Transcript Document

APES year in review
2012, The
year
everyone
gets a 5!
Chapter 1: Introduction
•Understand how natural world works
•Understand how human systems
interact with natural system
•Accurately determine environmental
problems
•Develop and follow a sustainable
relationship with natural world
Easter Island
Sustainability
- A system/process can continue
indefinitely without depleting
resources used.
*no sacrifice to future
generations*
Stewardship
Caring for something that does
not belong to you
Sound Science
Use the scientific method
A. Human population growth
•
•
•
•
More than 6.3 billion people currently
last 25 yrs population grew by 2 billion
projected that population will be 10 billion by 2050
increase pop → increase need for resources
B. Soil degradation
•
Demand for food destroys the soil
–
–
–
–
–
erosion
minerals in soil are depleted
salinization
increased use of pesticides
Overuse of fresh water
C. Global Atmospheric Changes
Global Warming
– CO2 produced from fossil fuel burning acts like a
blanket around the earth.
– Plants take CO2 out of the atmosphere through
photosynthesis
• 6CO2 +6H2O => 602 + C6H12O6
Ozone depletion
– Chemicals released from the surface of the earth
destroy our ozone shield.
– No stratospheric ozone, no protection from the UV
rays of the sun.
•Rachel Carson was a scientist who wrote Silent
Spring in 1962.
•It addressed the growing use of pesticides (DDT)
and their unpredicted effects on song birds.
•Original users of pesticides did not know that the
poisons used to kill insects would accumulate in
other living things and kill them too.
BIOACCUMULATION
More Cool Environmentalist
•
•
•
•
•
John Muir – Sierra Club
Ansel Adams – Photography (Yosemite)
Aldo Leopold – Sand County Almanac
Henry David Thoreau – Walden
Garrett Hardin – Tragedy of the Commons
Earth’s Energy Budget
Figure 2.8
• Tropics receive more concentrated insolation (2.5x
more) than the poles due to the Earth’s curvature
Figure 2.9
Varied Habitat calls for
varied forms
Biomes determined by
latitude and precipitation
Notice, more precipitation bigger the plant life
Habitats are dynamic… constantly
changing.. Succession
• Hydric succession
• Mother nature is
always busy.
• Wet moves to dry
• Notice
replacement
organisms
Primary
Succession
Where there
was no life
previously
Examples
-after a lava flow and at the edge
of a receding glacier.
Secondary
Succession- recolonization
Secondary successionfrom abandoned field to
mature forest
Succession and
Chemical Cycling
Basic Concepts of Biological
Diversity
• Bio diversity refers to the variety of life forms in an area.
– Expressed as # of species in an area
– Or # of genetic types in an area
• Genetic diversity:
– total # of genetic characteristics of a specific species, sub
species or group of species.
• Habitat diversity:
– the different kinds of habitat in a given unit area.
• Species diversity:
– Species richness- total # of sp
– Species evenness- the relative abundance of sp
– Species dominance- the most abundant sp
Species Diversity
Merely counting the number of species is not enough to
describe biological diversity.
Questions?
Take a few minutes to look over the spread sheet
1. Write down 3 observations
2. Which ecosystems are more diverse; those with larger DI numbers or
smaller ? Explain
3. Compare Ecosystems A and B- How do their indices compare? Each
has 10 different species, Ecosystem A has only 29 organisms and
Ecosystem B has over 300
Which has a healthier Diversity Index? Why
4. Compare the last two Ecosystem indices. What do you notice?
5. Why is it important to use a Diversity Index?
a
Totals
b
c
pop.
DI
pop.
DI
pop.
