Download Lecture PowerPoint - Biology

Section 14-1 and 14-2
“Habitats and
Communities”
14.1 Habitat & Niche / 14.2 Community Interactions
Section 14.1 KEY CONCEPT:
Every organism has a habitat and a niche.
14.1 Habitat & Niche / 14.2 Community Interactions
A habitat is all aspects of the
area in which an organism lives.
Includes:
–biotic
factors
–abiotic
factors
A niche includes all of the factors
that a species needs to survive,
stay healthy, and reproduce.
Includes:
–food
–abiotic
conditions
–behavior
“What are 5 things in a
habitat that I need to
survive?”
• The needs of an organism are
1
AIR
2
3
WATER
FOOD
4 SHELTER
5
SPACE
“I need air, water, food,
shelter and space to
survive!
Fill in with your words to describe each
All living and
nonliving
factors in the
area where an
organism lives
All physical,
chemical, and
biological factors
that a species
needs to survive
• What is competition?
• How would competition be defined
in the field of ecology?
Resource availability gives
structure to a community.
• Species can share habitats and
resources.
• Competition occurs when two
species use resources in the same
way.
• Competitive exclusion keeps two
species from occupying the same
niche.
Intraference competition
Occurs directly between individuals via aggression etc. when the individuals
interfere with foraging, survival, reproduction of others, or by directly
preventing their physical establishment in a portion of the habitat
• Even plants compete for space, water and sunlight
• Possible Outcomes of Competitive Exclusion:
–One species is better suited to the
niche and the other will either be
pushed out or become extinct.
–The niche will be divided.
–The two species will further diverge.
When two species are competing for the
same resources
- one species will be better adpated
to the niche
- the other will be pushed into
another niche or go extinct
The niche will be
divided.
The two species will
further diverge
• Ecological equivalents are species that
occupy similar niches but live in
different geographical regions.
Madagascar
South America
Live in similar niches but in
different geographic locations
and for that reason do not
compete for the same resources.
Check Your Learning
1. How is a habitat different from a niche?
2. What are the possible outcomes of
competitive exclusion?
3. How can ecological equivalents occur?
Check Your Learning
1. How is a habitat different from
a niche?
1. a niche is a part of a habitat; a habitat is all
of the living and nonliving factors in the
area where an organism lives, while a niche
includes all the specific physical, chemical,
and biological factors needed by an
organism to survive, stay healthy, and
reproduce
Check Your Learning
2. What are the possible outcomes
of competitive exclusion?
2. one species will go extinct; the resources
of the niche will be divided and the two
species will coexist; an evolutionary
response will result in selection of different
traits that are successful in different parts
of the niche
Check Your Learning
3. How can ecological equivalents occur?
3. while the two species occupy similar
niches, they live in different geographical
regions
14.1 Habitat & Niche / 14.2 Community Interactions
Section 14.2
KEY
CONCEPT :
Organisms
interact as
individuals
and as
populations
.
14.1 Habitat & Niche / 14.2 Community Interactions
• Competition occurs when two
organisms fight for the
same limited resource.
Competition can
be:
• within the same
species
(Intraspecific)
• or between
different species
(Interspecific)
Two organisms
fight for the
same limited
resources
14.1 Habitat & Niche / 14.2 Community Interactions
• Predation occurs when one
organism captures and eats
another.
Close
relationship
between two or
more different
species
One organism
captures and
eating
another
organism
14.1 Habitat & Niche / 14.2 Community Interactions
• There are three major types of symbiotic
relationships:
1. Mutualism: both organisms benefit
14.1 Habitat & Niche / 14.2 Community Interactions
2. Commensalism: one organism
benefits, the other is not harmed
+
Demodicids Eyelash
mites find all they
need to survive in
the tiny follicles
of eyelashes.
Magnified here 225
times, these
creatures measure
0.4 mm in length and
can be seen only
with a microscope.
Ø
Human Our
eyelashes are home
to tiny mites
that feast on oil
secretions and dead
skin. Without
harming us, up to 20
mites may be living
in one eyelash
follicle.
Ø
Organism is not affected
+
Organism benefits
14.1 Habitat & Niche / 14.2 Community Interactions
3. Parasitism: one organism benefits,
+
the other is harmed
_
Hornworm
caterpillar
The host
hornworm will
eventually die
as its organs are
consumed
by wasp larvae.
_
Organism is harmed
Braconid wasp
Braconid larvae
feed on their
host and
release
themselves
shortly before
reaching
the pupae stage
of development
+
Organism benefits
14.1 Habitat & Niche / 14.2 Community Interactions
– Parasites meet their needs as
ectoparasites (such as leeches) and
endoparasites (such as hookworms)
Close
relationship
between two or
more different
species
Both benefit
+
+
One benefits other
not affected
+
0
One benefits other
harmed
+
-