Transcript File - AP Environmental Science

Fall Exam
Review
The Earth Around
the Sun
Impact of Earth Rotation and
Axis Tilt on Climate
Greenhouse Effect
Climate and Air Circulation
Patterns
Convection Cell
Rain Shadow
Wind and Water - ENSO
 Normal
Years VIDEO
Wind and Water ENSO
•
•
•
•
•
•
Generally speaking El Niño brings:
cooler and wetter weather to the southern
United States
warmer weather to western Canada and
southern Alaska
drier weather to the Pacific Northwest
cooler weather to northern Canada
wetter weather to southern California
WATER Cycle
Aquatic Biomes
Streams and Rivers
Estuaries
Marshes and Swamps
Oceans:
- pelagic, benthic, coral reefs, intertidal
zones
Stratification in Aquatic Biomes
Intertidal zone
Neritic zone
Littoral
zone
Limnetic
zone
0
Oceanic zone
Photic zone
200 m
Continental
shelf
Pelagic
zone
Benthic
zone
Photic
zone
Aphotic
zone
Pelagic
zone
Benthic
zone
Aphotic
zone
2,500–6,000 m
Abyssal zone
(deepest regions of ocean floor)
(a) Zonation in a lake. The lake environment is generally classified on the basis
of three physical criteria: light penetration (photic and aphotic zones),
distance from shore and water depth (littoral and limnetic zones), and
whether it is open water (pelagic zone) or bottom (benthic zone).
Figure 50.16a, b
(b) Marine zonation. Like lakes, the marine environment is generally
classified on the basis of light penetration (photic and aphotic zones),
distance from shore and water depth (intertidal, neritic, and oceanic
zones), and whether it is open water (pelagic zone) or bottom (benthic
and abyssal zones).
LAKES
Lakes and Ponds
Figure 50.17
An oligotrophic lake in
Grand Teton, Wyoming
A eutrophic lake in Okavango
delta, Botswana
Oligotrophic vs. Eutrophic




