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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
By Ruchi Modgekar (p20015)