Transcript Ecology BIO 2215 Oklahoma City Community College Dennis Anderson Ecology • Study of the interactions of living organisms with each other and their environment.

Ecology
BIO 2215
Oklahoma City Community College
Dennis Anderson
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Ecology
• Study of the
interactions of living
organisms with each
other and their
environment
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• Scales of Life
– Populations—All members of a single
species that live together in a specified
geographic region.
– Communities—All species that potentially
interact with one another, in a given region.
– Ecosystems—Communities of living things
and their nonliving environment.
– Biosphere—Entire interactive collection of the
Earth’s ecosystems.
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Biosphere
Population
Ecosystem
Organism
Community
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• The Ecosystem: The Fundamental Unit
of Ecology
– Ecosystem—A self-sustaining community of
organisms and the physical environment with
which they interact.
– Consist of biotic (living) and abiotic
(nonliving) factors.
– Depend on Sun for ultimate source of energy;
there’s one-way flow of energy through an
ecosystem.
– Some nutrients and water are taken up by
living organisms and then cycled back to the
abiotic component of an ecosystem.
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Producer
• Produces food
• Energy from sunlight
converted into
chemical energy
• Plants
• Algae
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Consumer
• Consume food by
eating
• Primary
• Secondary
• Tertiary
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Decomposer
• Decompose dead
bodies and organic
matter
• Fungi
• Bacteria
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Pyramid of Numbers
Consumer 1
Consumer 90,000
Consumer
200,000
Producers
1,500,000
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Pyramid of Biomass
Consumer
Consumer
1 g/m2
11 g/m2
Consumer
37 g/m2
Producers
809 g/m2
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Man
Cattle
Alfalfa
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Man
Cattle
Alfalfa
Man
Rice
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1st trophic level
3rd trophic level
2nd trophic level
producers
(photosynthesizers)
4th trophic level
Secondary
consumers
(herbivore predators)
Primary
consumers
(plant predators)
Tertiary
consumers
(carnivore predators)
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kingfisher
merganser
otter
great blue heron
dipper
garter snake
steelhead
roach
stickleback
water scavenger frog tadpole
beetle larva
newt
caddis fly larva
snail
crayfish
tuft midge
blue-green algae
diatoms
green algae
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Abiotic Components of an
Ecosystem
•
•
•
•
•
•
Carbon
Nitrogen
Water
Temperature
Sunlight
Etc
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THE CARBON CYCLE
atmospheric CO2
5 burning
of fossil
fuels
1 photosynthesis
respiration
2 respiration
plants
4
fossil fuels
animals
3
dead organisms
decomposition by
bacteria and fungi
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THE NITROGEN CYCLE
atmospheric N2
bacteria in
root nodules
of plants, and
in soil
assimilation
into animals
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denitrifying
bacteria
2 assimilation
into plants
1 nitrogen fixation animal waste
dead organisms
ammonia (NH3)
ammonium NH4+)
3 decomposition
by bacteria and fungi
4 nitrifying
bacteria
nitrate (NO3)
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THE HYDROLOGIC CYCLE
90%
precipitation
over ocean
water
vapor
10%
precipitation
over land
transpiration,
evaporation
evaporation
surface
runoff
ocean
groundwater
groundwater
runoff
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Sun
1,000,000
Calories
20,000
5,000
Producer
10,000
5,000
1,000
Consumer
2,000
2,000
500
Consumer
1,000
500
200
Decomposer
Consumer
300
6,700
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Total 20,000
Energy
• Does not cycle in an ecosystem
• Usable energy lost at each trophic level
• Sun is the source of energy
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Habitat
• Where an organism is found
– Marine
– Fresh water
– Tree tops
– Under ground
– etc
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Niche
• How an organism
obtains food and
resources to survive
– “occupation”
• Black rhino feeds on
leaves and woody
plants
• White Rhino feed on
grasses and herbs
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Competitive
exclusion
Population size
P. aurelia
P. caudatum
Resource
partitioning
Population size
Time (days)
P. aurelia
P. bursaria
Time (days)
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Territory: Area defended against
others of the same species.
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30
16
peak
peak
Song level
12
8
4
Testosterone level
0
1200
CH3 OH
800
CH3
400
O
0
January
April
August
Month
December
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Animal Societies
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Advantages of Group Living
• Easier to detect
predator
• Easier to repel
predator
• Protect young
• Easier to find food
• Easier to find a mate
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Disadvantages of Group Living
• More competition
• More disease
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Dominance Hierarchy
• Each member has a
rank in the pack
• Alpha—highest rank
• Beta—second rank
• Omega—lowest rank
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Dominance Hierarchy
• Reduces conflict
• Promotes social order
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Predator and Prey
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Predators Benefit Prey
• Prevent overpopulation
• Remove weak and sick from population
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Snowshoe Rabbit and Lynx
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Snowshoe Rabbit and Lynx
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Coyote and Jackrabbit
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Symbosis
•
•
•
•
Living together
Parasitism
Commensalism
Mutualism
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Parasitism
• Parasite benefits
• Host harmed
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Mutualism
Both benefit
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Commensalism
• Shark and Remora
• Remora benefits
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Populations
• Capacity to grow
exponentially
2-4-8-16-32-64
128……1,000,000
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Population Growth
• Birth rate
• Death rate
• Example
– Population of 100
– 10 births and 8 deaths
– Rate of growth is 2%
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Number in
Population
Carry Capacity
Log Phase
Lag Phase
Time
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Carrying Capacity
• Optimum number of
individuals an
ecosystem can
support for an
extended period of
time.
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Environment Resistance
•
•
•
•
Food
Space
Disease
Predators
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TYPES OF POPULATION GROWTH
exponential growth
J shaped growth
Population size
logistic growth
K
S shaped growth
more complex growth
K
Time
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Population Crash
• 1944 29 reindeer
introduced to St.
Matthew island
• 1964 population
increased to 6,000
• Crashed to only
reindeer 42
• All died a few years
later
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Kiabab Forest
1907 population = 4,000
1925 population 100,000
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Easter Island
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Link for today's human population
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Challenges of Expanding Human
Population
• 250,000 babies born each day
• 19,000 people starve to death each day
• Carrying capacity for American lifestyle is
2.5 billion
• 2 billion people do not have enough food,
water and clean air.
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Expanding Economies Stress
Ecosystems
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Biodiversity
• Diversity of species
• Decrease Biodiversity
– Habitat destruction
– Pollution
– Excessive
• Hunting
• Fishing
• poaching
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Coral Reefs
• 10% of coral reefs
lost in 1992
• 27% of coral reefs
lost in 2000
• Global warming
• Over fishing
• Mining
• Pollution
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The End
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