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ECOLOGY
What is ecology?

Ecology is the scientific study of
interactions between ___________

term ecology comes from the Greek
oikos, _______, and logos, to study
.
biotic and abiotic factors
What are biotic factors? Give examples.
What are abiotic factors? Give examples.
.
climate
What is climate?
What abiotic factors are the major
components of climate?
.
climate
What effects do bodies of water have on
climate?
What effects do mountains have on climate?
Include descriptions of how elevation
affects temperature, and of rain shadows.
.
Fig. 52-12
Fig. 52-13
climate
What effects do seasons have on
climate?
Describe what causes seasons; include
the terms solstice and equinox in
your description.
.
Fig. 52-10c
60ºN
30ºN
March equinox
0º (equator)
June solstice
30ºS
December solstice
Constant tilt
of 23.5º
September equinox
What are biomes?
.
aquatic biomes
List the major aquatic biomes and their
defining physical features.
define the following:
photic zone
aphotic zone
benthic zone
.
Fig. 52-16
Lakes
• Oligotrophic lakes are nutrient-poor and generally
oxygen-rich
• Eutrophic lakes are nutrient-rich and often
depleted of oxygen if ice covered in winter
• Rooted and floating aquatic plants live in the shallow
and well-lighted littoral zone
• Water is too deep in the limnetic zone to support
rooted aquatic plants; small drifting animals called
zooplankton graze on the phytoplankton
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 52-18a
Fig. 52-18b
Fig. 52-18c
Wetlands
• A wetland is a habitat that is inundated by
water at least some of the time and that
supports plants adapted to water-saturated soil
• Wetlands can develop in shallow basins, along
flooded river banks, or on the coasts of large
lakes and seas
• Wetlands are among the most productive
biomes on earth and are home to diverse
invertebrates and birds
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 52-18d
Fig. 52-18e
Streams and Rivers
• The most prominent physical characteristic of
streams and rivers is current
• A diversity of fishes and invertebrates inhabit
unpolluted rivers and streams
• Damming and flood control impair natural
functioning of stream and river ecosystems
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 52-18f
Estuaries
• An estuary is a transition area between river
and sea
• Salinity varies with the rise and fall of the tides
• Estuaries are nutrient rich and highly
productive
• An abundant supply of food attracts marine
invertebrates and fish
Video: Flapping Geese
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 52-18g
Intertidal Zones
• An intertidal zone is periodically submerged
and exposed by the tides
• Intertidal organisms are challenged by
variations in temperature and salinity and by
the mechanical forces of wave action
• Many animals of rocky intertidal environments
have structural adaptations that enable them to
attach to the hard substrate
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 52-18h
Oceanic Pelagic Zone
• The oceanic pelagic biome is a vast realm of
open blue water, constantly mixed by winddriven oceanic currents
• This biome covers approximately 70% of
Earth’s surface
• Phytoplankton and zooplankton are the
dominant organisms in this biome; also found
are free-swimming animals
Video: Shark Eating a Seal
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Fig. 52-18i
Coral Reefs
• Coral reefs are formed from the calcium
carbonate skeletons of corals (phylum
Cnidaria)
• Corals require a solid substrate for attachment
• Unicellular algae live within the tissues of the
corals and form a mutualistic relationship that
provides the corals with organic molecules
Video: Coral Reef
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Video: Clownfish and Anemone
Fig. 52-18j
A deep-sea hydrothermal vent community
Marine Benthic Zone
• The marine benthic zone consists of the
seafloor below the surface waters of the
coastal, or neritic, zone and the offshore
pelagic zone
• Organisms in the very deep benthic, or
abyssal, zone are adapted to continuous cold
and extremely high water pressure
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• Unique assemblages of organisms are
associated with deep-sea hydrothermal vents
of volcanic origin on mid-oceanic ridges; here
the autotrophs are chemoautotrophic
prokaryotes
Video: Hydrothermal Vent
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Video: Tubeworms