Oligo - little or few nutrients - low productivity
due to few producers - high oxygen content few organisms - clean and clear
Eu - nutrient rich - high productivity due to
high number of producers - low oxygen
content - many organisms - murky water
Mesotrophic - an oligo that is becoming a eu
- due to influx of extra nutrients - usually due
to erosion, run off of fertilizers from agriculture
or animal poo - extra nutrients increase the
activity of the producers
Eutrophication:
http://www.eoearth.org/article/Eutrophicatio
n
Lakes
Are sensitive to seasonal temperature change
Experience seasonal turnover
2 In spring, as the sun melts the ice, the surface water warms to 4°C
and sinks below the cooler layers immediately below, eliminating the
thermal stratification. Spring winds mix the water to great depth,
bringing oxygen (O2) to the bottom waters (see graphs) and
nutrients to the surface.
Lake depth (m)
In winter, the coldest water in the lake (0°C) lies just
below the surface ice; water is progressively warmer at
deeper levels of the lake, typically 4–5°C at the bottom.
O2 (mg/L)
0
4
Spring
Winter
8
12
8
16
2
4
4
4
4C
24
O2 concentration
0
Lake depth (m)
1
O2 (mg/L)
0
4 8
12
8
16
4
4
4
4
4
4C
24
High
Medium
O2 (mg/L)
0
8
12
8
16
24
4
4
Autumn
4
4
4
4C
4
In autumn, as surface water cools rapidly, it sinks below the
underlying layers, remixing the water until the surface begins
to freeze and the winter temperature profile is reestablished.
4
Thermocline
3
22
20
18
8
6
5
4C
Summer
Lake depth (m)
Lake depth (m)
Low
O2 (mg/L)
0
4
8
12
8
16
24
In summer, the lake regains a distinctive thermal profile, with
warm surface water separated from cold bottom water by a narrow
vertical zone of rapid temperature change, called a thermocline.
Importance: Seasonal Turnover Brings Oxygen from the Surface to
the Benthic Detrivores and Returns the Nutrients of the Decomposed
Detritus (dead stuff) to the Surface for the Producers
Wetlands: Swamps and Marshes
WETLANDS
Okefenokee National Wetland Reserve in Georgia
Wetlands
 Marsh
vs. Swamp: Swamps have trees
 Characteristics: soil is waterlogged and
without oxygen for variable periods of
time - lack of O2 causes a large build up
of organic material
 IMPORTANCE: Most biologically
productive per square meter, filter water
moving through them - detoxify water,
control flooding
Streams and rivers
STREAMS AND RIVERS
Figure 50.17
A headwater stream in the
Great Smoky Mountains
The Mississippi River far
form its headwaters
Streams and Rivers
Characteristics: Flowing water
IMPORTANCE: Water source, hydroelectric power,
transportation
Estuaries
ESTUARIES
Figure 50.17 An estuary in a low coastal plain of Georgia
Estuaries
Characteristics: Where freshwater rivers meet the ocean mixing of fresh and salt water - salinity fluctuates - plants
and animals must be adapted - highly productive due to
nutrient input from river, frequent mixing of water by
ocean tides (circulates nutrients and waste) and large
photic zone
IMPORTANCE: control flooding- prevent wave surges from
reaching inland - highly productive
Intertidal zones
INTERTIDAL ZONES
Figure 50.17
Rocky intertidal zone on the Oregon coast
Intertidal Zones
Characteristics: Transition between land
and ocean - experience daily extremes
of salinity, oxygen content and
temperature due to changing tide
IMPORTANCE: Biologically productive,
species rich
Oceanic pelagic biome
OCEANIC PELAGIC BIOME
Figure 50.17 Open ocean off the island of Hawaii
Ocean Pelagic Biome
Characteristics: Open ocean, about 3% salt
content
Vegetation: mainly photoplankton and
algae, some sea grass and kelp
Animals: zooplankton, fish, jellyfish, whales,
porpoises, sea turtles, penguins
IMPORTANCE: Most productive biome due
to size (not per m2), food source (fish)
OVERFISHING - Regulation?
Coral reefs
CORAL REEFS
Figure 50.17
A coral reef in the Red Sea
Coral Reefs
Characteristics: Mounds of calcium carbonate secreted by
coral, shallow, warm waters, nutrient poor
Vegetation: Algae (Zooxanthelle)
Symbiosis: Coral and Zooxanthelle
Animals: Coral, huge numbers of fishes, echinoderms,
shellfish (8% of fish species in 0.1% of earth)
IMPORTANCE: Biodiversity of Species, Very productive
DANGERS: Human pollution, river runoff (excess sediment and
nutrients), over fishing
Subject to bleaching from increased ocean temperatures.
Subject to Coral skeleton loss from ocean acidification
due to increased CO2 levels.
Marine benthic zone
MARINE BENTHIC ZONE
Figure 50.17 A deep-sea hydrothermal vent community
Marine Benthic Zone
