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AP Environmental Science: Chapter 8 Studying Forest Succession
Background: Ecologists collect data about succession in different communities in different ways.
One of the techniques used on prairies and in forests is called the quadrat.
A quadrat is nothing more than four stakes with twine or clothesline set out in a square or
rectangle of exact dimensions. Ecologists collect data inside the quadrat. On a prairie where
plants grow very close together, ecologists may set up a quadrat enclosing only one square
meter. In a forest they may find it more useful to set up quadrats of 100 square meters (100 m\
If they are studying shrubs or herbs, they may use rectangles of 10 square meters. Sometimes
they will set up both kinds of quadrats in the same area. The line drawing on the following page
will give you an idea of how a quadrat is set up. The canopy consists of the trees that form the
uppermost branchy layer of the forest. The understory includes all other lower trees and shrubs.
Directions for compl~ting the problem:
On the pages following Fig. AO (A model), you will find a series of five figures showing
five different quadrats.-Each quadrat is an example of what you might find in a forest in southern
Indiana (or IlIinois)jf you studied that forest over a period of 45 years. The first quadrat (Fig. AA)
is a seedling countin afield after it had been taken out of cultivation for 5 years. The next t'M>
quadrats (Figs. AS and AC) are canopy and understory quadrats 20 years after cultivation
stopped. The last t'M> quadrats (Figs. AD and AE) are canopy and understory quadrats 50 years
after the field was abandoned. With three of these quadrats you will find air and soil temperature
data.
Study each quadrat and figure out and record the total populations in each. Also
compute the percentages for each as was done in the model (Fig. AO). When you have collected
all the data, you should be able to draw some important conclusions about this kind of
succession.
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Succession
Bare Rock to Forest Soil
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A. Bare Rock Exposed to
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B. Rocks Become CoIO!'ized
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_D. Grasses and flowering
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E. Woody Shrubs Begin Replacing
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f. A forest Eventually Grows
Where Bare Ruck Once Existed
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Un.dastanding Basic Ecological Umapts
{Problem Noo JJ continued]
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Used for Canopy
MKI Understory
Used for
shrubs and
Herbs
Trees
(10 x 10 M)
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Ecologists use a quadrat map or worksheet to record exactly where the trees in the
quadrat are and what kinds there are. From this record they can work out the total
populations that exist in the quadrat. From this information they can draw conclusions
about the forest's characteristics in general. The ecologists may study several quadrats
and use averages to help them obtain the most accurate information about the makeup
offorest populations. Fig. AO (A Model) on page 72 is an example ofone forest quadrat,
Study this model.
In the model located on page 72 the ecologists were studying the canopy trees in a
forest 100 years old. Each tree species has its own symboL The records show that there
were six trees (made up ofthree species) in the canopy ofthis quadrat, These tree species
are typical oftrees found in a healthy older forest in southern Indiana or Illinois. Use the
records in Fig. AO to calculate the population densities of the canopy trees. Do this
before going on.
(continwd)
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Understanding Basic Ecological Concepts
(Problem No. 13 continued}
Figure AO-A Model
Tree Species Distributioa in a 100M" Quadrat
.FaeId in Southern IDdiana Abandoned 100 Yean
Canopy Species:
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Percent of
How Many
Key: Shagbark Hickory
Red Oak
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Total
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16.67
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Yellow Chestnut Oak
Total(%)
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33.33
3
50.00
6
100.00
Succ.asion
Note: The figures in the table on page i2 were determined by counting the number of
each species in the quadrat, This number is recorded in the blank to the right of each
species' name. When this column is complete, the total number is obtained by adding this
column. A percentage of th e total for each species is then calculated. These percentages
are added together to check the calculation.
(Problem No. l l amtinued]
FigureAA
Tree Species Distribution in a lOOW QU3drat
Field in Southern Indiana Abandoned 5 Years
Seedlings .Present:,'-
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How Many
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Percent ofTotal (%)
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Persimmon.
Total
June 15-11:00 A.M.
Air Temperature
Soil Surface Temperature
Sunny Day
27 Degrees C (80 0 F)
35 Degrees C (95 0 F)
. }.
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Urukrstanding Basic Ecological Concepts
(Problem No. 13 continued)
FigureAB
Tree Species Distribution in a 100M2 Quadrat
Field in Southern Indiana Abandoned 20 Years
Canopy Species:
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How Many
Key: Winged Elm
PercentofTo~(~)
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Persimmon.
Sassafras
l:l
Total
June 15-11:00 A.M.
Air Temperature
Soil Surface Temperature
Sunny Day
24 Degrees C (75° F)
29 Degrees C (840 F)
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Sucassion
(Problem No. 13 continued]
FigureAC
Tree Species Distribution in a lOOW Qu:adrat
Field in Southern Indiana Abandoned 20 Years
Understory Species:
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Understanding Basic ErologUal Uinaprs
(Problem No. 13 continued)
Figure AD
Tree Species Distribution in a lOOW Quadrat
Field in Southern IDdiaoa Abandoned 50 Yeus
Canopy Species:
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0
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0
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White Ash ()
Persimmon.
Winged Elm
0
Bitternut Hickory
0
WhiteOak ~
Total
June 15-10:00 A.M.
Air T ernperature
Soil Surface T emperarure
Sunny Day
21 Degrees C (700 F).
20 Degrees C (680 F)
Percent of Total (%)
.,
(Problem No. 13 continued]
Figw-eAE
Tree Species Distribution in a lOOMl Quadrat
Field in Southern Indiana Abandoned 50 Years
. Understory Species:
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Key: Bitternut Hickory @
Shagbark Hickory
White Oak
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Yellow Chestnut Oak
Red Oak
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Total
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(Problnn No. 13 amtinued)
Specific Tasks for This Problem
1. The 5-year quadrat you studied (Figure AA) represents a part of a field where
cultivation was discontinued only 5 years ago. Hypothesize why so few seedlings
appear in this quadrat,
2. Compare the understory quadrats (Figures AC and..AE) and the canopy quadrats
(Figures AB and AD). Place a check in the appropriate space below indicating
whether there are more trees in the understory or in the canopy at any given time.
