Download exam review chapter 1-11 - Campbell Hall Online Learning

Chapter 1
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Environment - the sum of conditions surrounding us that influence life (living and nonliving)
Environmental science - interactions among human systems and those found in nature
Ecosystem - location on earth whose interacting components include biotic (living) and abiotic (nonliving)
components
Ecosystem services - ways nature provide us with life supporting services
1. Clean water, oxygen, food, timber, etc
Environmental indicators - describe the current state of an environmental system. 5-indicators:
1. Biological diversity
 Genetic diversity – measure of genetic variations among individuals in a population (single
species)
 Tall, short, color, etc (humans)
 Species diversity – different species in a region (species are organisms that can breed with
one another)
 Ecosystem diversity – the number of productive ecosystems in a given area
2. Food production - refers to our ability to grow food to nourish the human population
3. Global temp and CO2 levels – CO2 and temps increase simultaneously. CO2 levels increasing due to
anthropogenic (human) activity
4. Human population – Currently close to 7 billion
5. Resource depletion
Sustainable development – ways to manage our resources for the future without compromising our lifestyle
Ecological footprint – the total amount of land required to support one person’s lifestyle (every activity we do
uses earth’s resources in some form)
Scientific method
1. Observe and question
2. Form hypothesis (testable state of affairs)
3. Experiment and collect data
 Appropriate sample size (number of times measurement is replicated)
 Independent (what is changed by the experimenter) variable vs. dependent (what changes
as a result of the independent variable) variable
 Accuracy is how close a measurement is to an actual value
 Precision is how close one another the repeated measurements are
4. Interpret/analyze results
 Inductive reasoning vs. deductive reasoning
5. Conclusions – retest, publish, confer, new tests
Chapter 2
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Matter - anything that occupies space and has mass
Law of conservation of matter – matter is not created nor destroyed. It simply changes form (nutrient cycles)
Mass – the amount of matter (weight is just the force of gravity)
Atom - smallest piece of an element that can contain the chemical properties of an element
Element - substance composed of atoms that cannot be broken down into simpler components (in other words, a
substance made up of one type of atom)
Molecule – substances with more than one type of atom (H2O, O2)
Compound - molecules that contain more than one element
o H20 and C6H12O6 are both molecules and compounds, but O2 is only a molecule because it is made of
two atoms of the same element
Nucleus – center of atom, made of protons (positive) and neutrons (neutral)
 # of protons (positive) = atomic number. Every atom of the same element ALWAYS has the same
number of protons (i.e. every oxygen atom in the universe has 8 protons)
 Number of neutrons can change within atoms of the same element (i.e. some gold have 8
neutrons, while others may have 7)
 Atoms with different numbers of neutrons are
called isotopes
Radioactive decay – when atoms lose material from nucleus, they release
energy in the process and they become new elements
o Half life - the amount of time it takes for half of the parent atom to
decay
Chemical bonds
o Covalent bonds - when two atoms share one or more pairs of
electrons (water) (only nonmetals) (liquids or gases) (weak)
o Ionic bonds - when electrons are transferred from one atom to
another. Contain a metal, solids, strong
o Hydrogen bond - the positive and negative sides of a molecule
attract each other (polar). (Water) (weak bond)
Properties of water
o Hydrogen bonding allows water molecules to stick to one another
(cohesion) and to other substances (adhesion)
o Capillary action allows water to climb up small tubes (this allows
plants to get water from the ground)
Acids and bases
o Acid is a substance that contributes hydrogen ions (H+) to a
substance
o Base is a substance that contributes a hydroxide (OH-) ion to a
substance
o pH scale (power of hydrogen) measures acidity. Each number on the
scale represents 10 times stronger base or acid (i.e. an acid with a pH
of 3 is 10 times stronger than an acid with a pH of 4, and 100 times
stronger than an acid with a pH of 5
Organic compounds contain C-C or C-H bond (C6H12O6 = organic, H2O = NOT organic)
o Carbohydrates – organic compounds composed of C, H, O; provide energy to cells; simple are sugars;
complex are starches
o Proteins - Organic compounds composed of C, H, O, N; made of amino acids; building structures; defense
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Lipids – Organic compounds that do not dissolve in water (fats, waxes, steroids). Structural components,
insulation, long term energy
o Nucleic acids – Organic compounds in all living things that store info (DNA, RNA)
Energy - the ability to do work, or transfer heat. Units are:
o Joule (J) (amount of energy used when one watt light bulb is turned on for one second)
o calorie (cal) – amount of energy it takes to heat 1g of water 1⁰C. BTU is English version (1lb of water 1⁰F)
o Calorie (kcal) – 1,000 calories (food calories)
o Potential energy is energy that is stored, but not yet released (chemical, elastic/spring, nuclear, gravity)
o Kinetic energy is the energy of motion (motion, radiant, thermal, sound)
o Temperature is the measure of the average kinetic energy of a substance (how fasts atoms are moving)
Laws of thermodynamics
o First law - Energy cannot be created nor destroyed. It can change form, but the total amount of energy
always remains the same
o Second law – when energy is transformed, the quantity of energy remains the same, but its ability to do
work diminishes. Nothing is 100% efficient
Feedback loop - a circular process in which a system’s output serves as input to that same system
o Negative feedback loop – moves to stabilize the
system (more rabbits means more lynx’s, but more
lynx’s leads to less rabbits which leads to less lynx’s
which leads to more rabbits…)
o Positive feedback loop - instead of stabilizing a
system, it drives it further toward one extreme or
another. It DOES NOT mean good!
