Transcript ecosystems & ecology

ECOSYSTEMS
ECOSYSTEMS & ECOLOGY
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Ecology is the
study of the
interactions of
living organisms
with one another
and their
physical
environment.
ECOSYSTEMS & ECOLOGY
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A population consists of all of the
individuals of one species that live
together in the same area.
A community is all of the different
populations (different species) that
live together in a defined area.
ECOSYSTEMS & ECOLOGY
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An ecosystem is
made up of a
community plus
all of the physical
aspects of the
environment (like
soil, water, sun,
etc.)
ECOSYSTEMS & ECOLOGY
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A biome is a
group of
ecosystems
that have the
same climate
& similar
communities.
ECOSYSTEMS & ECOLOGY
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The biosphere is
the entire living
earth, where life
exists, including
land, water & air.
ECOSYSTEMS & ECOLOGY
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The place where an organism lives is its
habitat.
An organism’s niche is its place (role) in
the ecosystem, including how it fits into the
food web, the environmental conditions it
needs in order to live & how it reproduces.
No 2 species share exactly the same niche
in the same habitat.
ECOSYSTEMS
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Abiotic factors – are all of the nonliving
parts of an ecosystem (like weather, soil,
gases and water).
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Biotic factors – are all of the living parts of
an ecosystem (like bacteria, protists, fungi,
plants and animals).
Energy Flow through
Ecosystems
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Energy flows through an ecosystem in one
direction:
SUN AUTOTROPHS  HETEROTROPHS
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Heterotrophs include animals such as
carnivores, herbivores and omnivores.
Sunlight is the main source of energy for
all life on Earth.
Energy Flow through
Ecosystems
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Producers
(Autotrophs):
Organisms that
capture energy
from the sun and
turn it into food.
Energy Flow through
Ecosystems
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Consumers
(Heterotrophs):
All animals
that obtain
energy by
eating
producers.
Energy Flow through
Ecosystems
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Every organism in an ecosystem is
assigned to a trophic level, which is
determined by the organism’s source of
energy (food sources).
Energy Flow through Ecosystems
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1st trophic level:
Producers – plants, algae & bacteria
2nd trophic level:
Herbivores – All animals that eat plants
3rd trophic level:
Carnivores – All animals that eat herbivores
(omnivores eat both plants & animals).
4th trophic level: Top carnivores – Carnivores that eat
other carnivores
Energy Flow through
Ecosystems
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Decomposers: Organisms that
break down organic matter
(Example: fungi and bacteria)
Energy Flow through
Ecosystems
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A food chain shows one path of energy flow in
an ecosystem. Most ecosystems support more
than one food chain and they generally
interweave into a food web.
Energy Flow through
Ecosystems
Energy Flow through Ecosystems
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The amount of energy in an ecosystem
can be represented by an ecological
pyramid.
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Each trophic level contains less
available energy than the level below it,
so there are always fewer organisms in
the higher levels of the food chain.
Energy Flow through Ecosystems
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Only about 10% of the energy available is
within one trophic level is passed on to the
next trophic level.
Succession
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Natural changes in the physical
environment of ecosystems happen all the
time.
EXAMPLE: When a volcano forms a new
island or fire burns all of the vegetation in
an area and a new habitat is created.
Succession
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As an ecosystem changes, older
inhabitants gradually die out and new
organisms move in.
Succession
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These changes in plant and animal life
that occur in a community over time
are called ecological succession.
Stages of Succession in a Pond
Succession
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When succession occurs on land where
nothing has grown before it is called
primary succession (Example: The
invasion of plants from water to land)
When succession occurs in areas where
there has been previous growth it is called
secondary succession (Example: A fire
wipes out the entire plant & animal life in
a forest and several years later new
plants & animals are present.
Community Interactions
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Community interactions refers to the ways
that animals and plants relate to each other.
Competition occurs when organisms
compete for resources such as water, food,
light or space.
Usually competition results in a winner and
a loser, often with the losing organism’s
failure to survive.
Coevolving in Opposition
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Predation:
When one
organism (the
predator) feeds
on another
organism (the
prey).
Symbiosis
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Symbiosis
occurs when
two species
live closely
together in
relative
harmony.
MUTUALISM
 Mutualism
is a type of symbiosis that
occurs when both organisms benefit
from their association with each other.
(Example: Lichens, Rhinos & tick bird)
COMMENSALISM
 Type
of symbiosis
in which one
species benefits
from an association
and the other
species is neither
helped nor harmed.
Example:
Barnacles are organisms that
attach themselves to whales to obtain a
free ride to food sources, while the whale is
unaffected by their presence.
Coevolving in Opposition
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Parasitism: A special type of
predation where one organism
(the parasite) lives in or on
another organism (a host) and
causes the host harm.
Parasites usually do not
intentionally kill their host
since they depend on it for
food, but often the host is
fatally harmed by this
association.
ECOSYSTEMS
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Limiting factor:
Any factor that
restricts the
existence or
number of
organisms. (See
the examples at
right:)
ECOSYSTEMS
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Carrying capacity – The maximum
number of individuals that an
environment can support. As
resources become less available, the
growth of a population tends to slow
or stop.
THE END