Characteristics: Bottom of the Ocean, may be
in a photic zone in the shallows
Neritic Zone: Shallow benthic zone, PHOTIC,
supports plant life (sea grass and kelp) and a
wide variety of fish and invertebrates
Abyssal Zone: APHOTIC - deepest part of sea no vegetation - hydrothermal vents
Animals: Decomposers, Very weird fish, tube
worms, chemosynthetic bacteria
IMPORTANCE: Decomposition of dead
materials, recycling on nutrients
Ocean Currents
Nutrient Cycles
Carbon
Water
Nitrogen
Phosphorous
Sulfur
General Nutrient Cycles
Reservoir a
Reservoir b
Organic
materials
available
as nutrients
Organic
materials
unavailable
as nutrients
Living
organisms,
detritus
Coal, oil,
peat
Reservoir c
Reservoir d
Inorganic
materials
available
as nutrients
Inorganic
materials
unavailable
as nutrients
Atmosphere,
soil, water
Minerals
in rocks
 Burning
of fossil fuels
 Weathering, erosion
 Sedimentation
 Respiration,
decomposition,excreti
on
 Assimilation,
photosynthesis
 Fossilization
General Nutrient Cycling
Reservoir a
Organic
materials
available
as nutrients
Living
organisms,
detritus
Assimilation,
photosynthesis
Reservoir b
Organic
materials
unavailable
as nutrients
Fossilization
Coal, oil,
peat
Respiration,
decomposition,
excretion
Burning
of fossil fuels
Reservoir c
Reservoir d
Inorganic
materials
available
as nutrients
Inorganic
materials
unavailable
as nutrients
Atmosphere,
soil, water
Weathering,
erosion
Formation of
sedimentary rock
Minerals
in rocks
Carbon Cycle
Processes: Increase or Decrease?
Cellular Respiration
Photosynthesis
Combustion of Fossil Fuels
Formation of Coral Reefs
Decomposition
Carbon Cycle
Processes: Increase or Decrease?
Cellular Respiration
Photosynthesis
Combustion of Fossil Fuels
Formation of Coral Reefs
Decomposition
Carbon Sinks (storage in
Environment)
 Fossil
Fuels
 Coral
 Ocean Sediment
 Trees
 Soil
Nitrogen Cycle
Nitrogen Cycle Processes
Ammonification
Nitrification
Denitrification
Nitrogen fixation
Assimilation
Decomposition
NH3  NO2NO2-  NO3NOx  N2
N2 NH4+
Proteins  NH4+
NH4+ or NO3- 
Proteins
Nitrogen Cycle Processes
Ammonification
Nitrification
Denitrification
Nitrogen fixation
Assimilation
Decomposition
NH3  NO2NO2-  NO3NOx  N2
N2 NH4+
Proteins  NH4+
NH4+ or NO3- 
Proteins
Phosphorous
Cycle
Sources of Phosphorous
 Erosion
 Mine
run off
 Fertilizer run off
 Poo
 Nutrient Upwelling
 Decomposition
Phytoplankton abundance parallels the abundance of phosphorus in the water (a). Nitrogen,
Impact
of Nutrients on Ecosystems
however, is immediately taken up by algae, and no free nitrogen is measured in the coastal waters. The
RESULTS
Inorganic
phosphorus
5
4
3
2
1
8
7
6
5
4
3
2
1
0
0
2
4
5
11 30 15 19 21
Station number
Great
Moriches
South Bay
Bay
30
Phytoplankton
(millions of cells per mL)
Phytoplankton
8
7
6
Inorganic phosphorus
(g atoms/L)
Phytoplankton
(millions of cells/mL)
addition of ammonium (NH4) caused heavy phytoplankton growth in bay water, but the addition of
phosphate (PO43) did not induce algal growth (b).
24
Ammonium enriched
Phosphate enriched
Unenriched control
18
12
6
0
Starting 2
algal
density
Shinnecock
Bay
(a) Phytoplankton biomass and phosphorus concentration
4
5 11 30
Station number
19
(b) Phytoplankton response to nutrient enrichment
Questions: 1) What does the first graph show?
2) Graph #2 – what is the limiting nutrient in the second graph?
Figure 54.6
15
21
Impact of Nutrients on Ecosystems
Inorganic
phosphorus
5
4
3
2
1
8
7
6
5
4
3
2
1
0
0
2
4
5
11 30 15 19 21
Station number
Great
Moriches
South Bay
Bay
30
Phytoplankton
(millions of cells per mL)
Phytoplankton
8
7
6
Inorganic phosphorus
(g atoms/L)
Phytoplankton
(millions of cells/mL)
RESULTS Phytoplankton abundance parallels the abundance of phosphorus in the water (a). Nitrogen,
however, is immediately taken up by algae, and no free nitrogen is measured in the coastal waters. The
addition of ammonium (NH4) caused heavy phytoplankton growth in bay water, but the addition of
phosphate (PO43) did not induce algal growth (b).
24
Ammonium enriched
Phosphate enriched
Unenriched control
18
12
6
0
Shinnecock
Bay
(a) Phytoplankton biomass and phosphorus concentration
Starting 2
algal
density
4
5 11 30
Station number
19
(b) Phytoplankton response to nutrient enrichment
Since adding phosphorus, which was already in rich supply, had no effect on
CONCLUSION
Nannochloris growth, whereas adding nitrogen increased algal density dramatically, researchers
concluded that nitrogen was the nutrient limiting phytoplankton growth in this ecosystem.
Figure 54.6
15
21
Sulfur Cycle
Trophic Levels