UNDERSTORY
CANOPY
How can you explain this observation?
3. Using the quadrat figures. provide the following information:
a.. List the tree species that disappeared from the understory between 20 and 50
years.
b. List the tree species that appeared in the understory between 20 and 50 years.
(amtintud)
If
Sucussion
(Problem No. 13 continued)
Specific Tasks for This Problem (continued)
c. Compare these two lists and note the differences below.
4. List the tree species that are found in the canopy at 50years.
Using the 50-year understory data (Figure AE). predict which of the trees you listed
above will not be in the canopy at 100 years. What is the basis for your prediction?
PREDICTION:
REASON:
_
5. There is a difference of 6° C in air temperature and of 15° C in soil surface tempera­
ture between the 5-year quadrat: and the 5O-year quadrat, }\'hat might account for this
difference?
6. A climax forest is a forest in which succession has. for the most pan. stopped. One
kind of climax forest is called an oak-hickory climax because oaks and hickories are
the predominant trees in it. Another kind is a beech-maple climax forest. Using
Figures AD and AE.. predict what kind of climax forest will be produced" here. What
are the reasons for your prediction?
('continued}
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Undaltanding Basic Ecological Concepts
(Problem No. 13 continued]
Specific Tasks for This Problem (continued)
PREDICrED CUMAX FOREST lYPE:
REASON:
---­
7. From the data you have gathered concerning the various quadrats. predict whether
persimmon or sassafras trees would ever be commonly found in a climax forest, Give
,the reasons for your prediction.
PREDICnON:
.:...-_-:...-
_
REASON:
_
8. Are there fewer or more trees in the canopy of Figure AO than the canopy ofFigure
AD? Check the appropriate answer (please note the age of each canopy):
MOREINAO
LESS IN AO
--­
Hypothesize why this might be the case.
9. After studying the data you have (including Figure AO). list the events (changes) that
take place during succession in a southern Indiana forest studied from the time that
it was abandoned until it is 100 years old. Do this below.
/3
APES ACTIVITY: BIODIVERSITY - WHY IS IT IMPORTANT?
When a habitat is very diverse with a variety of different species, it is much healthier and more stable.
One of the reasons for this is that disease doesn’t spread as easily in a diverse community. If one species gets a
disease, others of its kind are far enough away (due to the variety of other organisms) that disease is often
stopped at the one or two individuals.
Simulation #1
1) Each student receives a card marked with D to represent Douglas Firs.
2) Each person is to meet three other people and write their names on the card.
3) All are to remain standing after they write down the names.
4) The teacher symbolizes the disease and will touch one of the students. That person will sit down
(because he or she is “dead”) and read the names on his/her card. As the names are read, those
students sit as well because they have been “touched” by the disease.
5) Ask another one of those sitting (dead) to read the names on their card, and all those students
named will sit. Continue until all those sitting have read the names on their cards.
6) Number of students left standing: ________________
Simulation #2
1) Each student will receive a card that is marked with a letter that represents a particular species of
tree: 2 with D for Douglas Firs, the rest with other letters: N for Noble Fir, C for Western Red Cedar,
M for Vine Maples, H for Western Hemlocks, W for White Fir, L for Lodge Pole Pine, WP for
Western White Pine, B for Bigleaf Maple, WD for Western Dogwood.
2) Repeat steps 2-6 as for Simulation 1. This time, only those students that are the same variety as the
diseased tree that touched them will sit. Different variety trees don't sit (don't die) even if they are
touched by a diseased tree.
3) Number of students left standing: _______________
FOLLOW-UP QUESTIONS
1) What does biological diversity mean?
2) Why didn't all the different trees get the disease?
3) Why didn't the disease spread as fast among the Douglas Firs in Simulation #2 as it did in Simulation
#1?
4) In which forest would you need to use more chemicals to control disease: the Douglas Fir forest or the
more diversified, old growth forest? Why?
5) Summarize what this simulation symbolized.
6) Which forest would have more diversity of wildlife? Why?
7) If you cut down the variety in a piece of forest you owned and replanted with one type of tree, what
will happen too much of the wildlife that was adapted to the forest? (Hint: they cannot just move
elsewhere. If other habitats are good, they will probably be near carrying capacity already.)
8) Will this fate happen to all the wildlife? Explain.
9) Many species can only live/reproduce in one type of forest. The spotted owl is an example: it can only
live and successfully reproduce in old growth forests (big, old cedars, hemlocks, etc.). If these old growth
forests are cut down, it’s unlikely this owl will survive. Environmentalists call it an “indicator species.”
What does this mean?
Why be concerned about one species?
10) Growing one plant, as is the case of growing only Douglas Fir, is called monoculture.
Give examples of monocultures a) in your home and b) in agriculture.
11) Why would you need to use more insecticides in monoculture? Is this good or bad?
12) If you wanted to help wildlife, what would you do with regards to the landscaping of your own home?
Name ________________________
Cane Toad Essay
Background:
We have discussed in class the unique ecological problem caused by the countless exotic species which
have been introduced, either by accident or on purpose, into the United States. One of the most unique species
introduced into Australia is the Cane Toad. You have watched a video on this species and we have discussed
its introduction in class.
Assignment:
You are to write a formal ecological recommendation to the Australian government explaining how they
can best eliminate the Cane Toad from their soil. The ideas presented in your recommendation must be based
on the facts stated in the video and other reliable sources (not other students, this is an independent assignment).