DI
29 0.1058 311 0.1067 4400 0.1209
Species 1
Species 2
Species 3
2 0.0048
3 0.0107
4 0.0190
23 0.0055
23 0.0055
34 0.0120
100 0.0005
200 0.0021
500 0.0129
Species 4
Species 5
Species 6
Species 7
Species 8
Species 9
Species 10
3
2
3
4
2
3
3
22
33
44
33
22
33
44
600
400
700
600
300
700
300
0.0107
0.0048
0.0107
0.0190
0.0048
0.0107
0.0107
0.0050
0.0113
0.0200
0.0113
0.0050
0.0113
0.0200
0.0186
0.0083
0.0253
0.0186
0.0046
0.0253
0.0046
DI
Samp
Species Richness (diversity)
• Species richness not very informative
• Each community has 5 spp & 50
individuals
Spp Spp Spp Spp Spp
1
2
3
4
5
Comm
A
Comm
B
10
10
10
10
10
46
1
1
1
1
Simpson Diversity Index (D)

Ds = (n1(n1 -1)/N(N-1))
Where:
Ds = Bias corrected form for Simpson
Index
n1 = number of individuals of spp 1
N = Total number of spp in community
In this form as diversity increases index
value gets smaller
D. Loss of Biodiversity
• Habitat destruction is the major cause of
loss of Diversity
• exact # of species lost is unknown
because not all species are identified
• strong ecosystems need biodiversity
• 1959-1980 25% of all prescription drugs
from natural resources
• We are in the middle of the 6th great
extinction
Ch 2: Ecosystems
Levels of organization of matter
Universe
Ecosphere/biosphere
Ecosystems
Communities
Populations
Organisms
Cells
Atoms
Ecosystems
Plants and animals interacting with their abiotic
environment. Ecosystems exist in biomes.
•Climate – ave temperature over time
•*Weather – daily variations in temp and
precipitation
•Microclimate and Other Abiotic Factors
* light intensity
* Soil type
* topography
Physics
• Energy is measured in calories
– Calorie – amount of heat needed to raise 1 gram
of water 1 degree Celsius.
– Kilocalorie = 1,000 calories
• 1st law of thermodynamics
– Energy cannot be created nor destroyed, only
change forms (light to chemical)
• 2nd law of thermodynamics
– Energy transformation increases disorder
(entropy) of the universe.
– Heat is the lowest grade of energy.
Trophic Relationship
Food webs
• Trophic levels
* producers
* herbivores
*primary carnivores
10 % rule- only ten percent of the
energy can be passed from one
trophic level to the next.
90% energy lost as heat from web
Be able to fill in Kcal
when given one level.
All biomass gets its energy
from the sun
Only 10% of energy from
one trophic level moves to
the next trophic level
Energy released is high
potential energy molecules
(like glucose) then
converted to low potential
energy molecules (like
carbon dioxide)
Numbers Pyramid
Relationships
• Mutualism
* Flowers & insects
•Commensalism
•Predator/prey
• host parasite
• Competition
• habitat vs. niche
Limiting Factors
Temperature, light, oxygen,
carbon dioxide, precipitation
•
Optimum levels
•
Zones of stress
•
Limits of Tolerance
•
Range of Tolerance
Synergistic effects – The interaction of two or more factors is
greater than the sum of the effects when each acts alone.
Example: pollution and disease
Phosphorous is limiting factor in fresh water ecosystems
Add a limiting factor…. Result cultural eutrophication
Ch 3: Ecosystems, how they
work
MATTER CYCLED …………………………ENERGY FLOWS
•Recycle or Die
•All matter is recycled through the
lithosphere, hydrosphere, and
atmosphere.
•Nothing is created nothing is
destroyed
•All stable ecosystems recycle matter
and get energy from the sun
Energy... laws
• High Quality Energy: organized & concentrated; can
perform useful work (fossil fuel & nuclear)
• Low Quality Energy: disorganized, dispersed (heat in
ocean or air wind, solar)
• First Law of Thermodynamics: energy is neither created
nor destroyed, but may be converted from one form to
another (Law
• of Conservation of Energy)
• Second Law of Thermodynamics: when energy is changed
from one form to another, some useful energy is always
degraded
• into lower quality energy, usually heat
Photosynthesis
Building
organic from
inorganic
Respiration
Getting the energy out of food
• Photosynthesis (Only 1% of the energy from the
sun is used)
– Chlorophyll – absorbs light to drive photosynthesis
• Plants use glucose to:
–
–
–
–
Construct other molecules
Build their cell wall
Store energy
Source of energy
Carbon cycle
Nitrogen cycle
• Main reserve in the atmosphere N2 unusable!