List the first four trophic levels and give an example for each in an
aquatic system and in a terrestrial system.
Level
Aquatic
Terrestrial
Trophic Levels

List the first four trophic levels and give an example for each in an
aquatic system and in a terrestrial system.
Level
Primary Producer
Prim. Consumer
Sec. Cons.
Tert. Cons.
Aquatic
Terrestrial
Food Chains and Food Webs
Keystone Species
 Dominant
and keystone species exert
strong controls on community structure
 In general, a small number of species in a
community
Number of species
present
20
With Pisaster (control)
15
10
Without Pisaster (experimental)
5
0
1963 ´64 ´65 ´66 ´67 ´68 ´69 ´70 ´71 ´72 ´73
(a) The sea star Pisaster ochraceous feeds
preferentially on mussels but will
consume other invertebrates.
Figure 53.16a,b
What does the graph show?
Number of species
present
Importance of Keystone
Species
20
With Pisaster (control)
15
10
Without Pisaster (experimental)
5
0
1963 ´64 ´65 ´66 ´67 ´68 ´69 ´70 ´71 ´72 ´73
(a) The sea star Pisaster ochraceous feeds
preferentially on mussels but will
consume other invertebrates.
Figure 53.16a,b
(b) When Pisaster was removed from an intertidal zone,
mussels eventually took over the rock face and eliminated
most other invertebrates and algae. In a control area from
which Pisaster was not removed, there was little change
in species diversity.
Observation of sea otter populations and their
predation
Otter
number (%
max. count)
100
80
60
40
20
Grams per
0.25 m2
0
(a) Sea otter abundance
400
300
200
Number per
0.25 m2
100
0
(b) Sea urchin biomass
10
8
6
4
2
0
1972
Figure 53.17
Food chain before
killer whale involvement in chain
1985
(c) Total kelp density
1989
Year
1993 1997
Food chain after killer
whales started preying
on otters
Ecosystem “Engineers”
(Engineering and
Foundation Species)

Some organisms exert their influence

By causing physical changes in the environment
that affect community structure
Beaver dams
Can transform landscapes on a very large
scale
(engineering)
Figure 53.18
Foundation species act as facilitators

That have positive effects on the survival and
reproduction of some of the other species in the
community
Number of plant species
8
6
4
2
0
Figure 53.19
Salt marsh with Juncus
(foreground)
With
Juncus
Without
Juncus
Conditions
Ecosystem Dynamics
Tertiary
consumers
Microorganisms
and other
detritivores
Detritus
Secondary
consumers
Primary consumers
Primary producers
Heat
Key
Chemical cycling
Energy flow
Figure 54.2
Sun
Trophic Level Pyramids
5
4
3
2
1
Grass
Secondary Consumer
Tertiary Consumer
Decomposer
Vole
Grasshopper
Producer
Snake
Primary Consumer
Trophic Level Pyramids
5
4
3
2
1
Grass - 1
Secondary Consumer 3
Tertiary Consumer - 4
Decomposer - 5
Bird (insectivore) - 3
Grasshopper – 2
Producer - 1
Snake - 4
Primary Consumer - 2
Trophic Efficiency and
Ecological Pyramids

Trophic efficiency



Is the percentage of production transferred from
one trophic level to the next
Usually ranges from 5% to 20%
Average = 10%
Pyramids of Production

This loss of energy with each transfer in a food
chain

Can be represented by a pyramid of net production
Tertiary
consumers
Secondary
consumers
Primary
consumers
Primary
producers
Figure 54.11
10 J
100 J
1,000 J
10,000 J
1,000,000 J of sunlight
Pyramids of Biomass

One important ecological consequence of low
trophic efficiencies

Can be represented in a biomass pyramid
Most biomass pyramids
Show a sharp decrease at successively higher
trophic levels
Trophic level
Dry weight
(g/m2)
Tertiary consumers
1.5
Secondary consumers
11
Primary consumers
Primary producers
(a) Most biomass pyramids show a sharp decrease in biomass at
successively higher trophic levels, as illustrated by data from
a bog at Silver Springs, Florida.
Figure 54.12a
37
809
Certain aquatic ecosystems
Have inverted biomass pyramids
Trophic level
Dry weight
(g/m2)
Primary consumers (zooplankton)
21
Primary producers (phytoplankton)
4
(b) Why is this pyramid inverted?
Figire 54.12b
Certain aquatic ecosystems
Have inverted biomass pyramids
Trophic level
Dry weight
(g/m2)
Primary consumers (zooplankton)
21
Primary producers (phytoplankton)
4
(b) In some aquatic ecosystems, such as the English Channel,
a small standing crop of primary producers (phytoplankton)
supports a larger standing crop of primary consumers (zooplankton).
Figire 54.12b
Pyramids of Numbers
Trophic level
Tertiary consumers
Number of
individual organisms
3
Secondary consumers
354,904
Primary consumers
708,624
Primary producers
Figure 54.13
5,842,424
PBJ and Turkey