They must also be based on sound biological and ecological principles. The required length is 2-3 pages, 12
font, double spaced, 1 inch margins. This recommendation is due on _____________
Grading:
A- Detailed background information on introduction of the Cane Toad
1-10 pt _______
B- Review of ecological/economical damage caused by the Cane Toad
1-10 pt _______
C- Two different recommendations to the Australian government
1-10 pt _______
D- Biological/ecological soundness of your recommendations,
(discussion of drawbacks to recommendations)
E- Grammar, spelling, word usage, paragraph structure and neatness
1-10 pt _______
Notes from Video:
1-10 pt _______
Name _____________________________
Insert the Miller CD and click on:
Chapter 8
1. Species diversity by latitude
-What is the latitude of the North Pole? _______________
-At what latitude are ants and breeding birds’ species richness highest? ____________
2. Area and distance effects interaction
-What affects the rate at which new species immigrate in and existing species go extinct?
__________________________________________________________________
-What type of island has the highest immigration rate, lowest extinction rate and highest number of
species? ___________________________________________________________
3. How species interact interaction
-What two types of species interactions does one organism benefit at the expense of the other?
____________________, __________________
4. Gause’s competition experiment interaction
-What was the result when P. caudataum and P. Aurelia are grown together? _________________
___________________________________________________
5. Succession interaction
-What event left bare rock in the primary succession graphic? _____________________
-What succession type is more common? __________________
-How long approximately would natural restoration take of plant communities on an abandoned farm?
_________________________
6. Resource depletion and degradation interaction
-What is the only continent where the average woman has 6 or more children? _________________
-________ % of the Pacific Northwest coastal forest has been cut down
-What have mangroves been cleared for in Ecuador? _________________________________
-How many square kilometers of rain forest are destroyed in the Amazon basin each year?
_______________
-What has caused flooding in Bangladesh? ___________________________________
-How many pandas are left in the wild? _____________________
-Why is the snow leopard near extinction? _________________________________________
-What are the two threats to the Asian elephant? __________________________________________
-What happened to the golden frog of Costa Rica? _________________________________________
_______________________________
-What industry has an effect on the spotted owl? _______________________
-What happened to the black-footed ferret? _______________________________________________
-When was the peak of fish catches in the North Atlantic? _____________ How much has the industry
dropped off since? ________________
-What is the one of the world’s most polluted country? _________________
-What was once the world’s 4th largest freshwater lake, what happened to it? ______________________
_____________________________
Chapter 22
(Review humans affect biodiversity interaction and habitat loss and fragmentation interaction)
Chapter 23
1. Biodiversity hot-spots interaction
-Choose 5 hot-spots, for each give the name of and the countries it is located in, why it’s biologically
important and what is happening to it.
1. Hot-spot ______________________, Located in: _____________________________________
Important because: ______________________________________________________________
What is happening to this hot-spot? _________________________________________________
______________________________________________________________________________
2. Hot-spot ______________________, Located in: _____________________________________
Important because: ______________________________________________________________
What is happening to this hot-spot? _________________________________________________
______________________________________________________________________________
3. Hot-spot ______________________, Located in:______________________________________
Important because: ______________________________________________________________
What is happening to this hot-spot? _________________________________________________
______________________________________________________________________________
4. Hot-spot ______________________, Located in: _____________________________________
Important because: ______________________________________________________________
What is happening to this hot-spot? _________________________________________________
______________________________________________________________________________
5. Hot-spot ______________________, Located in: _____________________________________
Important because: ______________________________________________________________
What is happening to this hot-spot? _________________________________________________
______________________________________________________________________________
Chapter 8 Community Ecology: Structure, Species Interactions, Succession and Sustainability
Flying Foxes: Keystone Species in Tropical Forests
1. Durian- prized fruit in SE Asia, depend on flying foxes to pollinate the fruit (mutualism); Due to hunting
and deforestation flying foxes are listed as endangered; without ff‟s there will be a decline in bananas,
medicine, timber, dyes, and biofuels
8-1 Community Structure: Appearance and Species Diversity
What is community structure?
1. Physical appearance, species diversity (richness), species abundance, niche structure (# of niches)
How do communities differ in physical appearance and population distribution?
1. Differ based on terrestrial and aquatic biomes
2. ________________- transition zones or sharp edges between a forest and an open field leads to edge
effects-changes in sunlight, temperature, wind, etc.
a. Pheasants, white-tailed deer are more plentiful in edge and ecotones between forests and fields
b. More ecotones due to habitat fragmentation makes species more vulnerable to environmental stress
Where is most of the world‟s biodiversity found?
1. Coral reefs, tropical rain forests, deep sea vents, and large tropical lakes;
2. Biodiversity affected by latitudes, depth, pollution, precipitation, elevation
What determines the number of species on islands?
1. Affected by size of the island and how far it is from the mainland (a smaller island has less resources
and therefore less diverse habitats)
8-2 General Types of Species
What different roles do various species play in ecosystems?
1. Different labels- native, nonnative, indicator, keystone may be more than of these types
How can nonnative species cause problems?
1. Native species- normally live and thrive in a particular ecosystem
2. Nonnative- or alien, introduced by humans (ie. Killer bees of Africa)
Why are amphibians vanishing?
1. Since 1980, hundreds of species of amphibians have been disappearing; frog deformities in higher
numbers; 25% of all amphibian species are extinct, endangered or vulnerable
2. Main causes- habitat loss, prolonged drought, pollution, increase in uv light, increased parasitism,
overhunting, epidemic diseases, and introduction of nonnative species
What are indicator species?
1. Species that serve as early warning of damage to a community or an ecosystem; examples- migratory
song birds, trout species, and amphibians
What are keystone species?
