countin t'm> be - quia...quadrats (figs. as and ac) are canopy and understory quadrats 20...

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.

I

I

./

Bare Rock to Forest Soil .::t:

A. Bare Rock Exposed to ~---- the Elements

B. Rocks Become CoIO!'ized by Lichens

...-..... -._:".""... .J ".'-

..'--'-'-'. . . -, ' .._,.;'~.~-,: . . ~.•-._;'--'""'-r~~~• •~.~.-

-;;?>,. .:»: ;j?__: . ---~;~ -... : .r: "-... - C. Mosses Replace the:..•.--:: :;~'7_" ..,~._ . ..~.. ..;:J~ .. _:; Lichens : . '"f,. .-.~.~ "~. :J:.-..J.:?7

. ..' .e. ~~. 'IJ~ ~ -<j".....- ~'"'-jJoJ.. . ~'~~ - , ~--..~(-~ •.~..' ;'-.;;':l4',i 5:,. •.t:« 'J.)jJ-.__.

fL' :1 ~ :P.-'~~.' '. ... :.t.~."", .' •..--. "-' • p..:I/'~"..- '. ·~.1_Jc.1- _.~- •• _D. Grasses and flowering - .» .........__ .,,'~\"t"...;

Plants Replace the Mosses

E. Woody Shrubs Begin Replacing the Grasses and flowering Plants

f. A forest Eventually Grows Where Bare Ruck Once Existed

_ J

Succession ff1 •• 1,

I I I I I I t!I

I I I I I I II

I I

70 Un.dastanding Basic Ecological Umapts

{Problem Noo JJ continued]

fib·

e fA Used for

shrubs and Herbs

O(t x 10 M)

Used for Canopy MKI Understory Trees (10 x 10 M)

...._• -.ct

~

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.

!f------- 10 M -----__

(continwd)

72 Understanding BasicEcological 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:

\ .

~ e CD

-

_.

I

e -~

~

How Many Percent of Total(%)

Key: Shagbark Hickory <D Yellow Chestnut Oak e Red Oak 0 .

2

3

16.67

33.33

50.00

Total 6 100.00

I 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 ofth e total for each species is then calculated. These percentages are added together to check the calculation.

73 I I I

(Problem No. l l amtinued]

FigureAA

Tree Species Distribution in a lOOW QU3drat

Field in Southern Indiana Abandoned 5 Years

Seedlings .Present:,'-

Kev: Sassafras b.

Persimmon.

Total

June 15-11:00 A.M.

Air Temperature Soil Surface Temperature

How Many

Sunny Day 27 Degrees C (80 0 F) 35 Degrees C (950 F)

Percent ofTotal (%)

I I I I I I I I I I I I I

b.

• . b.

lD.

b. • b. ..'

. }. I I

74 Urukrstanding Basic EcologicalConcepts

(Problem No. 13 continued)

FigureAB

Tree Species Distribution in a 100M2 Quadrat


Canopy Species:

\

0

".. \ • -

l:l .

• •

l:l

l:l l:l

b..

How Many PercentofTo~(~)

Key: Winged Elm 0 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)

1

'0'.J II Sucassion 75

(Problem No. 13 continued]

FigureAC

Tree Species Distribution in a lOOW Qu:adrat

Field in Southern Indiana Abandoned 20 Years Understory Species:

:; ~",

'\

• • •• ~ ~

. ~ e c:~ l~ C> l1

11 0 • 0 0

l~ • 0 . 11 ° •

e C> 0• 0 0 •.0 • 0• • Cb 0 ° 0° e °0 ••

° •• • .0. C) C) ° • • 0•. ·0'

How Many Percent of Total (%)

•

Key: Winged Elm 0

Persimmon.

Sassafras ~

Black Cherry e White Ash C)

Total

I I I I I I I I I I I I I I I I I 1

\, . , 76 Understanding Basic ErologUal Uinaprs


Figure AD

Tree Species Distribution in a lOOW Quadrat

Field in Southern IDdiaoa Abandoned 50 Yeus

Canopy Species:

• e e

_.

0 0 . .

Q 0 Q

• .s: .

0

1":'\

" () •

Key: Black Cherry e White Ash ()

Persimmon.

Winged Elm 0 Bitternut Hickory 0

WhiteOak ~

Total

June 15-10:00 A.M.

Air Ternperature Soil Surface Temperarure

How Many Percent ofTotal (%)

Sunny Day 21 Degrees C (700 F). 20 Degrees C (680 F)


Figw-eAE

Tree Species Distribution in a lOOMl Quadrat


. Understory Species:

® e , <D

@ e

@ @ @

Q Q

Q -

<D e ~

Q

® Q Q

How Many Percent of Total (%)

Key: Bitternut Hickory @

Shagbark Hickory <D

White Oak Q Yellow Chestnut Oak e Red Oak ®

Total

. j I, I

I

(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 79


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 of6° C in air temperature and of 15°C in soil surface temperature between the 5-year quadrat: and the 5O-yearquadrat, }\'hat might account for this difference?

6. A climax forest is a forest in which succession has. for the most pan. stopped. One kind ofclimax 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}

.J

\

I I I I I I I I I I I I I I I I I I I

V

80 Undaltanding Basic Ecological Concepts


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 everbe commonly found in a climax forest, Give

,the reasons for your prediction.

PREDICnON: .:...-_-:...- _

REASON: _

8. Are there fewer or more trees in the canopy ofFigure 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, 1-10 pt _______

(discussion of drawbacks to recommendations)

E- Grammar, spelling, word usage, paragraph structure and neatness 1-10 pt _______

Notes from Video:

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? _________________________________________________

______________________________________________________________________________




______________________________________________________________________________

3. Hot-spot ______________________, Located in:______________________________________



______________________________________________________________________________




______________________________________________________________________________




______________________________________________________________________________

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 numbers-

schools 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 value-

usefulness 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 one-

time 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 2000-

internet 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

countin t'm> be - quia...quadrats (figs. as and ac) are canopy and understory quadrats 20...

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