The dynamics of energy flow through ecosystems


Have important implications for the human population
Eating meat

Is a relatively inefficient way of tapping photosynthetic
production
Worldwide agriculture could successfully feed many more
people
If humans all fed more efficiently, eating only plant
material
Trophic level
Secondary
consumers
Primary
consumers
Primary
producers
Figure 54.14
Biomagnification – reverse of other
ecological pyramids
Bioaccumulation vs.
Biomagnification
Bioaccumulation:
- toxins accumulate in tissues of organism
– may or may not be passed to higher
trophic levels
Biomagnification:
- increase of the toxic levels as they are
passed up trophic levels
GPP and NPP
 Gross
Primary Productivity – total increase
in biomass
 Net Primary Productivity – change in
biomass over a period of time (only the
difference) – this is what is passed to the
next trophic level
NPP of Various Ecosystems
Open ocean
Continental shelf
Estuary
5.2
0.3
0.1
0.1
Algal beds and reefs
Upwelling zones
Extreme desert, rock, sand, ice
4.7
Desert and semidesert scrub
Tropical rain forest
3.5
3.3
2.9
2.7
Savanna
Cultivated land
Boreal forest (taiga)
1.6
Tropical seasonal forest
Temperate deciduous forest
1.5
1.3
1.0
0.4
Temperate evergreen forest
Swamp and marsh
Lake and stream
Marine
10
3.0
90
0.04
0.9
2,200
22
900
7.9
9.1
600
9.6
800
600
700
5.4
3.5
0.6
140
1,600
7.1
1,200
1,300
4.9
3.8
2.3
0.3
2,000
250
20
30
40
(a) Percentage of Earth’s
surface area
50
60
0
500 1,000 1,500 2,000 2,500
(b) Average net primary
production (g/m2/yr)
Terrestrial
Freshwater (on continents)
0.9
0.1
500
0.4
0
1.2
2,500
1.7
Tundra
24.4
5.6
1,500
2.4
1.8
Temperate grassland
Woodland and shrubland
Key
125
360
65.0
Figure 54.4a–c
0
5
10
15
20
(c) Percentage of Earth’s net
primary production
25
Climate and Terrestrial Biomes
Temperate grassland
Desert
Tropical forest
Annual mean temperature (ºC)
30
Temperate
broadleaf
forest
15
Coniferous
forest
0
Arctic and
alpine
tundra
15
100
200
300
400
Annual mean precipitation (cm)
Overlapping Areas of Biomes = ECOTONE
The distribution of major terrestrial biomes
30N
Tropic of
Cancer
Equator
Tropic of
Capricorn
30S
Key
Tropical forest
Savanna
Figure 50.19
Desert
Chaparral
Tundra
Temperate grassland
High mountains
Temperate broadleaf forest
Polar ice
Coniferous forest
Tropical Rain forest
TROPICAL FOREST
Figure 50.20
A tropical rain forest in Borneo
Tropical Rain Forest
Rainfall: 200 – 400 cm/year
Temperature: 25 – 29 oC
Vegetation: Stratification, dense canopy,
broadleaf evergreen trees
Animals: High animal diversity, usually
smaller and adapted for life in canopy
Seasonal Variations: Little to none
Other Characteristics: Nutrient poor soil,
high rate of decomposition and turn over,
extremely high biodiversity
Desert
DESERT
Figure 50.20 The Sonoran Desert in southern Arizona
Desert
Rainfall: Less than 30 cm/year
Temperature: Wide variation both
seasonally and daily (-30 to 50 oC)
Vegetation: Low, scattered, deeply rooted
succulents (Cacti), dense root mats to
absorb water, adapted to heat and low
water
Animals: reptiles, insects, many nocturnal
Seasonal Variations: some have short wet
periods
Savanna
SAVANNA
