was popularized by the Millennium Ecosystem Assessment (MA) in the early 2000s.

ecosystem services into four broad categories: provisioning, such as the production of food and water; regulating, such as the control of climate and disease; supporting, such as nutrient cycles and crop pollination; and cultural, such as

spiritual and recreational benefits. "

the benefits people obtain from ecosystems. Four Categories

Supporting services

include services such as nutrient recycling, primary production and soil formation.

These services make it possible for the ecosystems to provide services such as food supply, flood regulation and water purification

Provisioning services "Products obtained from ecosystems"

food (including seafood and game), crops, wild foods, and spices

raw materials (including lumber, skins, fuel wood, organic matter, fodder, and fertilizer)

genetic resources (including crop improvement genes, and health care)

water

minerals (including diatomite)

medicinal resources (including pharmaceuticals, chemical models, and test and assay organisms)

energy (hydropower, biomass fuels)

ornamental resources (including fashion, handicraft, jewelry, pets, worship, decoration and souvenirs like furs, feathers,

ivory, orchids, butterflies, aquarium fish, shells, etc.)

Regulating services

"Benefits obtained from the regulation of ecosystem processes"

carbon sequestration and climate regulation

waste decomposition and detoxification

purification of water and air

pest and disease control

Cultural services

"Nonmaterial benefits people obtain from ecosystems through spiritual enrichment, cognitive development, reflection, recreation, and aesthetic experiences"

cultural (including use of nature as motif in books, film, painting, folklore, national symbols, architect, advertising, etc.)

spiritual and historical (including use of nature for religious or heritage value or natural)

recreational experiences(including ecotourism, outdoor sports, and recreation)

science and education (including use of natural systems for school excursions, and scientific discovery)

Ecosystem-Based Adaptation (EbA)

Ecosystem-Based Adaptation or EbA is an emerging strategy for community development and environmental management that seeks to use an ecosystem services framework to help communities adapt to the effects of climate

change.

The Convention on Biological Diversity currently defines Ecosystem-Based Adaptation as the use of biodiversity and ecosystem services to help people adapt to the adverse effects of climate change, which includes the use of sustainable management, conservation and restoration of ecosystems, as part of an overall adaptation strategy that takes into account

the multiple social, economic and cultural co-benefits for local communities

RAJESH NAYAK

Estuarine and coastal ecosystems are both marine ecosystems.

An estuary is defined as the area in which a river meets the sea or the ocean.

The waters surrounding this area are predominantly salty waters or brackish waters; and the incoming river water is dynamically motioned by the tide.

An estuary strip may be covered by populations of reed (or similar plants) and/or sandbanks (or similar form or land)

Buffer Zones

Coastal and estuarine ecosystems act as buffer zones against natural hazards and environmental disturbances, such as floods, cyclones, tidal surges and storms.

The role they play is to [absorb] a portion of the impact and thus [lessen] its effect on the land.

Wetlands, for example, and the vegetation it supports trees, root mats, etc. retain large amounts of water (surface water, snowmelt, rain, groundwater) and then slowly releases them back, decreasing the likeliness of floods.

Mangrove forests protect coastal shorelines from tidal erosion or erosion by currents; a process that was studied after the 1999 cyclone that hit India.

Villages that were surrounded with mangrove forests encountered less damages than other villages that werent protected by mangroves

BLUE CARBON

Blue carbon is the carbon captured by the world's oceans and coastal ecosystems. The carbon captured by living organisms in oceans is stored in the form of biomass and sediments from mangroves, salt marshes and seagrasses.

The rates of blue carbon sequestration and storage capacities in ecosystems are comparable to (and often higher than) those in carbon-rich terrestrial ecosystems such as tropical rainforests or peatlands.

Unlike most terrestrial systems, which reach soil carbon equilibrium within decades, deposition of carbon dioxide in coastal ecosystem sediment can continue over millennia.

However, when these coastal ecosystems are degraded or destroyed they can become carbon dioxide sources due to the oxidization of biomass and organic soil. coastal ecosystems do contain substantial amounts of carbon, and because this

carbon is in danger of being released, they are important in mitigating climate change.

However, the rate of loss of mangroves, sea grasses and salt marshes (driven mostly by human activities) is estimated to be among the highest of any ecosystem on the planet, prompting international interest in managing them more

effectively for their carbon benefits.

Sperm whales increase the levels of primary production and carbon export to the deep ocean by depositing iron rich faeces into surface waters of the Southern Ocean.

The iron rich faeces causes phytoplankton to grow and take up more carbon from the atmosphere.

When the phytoplankton dies, it sinks to the deep ocean and takes the atmospheric carbon with it.

By reducing the abundance of sperm whales in the Southern Ocean, whaling has resulted in an extra 2 million tonnes of carbon remaining in the atmosphere each year.

Carbon sequestration

is the process of capture and long-term storage of atmospheric carbon dioxide (CO2).

Carbon sequestration describes long-term storage of carbon dioxide or other forms of carbon to either mitigate or defer global warming and avoid dangerous climate change.

It has been proposed as a way to slow the atmospheric and marine accumulation of greenhouse gases, which are released by burning fossil fuels.

Biosequestration or carbon sequestration through biological processes affects the global carbon cycle.

Examples include major climatic fluctuations, such as the Azolla event, which created the current Arctic climate.

Such processes created fossil fuels, as well as clathrate and limestone.

By manipulating such processes, geoengineers seek to enhance sequestration.

Peat bogs are a very important carbon store.

By creating new bogs, or enhancing existing ones, carbon can be sequestered.

Wetland soil is an important carbon sink; 14.5% of the worlds soil carbon is found in wetlands, while only 6% of the worlds land is composed of wetlands.

Ocean iron fertilization is an example of such a geoengineering technique.

Iron fertilization attempts to encourage phytoplankton growth, which removes carbon from the atmosphere for at least a period of time.

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This technique is controversial due to limited understanding its complete effects on the marineecosystem, including side effects and possibly large deviations from expected behavior.

Such effects potentially include release of nitrogen oxides, and disruption of the ocean's nutrient balance.

Natural iron fertilisation events (e.g., deposition of iron-rich dust into ocean waters) can enhance carbon sequestration. Sperm whales act as agents of iron fertilisation when they transport iron from the deep ocean to the surface during prey

consumption and defecation.

Sperm whales have been shown to increase the levels of primary production and carbon export to the deep ocean by depositing iron rich feces into surface waters of the Southern Ocean.

The iron rich feces causes phytoplankton to grow and take up more carbon from the atmosphere.

When the phytoplankton dies, some of it sinks to the deep ocean and takes the atmospheric carbon with it.

By reducing the abundance of sperm whales in the Southern Ocean, whaling has resulted in an extra 2 million tonnes of carbon remaining in the atmosphere each year.

Bio-energy with carbon capture and storage (BECCS)

BECCS refers to biomass in power stations and boilers that use carbon capture and storage.

The carbon sequestered by the biomass would be captured and stored, thus removing carbon dioxide from the atmosphere.

This technology is sometimes referred to as bio-energy with carbon storage, BECS, though this term can also refer to the carbon sequestration potential in other technologies, such as biochar

Landfills also represent a physical method of sequestration.

Biochar is charcoal created by pyrolysis of biomass waste.

The resulting material is added to a landfill or used as a soil improver to create terra preta.

Biogenic carbon is recycled naturally in the carbon cycle.

Pyrolysing it to biochar renders the carbon relatively inert so that it remains sequestered in soil.

Further, the soil encourages bulking with new organic matter, which gives additional sequestration benefit.

Carbon carousel

uses panels that, after being depleted of CO2 in the regeneration chamber, exit this chamber and enter the carousel.

The carousel rotates the CO2-sorbent panels through the air, collecting CO2 all the while, until the CO2-saturated panels reach the point of entry to the regeneration chamber.

The regeneration process provides new panels for the exit to the recovery process.

Carbon capture and storage (CCS) (or carbon capture and sequestration)

is the process of capturing waste carbon dioxide (CO2) from large point sources, such as fossil fuel power plants, transporting it to a storage site, and depositing it where it will not enter the atmosphere, normally an

underground geological formation.

The aim is to prevent the release of large quantities of CO2 into the atmosphere (from fossil fuel use in power generation and other industries).

It is a potential means ofmitigating the contribution of fossil fuel emissions to global warming and ocean acidification.

