Food Chain(1)

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    Ecosystem

    An ecosystem consists of the biological community thatoccurs in some locale, and the physical and chemicalfactors that make up its non-living or abioticenvironment.

    The study of ecosystems mainly consists of the study ofcertain processes that link the living, or biotic,components to the non-living, or abiotic, components.

    Energy transformations and biogeochemical cyclingare the main processes that comprise the field ofecosystem ecology.

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    Studies ofindividuals are concerned mostly about physiology, reproduction,development or behavior, and studies ofpopulations usually focus on the habitat

    and resource needs of individual species, their group behaviors, population

    growth, and what limits their abundance or causes extinction.

    Studies ofcommunitiesexamine how populations of many species interact withone another, such as predators and their prey, or competitors that share common

    needs or resources.

    In ecosystem ecologywe put all of this together and, insofar as we can, we try to

    understand how the system operates as a whole. This means that, rather than

    worrying mainly about particular species, we try to focus on major functional

    aspects of the system.

    Thesefunctional aspects include such things as the amount of energy that is

    produced by photosynthesis, how energy or materials flow along the many steps in

    a food chain, or what controls the rate of decomposition of materials or the rate atwhich nutrients are recycled in the system.

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    Components of an Ecosystem

    Aioticcompon

    ents Sunlight

    Temperature Precipitation

    Water orMoisture

    Soil

    Bioticcompon

    ents Primary

    producers

    Herbivores

    Carnivores

    Ominvores

    Detritivores

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    Processes of Ecosystem

    ecosystemshave energy

    flows ecosystems cyclematerials

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    Energy flows and material cycle

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    The Transformation of Energy

    The transformations of energy in an ecosystem begin first with the input of energyfrom the sun.

    Energy from the sun is captured by the process of photosynthesis. Carbon dioxideis combined with hydrogen (derived from the splitting of water molecules) toproduce carbohydrates (CHO). Energy is stored in the high energy bonds of

    adenosine triphosphate, or ATP (see lecture on photosynthesis).

    The prophet Isaah said "all flesh is grass", earning him the title of first ecologist,because virtually all energy available to organisms originates in plants.

    Because it is the first step in the production of energy for living things, it is calledprimary production.

    Herbivores obtain their energy by consuming plants or plant products, carnivoreseat herbivores, and detritivores consume the droppings and carcasses of us all.

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    Food Chain

    Food Chain is the sequence of populations ofan ecosystem which allows food and energy togo through it in a specified direction.

    Those on the lower end of chain become foodfor the ones who are on upper end.

    The one who is at top of the food chain is notconsumed by any.

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    Food Chain

    Energy from the sun, captured by plant photosynthesis,flows from trophic levelto trophic level via thefood chain.

    A trophic level is composed of organisms that make a

    living in the same way, that is they are allprimary

    producers (plants),primary consumers (herbivores) or

    secondary consumers (carnivores).

    Dead tissue and waste products are produced at all levels.

    Scavengers, detritivores, and decomposers collectively

    account for the use of all such "waste" -- consumers of

    carcasses and fallen leaves may be other animals, such as

    crows and beetles, but ultimately it is the microbes that

    finish the job of decomposition.

    Not surprisingly, the amount of primary production varies

    a great deal from place to place, due to differences in the

    amount of solar radiation and the availability of nutrientsand water.

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    Types of food chains

    PredatorChain

    ParasiteChain

    SaprophyticChain

    Micro organisms live

    on dead organic

    matter

    Plant eating animal is

    eaten by a flesh

    eating animal

    A smaller organism

    consumes part of a

    larger host and may

    itself be parasitized by

    even smaller

    organisms

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    Components of a food chain

    Producers Consumers

    first second

    tertiary and

    the fourthorder

    Decomposers

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    The Producers

    Producers are the beginning of a simple food chain.Producers are plants and vegetables.

    Plants are at the beginning of every food chain that involves

    the Sun. All energy comes from the Sun and plants are theones who make food with that energy. They use theprocess ofphotosynthesis. Plants also make loads of othernutrients for other organisms to eat.

    There are also photosynthetic protists that start foodchains. You might find them floating on the surface of theocean acting as food for small unicellular animals

    http://www.geography4kids.com/files/water_biomeaqua.htmlhttp://www.geography4kids.com/files/water_biomeaqua.htmlhttp://www.geography4kids.com/files/water_biomeaqua.html
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    Consumers

    Primary Consumers or Herbivores

    They are the plant eaters of the chain

    Example: Mouse

    Secondary Consumers or Carnivores

    Secondary consumers eat the primary consumers.

    Example: Cat

    Tertiary consumer or Omnivores

    These are consumers that eat the secondary and primary consumers

    Example: Wolf

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    Decomposers

    Whenever something that was alive dies, thedecomposers get it.

    Decomposers break down nutrients in the dead "stuff"

    and return it to the soil.

    The producers can then use the nutrients and elementsonce it's in the soil.