Figure 50.20
A typical savanna in Kenya
Savanna
Rainfall: 76 – 150 cm/year
Temperature: Continually warm, 24 – 29 oC
Vegetation: Scattered trees (acacia), wide
expanse of grasses, adapted to fires,
deep roots
Animals: Hoofed mammals, zebras, giraffe,
lions, hyenas
Seasonal Variations: Seasonal Drought
Other Characteristics: Frequent fires,
location of the LION KING
Chaparral
CHAPARRAL
Figure 50.20
An area of chaparral in California
Chaparral
Rainfall: 30 – 50 cm
Temperature: Fall, Winter, Spring  10 – 12 oC,
Summer 30 oC
Vegetation: tough evergreen woody shrubs and
small trees adapted to seasonal fires
Animals: Deer, goats, many small mammals,
amphibians, birds and reptiles
Seasonal Variations: Summers are hot and dry,
fall, winter and spring are cool and rainy
Temperate grassland
TEMPERATE GRASSLAND
Figure 50.20
Sheyenne National Grassland in North Dakota
Temperate Grassland
Rainfall: Dry winters, Wet summers – 30 to
100 cm
Temperature: Cold Winters (-10 oC), Hot
summers (30 oC)
Vegetation: ummm….Grass
Animals: Large Grazers (buffalo), prairie
dogs
Seasonal Variations: dry winters, wet
summers
Coniferous (Boreal) Forest or Taiga
CONIFEROUS FOREST
Rocky Mountain National Park in Colorado
Figure 50.20
Coniferous (Boreal) Forest or Taiga
Rainfall: 30 – 70 cm with periodic drought some may
receive up to 300 cm (Pacific North West)
Temperature: Cold, long winters (-70 oC in Siberia),
summers may be hot (30 oC)
Vegetation: Cone bearing trees (pine, spruce, fir,
hemlock), conical shape helps snow fall off so
branches don’t break
Animals: Moose, brown bears, Siberian tigers, lots of
insects during summer
Seasonal Variations: Cold, harsh winters, warm
summers
Temperate broadleaf forest
TEMPERATE BROADLEAF FOREST
Figure 50.20
Great Smoky Mountains National Park in North Carolina
Temperate broadleaf forest
Rainfall: 70 – 200 cm
Temperature: 0 oC (winter) to 30+ oC (summer)
Vegetation: Broadleaf Deciduous Trees (drop leaves
in fall to prevent water loss in winter), conifers,
shrubs and various grasses and herbaceous plants
Animals: Black bear, deer, squirrels, snakes, birds
(migratory and permanent), insects
Seasonal Variations: Distinct seasons of fall, winter,
spring and summer
Other: You live here
Temperate Rainforest
Temperate Rainforest
Rainfall: More than 125 cm, lots of fog
Temperature: Small amount of seasonal variation ( 3
– 18 oC)– mild winters, cool summers
Vegetation: Conifers, lots of lichens and epiphytic
plants
Animals: Squirrels, mule deer, elk, birds, amphibians
and reptiles
Seasonal Variations: Mild differences in season due
to location near coasts
Other: Low nutrient turnover due to low
temperatures. Results in a high accumulation of
biological detritus on forest floor
Tundra
TUNDRA
Figure 50.20
Denali National Park, Alaska, in autumn
Tundra
Rainfall: 20 – 60 cm
Temperature: Long cold winters (-30 oC), Short cool
summers (10 oC)
Vegetation: Herbaceous (non-woody), dwarf shrubs
and trees, lichens, moss, grasses
Animals: Ox, caribou, reindeer, Santa Claus, Bears,
wolves, foxes, lots of insects in summer
Seasonal Variations:
OTHER: Contains permanent layer of frozen soil call
PERMAFROST
Evolution
 Driving