1. Species in an ecosystem that are much more important than their abundance or biomass suggests due to
strong interactions with other species including making habitat modifications
2. Examples
a. Elephants- uproot trees to promote growth of grasses and accelerates nutrient cycling rates
b. Beavers- dams change a fast-moving stream into a pond that attract more fish, birds, and other
mammals
c. Top predators- wolves, lions, alligators and great white sharks all exert a stabilizing effect on
ecosytem
8-3 Species Interactions: Competition and Predation
How do species interact? An overview
1. May be harmed, benefitted or unaffected by other species
How do members of the same species compete for resources?
1. ____________________ competition- between the same species- use of territory among males
How do members of different species compete for resources?
1. Interspecific competition- different species can share resources if abundant, fundamental niches overlap;
if there is too much overlap, one species may migrate to another area, shift its feeding habits or suffer a
sharp population decline/go extinct
2. Interference competition- one species may limit another‟s access to resources (territorial hummingbirds
chase away other hummingbird species)
3. Exploitation competition- competing species have equal access to a specific resource but differ in how
fast they exploit it
Why should we care about alligators?
1. Keystone species- dig deep depressions to lay eggs, once eggs hatch, depression collects fresh water that
serve as a refuge for other aquatic animals- nesting/feeding site for heron, also a key predator of gar a
predatory fish that allow bass and bream to flourish
What is the competitive exclusion principle?
1. Two species needing the same resource cannot coexist indefinitely in an ecosystem (paramecium
experiment; bison arrival in North America led to Mammoth and other large fauna extinction?)
How have some species reduced or avoided competition?
1. __________________________- dividing up of scarce resources so that different species may use them
at different times, ways, and places.
2. Each competing species occupies a realized niche (a small part of fundamental niche) a very specialized
niche. Ex: hawks and owls hunt the same prey- one at night and one during the day, warbler species hunt
for insects in different heights of trees
How do predator and prey species interact?
1. Predator benefits, prey is harmed but may help the overall prey population- getting rid of sick, weak and
aged members- improves the genetic stock
Why are sharks important species?
1. Very important predator that keeps marine fish and mammal prey species regulated; human fear of
certain shark species is exaggerated (every human killed by a shark, 1 million shark are killed annually)
sharks are also killed for their fins (soup delicacy), liver, meat, hide and jaws and bycatch
2. Sharks highly effective immune system- no viruses, bacteria or cancer could be studied and used
How do predators increase their chances of getting a meal?
1. Pursuit and ambush- speed (cheetah), keen eyesight (eagle), cooperation (lions and wolves)
How do prey defend themselves against or avoid predators?
1. Speed, keen sense of smell and sight, protective shells, thick bark (sequoia), spines and thorns,
camouflage,
2. Chemical warfare- use of poison (ivy, oak); foul smelling (skunks, stinkbugs); bad tasting (monarch
butterflies)
3. Evolved warning colors- poison dart frogs, monarch butterflies, mimicry- monarch looking viceroy
butterfly
4. Behavioral- prey species make themselves look bigger (blowfish, peacocks); protection in numbersschools of fish, herds of antelope and flocks of birds)
8-4 Symbiotic Species Interactions: Parasitism, Mutualism, and Commensalism
What is symbiosis?
1. Intimate relationship between two species, 3 types- parasitism, mutualism, commensalism
What are parasites, and why are they important?
1. Parasitism- One species feeds on part of another organism (the host); may gradually weaken host but
rarely kills (tapeworms, ticks, mosquitoes) usually benefits biodiversity keeping other populations in
check
How do species interact so that both species benefit?
1. Mutualism- both species benefit- pollination, rhizobium bacteria convert nitrogen in a form useable by
plant roots; coral reefs and zooxanthellae; bacteria in human stomach; clownfish and sea anemones
How do species interact so that one benefits but the other is not harmed?
1. ___________________- one species benefits while the other is unharmed- redwood sorrel benefits from
the shade of redwood trees, orchids attach themselves to the branches of large trees in tropical forests
8-5 Ecological succession: Communities in Transition
How do ecosystems respond to change?
1. Ecological succession- species colonize an area, there population becomes more numerous where other
species become less numerous and even disappear
a. Primary succession- gradual establishment of biotic communities on lifeless ground
b. Secondary succession- more common type, involves reestablishment of biotic communities in an
area where soil and other biotic community is already present
What is primary succession? Establishing life on lifeless ground
1. No soil, bare rock from a volcano or retreating glacier, abandon highway/parking lot; takes 100s to
1,000s of years to produce fertile soil by hardy pioneer species (lichens and mosses) that are gradually
replaced by perennial grasses, herbs which eventually allows for midsuccessional plant species (grasses,
low shrubs), finally late successional species (trees) becomes a complex forest community
What is secondary succession?
1. The natural community of organisms has been disturbed, removed or destroyed but soil sediments
remain (abandon farmland, burned/cut forests, heavily polluted streams) as plants change so do the
animals and decomposers
How do species replace one another in ecological succession?
1. Facilitation- one set of species makes an area suitable for species with different niche requirements; i.e.
legumes add nitrogen to soil making it more suitable for later species
2. _________________- early species hinder the establishment and growth of other species; ie. Plants
release toxic chemicals that reduce competition
3. Tolerance- last successional plants are largely unaffected by earlier successional plants
How do disturbances affect succession and species diversity?
1. A disruption in an ecosystem caused by natural (tsunami, volcano, forest fire) or human-caused
(deforestation) will usually convert it to an earlier stage of succession
2. Intermediate disturbance hypothesis- communities that experience fairly frequent and moderate
disturbances have the greatest species diversity
How predictable is succession, and is nature in balance?
1. Climax community- dominated by a few long-lived plant species and in balance with its environment;
hard to predict succession; reflects ongoing struggle by different species for resources
8-6 Ecological Stability and Sustainability
What is stability?