• Living things must get N from ammonium (NH4) or
nitrate (NO3) for DNA, proteins
• N from the atmo must be fixed
• Change N2 into ammonium or nitrate
–
–
–
–
Rhizobium (bacteria living in roots of legumes) fig 3-10
Industrial
Lightning
Burning fossil fuels
Nitrogen Cycle
KNOW these Terms
• Nitrogen fixing: because atmospheric N2 cannot be used
directly by plants it must first be converted into ammonia
(NH3) by bacteria (rhizobium)
• Ammonification: decomposers convert organic waste
into ammonia
• Nitrification: ammonia (NH3) is converted to nitrate ions
(NO3)• Assimilation: inorganic nitrogen is converted into organic
molecules such as DNA/amino acids & proteins
• Denitrification: bacteria convert nitrate (NO3)- and nitrite
(NO2)- back into N2 gas
Phosphorus cycle
• No gas phase, only
solid and liquid
• Man-made fertilizers
contain organic
phosphates
• Because P is a
limiting factor in
aquatic systems, it
leads to
eutrophication
• The rain forest is
very good at
recycling P, except
when we cut it
down…
element
Main
nonliving
reservoir
Carbon
C
Atmo
CO2
Nitrogen Atmo
N2
N
Phos- Litho
phorous rocks as
P
PO4-3
*no gas
phase
Main living
reservoir
Other
nonliving
reservoir
Human-induced problem
Carbohydrate
s (CH2O)n
And all
organic
molecules
Hydro
Carbonate
(CO3-2)
Bicarbonate
(HCO3-)
Litho minerals
Global warming
Carbon from fossil fuels
underground are burned
and released into the air as
CO2
Proteins and
other Ncontaining
organic
molecules
Hydro
Ammonium
NH4+
Nitrate
NO3Nitrite NO2-
Eutrophication
Fertilizers contain humanmade nitrates that end up
in the water
DNA
ATP
phospholipids
Hydro
Phosphate
PO4-3
Eutrophication
Fertilizers contain humanmade phosphates that end
up in the water
Cutting down rainforest
stops recycling of P
Biosphere II (remember
ecocolumns)
• Purpose: recreate conditions of
Earth (Biosphere I)
* to understand our world better
* space travel
• 5 acres in Arizona, 4000 species,
10 humans
* problem: 02 + CO2
were absorbed by concrete
* ants and cockroaches took over
Fires in Ecosystem
• Maintain balance of species
and energy in ecosystems over
the long run.
• Beneficial b/c provide nutrients
for soil
• We avoid natural fires, but the
problems like Crown Fires- (not
natural) kill the whole tree
• 1988 Yellowstone fires
changed climax ecosystems of
white bark pine trees to huckle
berries. Grizzlies eat both
Succession - One species
gradually replaced by another in
an ecosystem
• Primary – new ecosystem
where there were no living
things before. Cooled lava,
receded glacier, mud slide
• Secondary- ecosystem used
to be there. Fire, humans
clear an area
• Aquatic – lakes taken over
by terrestrial ecosystem
• Climax ecosystem- in
balance only changes if
major interference
Primary succession
•Must create new soil for plants to grow
•The first plants to come in are called
pioneer species
•Lichen
•Moss
•Microbes
Why do species change?
•
Environmental resistance and biotic
potential
• Selective pressure on mutations
• Speciation
* creation of a new species based on
reproductive isolation
Populations isolated by rivers, mts,
civilization
Natural Selection
• Some individuals may be better suited
to the environment than others.
• Those better able to survive and
reproduce leave more offspring. Bird of
Paradise
• Their descendants form a larger
proportion of the next generation.
Who Lives Where and
Why?
Evolutionary response…
Resource Partitioning - Whenever there
is competition for the same resources,
someone loses out!
Evolution
Speciation (Galapagos
Finches)
Geological Context
(space and time for evolution)
•
•
•
•
•
•
Plate tectonics
Geological time scale (fig. 5-21)
Cambrian explosion
Selective breeding
Artificial selection
Natural selection
Island biogeography…. Founder effec
K- Selected Species
populations of a roughly constant size
have low reproductive rates.
offspring require extensive postnatal care until they have sufficiently matured.
They are very limited in resourses therefore they are a very competitive species.
