Download Symbiotic Relationships

Interactions Within an
Ecosystem
Interactions is an ecosystem are influenced
by the fact that all organisms are trying to
meet at least one of their basic needs –
food, water, shelter and space.
Ecosystem –
• All of the populations that live
in a certain area and
everything that affects them.
(both abiotic and biotic )
Abiotic –
• all the physical (non-living) parts of the
environment that affect organisms living in
the area.
– Temperature
– Water
– Soil
– Air
– Sunlight
Biotic –
• all living organisms and the organic matter
they produce, such as dead leaves and
molted skin.
How do you know if something
is “living”?
• Every living thing is made up of one or
more cells
• Living things sense and respond to
change
• Living things have DNA
• Living things reproduce
• Living things use energy
• Living things grow and develop
• Niche - the ecological role of an
organism in a community especially
in regard to food consumption.
– Every organism in an ecosystem occupies a
niche (plays a role), such as – producers,
consumers, decomposers, etc.
3 ways species interact
within an ecosystem:
I. Competition
II.Predation
III.Symbiosis
1. Competition –
• Occurs when 2 or more
organisms or populations try to
use the same limited resource.
. (ex. different species of trees
compete for living space and
sunlight)
Limiting factors –
• When one or more of the essential
needs of a population (food, water,
shelter) becomes scarce then the
ecosystem cannot support all
organisms of a population,
the strongest and smartest will
survive .
Carrying capacity –
• The largest population that can
live in an ecosystem.
When a population grows larger
than the ecosystem’s carrying
capacity, limiting factors cause the
population to get smaller.
2. Predation –
• Certain species interact with
each other by hunting and
killing other species.
Predation Niches
• Prey – the animal that is hunted,
killed, and eaten. Prey have
developed many adaptations to
keep from getting killed
(ex. camouflage, strength in
numbers, speed, bright colors, etc.)
Predator –
the animal that hunts, kills, and eats
another animal. Predators have
developed many adaptations to
allow them to be better hunters
(ex. speed, traps, hunting in
packs, sharp claws and teeth,
etc.)
3. Symbiosis –
• A close, long-term
association between 2 or
more species.
3 types – Mutualism,
Commensalism,
Parasitism
Mutualism –
• Both organisms are helped in
the interaction
– Ex. Birds eat leechs out of a
crocodile’s mouth obtaining
food, the crocodile gets
cleaned off.
Commensalism –
• One organism is helped while
the other is unaffected
• Ex. Remoras “hitch” a ride on
sharks eating scraps of food
left behind and sharks are
unaffected.
Parasitism –
• One organism benefits from
the relationship (parasite) and
the other is harmed (host)
• Ex. Ticks / fleas on a dog
using blood to survive while
harming your dog.
Practice – add as examples to notes
Mutualism
Parasitism
Mutualism
Parasitism
Mutualism
Commensalism
Mutualism
Parasitism