biol 1020: ecology - auburn university · 2014. 11. 18. · what is ecology? ecology is the...

ECOLOGY

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What is ecology?

Ecology is the scientific study of interactions between ___________

term ecology comes from the Greek oikos, _______, and logos, to study

http://www.auburn.edu/academic/classes/biol/1020/bowling/

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biotic and abiotic factors

What are biotic factors? Give examples.

What are abiotic factors? Give examples.


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climate

What is climate?

What abiotic factors are the major components of climate?


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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

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climate

What effects do seasons have on climate?

Describe what causes seasons; include the terms solstice and equinox in your description.


Fig. 52-10c

March equinox

60ºN

30ºN

0º (equator)

30ºS June solstice

Constant tilt of 23.5º

September equinox

December solstice

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What are biomes?


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aquatic biomes

List the major aquatic biomes and their defining physical features.

define the following:

photic zone

aphotic zone

benthic zone


Fig. 52-16

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

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

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

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

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

52_18FlappingGeese_SV.mpg

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

Fig. 52-18h


Oceanic Pelagic Zone

• The oceanic pelagic biome is a vast realm of

open blue water, constantly mixed by wind-

driven 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

52_18SharkEatSeal_SV.mpg

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 Video: Clownfish and Anemone

52_18CoralReef_SV.mpg

52_18ClownfishAnemone_SV.mpg

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


• 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 Video: Tubeworms

52_18HydrothermalVent_SV.mpg

52_18Tubeworms_SV.mpg

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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

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terrestrial biomes

List the major terrestrial biomes and their characteristic vegetation types and climate.


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terrestrial biomes


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

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

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

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

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

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

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


• The conical shape of conifers prevents too

much snow from accumulating and breaking

their branches

• Animals include migratory and resident birds,

and large mammals

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


• Mammals, birds, and insects make use of all

vertical layers in the forest

• In the Northern Hemisphere, many mammals

hibernate in the winter

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


• 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

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population ecology

Population ecology is the study of populations in relation to __________

A population is:


density

dispersion

range


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population ecology

How does the mark-recapture method to estimate population size work?

Include the formula and definition of the terms in the formula.


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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

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

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

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

Table 53-2

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population ecology

define and be able to use/interpret the exponential population growth model


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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


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Equation of exponential population growth:

dN dt

rmaxN


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The J-shaped curve of exponential growth characterizes some rebounding populations


Fig. 53-11

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population ecology

define and be able to use/interpret the logistic population growth model

define and understand the terms K and r


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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


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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

dN dt

(K N)

K rmax N


Table 53-3

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The logistic model of population growth produces a sigmoid (S-shaped) curve


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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 K-selected and r-selected.


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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

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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.


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Competition for Resources

In crowded populations, increasing population density intensifies competition for resources and results in a lower birth rate


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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


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Fig. 53-17a


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Fig. 53-17b

(b) Gannets


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Disease

Population density can influence the health and survival of organisms

In dense populations, pathogens can spread more rapidly


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Predation

As a prey population builds up, predators may feed preferentially on that species


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Toxic Wastes

Accumulation of toxic wastes can contribute to density-dependent regulation of population size


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Intrinsic Factors

For some populations, intrinsic (physiological) factors appear to regulate population size


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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?


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The Global Human Population

The human population increased relatively slowly until about 1650 and then began to grow exponentially


Fig. 53-23

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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


Fig. 53-24

1750 1800 1900 1950 2000 2050

Year

1850

Sweden Mexico

Birth rate Birth rate Death rate Death rate

0

10

20

30

40

50 B

irth

or

de

ath

ra

te p

er

1,0

00

pe

op

le

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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


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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


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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


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Global Carrying Capacity

How many humans can the biosphere support?


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Estimates of Carrying Capacity

The carrying capacity of Earth for humans is uncertain

The average estimate is 10–15 billion


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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

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Our carrying capacity could potentially be limited by food, space, nonrenewable resources, or buildup of wastes


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community ecology

Community ecology is the study of:

A biological community is:


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community ecology

describe the following interspecific interactions in general terms of the +/-/0 system

competition

predation

herbivory

parasitism

mutualism

commensalism


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community ecology

define the terms

(ecological) niche

resource partitioning

character displacement


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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


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Resource partitioning

Resource partitioning is differentiation of ecological niches, enabling similar species to coexist in a community


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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

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predation

Describe how these defenses can help animals avoid predation:

camouflage

warning coloration

Batesian mimicry

Müllerian mimicry


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mutualism

What is the difference between obligate and facultative mutualism?


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community ecology

What is symbiosis?

Which interspecific interactions are types of symbiosis?


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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?


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community ecology

Describe

ecological succession

primary succession

secondary succession


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ecosystems

Diagram the biogeochemical cycles of

water

carbon

nitrogen

phosphorus


Fig. 55-14a

Fig. 55-14b

Fig. 55-14c

Fig. 55-14d

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ecosystems

Describe how biomagnification (biological magnification) of a toxin works in an ecosystem.


Fig. 55-20

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How we almost killed ourselves:

the ozone hole story

Describe the importance of the ozone layer.


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Describe how human activities led to depletion of the ozone layer.


Fig. 55-24

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Describe what humans have done about the depletion of the ozone layer.


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How we still might kill ourselves:

global warming

Describe the greenhouse effect and why

CO2 is called a greenhouse gas.


realclimate.org Global cooling myth debunked

AP story

http://www.realclimate.org/

http://www2.sunysuffolk.edu/mandias/global_warming/global_cooling.html

http://www.foxnews.com/story/0,2933,569639,00.html

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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.


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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.


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biodiversity

Define

ecosystem biodiversity

species biodiversity

genetic biodiversity


Fig. 56-3

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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

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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

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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

http://www.nmfs.noaa.gov/fishwatch

.

What is the sixth extinction?

What can humans do about it?


biol 1020: ecology - auburn university · 2014. 11. 18. · what is ecology? ecology is the...

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