aquatic biomes
Describe the process of turnover in a
lake, and why it is important.
What is eutrophication, and what are
some likely consequences of it?
.
Fig. 52-17-1
Fig. 52-17-2
Fig. 52-17-3
Fig. 52-17-4
terrestrial biomes
List the major terrestrial biomes and their
characteristic vegetation types and
climate.
.
terrestrial biomes
define the following:
climograph
ecotone
Be sure that you can interpret a climograph.
.
Fig. 52-19
Terrestrial Biomes
• Terrestrial biomes can be characterized by
distribution, precipitation, temperature, plants,
and animals
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Fig. 52-21a
Tropical Forest
• In tropical rain forests, rainfall is relatively
constant, while in tropical dry forests
precipitation is highly seasonal
• Tropical forests are vertically layered and
competition for light is intense
• Tropical forests are home to millions of animal
species, including an estimated 5–30 million
still undescribed species of insects, spiders,
and other arthropods
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 52-21b
Desert
• Precipitation is low and highly variable, generally less
than 30 cm per year; deserts may be hot or cold
• Desert plants are adapted for heat and desiccation
tolerance, water storage, and reduced leaf surface
area
• Common desert animals include many kinds of snakes
and lizards, scorpions, ants, beetles, migratory and
resident birds, and seed-eating rodents; many are
nocturnal
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 52-21c
A savanna in Kenya
Savanna
• Savanna precipitation and temperature are
seasonal
• Grasses and forbs make up most of the ground
cover
• Common inhabitants include insects and
mammals such as wildebeests, zebras, lions,
and hyenas
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 52-21d
Chaparral
• Chaparral climate is highly seasonal, with cool
and rainy winters and hot dry summers
• The chaparral is dominated by shrubs, small
trees, grasses, and herbs; many plants are
adapted to fire and drought
• Animals include amphibians, birds and other
reptiles, insects, small mammals and browsing
mammals
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 52-21e
Temperate Grassland
• Temperate grasslands are found on many
continents
• Winters are cold and dry, while summers are
wet and hot
• The dominant plants, grasses and forbs, are
adapted to droughts and fire
• Native mammals include large grazers and
small burrowers
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 52-21f
Northern Coniferous Forest
• The northern coniferous forest, or taiga,
extends across northern North America and
Eurasia and is the largest terrestrial biome on
Earth
• Winters are cold and long while summers may
be hot
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• The conical shape of conifers prevents too
much snow from accumulating and breaking
their branches
• Animals include migratory and resident birds,
and large mammals
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 52-21g
Temperate Broadleaf Forest
• Winters are cool, while summers are hot and
humid; significant precipitation falls year round
as rain and snow
• A mature temperate broadleaf forest has
vertical layers dominated by deciduous trees in
the Northern Hemisphere and evergreen
eucalyptus in Australia
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Mammals, birds, and insects make use of all
vertical layers in the forest
• In the Northern Hemisphere, many mammals
hibernate in the winter
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 52-21h
Tundra
• Tundra covers expansive areas of the Arctic;
alpine tundra exists on high mountaintops at all
latitudes
• Winters are long and cold while summers are
relatively cool; precipitation varies
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
• Permafrost, a permanently frozen layer of soil,
prevents water infiltration
• Vegetation is herbaceous (mosses, grasses,
forbs, dwarf shrubs and trees, and lichen) and
supports birds, grazers, and their predators
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
population ecology
Population ecology is the study of populations in
relation to __________
A population is:
define the following:
density
dispersion
range
.
population ecology
How does the mark-recapture method to
estimate population size work?
Include the formula and definition of the
terms in the formula.
.
population ecology
What is demography?
define and be able to use/interpret:

life tables

survivorship curves

reproductive tables
.
Life Tables
• A life table is an age-specific summary of the
survival pattern of a population
• It is best made by following the fate of a
cohort, a group of individuals of the same age
• The life table of Belding’s ground squirrels
reveals many things about this population
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Table 53-1
Survivorship Curves
• A survivorship curve is a graphic way of
representing the data in a life table
• The survivorship curve for Belding’s ground
squirrels shows a relatively constant death rate
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 53-5
• Survivorship curves can be classified into three
general types:
– Type I: low death rates during early and middle
life, then an increase among older age groups
– Type II: the death rate is constant over the
organism’s life span
– Type III: high death rates for the young, then a
slower death rate for survivors
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fig. 53-6
Reproductive Rates
• For species with sexual reproduction,
demographers often concentrate on females in
a population
• A reproductive table, or fertility schedule, is
an age-specific summary of the reproductive
rates in a population
• It describes reproductive patterns of a
population
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Table 53-2
population ecology
define and be able to use/interpret the
exponential population growth model
.
Exponential Growth

Exponential population growth is
population increase under idealized
conditions

Under these conditions, the rate of
reproduction is at its maximum, called the
intrinsic rate of increase
.

Equation of exponential population
growth:
dN 
rmaxN
dt
.

The J-shaped curve of exponential
growth characterizes some rebounding
populations
.
Fig. 53-11
population ecology
define and be able to use/interpret the
logistic population growth model
define and understand the terms K and r
.

Exponential growth cannot be sustained
for long in any population

A more realistic population model limits
growth by incorporating carrying capacity

Carrying capacity (K) is the maximum
population size the environment can
support
.
The Logistic Growth Model

In the logistic population growth model,
the per capita rate of increase declines as
carrying capacity is reached

We construct the logistic model by starting
with the exponential model and adding an
expression that reduces per capita rate of
increase as N approaches K
(K  N)
dN
 rmax N
dt
K
.
Table 53-3

The logistic model of population growth
produces a sigmoid (S-shaped) curve
.
population ecology
describe K-selection and r-selection

What sort of life tables and survivorship
curves would you expect for each type?

Give examples of organisms of each type.

If given a typical life history for an
organism be able to categorize it as Kselected and r-selected.
.

K-selection, or density-dependent
selection, selects for life history traits that
are sensitive to population density

r-selection, or density-independent
selection, selects for life history traits that
maximize reproduction
.
Fig. 53-13
Fig. 53-14
population ecology
List and describe six density-dependent
factors known to affect population
growth rates.
Describe how population cycles may be
linked between predators and their
prey.
.
Competition for Resources

In crowded populations, increasing
population density intensifies competition
for resources and results in a lower birth
rate
.
Territoriality

In many vertebrates and some
invertebrates, competition for territory
may limit density

Cheetahs are highly territorial, using
chemical communication to warn other
cheetahs of their boundaries
.
Fig. 53-17a
.
Fig. 53-17b
(b) Gannets
.
Disease

Population density can influence the
health and survival of organisms

In dense populations, pathogens can
spread more rapidly
.
Predation

As a prey population builds up, predators
may feed preferentially on that species
.
Toxic Wastes

Accumulation of toxic wastes can
contribute to density-dependent
regulation of population size
.
Intrinsic Factors

For some populations, intrinsic
(physiological) factors appear to regulate
population size
.
Human population history and future
Be sure that you understand figures 53.22-26.
What was industrial revolution and how did it affect
human population growth?
What is the demographic transition and how does it
affect human population growth?
What is the global carrying capacity for humans?
.
The Global Human Population

The human population increased relatively
slowly until about 1650 and then began to grow
exponentially
.
Fig. 53-23


To maintain population stability, a regional
human population can exist in one of two
configurations:

Zero population growth =
High birth rate – High death rate

Zero population growth =
Low birth rate – Low death rate
The demographic transition is the move
from the first state toward the second state
.
Birth or death rate per 1,000 people
Fig. 53-24
50
40
30
20
10
Sweden
Birth rate
Death rate
0
1750
1800
Mexico
Birth rate
Death rate
1850
1900
Year
1950
2000 2050

The demographic transition is associated
with an increase in the quality of health
care and improved access to education,
especially for women

Most of the current global population
growth is concentrated in developing
countries
.
Age Structure

One important demographic factor in
present and future growth trends is a
country’s age structure

Age structure is the relative number of
individuals at each age
.
Fig. 53-25

Age structure diagrams can predict a
population’s growth trends

They can illuminate social conditions and
help us plan for the future
.
Infant Mortality and Life Expectancy

Infant mortality and life expectancy at
birth vary greatly among developed and
developing countries but do not capture
the wide range of the human condition
.
Global Carrying Capacity