Bio-energy with carbon capture and storage (BECCS)

is a greenhouse gas mitigation technology which produces negative carbon dioxide emissions by combining bioenergy (energy from biomass) use with geologic carbon capture and storage.

The concept of BECCS is drawn from the integration of trees and crops, which extract carbon dioxide (CO2) from the atmosphere as they grow, the use of this biomass in processing industries or power plants, and the application of carbon capture and storage via CO2 injection into geological formations.

There are other non-BECCS forms of carbon dioxide removal and storage that include technologies such as biochar, carbon dioxide air capture and biomass burial.

RAJESH NAYAK

It was pointed out in the IPCC Fourth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC) as a key technology for reaching low carbon dioxide atmospheric concentration targets.

Bio-energy is derived from biomass which is a renewable energy source and serves as a carbon sink during its growth.

During industrial processes, the biomass combusted or processed re-releases the CO2 into the atmosphere.

The process thus results in a net zero emission of CO2, though this may be positively or negatively altered depending on the carbon emissions associated with biomass growth, transport and processing, see below under environmental

considerations.

Carbon capture and storage (CCS) technology serves to intercept the release of CO2 into the atmosphere and redirect it into geological storage locations.

CO2 with a biomass origin is not only released from biomass fuelled power plants, but also during the production of pulp used to make paper and in the production of biofuels such as biogas and bioethanol.

The main technology for CO2 capture from biotic sources generally employs the same technology as carbon dioxide capture from conventional fossil fuel sources.

Broadly, three different types of technologies exist: post-combustion, pre-combustion, and oxy-fuel combustion.

A negative carbon dioxide emission or negative emission

or a process that is carbon negative gives a permanent removal of the greenhouse gas carbon dioxide from Earth's atmosphere.

It is considered the direct opposite of carbon dioxide emission, hence its name.

It is the result of carbon dioxide removal technologies, such as bio-energy with carbon capture and storage, biochar, direct air capture or enhanced weathering.

Negative emissions is different from reducing emissions, as the former produces an outlet of carbon dioxide from Earth's atmosphere, whereas the latter decreases the inlet of carbon dioxide to the atmosphere.

Both have the same momentary net effect, but for achieving carbon dioxide concentration levels below present levels, such as 350 ppm, negative emissions are critical.

Also for meeting higher concentration levels, negative emissions are increasingly considered to be crucial as they provide the only possibility to fill the gap between needed reductions to meet mitigation targets and global emission

trends.

Carbonic acid

is a chemical compound with the chemical formula H2CO3 (equivalently OC(OH)2).

It is also a name sometimes given to solutions of carbon dioxide in water (carbonated water), because such solutions contain small amounts of H2CO3.

In physiology, carbonic acid is described as volatile acid or respiratory acid, because it is the only acid excreted as a gas by the lungs.

Carbonic acid, which is a weak acid, forms two kinds of salts, the carbonates and the bicarbonates.

In geology, carbonic acid causes limestone to dissolve producing calcium bicarbonate which leads to many limestone features such as stalactites and stalagmites.

Carbonic acid is one of the polyprotic acids:

It is diprotic - it has two protons, which may dissociate from the parent molecule.

Thus, there are two dissociation constants, the first one for the dissociation into the bicarbonate (also called hydrogen carbonate) ion HCO3.

Kelps

are large seaweeds (algae) belonging to the brown algae (Phaeophyceae) in the order Laminariales.

There are about 30 different genera.

RAJESH NAYAK

Kelp grows in underwater "forests" (kelp forests) in shallow oceans.

The organisms require nutrient-rich water with temperatures between 6 and 14 C (43 and 57 F).

They are known for their high growth rate the genera Macrocystis and Nereocystiscan grow as fast as half a metre a day, ultimately reaching 30 to 80 metres Giant kelp can be harvested fairly easily because of its surface canopy and

growth habit of staying in deeper water.

Bongo kelp ash is rich in iodine and alkali.

In great amount, kelp ash can be used in soap and glass production.

Mangroves

are various large and extensive types of trees up to medium height and shrubs that grow in salinecoastal sediment habitats in the tropics and subtropicsmainly between latitudes 25 N and 25 S.

The word is used in at least three senses: (1) most broadly to refer to the habitat and entire plant assemblage or mangal, for which the terms mangrove forest biome, mangrove swamp and mangrove forest are also used, (2) to

refer to all trees and large shrubs in the mangrove swamp, and (3) narrowly to refer to the mangrove family of plants,

the Rhizophoraceae, or even more specifically just to mangrove trees of the genus Rhizophora.

The mangrove biome, or mangal, is a distinct saline woodland or shrubland habitat characterized bydepositional coastal environments, where fine sediments (often with high organic content) collect in areas protected from high-energy wave

action.

The saline conditions tolerated by various mangrove species range from brackish water, through pure seawater (30 to 40 ppt (parts per thousand)), to water concentrated by evaporation to over twice the salinity of ocean seawater (up to 90

ppt)

Red mangroves,

which can survive in the most inundated areas, prop themselves above the water level with stilt roots and can then absorb air through pores in their bark (lenticels).

Black mangroves

live on higher ground and make many pneumatophores (specialised root-like structures which stick up out of the soil like straws for breathing) which are also covered in lenticels.

These "breathing tubes" typically reach heights of up to 30 cm, and in some species, over 3 m.

The four types of pneumatophores are stilt or prop type, snorkel or peg type, knee type, and ribbon or plank type.

Knee and ribbon types may be combined with buttress roots at the base of the tree.

The roots also contain wide aerenchyma to facilitate transport within the plants.

A salt marsh or saltmarsh,

also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open salt water or brackish water that is regularly flooded by the tides.

It is dominated by dense stands of salt-tolerant plants such as herbs, grasses, or lowshrubs.

These plants are terrestrial in origin and are essential to the stability of the salt marsh in trapping and binding sediments.

Salt marshes play a large role in the aquatic food web and the delivery of nutrients to coastal waters.

They also support terrestrial animals and provide coastal protection.

Salt marshes occur on low-energy shorelines in temperate and high-latitudes which can be stable or emerging, or submerging if the sedimentation rate exceeds the subsidence rate.

Commonly these shorelines consist of mud or sand flats (known also as tidal flats or abbreviated to mudflats) which are nourished with sediment from inflowing rivers and streams.

These typically include sheltered environments such as embankments, estuaries and the leeward side of barrier islands and spits.

In the tropics and sub-tropics they are replaced by mangroves; an area that differs from a salt marsh in that instead of herbaceous plants, they are dominated by salt-tolerant trees.

RAJESH NAYAK

Most salt marshes have a low topography with low elevations but a vast wide area, making them hugely popular for human populations.

Salt marshes are located among different landforms based on their physical and geomorphological settings.

Such marsh landforms include deltaic marshes, estuarine, back-barrier, open coast, embayment and drowned-valley marshes.

Salt marshes are sometimes included in lagoons, and the difference is not very marked;

A swamp

is a wetland that is forested. Many swamps occur along large rivers where they are critically dependent upon natural water level fluctuations.

Other swamps occur on the shores of large lakes.

Some swamps have hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodic inundation.

The two main types of swamp are "true" or swamp forests and "transitional" or shrub swamps.

In the boreal regions of Canada, the word swamp is colloquially used for what is more correctly termed a bog or muskeg.

The water of a swamp may be fresh water, brackish water or seawater.

Some of the world's largest swamps are found along major rivers such as the Amazon, the Mississippi, and the Congo.

Swamps and other wetlands have traditionally held a very low property value compared to fields, prairies, or woodlands.

They have a reputation for being unproductive land that cannot easily be utilized for human activities, other than perhaps hunting and trapping.

Farmers, for example, typically drained swamps next to their fields so as to gain more land usable for planting crops.

Myristica swamps

are a type of freshwater swamp forest predominantly composed of species of Myristica.

These are found in two localities in India. Myristica swamps have adapted to inundation by way of stilt roots and knee roots.

Myristica swamps are found in the Uttara Kannada district of Karnataka State and in the southern parts of Kerala State.

The Millennium Ecosystem Assessment (MA)

is a major assessment of the effects of human activity on the environment.

It popularized the term ecosystem services, the benefits gained by humans from ecosystems.

Niche

"the set of biotic and abiotic conditions in which a species is able to persist and maintain stable population sizes.