1. Stability is maintained only by a constant dynamic change in response to changing environmental
conditions
a. Inertia- ability of a living system to resist being disturbed or altered
b. Constancy- ability of a living system such as a population to keep reasonable numbers based on
resources
c. __________________- ability of a living system to bounce back after an external disturbance that is
not too drastic
Does species diversity increase ecosystem stability?
1. Depends on the ecosystem: grasslands are less diverse than forests, have low inertia due to burning
easily but have high resilience to grow back due to root system, only way to destroy grasslands is to
plow through roots or overgraze
Why should we bother to protect natural systems? The Precautionary principle
1. By disrupting ecosystems, we disrupt ecosystem services that support all life and economies
2. Even if don‟t fully understand all cause and effect relationships scientifically, we should take
precautionary measures to prevent harm; “look before you leap”
Chapter 22 Sustaining Wild Species
The Passenger Pigeon: Gone Forever
1. Once the most common bird in North America, became extinct within a few decades due to uncontrolled
commercial hunting and loss of habitat
22-1 Human Impacts on Biodiversity
What major factors affect biodiversity?
1. Physically diverse habitat, moderate disturbances, little variation in resources, middle stages of
succession and evolution
How have human activities affected global biodiversity?
1. __________- Habitat fragmentation, Invasive Species, human Population, Pollution and Overharvesting
How can we reduce biodiversity loss?
1. Preserve/restoring ecosystems
22-2 Species Extinction
What are three types of species extinction?
1. Local extinction- species no longer found in a particular area, Ecological extinction- species no longer
plays an ecological role in communities due to too few members, Biological extinction- no longer found
anywhere on Earth, gone forever
What are endangered and threatened species?
1. Endangered- has so few individuals, that species could become biologically extinct; Threatened- still
abundant in its natural range but declining in number and may become extinct
How do biologists estimate extinction rates?
1. Evolutionary biologists estimate 99.9% of all species that ever existed are extinct due to background
extinction rate, mass extinctions, and extinction spasms (mass extinctions in less than 1,000 years)
2. Mass extinctions can promote biodiversity- adaptation radiation- 5 million years, based on fossil record
for biological diversity to rebuild after a large loss
3. Estimating species extinction rate are based on observations, i.e. if 90% of habitat is removed, 50% of
all species will disappear; using population viability models through computer simulations and
minimum dynamic area
What effects are human activities having on extinction rates?
1. Before humans, background extinction was .0001% per year, humans have increased it to .1% (1000x
more); amounts to 5,000 species per year on a conservative basis; 50% of all species could be eliminated
by 2100
Bats are getting a bad rap
1. Vulnerable to extinction- reproduce slowly, and live in large groups (White Nose Syndrome); play an
important niches as pollinators and pest reducers (insects); bats need to be viewed as an ally not as
enemies
22-3 Why Should We Care About Biodiversity?
Why preserve wild species and ecosystems?
1. It will take 5 million years for a speciation to rebuild biodiversity; they have instrumental valueusefulness to us; intrinsic value- they exist, regardless of whether they have any usefulness to us
What are the instrumental values of biodiversity?
1. Economic goods-provide foods, fuel, fiber, lumber, paper, medicine
a. 40% of all medicines and 805 of the top 150 prescription drugs were derived from living organisms
in mainly tropical developing countries
1) World‟s flowering plants have alkaloids, a class of natural chemicals that are potent agents
against cancer and other diseases, i.e. Pacific yew- ovarian cancer, Cinchona- malaria treatment,
Rosy Periwinkle-, Hodgkin‟s disease and lymphocytic leukemia
2. Ecological Services- pollination, soil formation, nutrient recycling, pest control, climate regulation,
flood control, clean water, waste decomposition, clean air, etc.
3. Information- genetic information allows us to produce new foods, and vaccines
4. Recreation- Nature photography, nature walks, bird-watching; i.e. American spend 3x more to watch
wildlife than watching movies/professional sporting events
a. _________________- $500 billion industry; i.e. one male lion generates $515,000 in tourist dollars
over 7 years in Kenya but only $1,000 if killed for its skin
5. Nonutilitarain values- existence- we find value knowing that a redwood forest even we don‟t ever see
one; aesthetic- nature‟s beauty; bequest- people are willing to pay to protect natural capital
What is the total economic value of the earth‟s biodiversity?
1. Ecologists and economists have attempted to place a monetary value to alert people to the value of
nature
What is the economic value of the earth‟s ecological services?
2. Ecologists estimate- $36 trillion, close to $41 million-annual world product; could be too low of an
estimate
What is the intrinsic value of biodiversity?
1. Each species is said to have inherent value (a right to exist that is unrelated to their use to humans);
2. According to intrinsic view, humans have an ethical responsibility to protect species from human
threats; basis message from biologists: biodiversity matters and should not be depleted/degraded by our
activities
Biophilia
1. An inherent affinity for the natural world, prefer natural landscapes over urban, more people visit zoos
and aquariums than all pro sports combined
22-4 Extinction Threats from Habitat Loss and Degradation
What is the role of habitat loss and degradation?
1. Greatest threat to species is habitat loss; temperate biomes hit hardest by development
What is the role of habitat fragmentation?
1. Divided into a patchwork of isolated areas causing decreased population, increased surface area or edge,
making some species more vulnerable to predators, competition and abiotic factors, and a creation of
barriers that limit a species‟ ability to disperse, eat, or find a mate
22-5 Extinction Threats from Nonnative Species
What harm do nonnative species cause in the U.S.?
1. #2 reason for species extinction, cost US ~$137 billion per year
The plight of migrating birds
1. Significant drops in certain species can be linked to logging of tropical forests, habitat fragmentation in
temperate biomes- grassland and forests, flying into tall structures
2. Serve as an indicator species and important ecological roles- pollinators, predators, spread plant seeds
What is the role of deliberately introduced species?
