ECOLOGICAL
INTERACTIONS

COMPETITION

  • This is a type of interaction
    in which presence of one
    organism may limit the
    distribution of other organisms.
  • This can take place between
    organisms of 2 different species
    or between organisms of the
    same species.
  • This type of interaction is seen
    for many other reasons apart
    from nutrition like shelter,
    mates and even light in case of
    plants.

SYMBIOSIS

  • It is an interaction
    between 2 or more
    organisms living
    physically close, which can
    be both beneficial
    and harmful for them.
  • There are 3 different
    types of symbiotic
    interactions, depending
    upon the outcome.

INTRASPECIFIC

  • This is a type of interaction
    observed in members of same species.
  • Mating and nutritions are generally where this competition is seen.
  • A few examples are as follows,

COMMENSALISM

  • It is a type of interaction in
    which 2 or more organisms
    are associated to each other
    and atleast 1 of it derives
    benefits from this association
    where as the other is not
    benefitted neither harmed.
  • This interaction is usually
    seen majorly for food and
    support to grow.
  • A few examples are as follows,

MUTUALISM

  • It is a mandatory, positive
    interaction between organisms
    of 2 different species, that is
    beneficial to both of them.
  • Strong physiological
    interaction and exchange is
    seen in these organisms
    that is essential for their survival.
  • A few examples are as follows

Lichens

  • The body of lichens is made
    from a matrix formed by a
    fungus, within the cells of which
    an algae is present.
  • The fungus makes moisture
    and nutrients available for algae.
  • The algae synthesize food
    by photosynthesis.
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Mycorrhizae

  • It is a fungus usually associated
    with trees and the fungal hyphae
    infest the tree roots.
  • The fungus derives food from
    the tree roots and fungal
    hyphae provide water and
    minerals from the soil.
  • The fungus also helps in
    regulation of pH and sugar
    levels for proper root growth.
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PARASITISM

  • This is a harmful interaction
    in which 2 organisms of different
    species survive together in which
    one is benefitted and other dies.
  • The one who benefits is
    known as a parasite, and the one which dies is called the host.
  • This type of interaction is often
    observed in organisms to
    procure either nutrition or shelter.
  • The host often dies due to
    secondary infections, but not
    until the parasite completes its
    reproductive stage.
  • A few examples are as follows,

Lianas

  • These are long stemmed,
    woody vines growing near the
    ground in tropical forests.
  • In order to acquire sunlight,
    these take the help of
    tall trees to reach the
    canopy and acquire sunlight.
  • Lianas don’t engage in any
    nutritional relationship with the tree,
    but only for support.
  • Lianas benefit here, while
    the tree providing support is
    neither benefitted nor harmed.
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Epizoans

  • These are the organisms that grow on the
    surfaces of animals.
  • These organisms only acquire support from the animals in order to grow without any nutritional benefits.
  • In such cases the organisms
    are benefitted whereas the animal is neither harmed nor benefitted.
  • A few examples include some green algae and Basicladia which grow on the turtle back.
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Phytoparasites

  • These are one of the types
    of parasitic plants that grow
    on other plants and derive
    nutrition, eventually leading
    to the death of the host plant.
  • Examples include species of
    Cuscuta (Doddar), Conopholis,
    Balanophora.
    848CEC65-CB87-4BAD-A979-A875B3E1D997

Zooparasites

  • These are animals that grow
    inside other animals and
    procure nourishment, often
    leading to severe illness or
    even death of the host animal.
  • Examples include nematodes,
    platyhelminthes, arthropods.
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PREDATION

  • It is a type of interaction between
    organisms of 2 different species
    in which one devoures on other.
  • It usually involves killing of
    the prey by the predator.
  • It results in reducing the abundance
    and keeping populations under control.
  • It is also a major selective force
    and helps in developing new
    adaptation strategies.
  • A few examples are as follows,

Carnivorous animals

  • These are the animals that
    survive by killing smaller
    animals and consuming
    them for nourishment.
  • There exists multiple
    techniques by which the
    predators catch their prey, few
    of which include direct hunting,
    paralysing the prey by injecting
    toxins, developing webs, etc.
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Carnivorous plants

  • Plants are often considered
    as the primary producers, yet
    there also exists some species
    of plants which have developed
    certain characteristics and part
    which help them capture small
    insects as a source of food.
  • These specialised structures often
    attract, trap, ingest the insects and
    produce a proteolytic enzyme to
    digest the captured insect.
  • Drosera, Venus flytrap, picture
    plant, Sarracenia are a few examples.
    1D59B197-CC56-443F-BA29-6161FCC8C340

INTERSPECIFIC

  • This is the type of interaction
    seen in organisms involving
    2 different species.
  • This competition between organism is majorly for nutrition and shelter.
  • A few examples are as follows,

In plants

  • Tall trees, usually seen in
    tropical rainforests, grow very
    tall in order to receive
    maximum sunlight.
  • Other plant species which
    do not grow tall, often perish
    due to lack of sunlight.
    87E7B094-1B2B-4FD8-906D-438E59E79436

In animals

  • In marine ecosystems,
    sharks and dolphins both
    are found living in similar depths of water and feed
    on small fishes.
  • Maximum amount of small
    fishes eaten by one of the two survives, while the other one faces challenges.
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Mating

  • Often males fight with other
    males of the community
    in order to procreate
    with the female.
  • The strongest male of the community that defeats rest of the males often gets to procreate.
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Nourishment

  • This is seen in a groups of
    animals when they hunt for prey.
  • Usually, in a clan of hyenas, the
    ones which can hunt swiftly, often
    recieve maximum portion of food
    as compared to others.
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By Ruchi Modgekar (p20015)