    The decomposers complete the system, returningessential molecules to the producers.

    http://www.geography4kids.com/files/land_soil.htmlhttp://www.geography4kids.com/files/land_soil.html
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    However

    Energy transfer through the food chain is inefficient.

    In many circumstances the principal energy input is not green plants butdead organic matter. These are called detritus food chains.

    the organization of biological systems is much more complicated than canbe represented by a simple "chain". There are many food links and chainsin an ecosystem, and we refer to all of these linkages as afood web.

    Food webs can be very complicated, where it appears that "everything isconnected to everything else", and it is important to understand what are

    the most important linkages in any particular food web.

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    Why there are more herbivores than

    carnivores In a food chain, energy is passed from one link to another.

    When a herbivore eats, only a fraction of the energy (that it gets from the plantfood) becomes new body mass; the rest of the energy is lost as waste or used upby the herbivore to carry out its life processes (e.g., movement, digestion,reproduction).

    Therefore, when the herbivore is eaten by a carnivore, it passes only a smallamount of total energy (that it has received) to the carnivore.

    Of the energy transferred from the herbivore to the carnivore, some energy will be"wasted" or "used up" by the carnivore.

    The carnivore then has to eat many herbivores to get enough energy to grow.

    Because of the large amount of energy that is lost at each link, the amount ofenergy that is transferred gets lesser and lesser ...

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    The further along the food chain you

    go, the less food remains available

    The energy pyramid alongside shows many

    trees & shrubs providing food and energy to

    giraffes.

    As we go up, there are fewer giraffes than trees

    & shrubs and even fewer lions than giraffes ...

    as we go further along a food chain, there are

    fewer and fewer consumers.

    In other words, a large mass of living things at

    the base is required to support a few at the top

    ... many herbivores are needed to support a

    few carnivores

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    Most food chains have no more than

    four or five links

    There cannot be too many links in a single food

    chain because the animals at the end of the chain

    would not get enough food (and hence energy) to

    stay alive.

    Most animals are part of more than one food chain

    and eat more than one kind of food in order to

    meet their food and energy requirements. These

    interconnected food chains form a food web.

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    Food Web

    In nature, food chain relationships are notisolated. They are very complex, as one organismmay form the food source of many organisms.

    Thus, instead of a simple linear food chain, thereis a web like structure formed by theseinterlinked food chains. Such interconnectedmatrix of food chains is called 'food web'.

    Food web can be defined as, "a network of foodchains which are interconnected at varioustrophic levels, so as to form a number of feedingconnections amongst different organisms of abiotic community".

    Food webs are indispensable in ecosystems asthey allow an organism to obtain its food frommore than one type of organism of the lower

    trophic level.

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    Generally, a food web operates according to taste and food

    preferences of the organism, yet availability of food source and

    other compulsions are equally important.

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    A Food Web in Terrestrial and Aquatic

    Ecosystem

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    Case Study: Bat disease could allow

    insects to destroy crops

    A deadly disease to bats could become a major financial

    headache for agriculture, costing Ohio farmers as much as

    $1.7 billion a year.

    A new study is the first to tie a dollar value to the millions

    of crop-damaging insects that bats routinely devour eachyear. Now, the night-flying hunters face the threat of a

    fungal disease that kills most of the bats it infects.

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    White Nose Syndrome

    White-nose syndrome, named for the fungus thatspreads over bats while they hibernate, has killed atleast 1 million bats in 15 states and Canada since it wasdiscovered in New York in 2006.

    On March 30, Ohio officials announced that they foundthe disease among bats hibernating in an abandonedlimestone mine in the Wayne National Forest.

    They feared it will march through Ohio as it has nearlyeverywhere else.

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    The Effect

    In the April edition of the journal Science, researchers estimate thatU.S farmers would see annual economic losses of $3.7 billion to $53billion if the nation's bat population were wiped out.

    Losses to Ohio farmers would range from $740 million to $1.7

    billion a year through a combination of crop damage and costs topurchase additional pesticides.

    The biggest losses, according to the study, would be felt in Darke,Putnam, Mercer, Wood and Pickaway counties, which have themost land in crop production. Losses in each county would rangefrom $3million a year to more than $40million.

    The estimates are based largely on studies that examined thebenefits of bats to Texas cotton growers.

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    Importance of Bats

    Bats are prodigious insect eaters. Studies have shown that a single colony of 150big brown bats can eat as many as 1.3 million insects a year.

    White-nose syndrome causes bats to burn through their fat reserves before winterends, leaving them starving and with no insects to hunt for food.

    Paul Cryan, a U.S. Geological Survey research biologist and a co-author of thestudy, said the estimates should serve as a starting point for a discussion of bats'importance to people.

    In Ohio, bats eat pests that include cucumber beetles, stink bugs and leafhoppers,said Marne Titchenell, an Ohio State University Extension wildlife programspecialist.

    By eating moths that develop from crop-damaging worms, bats break thereproductive cycle.