1. Good-corn, wheat, rice, poultry, cattle, and other food crops supply 98% of U.S. food supply
2. Some not so good- kudzu vine, European wild (feral) pigs, feral cats
Deliberate introduction of the kudzu vine
1. Imported from Japan in the 1930s to help control erosion, could be used a source of tree-free paper
What is the role of accidentally introduced species?
1. Argentine fire ant introduced by lumber or soil-containing ballast water of cargo ships; usually decimate
native populations of ants; other examples- brown tree snake, Asian tiger mosquitoes and long-horned
beetle
Solutions: What can be done to reduce the threat from nonnative species?
1. Prevention is key solution, almost impossible to eliminate once a nonnative species is established; pass
international laws, require ships to discharge ballast/replace with salt water before entering port
The termite from hell
1. Formosan termite- most aggressive of all termite species; very large nests 73x larger than native
termites, consume wood 9x faster
22-6 Extinction Threats from Hunting and Poaching
What is the role of commercial hunting and poaching?
1. Organized crime has moved in because so profitable (2nd only drug smuggling); demand comes from
wealthy collectors; a live gorilla: $150,000, a panda pelt- $100,000, a chimpanzee: $50,000
2. Bushmeat- important source of protein also demand in international markets
Killing invading species and saving shipping companies money
1. By pumping nitrogen gas into ballast tanks, it removes all dissolved oxygen, will also save ships $$
(painting and maintenance costs) and eliminates invasives
Case Study: How should we protect elephants from extinction?
1. A ban on elephant ivory has increased demand from walruses and hippos; CITES voted to allow a onetime sale of elephant ivory from culled and natural death- many oppose this because it drives demand
22-7 Other Extinction Threats
What is the role of predators and pest control?
1. People try to exterminate pest species without looking at consequences; i.e. 99% of prairie dogs were
wiped out because livestock would break their legs on their burrows- has nearly wiped out prairie dog
predator- black-footed ferret
What is the role of the market for exotic pets and decorative plants?
1. High prices for smuggling rare species leads to huge profits but not as much if left in wild; i.e. a
threatened hyacinth macaw from Brazil will cost $10,000, left in the wild it is worth $165,000 in tourist
revenue
What are the roles of climate change and pollution?
1. Some species may not be able to adapt quickly enough- high altitude and boreal ecosystems
22-8 Protecting Wild Species from Depletion and Extinctions: The Research and Legal Approach
How can bioinformatics help protect biodiversity?
1. The applied science of managing, analyzing, and communicating biological information; Species 2000internet based research project to name all known species on Earth
How can international treaties protect endangered species?
1. CITES- Convention on International Trade of Endangered Species; difficult to enforce, not every
country signed on
How can national laws help protect endangered species?
1. Lacey Act of 1900- no transport of live/dead animals across state lines; Endangered Species Act 1973
How can private landowners be encouraged to protect endangered species?
1. National Assoc. of Homebuilders suggest planting crops, plowing fields to prevent native vegetation and
endangered species from occupying fields, clearing forests, and burning vegetation to make it unsuitable
for E.Species.
2. In 1999, 2 new approaches- safe harbor: land owners voluntarily agree to restore habitat face less
restrictions and voluntary candidate conservation agreements- ease of additional restrictions on land
Should the Endangered Species Act be weakened?
1. Causes severe economic losses, attempts to protect E.S. on private land voluntary, making it harder to
list an E.S., Sec. of Interior can allow a species go extinct without trying to save it, states can be exempt
Should the Endangered Species Act be strengthened?
1. Need to protect more plants and invertebrates; give private landowners more incentives- (tax breaks)
Should we try to protect all endangered and threatened species?
1. Because of limited funds, not all species can be saved; emphasize species that play key roles, more
tolerant of varying abiotic changes; criticism- we don‟t fully understand all species, too selective an
approach
Accomplishments of the Endangered Species Act
1. Based on successes- $126 million a year, each taxpayer- $.44 a year= Shoestring budget!!!!
22-9 Protecting Wild Species from Depletion and Extinction: The Sanctuary Approach
How can wildlife refuges and other protected areas help protect endangered species?
1. 524 refuges- mainly wetlands, protects 20% of all endangered species
Can gene banks, botanical gardens and farms help save most endangered species?
1. Gene banks- store seeds of most food crops in safe vaults; botanical gardens contain 30% of all plant
species, educate public 150 million/year; raise certain species on farms- alligators in Florida-hides/meat
Can zoos and aquariums help protect most endangered species?
1. Egg pulling and captive breeding allow for saving/protecting many endangered species; others view
them as prisons; not a viable long term solution for endangered species
22-10 Wildlife Management
How can wildlife populations be managed?
1. Wildlife management approach- allow hunting to maintain populations- white tailed deer, turkeys, etc
must estimate maximum sustained yield
How can vegetation and water supplies be manipulated to manage wildlife?
1. Species are classified based on eco. succession type; promote those species by controlling vegetation
How useful is sport hunting in managing wildlife populations?
1. Wild game would surpass carrying capacity and destroy ecosystems- deer; hunting stimulate economy;
some oppose hunting- reintroduce natural predators- wolves
How can population of migratory waterfowl be managed?
1. Use flyways to move from one habitat to another are protected by many countries; also managed by
hunting
What should be done about snow geese?
1. Population has grown too large threaten the Arctic tundra and wetland habitats; do we let nature take its
course? Geese will destroy their winter breeding ground and population will crash; use hunters?
Chapter 23 Sustaining Terrestrial Biodiversity: The Ecosystem Approach
Who is afraid of the big gray wolf?
1. To make the great plains safe for livestock, 2 million wolves were shot, listed as endangered in 1974 by
Fish and Wildlife; play an important role ecologically (Yellowstone case study)
23-1 Land Use in the World and the U.S.