The ecological niche is a central concept in the ecology of organisms and is sub-divided into the fundamental and the realized niche.

The fundamental niche is the set of environmental conditions under which a species is able to persist.

Termite mounds with varied heights of chimneys regulate gas exchange, temperature and other environmental parameters that are needed to sustain the internal physiology of the entire colony.

Biomes are larger units of organization that categorize regions of the Earth's ecosystems, mainly according to the structure and composition of vegetation.

There are different methods to define the continental boundaries of biomes dominated by different functional types of vegetative communities that are limited in distribution by climate, precipitation, weather and other environmental

variables.

Biomes include tropical rainforest, temperate broadleaf and mixed forest, temperate deciduous forest, taiga, tundra, hot desert, and polar desert.

Other researchers have recently categorized other biomes, such as the human and oceanic micro biomes.

To a microbe, the human body is a habitat and a landscape.

Micro biomes were discovered largely through advances in molecular genetics, which have revealed a hidden richness of microbial diversity on the planet.

RAJESH NAYAK

The oceanic micro biome plays a significant role in the ecological biogeochemistry of the planet's oceans.

Community ecology is the study of the interactions among a collections of species that inhabit the same geographic area.

Research in community ecology might measure primary production in a wetland in relation to decomposition and consumption rates.

This requires an understanding of the community connections between plants (i.e., primary producers) and the decomposers (e.g., fungi and bacteria), or the analysis of predator-prey dynamics affecting amphibian biomass.

Food webs and trophic levels are two widely employed conceptual models used to explain the linkages among species. Interspecific interactions such as predation are a key aspect of community ecology.

A food web is the archetypal ecological network. Plants capture solar energy and use it to synthesize simple sugars during photosynthesis.

As plants grow, they accumulate nutrients and are eaten by grazing herbivores, and the energy is transferred through a chain of organisms by consumption.

The simplified linear feeding pathways that move from a basal trophic species to a top consumer is called the food chain.

The larger interlocking pattern of food chains in an ecological community creates a complex food web.

Food webs are a type of concept map or a heuristic device that is used to illustrate and study pathways of energy and material flows.

A trophic level (from Greek troph, , troph, meaning "food" or "feeding") is "a group of organisms acquiring a considerable majority of its energy from the adjacent level nearer the abiotic source."

Links in food webs primarily connect feeding relations or trophism among species.

Biodiversity within ecosystems can be organized into trophic pyramids, in which the vertical dimension represents feeding relations that become further removed from the base of the food chain up toward top predators, and the

horizontal dimension represents the abundance or biomass at each level.

When the relative abundance or biomass of each species is sorted into its respective trophic level, they naturally sort into a 'pyramid of numbers'.

Species

are broadly categorized as autotrophs (or primary producers), heterotrophs (or consumers), and Detritivores (or decomposers).

Autotrophs are organisms that produce their own food (production is greater than respiration) by photosynthesis or chemosynthesis.

Heterotrophs are organisms that must feed on others for nourishment and energy (respiration exceeds production).[5]

Heterotrophs can be further sub-divided into different functional groups, including primary consumers (strict herbivores),secondary consumers (carnivorous predators that feed exclusively on herbivores) and tertiary consumers

(predators that feed on a mix of herbivores and predators).

Omnivores do not fit neatly into a functional category because they eat both plant and animal tissues.

It has been suggested that omnivores have a greater functional influence as predators, because compared to herbivores they are relatively inefficient at grazing.

Trophic levels are part of the holistic or complex systems view of ecosystems.

Each trophic level contains unrelated species that are grouped together because they share common ecological functions, giving a macroscopic view of the system.

While the notion of trophic levels provides insight into energy flow and top-down control within food webs, it is troubled by the prevalence of omnivory in real ecosystems.

This has led some ecologists to "reiterate that the notion that species clearly aggregate into discrete, homogeneous trophic levels is fiction."

RAJESH NAYAK

Nonetheless, recent studies have shown that real trophic levels do exist, but "above the herbivore trophic level, food webs are better characterized as a tangled web of omnivores."

A keystone species is a species that is connected to a disproportionately large number of other species in the food-web.

Keystone species have lower levels of biomass in the trophic pyramid relative to the importance of their role.

The many connections that a keystone species holds means that it maintains the organization and structure of entire communities.

The loss of a keystone species results in a range of dramatic cascading effects that alters trophic dynamics, other food web connections, and can cause the extinction of other species.

Sea otters (Enhydra lutris) are commonly cited as an example of a keystone species because they limit the density of sea urchins that feed on kelp.

If sea otters are removed from the system, the urchins graze until the kelp beds disappear and this has a dramatic effect on community structure.

[92] Hunting of sea otters, for example, is thought to have indirectly led to the extinction of

the Steller's Sea Cow (Hydrodamalis gigas).

While the keystone species concept has been used extensively as a conservation tool, it has been criticized for being poorly defined from an operational stance.

It is difficult to experimentally determine what species may hold a keystone role in each ecosystem.

Furthermore, food web theory suggests that keystone species may not be common, so it is unclear how generally the keystone species model can be applied

Complexity is understood as a large computational effort needed to piece together numerous interacting parts exceeding the iterative memory capacity of the human mind.

Global patterns of biological diversity are complex.

This bio complexity stems from the interplay among ecological processes that operate and influence patterns at different scales that grade into each other, such as transitional areas or Eco tones spanning landscapes.

Complexity stems from the interplay among levels of biological organization as energy and matter is integrated into larger units that superimpose onto the smaller parts. "What were wholes on one level become parts on a higher one."

Small scale patterns do not necessarily explain large scale phenomena, otherwise captured in the expression (coined by Aristotle) 'the sum is greater than the parts'"

Complexity in ecology is of at least six distinct types: spatial, temporal, structural, process, behavioral, and geometric."

From these principles, ecologists have identified emergent and self-organizing phenomena that operate at different environmental scales of influence, ranging from molecular to planetary, and these require different explanations at each

integrative level.

Ecological complexity relates to the dynamic resilience of ecosystems that transition to multiple shifting steady-states directed by random fluctuations of history.

Long-term ecological studies provide important track records to better understand the complexity and resilience of ecosystems over longer temporal and broader spatial scales.

Holism remains a critical part of the theoretical foundation in contemporary ecological studies.

Holism addresses the biological organization of life that self-organizes into layers of emergent whole systems that function according to non-reducible properties.

This means that higher order patterns of a whole functional system, such as an ecosystem, cannot be predicted or understood by a simple summation of the parts.

"New properties emerge because the components interact, not because the basic nature of the components is changed.

Behavioural ecology

All organisms can exhibit behaviours.

Even plants express complex behaviour, including memory and communication.

RAJESH NAYAK

Behavioural ecology is the study of an organism's behaviour in its environment and its ecological and evolutionary implications.

Ethology is the study of observable movement or behaviour in animals.

This could include investigations of motile sperm of plants, mobile phytoplankton, zooplanktons wimming toward the female egg, the cultivation of fungi by weevils, the mating dance of a salamander, or social gatherings of amoeba.

Cognitive ecology

Cognitive ecology integrates theory and observations from evolutionary ecology and neurobiology, primarily cognitive science, in order to understand the effect that animal interaction with their habitat has on their cognitive systems and

how those systems restrict behavior within an ecological and evolutionary framework.

"Until recently, however, cognitive scientists have not paid sufficient attention to the fundamental fact that cognitive traits evolved under particular natural settings.

With consideration of the selection pressure on cognition, cognitive ecology can contribute intellectual coherence to the multidisciplinary study of cognition."

As a study involving the 'coupling' or interactions between organism and environment, cognitive ecology is closely related to enactivism, a field based upon the view that "...we must see the organism and environment as bound together

in reciprocal specification and selection.

Social ecology

Social ecological behaviours are notable in the social insects, slime moulds, social spiders, human society, and naked mole-rats where eusocialism has evolved.

Social behaviours include reciprocally beneficial behaviours among kin and nest mates and evolve from kin and group selection.

Kin selection explains altruism through genetic relationships, whereby an altruistic behaviour leading to death is rewarded by the survival of genetic copies distributed among surviving relatives.

The social insects, including ants, bees and wasps are most famously studied for this type of relationship because the male drones are clones that share the same genetic make-up as every other male in the colony.