How many humans can the biosphere
support?
.
Estimates of Carrying Capacity

The carrying capacity of Earth for
humans is uncertain

The average estimate is 10–15 billion
.
Limits on Human Population Size

The ecological footprint concept
summarizes the aggregate land and
water area needed to sustain the people
of a nation

It is one measure of how close we are to
the carrying capacity of Earth

Countries vary greatly in footprint size
and available ecological capacity
.
Fig. 53-27

Our carrying capacity could potentially be
limited by food, space, nonrenewable
resources, or buildup of wastes
.
community ecology
Community ecology is the study of:
A biological community is:
.
community ecology
describe the following interspecific interactions
in general terms of the +/-/0 system

competition

predation

herbivory

parasitism

mutualism

commensalism
.
community ecology
define the terms
(ecological) niche
resource partitioning
character displacement
.
Ecological Niches

The total of a species’ use of biotic and
abiotic resources is called the species’
ecological niche

An ecological niche can also be thought of
as an organism’s ecological role

Ecologically similar species can coexist in a
community if there are one or more
significant differences in their niches
.
Resource partitioning

Resource partitioning is differentiation of
ecological niches, enabling similar species
to coexist in a community
.
Character Displacement

Character displacement is a tendency for
characteristics to be more divergent in
sympatric populations of two species than in
allopatric populations of the same two
species

An example is variation in beak size
between populations of two species of
Galápagos finches
.
Fig. 54-4
predation
Describe how these defenses can help
animals avoid predation:

camouflage

warning coloration

Batesian mimicry

Müllerian mimicry
.
mutualism
What is the difference between obligate
and facultative mutualism?
.
community ecology

What is symbiosis?

Which interspecific interactions are
types of symbiosis?
.
community ecology

What is keystone species and a
pivotal niche?
.
community ecology

What is a food web?

How do energetic
limits affect food
webs/chains?
.
community ecology
Describe

ecological
succession

primary
succession

secondary
succession
.
ecosystems
Diagram the biogeochemical cycles of

water

carbon

nitrogen

phosphorus
.
Fig. 55-14a
Fig. 55-14b
Fig. 55-14c
Fig. 55-14d
ecosystems
Describe how
biomagnification
(biological
magnification) of
a toxin works in
an ecosystem.
.
Fig. 55-20
How we almost killed ourselves:
the ozone hole story
Describe the importance of the ozone layer.
.
How we almost killed ourselves:
the ozone hole story
Describe how human activities led to
depletion of the ozone layer.
.
Fig. 55-24
How we almost killed ourselves:
the ozone hole story
Describe what humans have done about
the depletion of the ozone layer.
.
How we still might kill ourselves:
global warming
Describe the greenhouse effect and why
CO2 is called a greenhouse gas.
.
AP story
realclimate.org
Global cooling myth debunked
How we still might kill ourselves:
global warming
Describe how human activities
increase CO2 in the atmosphere,
the logic behind how that leads to
global warming, and the evidence
that global warming is occurring.
.
How we still might kill ourselves:
global warming
Describe what effects global warming
may have. What is the feed-forward
effect of thawing tundra?
Describe what humans have done about
global warming.
.
biodiversity
Define

ecosystem biodiversity

species biodiversity

genetic biodiversity
.
Fig. 56-3
biodiversity
Describe the value of biodiversity in

maintaining the global ecosystem and
biogeochemical cycles

providing unique resources such as food,
remediation, drugs

intrinsic value of biodiversity
.
Fig. 56-5
Fig. 56-6
Fig. 56-4
The sixth extinction
...or how we are killing lots of things (and perhaps
ultimately ourselves as well)

What is habitat loss and how is it affecting life on Earth today?

What are introduced species and how are they affecting life on
Earth today?

What is overexploitation and how is it affecting life on Earth
today?
.
Fig. 56-2
Fig. 56-7
Fig. 56-8
(a) Brown tree snake
(b) Kudzu
The sixth extinction
...or how we are killing lots of things (and perhaps
ultimately ourselves as well)

What is overexploitation and how is
it affecting life on Earth today?
.
Fig. 56-9
http://www.nmfs.noaa.gov/fishwatch
What is the sixth extinction?
What can humans do about it?
.