Elephants, Rhinos and long lived plants are examples of a k-selected species.
R-Selected Species
populations that experience rapid growth of the J-curve variety.
offspring produced are numerous, mature quite rapidly, and require very little
postnatal care.
this population grows fast, reproduces quickly, and dies quickly.
Bacteria and mice are examples of r- selected species.
Carrying capacity
changes…
Carrying Capacity-------------------------------------------------K-species
exponential
r-species
Carrying Capacity
-------------------------------------------------K-species
exponential
r-species
Ch 6 and 7: The Human
Population
Chapter 6
•World population trends
•Calculations
•Demographic transition
•Age structure diagrams
•Developed vs. developing
countries
Chapter 7
•Fertility rates
•World bank
•1994 UN conference in
Cairo- program of action
Population Density
• Population Density (or ecological population
density) is the amount of individuals in a
population per unit habitat area
– Some species exist in high densities - Mice
– Some species exist in low densities - Mountain
lions
• Density depends upon
– social/population structure
– mating relationships
– time of year
Population Dispersion
Population dispersion is the spatial pattern
of distribution
There are three main classifications
Clumped: individuals are
lumped into groups
ex. Flocking birds or
herbivore herds due to
resources that are clumped
or social interactions
most common
http://www.johndarm.clara.net/galleryphots/
Population
Dispersion
Uniform: Individuals are regularly
http://www.calflora.net/bloomingplants/creosotebush2.html
spaced in the environment - ex.
Creosote bush due to antagonism
between individuals, or do to regular
spacing of resources rare because
resources are rarely evenly spaced
Random: Individuals are randomly
dispersed in the environment ex.
Dandelions due to random
distribution of resources in the
environment, and neither positive nor
negative interaction between
individuals rare because these
conditions are rarely met
www.agry.purdue.edu/turf/ tips/2002/clover611.htm
Age Structure
• The age structure of a population is
usually shown graphically
• The population is usually divided up into
prereproductives, reproductives and
postreproductives
• The age structure of a population
dictates whether is will grow, shrink, or
stay the same size
Age Structure Diagrams
Positive Growth
Pyramid Shape
Zero Growth
(ZPG)
Vertical Edges
Negative Growth
Inverted Pyramid
Population Dynamics
Outline
• Characteristics of a Population
• Population Dynamics and
Carrying Capacity
•
•
•
•
Reproductive Strategies
Conservation Biology
Human Impacts
Working with Nature
• Biotic Potential
–factors allow a population to
increase under ideal conditions,
potentially leading to exponential
growth
• Environmental Resistance
–affect the young more than the
elderly in a population, thereby
affecting recruitment (survival to
reproductive age)
(b) crude birth rate= number birth per 1000 individuals
(d) crude death rate= number death per 1000 individuals
(r) growth rate = natural increase in population expressed as percent
per years (If this number is negative, the population is shrinking.)
equation:
rate = birth – death
But other factors affect population growth in a certain area…
Population growth rates
increase population
births

immigration 
decrease population

deaths
 emigration (exit)
r = (birth - death)+ (immigration-emigration)
immigration = migration of individuals into a population
from another area or country
emigration = migration of individuals from a population
bound for another country
r = (birth - death)+ (immigration-emigration)
example: population of 10,000 has
100 births (10 per 1000)
50 deaths (5 per 1000)
10 immigration (1 per 1000)
100 emigration (10 per 1000)
You try.
B
D
I
E
r=( 10/1000) – (5/1000) + (1/1000) – (10/1000)
r=(0.01-0.005) + (0.001 – 0.01)
r = 0.005 – 0.009 = -0.004 or –0.4% per year
Know Rule of 70
If the growth rate is 1% and the population size is
10,000, how many years will it take to get to a
population of 40,000?
Population doubling:
70/rate =70/1% =70 years to double
In 70 years the population will be 20,000
1 D.T.  20,000
2 D.T.  40,000
(70 years)(2) =140 years
In 140 years, the population will be 40,000 people.
SHOW YOUR WORK!!!!!!!!!