In contrast, group selectionists find examples of altruism among non-genetic relatives and explain this through selection acting on the group, whereby it becomes selectively advantageous for groups if their members express altruistic

behaviours to one another.

Groups with predominantly altruistic members beat groups with predominantly selfish members.

Bumblebees and the flowers theypollinate have coevolved so that both have become dependent on each other for survival.

Molecular ecology

The important relationship between ecology and genetic inheritance predates modern techniques for molecular analysis.

Molecular ecological research became more feasible with the development of rapid and accessible genetic technologies, such as the polymerase chain reaction (PCR).

The rise of molecular technologies and influx of research questions into this new ecological field resulted in the publication Molecular Ecology in 1992.

Molecular ecology uses various analytical techniques to study genes in an evolutionary and ecological context.

In 1994, John Avise also played a leading role in this area of science with the publication of his book, Molecular Markers, Natural History and Evolution.

Newer technologies opened a wave of genetic analysis into organisms once difficult to study from an ecological or evolutionary standpoint, such as bacteria, fungi and nematodes.

Molecular ecology engendered a new research paradigm for investigating ecological questions considered otherwise intractable.

Molecular investigations revealed previously obscured details in the tiny intricacies of nature and improved resolution into probing questions about behavioural and biogeographical ecology.

RAJESH NAYAK

For example, molecular ecology revealed promiscuous sexual behaviour and multiple male partners in tree swallows previously thought to be socially monogamous.

In a biogeographical context, the marriage between genetics, ecology and evolution resulted in a new sub-discipline called phylogeography.

The architecture of the inflorescencein grasses is subject to the physical pressures of wind and shaped by the forces of natural selection facilitating wind-pollination (anemophily).

Agroecology

the study of ecological processes that operate in agricultural production systems.

The prefix agro- refers to agriculture.

Bringing ecological principles to bear in agroecosystems can suggest novel management approaches that would not otherwise be considered.

The term is often used imprecisely and may refer to "a science, a movement, [or] a practice."

Agroecologists study a variety of agroecosystems, and the field of agroecology is not associated with any one particular method of farming, whether it be organic,integrated, or conventional; intensive or extensive.

Although it has much more common thinking and principles with some of the before mentioned farming systems.

Cultural ecology

the study of human adaptations to social and physical environments.

Human adaptation refers to both biological and cultural processes that enable a population to survive and reproduce within a given or changing environment.

This may be carried out diachronically (examining entities that existed in different epochs), or synchronically (examining a present system and its components).

The central argument is that the natural environment, in small scale or subsistence societies dependent in part upon it, is a major contributor to social organization and other human institutions.

Chemical ecology

is the study of chemicals involved in the interactions of living organisms.

It focuses on the production of and response to signalling molecules (i.e. semiochemicals) and toxins.

Chemical ecology is of particular importance among ants and other social insects including bees, wasps, and termites as a means of communication essential to social organization.

In addition, this area of ecology deals with studies involving defensive chemicals which are utilized to deter potential predators or pathogens, which may attack a wide variety of species.

Other aspects of chemical ecology deal with chemical responses of organisms to abiotic factors such as temperature and radiation. Primary production is the production of organic matter from inorganic carbon sources.

Overwhelmingly, this occurs through photosynthesis.

The energy incorporated through this process supports life on earth, while the carbon makes up much of the organic matter in living and dead biomass, soil carbon and fossil fuels.

It also drives the carbon cycle, which influences global climate via the greenhouse effect.

Through the process of photosynthesis, plants capture energy from light and use it to combine carbon dioxide and water to produce carbohydrates and oxygen.

The photosynthesis carried out by all the plants in an ecosystem is called the gross primary production (GPP).

The carbon and energy incorporated into plant tissues (net primary production) is either consumed by animals while the plant is alive, or it remains uneaten when the plant tissue dies and becomes detritus.

RAJESH NAYAK

In terrestrial ecosystems, roughly 90% of the NPP ends up being broken down by decomposers. The remainder is either consumed by animals while still alive and enters the plant-based trophic system, or it is consumed after it has died, and

enters the detritus-based trophic system.

In aquatic systems, the proportion of plant biomass that gets consumed by herbivores is much higher.

In trophic systems photosynthetic organisms are the primary producers.

The organisms that consume their tissues are called primary consumers or secondary producersherbivores.

Organisms which feed on microbes (bacteria and fungi) are termed microbivores.

Animals that feed on primary consumerscarnivoresare secondary consumers. Each of these constitutes a trophic level.

[18]

The sequence of consumptionfrom plant to herbivore, to carnivoreforms a food chain.

Real systems are much more complex than thisorganisms will generally feed on more than one form of food, and may feed at more than one trophic level.

Carnivores may capture some prey which are part of a plant-based trophic system and others that are part of a detritus-based trophic system (a bird that feeds both on herbivorous grasshoppers and earthworms, which consume detritus).

Real systems, with all these complexities, form food webs rather than food chains.

The carbon and nutrients in dead organic matter are broken down by a group of processes known as decomposition.

This releases nutrients that can then be re-used for plant and microbial production, and returns carbon dioxide to the atmosphere (or water) where it can be used for photosynthesis.

In the absence of decomposition, dead organic matter would accumulate in an ecosystem and nutrients and atmospheric carbon dioxide would be depleted.

Decomposition processes can be separated into three categoriesleaching, fragmentation and chemical alteration of dead material.

As water moves through dead organic matter, it dissolves and carries with it the water-soluble components.

These are then taken up by organisms in the soil, react with mineral soil, or are transported beyond the confines of the ecosystem (and are considered "lost" to it).

Newly shed leaves and newly dead animals have high concentrations of water-soluble components, and include sugars, amino acids and mineral nutrients.

Leaching is more important in wet environments, and much less important in dry ones.

The chemical alteration of dead organic matter is primarily achieved through bacterial and fungal action.

Fungal hyphae produce enzymes which can break through the tough outer structures surrounding dead plant material.

They also produce enzymes which break down lignin, which allows to them access to both cell contents and to the nitrogen in the lignin.

Fungi can transfer carbon and nitrogen through their hyphal networks and thus, unlike bacteria, are not dependent solely on locally available resources.

Decomposition rates vary among ecosystems.

The rate of decomposition is governed by three sets of factorsthe physical environment (temperature, moisture and soil properties), the quantity and quality of the dead material available to decomposers, and the nature of the microbial

community itself.

Temperature controls the rate of microbial respiration; the higher the temperature, the faster microbial decomposition occurs. It also affects soil moisture, which slows microbial growth and reduces leaching.

Freeze-thaw cycles also affect decompositionfreezing temperatures kill soil microorganisms, which allows leaching to play a more important role in moving nutrients around.

This can be especially important as the soil thaws in the Spring, creating a pulse of nutrients which become available.

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Decomposition rates are low under very wet or very dry conditions.

Decomposition rates are highest in wet, moist conditions with adequate levels of oxygen.

Wet soils tend to become deficient in oxygen (this is especially true in wetlands), which slows microbial growth. In dry soils, decomposition slows as well, but bacteria continue to grow (albeit at a slower rate) even after soils become too dry

to support plant growth.

When the rains return and soils become wet, the osmotic gradient between the bacterial cells and the soil water causes the cells to gain water quickly.

Under these conditions, many bacterial cells burst, releasing a pulse of nutrients. Decomposition rates also tend to be slower in acidic soils.

Soils which are rich in clay minerals tend to have lower decomposition rates, and thus, higher levels of organic matter.

The smaller particles of clay result in a larger surface area that can hold water.

The higher the water content of a soil, the lower the oxygen content and consequently, the lower the rate of decomposition.

Clay minerals also bind particles of organic material to their surface, making them less accessibly to microbes.[20]

Soil disturbance like tilling increase decomposition by increasing the amount of oxygen in the soil and by exposing new organic matter to soil microbes

When natural resource management is applied to whole ecosystems, rather than single species, it is termed ecosystem management.

Although definitions of ecosystem management abound, there is a common set of principles which underlie these definitions.

A fundamental principle is the long-term sustainability of the production of goods and services by the ecosystem; "intergenerational sustainability [is] a precondition for management, not an afterthought".

It also requires clear goals with respect to future trajectories and behaviors of the system being managed.

Other important requirements include a sound ecological understanding of the system, including connectedness, ecological dynamics and the context in which the system is embedded.

