Transcript File

Introduction to Ecology
Organism
 An
individual living
thing
Species
A
group of the same organisms
that are able to breed and produce
fertile organisms.
Organism
Ecology
 The
study of organisms and
their interactions with their
environment (biotic and
abiotic) upon which determine
distribution and abundance of
organisms.
Habitat
A
place where an organism lives
or can be found.
Ecosystem
 An
interacting system that
consists of groups of organisms
and their non-living environment
with in a boundary.
Two parts of an Ecosystem
Biotic and Abiotic
 Biotic
–
–factors that are or were
alive/living in an ecosystem.
 Examples: animals, plants,
insects, bacteria, fungi, and dead
organisms.
Abiotic
 Factors
in an environment that are
not or never were alive.
 Examples: rock island, gases, water,
sun, minerals and temperature.
Climate
 Definition-the
weather
conditions prevailing in an area
in general or over a long period.
 The overriding factor that
determines the general nature of
an ecosystem.
If the climate is always hot and
dry, the soil will be sandy. The
plants, animals and other life will
be specially adapted for survival
in a desert.
Climate cont.
 If
the climate is hot and moist, then
there will be many trees,
characteristic of a Rainforest. Some
animals and insects will be adapted
for living in trees. They are called
arboreal and include monkeys and
spiders.
Levels of Biological Organization
It is important to remember that all
parts of an ecosystem are interrelated.
Each part is affected
by all other parts.

If we remove one
species from an ecosystem,
there could be severe
consequences for that
ecosystem.

Cont.
 If
we remove all the spiders from a
given ecosystem, the insect
population will grow rapidly and
destroy forest and crops.
 Who
do you think would benefit?
 What would happen to their
population?
 Who would be affected then?
Levels of Organization
 Ecologists
tend to label groups of
organisms.
 Let’s look at a familiar setting for
example: Your house is part of a
town, this is part of a state,
which is part of a country, which
is part of a continent.
Levels of Organization Cont.
 No
individual organism lives
completely on its own. It may live
with other individuals of the same
species to form a population.
 Several populations living
together make up a community.
 Several communities in a given
area make up a biome.
Organization Cont.
Collectively, all the biomes of the
planet earth make up the biosphere.
 Again, the most basic level of
ecological organization is the
individual/species.
 A group of individuals of
The same species make up a
population.
 A community is all the
populations of living
organisms in an area.

Levels of organization
Organization Cont.
 The
boundary of a community is
determined by the
distribution of its members.
 The boundary of one
community is not
necessarily the
Boundary of another
community.
We say these
communities overlap.
Organization Cont.
A
biome is a large geographical
area with a similar climate.
Biosphere
The
biosphere is the
region on Earth where
all life exists.
Habitat and Niche
 Each
organism confronts the
challenge of survival in a
different way.
 The niche an organism
occupies is the sum of all the
ways it utilizes the resources
of its environment.
 Part of this role may be
played as the predator and
part may be played as the
prey.
Niche
 Example:
Snakes eat mice and
other birds and rodents but
snakes are also eaten by birds
of prey and mice eat
grasshoppers and other insects.
Niche
A
niche may be described in
terms of space utilization, food
consumption, temperature range
and mating requirements.
 An organism’s niche would also
take into account its behavior.
You can think of an organism’s
niche as its job/role in the
environment.
A
Niche
beaver is an ecosystem engineer.
It cuts down trees and dams up a
river which will flood the forest with
a pond. Eventually the trees will
dies, new species of plants and
wildlife will arrive to take advantage
of the new conditions. Eventually,
this forest will become a meadow.
The beaver’s NICHE is the role it
plays in shaping the environment.
 But… it is also a main prey
species for predators.
Habitat
 Niche
is not synonymous with
habitat. Habitat is a place, niche is a
pattern of living. Habitat is the
address and niche is the job or
occupation.
 If two organisms have the same
habitat and similar niches, they will
compete with each other over the
available resources.
 (food- water -shelter)
Habitat
 Competition
is the struggle
between two organisms within
their habitat.
 If a species can avoid competing
they may co-exist. But if they
compete, one will eventually drive
the other out of the habitat, unless
they have slightly different niches.
 Example: times of
activity
Different Niches to avoid
competiton:
 Nocturnal
 Diurnal
– active at night
- active during the day
 Crepuscular
dusk
– active at dawn and
Different Niches to avoid
competiton: cont…
 Migration
– moving from one
area to another to use resources
 Hibernation
– reducing activity
severely for a period of time.
Bibliography
 Pictures
by Microsoft ClipArt
mjdestiny.blogspot.com