How is land used?
1. U.S. leads the world with more land set aside for public use and resource extraction, most is in Alaska
What are the major types of U.S. public lands?
Multiple-Use Lands
a. National Forest system- used for logging, mining, grazing, farming, recreation; off-road vehicles
usually restricted- managed by the US Forest Service
Moderately Restricted-Use Lands
a. National Wildlife Refuges- protect habitats; permitted- hunting and fishing- managed by US Fish
and Wildlife
Restricted-Use Lands
a. National Parks managed by NPS; only allowed to camp, hike, sport fishing and boating
How should U.S. public lands be managed?
1. Conservation biologists: protect biodiversity, no subsidies resource extractors; $1 billion a year is spent
to do the opposite
Case Study: Livestock and U.S. public rangeland
1. Ranchers get permits to graze on public lands- highly subsidized $60,000/rancher- produced 2% of
country‟s beef and 10% of mutton
23-2 Managing and Sustaining Forests
What are the major types of forests?
1. Old Growth forests- undisturbed forests for hundreds of years, most diverse
Second Growth forests- secondary ecological succession after the trees have been removed
2. Tree Plantations- tree farms, one species, clear cut and regrown in 6-30 year cycles
What are the major types of forest management?
1. Even-aged mgmt.- maintaining trees in a given stand about the same age and size; replaces a diverse
old growth forests;
2. Uneven-aged mgmt.- involves maintaining a variety of tree species at many ages and sizes with the
goal of biological diversity; long term sustainability
How are trees harvested?
1. Roads are built with harmful effects, then trees are harvested
a. selective cutting- intermediate-aged or mature trees in an uneven-aged forest; reduces crowding,
encourages growth of younger trees; maintains higher diversity
b. shelterwood cutting- removes all mature trees in 2-3 cuttings over 10 years
c. seed-tree cutting- harvests nearly all trees in one cutting, leaving just a few to reseed
d. clear cutting- removes all trees in a single cutting
e. strip cutting- clearing a strip of land along a contour of the land; allows minimal damage
What is happening to the world‟s forests?
1. Removing more than replanting; cleared for crops, livestock or urban growth; reduces nutrients,
diminishes biodiversity, increases erosion, adds to CO2 to atmosphere
How can forests be managed more sustainably?
1. Grow timber on longer rotations; emphasize selective cutting, strip cutting; don‟t build roads in forested
areas, certify sustainable methods; never use old-growth forests
Certifying sustainability grown timber
1. Scientific Certification Systems and other companies evaluate timber production with U.S. timber
companies with the goal of sustainability labels on all products
How can pathogens and insects affect forests?
1. 3 deadly diseases due to invasive parasitic fungi- chestnut blight, Dutch elm disease, white pine blister
rust; invasive insects- bark beetles, gypsy moths, hemlock woolly adelgid; need to ban foreign fuelwood
How do fires affect forest ecosystems?
1. Fires set by lightning- part of ecological cycle for savannas, temperate grasslands, chaparral, many
coniferous forests, and sequoia forests
2. Surface fires- burn undergrowth and leaf litter kill small saplings but spare mature trees and almost all
wild animals; prevent more destructive fires, increase nitrogen fixation, release valuable minerals,
germinate certain speeds, maintains habitats
3. Crown fires- burn all trees, leaping from treetop to treetop, kill wildlife, increase soil erosion
How can we protect forests from fire?
1. 4 approaches- prevention (Smokey the Bear- evil??), prescribed burning, presuppresion and suppression
(actually fighting fires)
How do air pollution and climate change threaten forests?
1. Increased forest fires due to climate change, acid deposition in coniferous forests
23-3 Forest Resources and Management in the U.S.
What is the status of forests in the U.S?
1. Cover 30% of U.S. land, provide 80% of species habitat, 2/3 of all water runoff; more forests now than
in 1920, however very little old-growth forests left
Why should we care about national forests?
1. Economic- 19% of country‟s forests, 3% of timber (down from 15% in 1980); grazing for 3 million
cattle; $4 billion in minerals, oil, and natural gas
2. Ecological- habitat for ~200 endangered /threatened species; principle habitat for pollinators- $4-7
billion value; provide cleanest drinking water for 60 million Americans worth more than all timber sales
3. Recreational-use has risen sharply since 1930
Case Study: How should U.S. national forests be managed?
1. Forest Service is required by law to use sustained yield for timber and multiple use- timber, recreation,
grazing, watershed protection and wildlife)
2. Timber companies have lobbied to increase yields at weaken the Forest service
How can we cut fewer trees by using wood more effectively?
1. 60% of wood is wasted due to inefficient construction, excess packaging, junk mail, inadequate paper
recycling, reuse of wooden shipping containers
2. Use of steel/aluminum framing, concrete slabs and carpet are all more inefficient and not an alternative
How can we cut fewer trees by making paper from tree-free fibers?
1. Paper is the fastest growing use of wood; alternatives to trees- agricultural residues, fast growing crops
kenaf and hemp- need less pesticides and less energy to break down its fibers
23-3 Tropical Deforestation and the Fuelwood Crisis
How fast are tropical forests being cleared and degraded?
1. Cover 6% of Earth‟s land area/47% of forest cover; 15% of Amazon has been removed, Haiti-99%,
Philippines 97% and Madagascar- 84%
Why should we care about tropical forests?