Other important principles include an understanding of the role of humans as components of the ecosystems and the use of adaptive management.

While ecosystem management can be used as part of a plan for wilderness conservation, it can also be used in intensively managed ecosystems (see, for example,agroecosystem and close to nature forestry).

Ecosystem ecology studies "the flow of energy and materials through organisms and the physical environment".

It seeks to understand the processes which govern the stocks of material and energy in ecosystems, and the flow of matter and energy through them.

The study of ecosystems can cover 10 orders of magnitude, from the surface layers of rocks to the surface of the planet.

An aquatic ecosystem

an ecosystem in a body of water.

Communities of organisms that are dependent on each other and on their environment live in aquatic ecosystems.

The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems.

The intertidal zone is the area between high and low tides; in this figure it is termed the littoral zone.

Other near-shore (neritic) zones can include estuaries, salt marshes, coral reefs, lagoons and mangrove swamps.

In the deep water, hydrothermal vents may occur where chemosynthetic sulfur bacteria form the base of the food web.

There are three basic types of freshwater ecosystems:

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Lentic: slow moving water, including pools, ponds, and lakes.

Lotic: faster moving water, for example streams and rivers.

Wetlands: areas where the soil is saturated or inundated for at least part of the time.

Lake ecosystems can be divided into zones.

One common system divides lakes into three zones.

The first, the littoral zone, is the shallow zone near the shore. This is where rooted wetland plants occur.

The offshore is divided into two further zones, an open water zone and a deep water zone.

In the open water zone (or photic zone) sunlight supports photosynthetic algae, and the species that feed upon them.

In the deep water zone, sunlight is not available and the food web is based on detritus entering from the littoral and

photic zones.

The off shore areas may be called the pelagic zone, and the aphotic zone may be called the profundal zone.

Inland from the littoral zone one can also frequently identify a riparian zone which has plants still affected by the

presence of the lakethis can include effects from windfalls, spring flooding, and winter ice damage.

The production of the lake as a whole is the result of production from plants growing in the littoral zone, combined with

production from plankton growing in the open water.

Wetlands can be part of the lentic system, as they form naturally along most lakeshores, the width of the wetland and

littoral zone being dependent upon the slope of the shoreline and the amount of natural change in water levels, within

and among years.

Often dead trees accumulate in this zone, either from windfalls on the shore or logs transported to the site during floods.

This woody debris provides important habitat for fish and nesting birds, as well as protecting shorelines from erosion.

Two important subclasses of lakes are ponds, which typically are small lakes that intergrade with wetlands, and

water reservoirs.

Over long periods of time, lakes, or bays within them, may gradually become enriched by nutrients and slowly fill in

with organic sediments, a process called succession.

When humans use the watershed, the volumes of sediment entering the lake can accelerate this process.

The addition of sediments and nutrients to a lake is known as eutrophication.

The major zones in river ecosystems are determined by the river bed's gradient or by the velocity of the current.

Faster moving turbulent water typically contains greater concentrations of dissolved oxygen, which supports greater

biodiversity than the slow moving water of pools.

These distinctions form the basis for the division of rivers into upland and lowland rivers.

The food base of streams within riparian forests is mostly derived from the trees, but wider streams and those that lack

a canopy derive the majority of their food base from algae. Anadromous fish are also an important source of nutrients.

Environmental threats to rivers include loss of water, dams, chemical pollution and introduced species.

A dam produces negative effects that continue down the watershed.

The most important negative effects are the reduction of spring flooding, which damages wetlands, and the retention of

sediment, which leads to loss of deltaic wetlands.

Wetlands are dominated by vascular plants that have adapted to saturated soil.

There are four main types of wetlands: swamp, marsh, fen and bog (both fens and bogs are types of mire).

Wetlands are the most productive natural ecosystems in the world because of the proximity of water and soil. Hence

they support large numbers of plant and animal species.

Due to their productivity, wetlands are often converted into dry land with dykes and drains and used for agricultural

purposes.

The construction of dykes, and dams, has negative consequences for individual wetlands and entire watersheds.

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Their closeness to lakes and rivers means that they are often developed for human settlement.

Once settlements are constructed and protected by dykes, the settlements then become vulnerable to land subsidence and

ever increasing risk of flooding.

Marine ecosystems

the largest of Earth's aquatic ecosystems.

They include oceans, salt marshes, intertidal zones, estuaries, lagoons, mangroves, coral reefs, the deep sea, and the sea floor.

They can be contrasted with freshwater ecosystems, which have a lower salt content.

Marine waters cover two-thirds of the surface of the Earth.

Such places are considered ecosystems because the plant life supports the animal life and vice versa. See food chains.

Marine ecosystems are very important for the overall health of both marine and terrestrial environments.

According to the World Resource Centre, coastal habitats alone account for approximately 1/3 of all marine biological productivity, and estuarine ecosystems (i.e., salt marshes, seagrasses, mangrove forests) are among the most productive

regions on the planet.

In addition, other marine ecosystems such as coral reefs, provide food and shelter to the highest levels of marine diversity in the world.

Marine ecosystems usually have a large biodiversity and are therefore thought to have a good resistance against invasive species.

However, exceptions have been observed, and the mechanisms responsible in determining the success of an invasion are not yet clear

Large marine ecosystems (LMEs)

are regions of the world's oceans, encompassing coastal areas from river basins and estuaries to the seaward boundaries ofcontinental shelves and the outer margins of the major ocean current systems.

They are relatively large regions on the order of 200,000 km or greater, characterized by distinct bathymetry, hydrography, productivity, and trophically dependent populations.

The system of LMEs has been developed by the US National Oceanic and Atmospheric Administration (NOAA) to identify areas of the oceans for conservation purposes.

The objective is to use the LME concept as a tool for enabling ecosystem-based management to provide a collaborative approach to management of resources within ecologically-bounded transnational areas.

This will be done in an international context and consistent with customary international law as reflected in 1982 UN Convention on the Law of the Sea.

LME-based conservation is based on recognition that the worlds coastal ocean waters are degraded by unsustainable fishing practices, habitat degradation,eutrophication, toxic pollution, aerosol contamination, and emerging diseases, and

that positive actions to mitigate these threats require coordinated actions by governments and civil society to recover

depleted fish populations, restore degraded habitats and reduce coastal pollution.

Although the LMEs cover only the continental margins and not the deep oceans and oceanic islands, the 64 LMEs produce 95% of the world's annual marine fishery biomass yields.

Most of the global ocean pollution, overexploitation, and coastal habitat alteration occur within their waters.

NOAA has conducted studies of principal driving forces affecting changes in biomass yields for 33 of the 64 LMEs, which have been peer-reviewed and published in ten volumes.

Freshwater ecosystems

are a subset of Earth's aquatic ecosystems.

They include lakes and ponds, rivers, streams,springs, and wetlands.

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They can be contrasted with marine ecosystems, which have a larger salt content.

Freshwater habitats can be classified by different factors, including temperature, light penetration, and vegetation.

Freshwater ecosystems can be divided into lentic ecosystems (still water) and lotic ecosystems (flowing water).

Limnology (and its branch freshwater biology) is a study about freshwater ecosystems. It is a part of hydrobiology.

Original efforts to understand and monitor freshwater ecosystems were spurred on by threats to human health (ex. Cholera outbreaks due to sewage contamination).

Early monitoring focussed on chemical indicators, then bacteria, and finally algae, fungi and protozoa.

A new type of monitoring involves differing groups of organisms (macroinvertebrates,macrophytes and fish) and the stream conditions associated with them.

Current biomonitering techniques focus mainly on community structure or biochemical oxygen demand.

Responses are measured by behavioural changes, altered rates of growth, reproduction or mortality.

Macro invertebrates are most often used in these models because of well known taxonomy, ease of collection, sensitivity to a range of stressors, and their overall value to the ecosystem. Most of these measurements are difficult to extrapolate

on a large scale, however.

The use of reference sites is common when assessing what a healthy freshwater ecosystem should look like.

Reference sites are easier to reconstruct in standing water than moving water.

Preserved indicators such as diatom valves, macrophyte pollen, insect chitin and fish scales can be used to establish a reference ecosystem representative of a time before large scale human disturbance.

Common chemical stresses on freshwater ecosystem health include acidification, eutrophication and copper and pesticide contamination.