forces:
Genetic variation
Competition for resources
Survival of the Fittest
Microevolution vs. Macroevolution
Species Interactions

A biological community

Is an assemblage of populations of various
species living close enough for potential
interaction


A community’s interactions include competition,
predation, herbivory, symbiosis, and disease
Populations are linked by interspecific interactions

That affect the survival and reproduction of the
species engaged in the interaction
Table 53.1
Competition

Strong competition can lead to competitive exclusion

The local elimination of one of the two competing
species
The Competitive Exclusion
Principle

The competitive exclusion principle

States that two species competing for the same
limiting resources cannot coexist in the same
place
Ecological Niches

The ecological niche

Is the total of an organism’s use of the biotic and
abiotic resources in its environment
EXPERIMENT
Ecologist Joseph Connell studied two barnacle
speciesBalanus balanoides and Chthamalus stellatus that have a
stratified distribution on rocks along the coast of Scotland.
RESULTS
When Connell removed Balanus from the lower
strata, the Chthamalus population spread into that area.
High tide
High tide
Chthamalus
Balanus
Chthamalus
realized niche
Chthamalus
fundamental niche
Balanus
realized niche
Ocean
Figure 53.2
Low tide
In nature, Balanus fails to survive high on the rocks because it is
unable to resist desiccation (drying out) during low tides. Its realized
niche is therefore similar to its fundamental niche. In contrast,
Chthamalus is usually concentrated on the upper strata of rocks. To
determine the fundamental of niche of Chthamalus, Connell removed
Balanus from the lower strata.
Ocean
Low tide
CONCLUSION
The spread of Chthamalus when Balanus was
removed indicates that competitive exclusion makes the realized
niche of Chthamalus much smaller than its fundamental niche.
Results of Competition – more
specific niches

As a result of competition


A species’ fundamental niche may be different from its
realized niche
Resource partitioning is the differentiation of niches

That enables similar species to coexist in a community
Resource Partitioning
A. insolitus
usually perches
on shady branches.
A. ricordii
A. distichus perches
on fence posts and
other sunny
surfaces.
A. insolitus
A. alinigar
A. christophei
A. distichus
A. cybotes
A. etheridgei
Figure 53.3
Species Interactions


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Predation
Predator, Prey Plant Connection
Competition
Herbivory
Parasitism


Um….gross
Even nastier


Ants and caterpillars
Goby and shrimp
Disease
Mutualism
Commensalism
Predation

Predation refers to an interaction

Where one species, the predator, kills and eats
the other, the prey

Feeding adaptations of predators include


Claws, teeth, fangs, stingers, and poison
Animals also display

A great variety of defensive adaptations
Cryptic coloration, or
camouflage

Figure 53.5
Makes prey difficult to spot
Aposematic coloration
Figure 53.6
Batesian mimicry
(b) Green parrot snake
Figure 53.7a, b
(a) Hawkmoth larva
Müllerian mimicry
(a) Cuckoo bee
Figure 53.8a, b
(b) Yellow jacket
Herbivory

Herbivory, the process in which an herbivore
eats parts of a plant

Has led to the evolution of plant mechanical
and chemical defenses and consequent
adaptations by herbivores
Parasitism

In parasitism, one organism, the parasite

Derives its nourishment from another organism,
its host, which is harmed in the process
Disease

The effects of disease on populations and
communities

Is similar to that of parasites
Mutualism
Figure 53.9

Commensal interactions have been difficult to
document in nature

Because any close association between species
likely affects both species
Interspecific Interactions and
Adaptation

Evidence for coevolution

Which involves reciprocal genetic change by
interacting populations, is scarce
Species Diversity

The species diversity of a community


Is the variety of different kinds of organisms that
make up the community
Has two components

Species richness


Is the total number of different species in the
community
Relative abundance

Is the proportion each species represents of the total
individuals in the community
Two different communities
Can have the same species richness, but a different
relative abundance
A
B
C
D
Figure 53.11
A: 25%
Community 1
B: 25%
C: 25%
D: 25%
A: 80%
Community 2
B: 5%
C: 5%
D: 10%
Ecological Succession