Bottom Line= as countries develop, first their death rate
drops and then their birth rate drops
Reasons for the phases:
Phase II:
 medical care
 nutrition
(births still high)
 technology
Phase III:
 birth control
 education (of women)
 lower mortality rate of infants
 less child labor
Developed Countries
 Canada, U.S., Australia, Western Europe
(Denmark)
Developing Countries
 Latin America, China, Africa (Kenya)
 1/5 of the world’s pop. Lives in absolute
poverty, illiterate, lack clean H2O and don’t
have enough food
 80% of world’s pop. Lives in developing co.
and growing
• Total fertility= avg. # of children born per
woman
• For developed countries = 2.1
• For developing countries = 2.6
• Fertility of 2.0= replacement level
– Under 2.0 = shrinking population
– Over 2.0 = growing pop.
• For developed countries = 2.1
• For developing countries = 2.6(or higher)
• Special agency of the United Nations
• Receives $$ from developed co. and loans $$ to
developing co.
– Sometimes this backfires by increasing debt
• Oversees all types of issues, not just environmental issues
– Ex. electricity, roads, new modern technology
Soil (pg 281)
Basis for life
(Dust Bowl(pg 304), Porosity
and Permeability Lab)
• Sand 2.0-.02 mm
• Silt .02-.002 mm
• Clay.002mm ≥
some microscopic
Texture
Characteristics
Sands have large pore spaces, whereas clays
have many small pore spaces. Both sand and
clay can have high porosity
Permeability is a measure of a soil's or rock's
ability to transmit a fluid, usually water.
The most rapid water and air movement is in
sands
Clay has low permeability due to small grain
sizes with large surface areas, which results in
increased friction. Also these pore spaces are
not well connected. Clay often creates
confining layers in the subsurface.
LOAM:
40%sand 40% silt 20% clay
Loam is theoretically the ideal soil
Classes of Soil
Mollisols- very fertile, dark, found in temperate
grasslands, best agricultural soil, Deep A horizon
Oxisols- soil of tropical and subtropical rainforest layer of iron
and Al oxides in B horizon, little O horizon
Alfisols- weathered forest soil, not deep, but
developed OAE+B typical of most temperate
forest biome. Need fertilizer for agriculture
Aridsols- dry lands + desert, lack of vegetation, lack of
rain  unstructured vertically, irrigation leads to
salinization b/c of high evaporation.
Soil Fertility improvement
• Organic fertilizer
– Animal manure, green manure, compost
Improves water holding content,
Reduces soil erosion
Maintains texture
Maintains fertility
Maintains soil diversity
Water
• Figure 9-1 Earth’s water supply
Water Facts
Read water resources (conflicts in ME Case study- page
314case
• The primary use for fresh water in U.S. is
for agriculture.
• In our homes, we use the most fresh water
to wash, clean and flush.
• The typical person in an industrialized
nation uses 700-1000 gallons per week!
Human effects on the
Hydrologic Cycle
Figure 9-3 The Hydrologic cycle
• Figure 9-5a Global air circulation
Rain shadow
Figure 9-6 Rain shadow
Largest
freshwater
aquifer in
world
The Ogallala Aquifer
Remember
overdrawn
Water is
the New Oil
Figure 9-16 Exploitation of an aquifer
Mono Lake
• Excellent example of human interference
with the water supply.
• The water in the lake was diverted from
the lake to the city of Los Angeles. It
became a salt bed.