A lake ecosystem

includes biotic (living) plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions.

Lake ecosystems are a prime example of lentic ecosystems.

Lentic refers to stationary or relatively still water, from the Latin lentus, which means sluggish.

Lentic waters range from ponds to lakes to wetlands, and much of this article applies to lentic ecosystems in general. Lentic ecosystems can be compared with lotic ecosystems, which involve flowing terrestrial waters such as rivers and

streams.

Together, these two fields form the more general study area of freshwater or aquatic ecology.

Lentic systems are diverse, ranging from a small, temporary rainwater pool a few inches deep to Lake Baikal, which has a maximum depth of 1740 m.

The general distinction between pools/ponds and lakes is vague, but Brown states that ponds and pools have their entire

bottom surfaces exposed to light, while lakes do not.

In addition, some lakes become seasonally stratified (discussed in more detail below.) Ponds and pools have two regions: the pelagic open water zone, and the benthic zone, which comprises the bottom and shore regions.

Since lakes have deep bottom regions not exposed to light, these systems have an additional zone, the profundal.

These three areas can have very different abiotic conditions and, hence, host species that are specifically adapted to live there.

Water striders are predatory insects which rely on surface tension to walk on top of water.

They live on the surface of ponds, marshes, and other quiet waters.

They can move very quickly, up to 1.5 m/s.

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Important abiotic factors

Light, Temperature, Wind, Chemistry

Lentic system biota

Algae, including both phytoplankton and periphyton are the principle photosynthesizers in ponds and lakes. Phytoplankton are found drifting in the water column of the pelagic zone.

Many species have a higher density than water which should make them sink and end up in the benthos.

To combat this, phytoplankton have developed density changing mechanisms, by forming vacuoles and gas vesicles or by changing their shapes to induce drag, slowing their descent.

A very sophisticated adaptation utilized by a small number of species is a tail-like flagellum that can adjust vertical position and allow movement in any direction.

Phytoplankton can also maintain their presence in the water column by being circulated in Langmuir rotations.

Periphytic algae, on the other hand, are attached to a substrate. In lakes and ponds, they can cover all benthic surfaces. Both types of plankton are important as food sources and as oxygen providers

Aquatic plants live in both the benthic and pelagic zones and can be grouped according to their manner of growth: 1) emergent = rooted in the substrate but with leaves and flowers extending into the air, 2) floating-leaved = rooted in the

substrate but with floating leaves, 3) submersed = growing beneath the surface and 4) free-floating macrophytes = not

rooted in the substrate and floating on the surface

These various forms of macrophytes generally occur in different areas of the benthic zone, with emergent vegetation nearest the shoreline, then floating-leaved macrophytes, followed by submersed vegetation.

Free-floating macrophytes can occur anywhere on the systems surface.

Aquatic plants are more buoyant than their terrestrial counterparts because freshwater has a higher density than air.

This makes structural rigidity unimportant in lakes and ponds (except in the aerial stems and leaves).

Thus, the leaves and stems of most aquatic plants use less energy to construct and maintain woody tissue, investing that energy into fast growth instead.

In order to contend with stresses induced by wind and waves, plants must be both flexible and tough.

Light, water depth and substrate types are the most important factors controlling the distribution of submerged aquatic plants.

Macrophytes are sources of food, oxygen, and habitat structure in the benthic zone, but cannot penetrate the depths of the euphotic zone and hence are not found there

Zooplankton are tiny animals suspended in the water column.

Like phytoplankton, these species have developed mechanisms that keep them from sinking to deeper waters, including drag-inducing body forms and the active flicking of appendages such as antennae or spines

Remaining in the water column may have its advantages in terms of feeding, but this zones lack of refugia leaves zooplankton vulnerable to predation.

In response, some species, especially Daphnia sp., make daily vertical migrations in the water column by passively sinking to the darker lower depths during the day and actively moving towards the surface during the night.

Also, because conditions in a lentic system can be quite variable across seasons, zooplankton have the ability to switch from laying regular eggs to resting eggs when there is a lack of food, temperatures fall below 2 C, or if predator

abundance is high.

These resting eggs have a diapause, or dormancy period that should allow the zooplankton to encounter conditions that are more favorable to survival when they finally hatch.

The invertebrates that inhabit the benthic zone are numerically dominated by small species and are species rich compared to the zooplankton of the open water.

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They include Crustaceans (e.g. crabs, crayfish, and shrimp), molluscs (e.g. clams and snails), and numerous types of insects.

These organisms are mostly found in the areas of macrophyte growth, where the richest resources, highly oxygenated water, and warmest portion of the ecosystem are found.

The structurally diverse macrophyte beds are important sites for the accumulation of organic matter, and provide an ideal area for colonization.

The sediments and plants also offer a great deal of protection from predatory fishes

Very few invertebrates are able to inhabit the cold, dark, and oxygen poor profundal zone.

Those that can are often red in color due to the presence of large amounts of hemoglobin, which greatly increases the amount of oxygen carried to cells.

Because the concentration of oxygen within this zone is low, most species construct tunnels or borrows in which they can hide and make the minimum movements necessary to circulate water through, drawing oxygen to them without

expending much energy

The ecosystem of a river is the river viewed as a system operating in its natural environment, and includes biotic(living) interactions amongst plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical

interactions.

River ecosystems are prime examples of lotic ecosystems. Lotic refers to flowing water, from the Latin lotus, washed.

Lotic waters range from springs only a few centimeters wide to major rivers kilometers in width.

Much of this article applies to lotic ecosystems in general, including related lotic systems such as streams and springs.

Lotic ecosystems can be contrasted with lentic ecosystems, which involve relatively still terrestrial waters such as lakes and ponds.

Together, these two fields form the more general study area of freshwater or aquatic ecology.

The following unifying characteristics make the ecology of running waters unique from that of other aquatic habitats.

Flow is unidirectional.

There is a state of continuous physical change.

There is a high degree of spatial and temporal heterogeneity at all scales (microhabitats).

Variability between lotic systems is quite high.

The biota is specialized to live with flow conditions.

Energy sources can be autochthonous or allochthonous.

Autochthonous

energy sources are those derived from within the lotic system.

During photosynthesis, for example,primary producers form organic carbon compounds out of carbon dioxide and inorganic matter.

The energy they produce is important for the community because it may be transferred to higher trophic levels via consumption.

Additionally, high rates of primary production can introduce dissolved organic matter (DOM) to the waters.

Another form of autochthonous energy comes from the decomposition of dead organisms and feces that originate within the lotic system.

In this case, bacteria decompose the detritus or coarse particulate organic material (CPOM; >1 mm pieces) into fine particulate organic matter (FPOM;

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In addition, terrestrial animal-derived materials, such as feces or carcasses that have been added to the system are examples of allochthonous CPOM.

The CPOM undergoes a specific process of degradation.

When leaf fallen into a stream?

First, the soluble chemicals are dissolved and leached from the leaf upon its saturation with water.

This adds to the DOM load in the system.

Next, microbes such as bacteria and fungi colonize the leaf, softening it as the mycelium of the fungus grows into it.

The composition of the microbial community is influenced by the species of tree from which the leaves are shed (Rubbo and Kiesecker 2004).

This combination of bacteria, fungi, and leaf are a food source for shredding invertebrates, which leave only FPOM after consumption.

These fine particles may be colonized by microbes again or serve as a food source for animals that consume FPOM. Organic matter can also enter the lotic system already in the FPOM stage by wind, surface runoff, bank erosion,

or groundwater.

Similarly, DOM can be introduced through canopy drip from rain or from surface flows.

A wetland is a land area that is saturated with water, either permanently or seasonally, such that it takes on the

characteristics of a distinct ecosystem.

The primary factor that distinguishes wetlands from other land forms or water bodies is the

characteristic vegetation of aquatic plants, adapted to the unique hydric soil.

Wetlands play a number of roles in the environment, principally water purification, flood control, carbon sink and

shoreline stability.

Wetlands are also considered the most biologically diverse of all ecosystems, serving as home to a wide range of plant

and animal life.

Wetlands occur naturally on every continent except Antarctica, the largest including the Amazon River basin, the West

Siberian Plain and the Pantanal in South America.

The water found in wetlands can be freshwater, brackish, orsaltwater

The main wetland types include swamps, marshes, bogs, and fens and sub-types include mangrove, carr,pocosin,

and varzea.

