Ecology
Ecology
is the study of the
interactions between
organisms and their
interrelationships with
the environment.
Ecology

Organisms
Environment
 No organism exists as an
entity, separate and distinct
from its environment.
 All living organisms are
dependent upon other living
things as well as dependent on
the nonliving environment.
Ecological
Organization
Arrange these from largest to
smallest
Community
 Population
 Biosphere
 Ecosystem

Answer:
Biosphere
Ecosystem
Community
Population
Biosphere
is the portion of the
earth in which life
exists – oceans, land &
sky.
Ecosystem
is the living community and
the physical environment
functioning together as an
interdependent, selfsufficient, and relatively
stable system.
* The ecosystem is the
structural and functional
unit studied in ecology
Community
All the plant and
animal populations of
a given area make up
a community.
Population
is all the members of a
species living in a given
location.
Ex #1: all the gray squirrels living
in a forest
Ex #2: All the dandelions growing
in a field
species
A group of organisms
capable of interbreeding
and producing fertile
offspring
The Liger
http://www.youtube.com/watch?v=CD6vpheUoPE
How is the meaning of the word
“population” in Biology different from
its everyday (common) meaning?
In Biology, a population is a
smaller group than a community
SUN (radiant energy)
What do the arrows represent?
Energy
Energy
Energy
A Food Chain
An ecosystem is a
self-sustaining unit if
the following
requirements are
met:
Characteristics of
Ecosystems
1) constant source of energy
.
2) organisms that can store
this energy into organic
compounds
3) A flow of energy from
one population to another
- food chains, food webs
4) cycling of materials
between the organisms and
their environment.
A. Ecosystem Structure &
Function
 An ecosystem involves
interactions between
abiotic (nonliving) and
biotic (living) factors.
Abiotic Factors
The abiotic environment
includes physical (non-living)
factors which affect the ability
of organisms to live and
reproduce.
The abiotic factors include:
• gases - O 2, CO 2, N 2
• temperatures
• moisture
• substratum
• inorganic substances - minerals
• light
• pH
Each of these factors may act as a
limiting Factor determines the types of
organisms which may exist
in that environment.
Examples of limiting factors
include:
• The amount of
available water
determines the kinds of
organisms that can live
in a desert.
• The low temperature of
regions at high latitude
or altitudes.
• The salt concentration
in the oceans and
seashore regions.
Some species of fish,
shellfish, and other marine
species would die in
freshwater due to an
imbalance of water
pressure in their tissues.
• Some plants live well
on a forest floor under
tall trees, but would not
do well in an open field
due to the increased
intensity of light.
Biotic Factors
are all the living
things that directly,
or indirectly, affect
the environment.
 Thus, the organisms, their
presence, parts, interaction,
and wastes, all act as biotic
factors.
 Biotic factors interact in
many ways such as in
nutritional relationships and
symbiotic relationships.
Nutritional
Relationships
involve the transfer of
nutrients from one
organism to another.