Ecological succession

Is the sequence of community and ecosystem
changes after a disturbance

Primary succession


Occurs where no soil exists when succession begins
Secondary succession

Begins in an area where soil remains after a
disturbance
Soil Formation
Population Density vs.
Dispersion
Density: individuals per given area
Dispersion: arrangement of individuals in
an area
Types of Dispersion
Type:
1 Random
2 Clumping
3 Uniform
Reason:
- competition for resources
- based on availability of
nutrients
- enhances survival of the
group
- not influenced by the
patterns of other members
of the species
- resources tend to be
uniform
Types of Dispersion
Type:
1 Random
2 Clumping
3 Uniform
Reason:
3 competition for resources
2 based on availability of
nutrients
2 enhances survival of the
group
1 not influenced by the
patterns of other members of
the species
1 and 3 resources tend to be
uniform
Types of Dispersion
Type:
1 Random
2 Clumping
3 Uniform
Example
- Dandelions in the
NDHS Parking Lot
- Dandelions in your
front yard
- Male squirrel territory
Types of Population Growth
Based on:
- biotic potential
- possible growth if no barriers
- carrying capacity
- max population an area can hold
Carrying Capacity
Determined by:
- light
- water
- food
- space
- accumulation of toxins (wastes)
- disease
Growth of Populations
Exponential:
- graph = J curve
- follows biotic
potential
- includes lag time
- r selected populations
Logistic
- graph = S curve
- incorporates carrying
capacity
- line of growth usually
fluctuates around the
carrying capacity
- k selected
populations
Population Types
R-selected:
- opportunistic
- produce early in life
- lots of small offspring
- high growth rate
- experience boom
bust cycles
- semelparous
K-selected:
- live near carrying
capacity
- few offspring
- more parental care
- iteroparous
- slow growth rate
Boom Bust Cycle
Population climbs beyond the carrying
capacity and then crashes
Predator-Prey Cycle
Population Change
Growth Rate (percentage):
r = (b-d)/population (x100)
Crude Birth and Death Rates
Based on the number of births or deaths per
_______ members of the population.
Crude Birth and Death Rates
Based on the number of births or deaths per
1000 members of the population.
Factors Affecting Human
Population Growth
Economic Development
Availability of Birth Control
Cultural and Religious Attitudes
Education of Women
Population Changes
Doubling Time:
Rule of 70: Divide the current growth rate
into 70
Ex: A growth rate of 2%
Doubling time = 70/2 = 35 years
Population Pyramids
Population Pyramids
Demographic Transition Model
Demographic Transition Model
1.
Pre-industrial:
- issues: high birth rate
high infant mortality rate
low life expectancy due to lack
of medicine and sanitation
mostly agricultural
OVERALL - slow growth rate
Demographic Transition Model
2. Transitional State:
- issues: development - more resources
- high birth rate, high infant
mortality
- greater availability of medicine
and sanitation
- population grows faster
- high levels of pollution
Demographic Transition Model
Industrial State:
- issues: high level of productivity
- greater amounts of resources
- better health care
- population growth levels off
Demographic Transition Model
Post-Industrial:
- issues: high levels of affluence
- children do not add
economic value (can actually be a
burden)
- birth rates fall below
death rates or are at replacement
levels
Problems with Human Population
Growth - The Human Virus
-
-
consumption of resources
Pollution
Overgrazing
Loss of habitat for other species
Suburban Sprawl
Ecological Footpring
IPAT MODEL
I=PxAxT
I = Impact
P = Population
A = Affluence (amount of consumption)
T = Level of Technology
Humans and Other Species
-
-
loss of habitat
Habitat fragmentation
Habitat degradation
Threatened Species
Endangered Species
ESA
Resources
Consumption
Conservation
Preservation
Sustainable
Renewable
Non-renewable
Toxicity
Based on Dosage
LD50
LC50
Threshold Dose
Acute
Chronic
Acid Precipitation
NOx + H2O  HNO2 or HNO3
SOx + H2O  H2SO4 or H2SO3
Impact:
- acid shock – pH of water systems
- leach of minerals
- S and N in soil
- Calcium from conifers
- Release of Al3+ from soil
- human respiration
- chemical erosion
Math Problems
Set up a conversion table (fence post)
Calculate the 2 year cost of power for a factor that uses 120 GWh
of electricity per month at a rate of 0.05 dollars per KWh
120 GWh
month
24 months
1000 KWh
1 GWh
0.05 $
KWh
Math Problems
Set up a conversion table (fence post)
Calculate the 2 year cost of power for a factor that uses 120 GWh
of electricity per month at a rate of 0.05 dollars per KWh
120 GWh
month
24 months
1000 KWh
1 GWh
0.05 $
KWh
Legal Arsenal


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

CAA
CWA
SDWA
ESA
RCRA -Resouce Conservation and Recovery Act
CERCLA (Super Fund) -Comprehensive Environmental
Response, Compensation and Liability Act
FIFRA – Federal Insecticide, Fungicide, Rodenticide
Act
NEPA - EIS
Indicator Species
Crash Course Ecology
 Play
List
 - its 12 videos.