The UN Millennium Ecosystem Assessment determined that environmental degradation is more prominent within

wetland systems than any other ecosystem on Earth. International conservation efforts are being used in conjunction

with the development of rapid assessment tools to inform people about wetland issues.

Constructed wetlands can be used to treat municipal and industrial wastewater as well as stormwater runoff, They may

also play a role in water-sensitive urban design.

The biota of a wetland system includes its vegetation zones and structure as well as animal populations.

The most important factor affecting the biota is the duration of flooding.

Other important factors include fertility and salinity.

In fens, species are highly dependent on water chemistry.

The chemistry of water flowing into wetlands depends on the source of water and the geological material in which it

flows throughas well as the nutrients discharged from organic matter in the soils and plants at higher elevations in slope

wetlands.

Biota may vary within a wetland due to season or recent flood regimes.

Flora

There are four main groups of hydrophytes that found in wetland systems throughout the world.

Submerged water plants.

This type of vegetation is found completely underwater.

Submerged wetland vegetation can grow in saline and fresh-water conditions.

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Some species have underwater flowers, while others have long stems to allow the flowers to reach the surface.

Submerged species provide a food source for native fauna, habitat for invertebrates, and also possess filtration capabilities.

Examples include seagrasses and eelgrass.

Floating water plants.

Floating vegetation is usually small although it may take up a large surface area in a wetland system.

These hydrophytes have small roots and are only found in slow-moving water with rich-nutrient level water Floating aquatic plants are a food resource for avian species.

Examples include water lilies, lily pad and duckweed.

Emergent water plants.

Emergent water plants can be seen above the surface of the water but whose roots are completely submerged.

Many have aerenchyma to transmit oxygen from the atmosphere to their roots. Extensive areas of emergent plants are usually termed marsh.

Examples include cattails (Typha) and arrow arum (Peltandra virginica).

Surrounding trees and shrubs.

Forested wetlands are generally known as swamps.

The upper level of these swamps is determined by high water levels, which are negatively affected by dams.

Some swamps can be dominated by a single species, such as silver maple swamps around the Great Lakes.

Others, like those of the Amazon Basin, have large numbers of different tree species. Examples include cypress (Taxodium) and mangrove.

Fauna

Fish:

Fish are more dependent on wetland ecosystems than any other type of habitat. 75% of the United States' commercial fish and shellfish stocks depend solely on estuaries to survive.

Tropical fish species need mangroves for critical hatchery and nursery grounds and the coral reef system for food.

Amphibians:

Frogs are the most crucial amphibian species in wetland systems.

Frogs need both terrestrial and aquatic habitats in which to reproduce and feed.

While tadpoles control algal populations, adult frogs forage on insects.

Frogs are used as an indicator of ecosystem health due to their thin skin which absorbs both nutrient and toxins from the surrounding environment resulting in an above average extinction rate in unfavorable and polluted environmental

conditions.

Reptiles:

Alligators and crocodiles are two common reptilian species. Alligators are found in fresh water along with the fresh water species of the crocodile.

The saltwater crocodile is found in estuaries and mangroves and can be seen in the coastline bordering the Great Barrier Reef in Australia.

The Florida Everglades is the only place in the world where both crocodiles and alligators co-exist.

Snakes, lizards, goannas, and turtles also can be seen throughout wetlands.

Snapping turtles are one of the many kinds of turtles found in wetlands.

Mammals:

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Multiple small mammals as well as large herbivore and apex species such as the Florida Panther live within and around wetlands.

The wetland ecosystem attracts mammals due to its prominent seed sources, invertebrate populations, and numbers of small reptiles and amphibians.

Monotremes:

The platypus (Ornithorhynchus anatinus) is found in eastern Australia living in freshwater rivers or lakes, and much like the beaver creates dams, create burrows for shelter and protection.

The platypus swims through the use of webbed feet.

Platypuses feed on insect larvae, worms, or other freshwater insects hunting mainly by night by the use of their bill.

They turn up mud on the bottom of the lake or river, and with the help of the electroreceptors located on the bill, unearth insects and freshwater insects.

The platypus stores their findings in special pouches behind their bill and consumes its prey upon returning to the surface.

Insects and invertebrates:

These species total more than half of the 100,000 known animal species in wetlands.

Insects and invertebrates can be submerged in the water or soil, on the surface, and in the atmosphere.

Algae

Algae are diverse water plants that can vary in size, color, and shape.

Algae occur naturally in habitats such as inland lakes, inter-tidal zones, and damp soil and provide a dedicated food source for animals, fish, and invertebrates. There are three main groups of algae:

Plankton are algae which are microscopic, free-floating algae.

This algae is so tiny that on average, if fifty of these microscopic algae were lined up end-to-end, it would only measure one millimetre.

Plankton are the basis of the food web and are responsible for primary production in the ocean using photosynthesis to make food. Filamentous algae are long strands of algae cells that form floating mats.

Chara and Nitella algae are upright algae that look like a submerged plant with roots.

List of wetland types

Wetland types:

AMarine and Coastal Zone wetlands

1. Marine waterspermanent shallow waters less than six metres deep at low tide; includes sea bays, straits 2. Subtidal aquatic beds; includes kelp beds, seagrasses, tropical marine meadows 3. Coral reefs 4. Rocky marine shores; includes rocky offshore islands, sea cliffs 5. Sand, shingle or pebble beaches; includes sand bars, spits, sandy islets 6. Intertidal mud, sand or salt flats 7. Intertidal marshes; includes saltmarshes, salt meadows, saltings, raised salt marshes, tidal brackish and freshwater

marshes

8. Intertidal forested wetlands; includes mangrove swamps, nipa swamps, tidal freshwater swamp forests 9. Brackish to saline lagoons and marshes with one or more relatively narrow connections with the sea 10. Freshwater lagoons and marshes in the coastal zone 11. Non-tidal freshwater forested wetlands

BInland wetlands

1. Permanent rivers and streams; includes waterfalls 2. Seasonal and irregular rivers and streams

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3. Inland deltas (permanent) 4. Riverine floodplains; includes river flats, flooded river basins, seasonally flooded grassland, savanna and palm savanna 5. Permanent freshwater lakes (> 8 ha); includes large oxbow lakes 6. Seasonal/intermittent freshwater lakes (> 8 ha), floodplain lakes 7. Permanent saline/brackish lakes 8. Seasonal/intermittent saline lakes 9. Permanent freshwater ponds (< 8 ha), marshes and swamps on inorganic soils; with emergent vegetation waterlogged for

at least most of the growing season

10. Seasonal/intermittent freshwater ponds and marshes on inorganic soils; includes sloughs, potholes; seasonally flooded meadows, sedge marshes

11. Permanent saline/brackish marshes 12. Seasonal saline marshes 13. Shrub swamps; shrub-dominated freshwater marsh, shrub carr, alder thicket on inorganic soils 14. Freshwater swamp forest; seasonally flooded forest, wooded swamps; on inorganic soils 15. Peatlands; forest, shrub or open bogs 16. Alpine and tundra wetlands; includes alpine meadows, tundra pools, temporary waters from snow melt 17. Freshwater springs, oases and rock pools 18. Geothermal wetlands 19. Inland, subterranean karst wetlands

CHuman-made wetlands

1. Water storage areas; reservoirs, barrages, hydro-electric dams, impoundments (generally > 8 ha) 2. Ponds, including farm ponds, stock ponds, small tanks (generally < 8 ha) 3. Aquaculture ponds; fish ponds, shrimp ponds 4. Salt exploitation; salt pans, salines 5. Excavations; gravel pits, borrow pits, mining pools 6. Wastewater treatment; sewage farms, settling ponds, oxidation basins 7. Irrigated land and irrigation channels; rice fields, canals, ditches 8. Seasonally flooded arable land, farm land

A terrestrial ecosystem

is an ecosystem found only on landforms. Six primary terrestrial ecosystems exist: tundra, taiga, temperate deciduous forest, tropical rain forest, grassland and desert.

A community of organisms and their environment that occurs on the land masses of continents and islands.

Terrestrial ecosystems are distinguished from aquatic ecosystems by the lower availability of water and the consequent importance of water as a limiting factor.