• ↑ Salt concentration due to evaporation
Three Gorges Dam in China
• China needs to meet the growing demand
for energy
• Huge environmental impact
• Hundreds of thousands of people will be
displaced (not to mention the ecosystems
which will be flooded)
Modern Food Production
Air
•Greenhouse gas emissions from fossil fuels
•Other air pollutants from fossil fuels
•Pollutions from pesticide sprays
Water
Soil
•
•
•
•
•
•Aquifer depletion
Erosion
Loss of fertility
Salinization
Waterlogging
Desertification
•Increased runoff and flooding from
land cleared to grow crops
•Fish kills from pesticide runoff
•Surface and groundwater pollution
from pesticides and fertilizers
•Over fertilization of lakes >>
eutrophication
Major Environmental Effects of Food
Production
Biodiversity Loss
• Loss and degradation of habitat
from clearing grasslands and forests
and draining wetlands
• Fish kills from pesticide runoff
• Killing of wild predators to protect
live stock
• Loss of genetic diversity from
replacing thousands of wild crop
strains with a few monoculture
strains
Human Health
•Nitrates in drinking water
•Pesticide residues in drinking
water, food, and air
•Contamination of drinking
and swimming water with
disease organisms from
livestock wastes
The Green Revolution
• To eliminate hunger by improving crop performance
• Movement to increase yields by using:
–
–
–
–
–
New crop cultivars
Irrigation
Fertilizers
Pesticides
Mechanization
Results:
•
•
•
•
•
Did not eliminate famine
Population still increasing
Increase cost of production
An increased negative environmental impact
Didn’t work for everyone
Agriculture
• Animal Feedlots– ADV- incresed meat, less land use, higher
profit, reduced soil erosion, protect
biodiversity
– Disadv- Large inputs of grain, fish meal, fossil
fuels, Greenhouse gases, methane and CO2,
concentration of animal waste(pollution), use
antibiotics....Bad
Aquaculture
– Advantages• High efficiency, high yield/ vol, reduce over
harvesting, low fuel, high profit
– Disadvantages•
•
•
•
•
Large inputs of land, feed, water
Large waste, water pollution
Uses grain
Destroy estuaries and mangroves,
Dense populations... disease
Pesticides
• Advantages
– Save lives
– Increase food supplies
– Work fast and profitable
– Safe if used properly
• Disadvantages
– Promote genetic resistence
– Kill natural enemies
– Harm wildlife and people
– expensive
Alternatives to Pesticides
• Cultivation practices fool the pest
– Rotting crops, alternating planting times
– Pheromones-sex attractants lure pest in trap
• Provide homes for pest predators
– Polyculture
• Biololgical control
– Bring in natural enemies
• Implant genetic resistence
– GMO resist pest
Ch 11 and 12:Protection of
Biodiversity and Ecosystems
• Threatened – if the trend continues, the species will be
endangered.
•Endangered – if the trend continues, the species will go
extinct.
•Pharmaceuticals and native plants  Approximately 25%
of drugs used as medicines come from natural plant
sources.
•The Exxon Valdez Oil Spill (1989)  300,000 birds died as
a result of that particular oil spill. The area, Prince William
Sound, is still recovering.
Know Specific Details about…
Bioaccumulation and Biomagnification
These Endangered animals (and check Barron’s examples):
• Wild Turkey – a success story
• Whooping Crane- Eggs raised by sandhill cranes led to
problems, but the efforts proved successful overall.
• Peregrine Falcon- DDT
• Spotted Owl- deforestation
• Fish living in George’s Bank (off New England)-The
marketable fish were over fished and other species took
over. An example of poor management of fisheries.
Endocrine Disrupters
•
•
•
•
Interfere with normal hormone action
Can interfere with development
Are often connected to cancer
Can interfere with sexual activity
(alligators)
• Are found in plastics and some
pesticides
•
Environmental Health Effects of
Pollution
Toxicology
– Response is
amount of damage
to dose of toxicant
– ED50
• Effective dose
that causes 50%
of population to
exhibit a
response
– LD50 Dose lethal to
50% of population
Note threshold
before see effect or
when effect begins
to show
WATER
Laws
• Safe Drinking Water Act: (SDWA, 1974) set maximum
contaminant levels for pollutants in drinking water that
may have adverse effects on human health
• Clean Water Act: (CWA, 1972) set maximum
permissible amounts of water pollutants that can be
discharged into waterways; aims to make surface waters
swimmable and fishable, including wetlands
• Ocean Dumping Ban Act: (1988) bans ocean dumping
of sewage sludge and industrial waste in the ocean
Laws to Protect Life
• Endangered Species Act: (1973) identifies threatened
and endangered species in the U.S., and puts their
protection ahead of
• economic considerations
• Convention on International Trade in Endangered
Species (CITES): (1973) lists species that cannot be
commercially traded
• as live specimens or wildlife products
• Magnuson-Stevens Act: (1976) Management of marine
fisheries
• Food Quality Protection Act: (1996) set pesticide limits
in food, & all active and inactive ingredients must be
screened for
• estrogenic/endocrine effects