1. Numerous ecological, economic services: i.e. medicines
Case Study: Madagascar: A threatened jewel of biodiversity
1. 4th largest island, 40 million years of geographic isolation due to continental drift resulting in 85% of
animals are endemic species; at risk of illegal logging and smuggling of endangered species; world‟s
most eroded country; must slow population growth
Case Study: Cultural extinction in tropical forests
1. 250 million people part of ______________cultures- many tribes are vanishing; have value- how to live
sustainably in tropical forests, which plants and animals are useful as food and medicine
The incredible Neem tree
1. Broadleaf evergreen of the mahogany that quickly reforests bare land in 5-7 years, supplies fuelwood,
used to treat various diseases; native to India and Burma; drawbacks- nonnative species outside of range
What causes tropical deforestation and degradation?
1. Population growth, poverty, and govt. policies;
a. Commercial logging- largest importers: U.S., Japan, Europe and China; depleted much of Asia, now
shifting to Latin American and Africa
b. Cattle Ranching- usually on exhausted or abandoned cropland; further erosion transforms into a
wasteland
c. Cash crops (sugarcane, bananas, etc.) increasing forest fires, mining, building dams
The downward spiral of tropical forest degradation
1. First cut a road into the forests, use selective cutting, sell the land to ranchers, lands becomes wasteland
Solutions: how can we reduce degradation and deforestation of tropical forests?
1. Practice small-scale sustainable agriculture, debt-for-nature swaps, label timber from sustainable
methods, reforest timber cutting sites, reduce wasteful timber practices
How serious is the fuelwood crisis in developing countries?
1. 80% of wood in developing countries used as fuelwood; used faster than replaced; some burn charcoal
or animal dung, not sustainable;
Sustainable agriculture and forestry in tropical forests
1. Taking methods from indigenous peoples, can grow crops/harvest timber more sustainably- example
___________________ is grown under shade trees labeled fair trade
Solutions: what can we do about the fuelwood crisis?
1. Plant fast-growing fuelwood (not Eucalyptus); burn wood more efficiently (solar oven); switch to other
fuels;
Kenya‟s Green Belt Movement
1. Wangari Maathai- first African women to receive Nobel prize for her efforts with women‟s self-help
group that established tree nurseries, raise seedlings, over 12 million by 2005
23-5 Managing and Sustaining National Parks
How popular is the idea of national parks?
1. U.S. has 55 parks, supplemented by state (have the most visitors), county and city parks
How are parks being threatened?
1. Developing country parks- paper parks (not protected); developed countries- very popular (U.S), too
many people visiting causing impact, 1 ranger for 84,200 visitors (mainly enforcers not educators)
New stoves help save India‟s forests and improve women‟s health
1. 300,000 women help spread the use of efficient smokeless stoves (made of dung, mud and hay for $5),
helps reduce deforestation, indoor air pollution
Solutions: How can management of U.S. national parks be improved?
1. Integrated management plans, provide shuttle services instead of tourists driving through parks;
concessions pays a cut of profits to national parks; raise entry fees; encourage volunteers
23-6 Establishing, Designing and Managing Nature‟s Reserves
How much of the earth‟s land should we protect from human exploitation?
1. Depends on who you ask: Conservation biologists: 20% of all land; Developers/extractors: less than 5%
What principles should be used to establish and manage nature reserves?
1. 3 ecological principles: ecosystems are ever-changing(nonequilibrium state), fairly frequent but
moderate disturbances have the greatest diversity of species (intermediate disturbance hypothesis), view
reserves as „habitat islands‟
2. Include local people in planning and designing a reserve, create buffer zones surrounding reserve
Parks in Costa Rica
1. Considered a superpower of biodiversity- 500,000 plant and animal species (one park has more birds
than the rest of North America); more land devoted to land conservancy than any other countries; = over
$1 billion in tourism revenue
The nature conservancy
1. Uses private and corporate donations to maintain a fund to buy ecologically important pieces of land;
How should nature reserves be designed?
1. Usually _____________________, allows better protection of the interior; Heterogeneous allows for a
variety of habitats; connected by corridors; allow for buffer zones to better protect the interior
What is gap analysis?
1. US Geological Survey has initiated a gap analysis to determine whether existing networks of nature
reserves provide enough protection of biodiversity
What areas should receive top priority for establishing reserves?
1. Biodiversity hot spots protection needs to be first priority
Biospheres Reserves
1. Must be protected by government; be a certain size and contain a core, buffer and transition zone
What is adaptive ecological management?
1. Integrate ecological, economic, and social principles; integrating various perspectives to achieve goals
What is wilderness?
1. Undeveloped land affected primarily by the forces of nature; Roosevelt-“leave it as it is, you cannot
improve it”; must be at least 1500 square miles in area
Why preserve wilderness?
1. Without wilderness, world is a cage; habitat protection; intrinsic value;
How should wilderness be managed?
1. Designate camping areas; volunteer cleanup after idiots who don‟t follow: leave no trace ethic; leave
areas that allow no human entry
The U.S. national wilderness preservation system
1. 4.6% of land; strong opposition to expand wilderness area- resource extractors, convert to private land
23-7 Ecological Restorations
How can we rehabilitate and restore damaged ecosystems?
1. Restoration, rehabilitation, replacement, creating artificial ecosystem- all methods that have been used
How can we restore or rehabilitate degraded ecosystems?
1. Mimic nature, recreate ecological niches, rely on ecological succession, identify what caused
degradation, reintroduce keystone species, monitor restoration efforts
Case Study: Tall-grass prairies restoration in Illinois
1. Ideal subjects for ecological restoration; native plants can be established within a few years; many
volunteers have aided
Ecological Restoration of a tropical dry forest in Costa Rica
1. Guanacaste National Park- rehabilitated by no grazing, enhance seed dispersal; replaced monoculture;
good case study for training ground in tropical forest restoration for scientists from all over the world
Is ecological restoration the best approach?
1. Prevention is cheaper; _____________________- trade off of destroying one ecosystem and „creating‟ a
similar one elsewhere
What is the next step? Individuals matter
1. Please read Edward Wilson‟s comments on page 630