Terrestrial ecosystems are characterized by greater temperature fluctuations on both a diurnal and seasonal basis than occur in aquatic ecosystems in similar climates.

The availability of light is greater in terrestrial ecosystems than in aquatic ecosystems because the atmosphere is more transparent in land than in water.

Gases are more available in terrestrial ecosystems than in aquatic ecosystems.

Those gases include carbon dioxide that serves as a substrate for photosynthesis, oxygen that serves as a substrate in aerobic respiration, and nitrogen that serves as a substrate for nitrogen fixation.

Terrestrial environments are segmented into a subterranean portion from which most water and ions are obtained, and an atmospheric portion from which gases are obtained and where the physical energy of light is transformed into the

organic energy of carbon-carbon bonds through the process of photosynthesis.

9. Terrestrial ecosystems occupy 55,660,000 mi (144,150,000 km), or 28.26% of Earth's surface.

10. Although they are comparatively recent in the history of life (the first terrestrial organisms appeared in the Silurian period, about 425 million years ago) and occupy a much smaller portion of Earth's surface than marine ecosystems,

terrestrial ecosystems have been a major site of adaptive radiation of both plants and animals.

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11. Major plant taxa in terrestrial ecosystems are members of the division Magnoliophyta (flowering plants), of which there are about 275,000 species, and the division Pinophyta (conifers), of which there are about 500 species.

12. Members of the division Bryophyta (mosses and liverworts), of which there are about 24,000 species, are also important in some terrestrial ecosystems.

13. Major animal taxa in terrestrial ecosystems include the classes Insecta (insects) with about 900,000 species, Aves (birds) with 8,500 species, and Mammalia (mammals) with approximately 4,100 species

14. Organisms in terrestrial ecosystems have adaptations that allow them to obtain water when the entire body is no longer bathed in that fluid, means of transporting the water from limited sites of acquisition to the rest of the body, and means

of preventing the evaporation of water from body surfaces.

15. They also have traits that provide body support in the atmosphere, a much less buoyant medium than water, and other traits that render them capable of withstanding the extremes of temperature, wind, and humidity that characterize

terrestrial ecosystems.

16. Finally, the organisms in terrestrial ecosystems have evolved many methods of transporting gametes in environments where fluid flow is much less effective as a transport medium.

17. The organisms in terrestrial ecosystems are integrated into a functional unit by specific, dynamic relationships due to the coupled processes of energy and chemical flow.

18. Those relationships can be summarized by schematic diagrams of trophic webs, which place organisms according to their feeding relationships.

19. The base of the food web is occupied by green plants, which are the only organisms capable of utilizing the energy of the Sun and inorganic nutrients obtained from the soil to produce organic molecules.

20. Terrestrial food webs can be broken into two segments based on the status of the plant material that enters them.

21. Grazing food websare associated with the consumption of living plant material by herbivores.

22. Detritus food webs are associated with the consumption of dead plant material by detritivores.

23. The relative importance of those two types of food webs varies considerably in different types of terrestrial ecosystems.

24. Grazing food webs are more important in grasslands, where over half of net primary productivity may be consumed by herbivores.

25. Detritus food webs are more important in forests, where less than 5% of net primary productivity may be consumed by herbivores.

The littoral zone

is the part of a sea, lake or river that is close to the shore.

In coastal environments the littoral zone extends from the high water mark, which is rarely inundated, to shoreline areas that are permanently submerged.

It always includes this intertidal zone and is often used to mean the same as the intertidal zone.

However, the meaning of "littoral zone" can extend well beyond the intertidal zone.

In oceanography and marine biology, the idea of the littoral zone is extended roughly to the edge of the continental shelf.

Starting from the shoreline, the littoral zone begins at the spray region just above the high tide mark.

From here, it moves to the intertidal region between the high and low water marks, and then out as far as the edge of

the continental shelf.

These three subregions are called, in order, the supralittoral zone, the eulittoral zone and the sublittoral zone.

Supralittoral zone[edit]

The supralittoral zone (also called the splash, spray or supratidal zone) is the area above the spring high tide line that is regularly splashed, but not submerged by ocean water.

Seawater penetrates these elevated areas only during storms with high tides.

Organisms here must cope also with exposure to fresh water from rain, cold, heat and predation by land animals and seabirds.

RAJESH NAYAK

At the top of this area, patches of dark lichens can appear as crusts on rocks. Some types

ofperiwinkles, Neritidae and detritus feeding Isopoda commonly inhabit the lower supralittoral.

Eulittoral zone

The eulittoral zone (also called the midlittoral or mediolittoral zone) is the intertidal zone also known as the foreshore.

It extends from the spring high tide line, which is rarely inundated, to the spring low tide line, which is rarely not inundated.

The wave action and turbulence of recurring tides shapes and reforms cliffs, gaps, and caves, offering a huge range of habitats for sedentary organisms.

Protected rocky shorelines usually show a narrow almost homogenous eulittoral strip, often marked by the presence of barnacles.

Exposed sites show a wider extension and are often divided into further zones.

Sublittoral zone

The sublittoral zone starts immediately below the eulittoral zone. This zone is permanently covered with seawater and is approximately equivalent to the neritic zone.

In physical oceanography, the sublittoral zone refers to coastal regions with significant tidal flows and energy dissipation, including non-linear flows, internal waves, river outflows and oceanic fronts. In practice, this typically

extends to the edge of the continental shelf, with depths around 200 meters.

In marine biology, the sublittoral refers to the areas where sunlight reaches the ocean floor, that is, where the water is never so deep as to take it out of the photic zone.

This results in high primary production and makes the sublittoral zone the location of the majority of sea life.

As in physical oceanography, this zone typically extends to the edge of the continental shelf.

The benthic zone in the sublittoral is much more stable than in the intertidal zone; temperature, water pressure, and the amount of sunlight remain fairly constant.

Sublittoral corals do not have to deal with as much change as intertidal corals. Corals can live in both zones, but they are more common in the sublittoral zone.

Within the sublittoral, marine biologists also identify the following:

The infralittoral zone is the algal dominated zone to maybe five metres below the low water mark.

The circalittoral zone is the region beyond the infralittoral, that is, below the algal zone and dominated by sessile animals

such as oysters.

A riparian zone or riparian area

is the interface between land and a river or stream.

Riparian is also the proper nomenclature for one of the fifteen terrestrial biomes of the earth. Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by hydrophilic plants.

Riparian zones are significant in ecology, environmental management, and civil engineering because of their role in soil conservation, their habitatbiodiversity, and the influence they have on fauna and aquatic ecosystems,

including grassland, woodland, wetlandor even non-vegetative. In some regions the terms riparian woodland, riparian

forest, riparian buffer zone, or riparian strip are used to characterize a riparian zone.

The word "riparian" is derived from Latin ripa, meaning river bank.

Riparian zones may be natural or engineered for soil stabilization or restoration.

These zones are important natural biofilters, protecting aquatic environments from excessive sedimentation, polluted surface runoff and erosion.

They supply shelter and food for many aquatic animals and shade that is an important part of stream temperature regulation.

When riparian zones are damaged by construction, agriculture or silviculture, biological restoration can take place, usually by human intervention in erosion control and revegetation.

If the area adjacent to a watercourse has standing water or saturated soil for as long as a season, it is normally termed a wetland because of its hydric soil characteristics.

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Because of their prominent role in supporting a diversity of species, riparian zones are often the subject of national protection in a Biodiversity Action Plan.

These are also known as a "Plant or Vegetation Waste Buffer".

A biodiversity action plan (BAP)

is an internationally recognized program addressing threatened species and habitats and is designed to protect and restore biological systems.

The original impetus for these plans derives from the 1992 Convention on Biological Diversity (CBD).

As of 2009, 191 countries have ratified the CBD, but only a fraction of these have developed substantive BAP documents.

The principal elements of a BAP typically include: (a) preparing inventories of biological information for selected species or habitats; (b) assessing the conservation status of species within specified ecosystems; (c) creation of targets

for conservationand restoration; and (d) establishing budgets, timelines and institutional partnerships for implementing

the BAP.

Subsurface lithoautotrophic microbial ecosystems, or "SLIMEs" (also abbreviated "SLMEs" or "SLiMEs"),

defined by Edward O. Wilson as "unique assemblages of bacteria and fungi that occupy pores in the interlocking mineral grains of igneous rock beneath Earth's surface.