o Steady state – inputs = outputs, so system does not
change over time
Chapter 3
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Ecosystem is the mix of biotic (living) and abiotic (nonliving) factors in a particular area
Edge effect is the increase in biodiversity near ecosystem boundaries
o Pros
 More sunlight allow more plants and new species to colonize area
 Allows animals to travel between two habitats and reap the benefits of both
o Cons
 Increases predation
 Boundaries may restrict animals to boarder
Producers/autotrophs convert energy from sun into carbohydrates(photosynthesis)
o Chloroplast is light absorbing pigment in plants
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o 6CO2 + 6H2O + Solar Energy  C6H12O6 + 6O2
o Plants really make sugar for themselves to build bark, roots, etc
Cellular respiration is when organisms get energy from plants through chemical rxn
o C6H12O6 + 6O2  6CO2 + 6H2O + Energy
o All animals respire, even plants!
o Aerobic respiration: making energy in the presence of oxygen (equation above)
o Anaerobic respiration: energy gained in absence of oxygen. By products include methane gas, acetic acid
Consumers/heterotrophs obtain energy by consuming other organisms
Herbivores/primary consumers are heterotrophs that consume producers, secondary consumers are carnivores
that eat primary consumers, tertiary consumers are animals that eat secondary consumers (rare)
Each level is called a trophic level
Detritivores get nutrients from dead organisms (soil insects)
Decomposers release nutrients back (fungi, bacteria)
A food chain is a sequence in which energy is transferred from one organism to the next as they consume each
other. It is one strand of a food web. Begin w/ producer
A food web is a network of food chains showing the feeding relationships in an ecosystem (arrows point to energy
transfer)
Bioaccumulation is when toxins get passes on through each trophic level (does not break down). Animals higher in
a food chain suffer more because more toxins “pile up” each step of a food web
10% rule – Only 10% of the energy gets passed along each step of a food web
Gross primary productivity (GPP), which is total solar energy producers in an ecosystem capture
Net primary productivity = GPP–respiration by producers (energy passed on to herbivores)
Biomass is the total mass of all living matter in an area. Used to measure energy
The amount of biomass present at a particular time is called standing crop
Hydrologic cycle = evaporation, condensation, precipitation, transpiration, runoff
o Humans affect water cycle
 Cut down trees reduces evapotranspiration
 Paving reduces evaporation from soil
 We divert water
Pools (reservoirs) are where there are build-ups
Flux is the rate materials move between pools
Carbon cycle is the transfer of carbon between the atm, land, water, and all living things.
o Plants convert CO2 from the atm into sugars
o Oceans capture CO2 from photosynthesis and calcium carbonate (decreases pH of water)
o When consumers eat producers, they consume carbon through carbs
o Some of this gets release back into atm through respiration
o Rest is released when organism dies through decomposers
o Some become fossil fuels
o Humans affect the carbon cycle by burning fossil fuels and tree harvesting
o Reduce carbon in 2 ways
 Minimize the amount we put into the atm
 Increase the rate we take it out of the atm through planting trees (carbon credits – countries get
paid for planting trees, but when trees die…)
Nitrogen cycle is transfer of nitrogen between air, bacteria, and other organisms
o Nitrogen fixation: conversion of gaseous nitrogen (N2) into ammonia (NH3), a form organisms can use.
Biotic or abiotic
o Nitrification: bacteria oxidizes it into NO3-, called nitrite
o Assimilation: plants roots absorb nitrites and pass it on to animals
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o Ammonification: when organisms die, nitrates go back to ammonia and release it back to nature
o Denitrification: breaks down back to a gas
o Human impacts = Eutrophication, wipes out old species
Phosphorus is essential for teeth and bones, energy transfer in a body, and nucleic acids
o Also heavily used in fertilizers
o Plants get phosphorus from water and soil, and transfer it to animals
o No atmospheric contributions
o Phosphorus comes from eroding rocks and waste
o Too much phosphorus can lead to algae blooms and eutrophication
Sulfur is necessary for proteins and vitamins
o Plants absorb sulfur in water, and animals eat them
o Most is found in rock
o Some in atmosphere from volcanoes and humans
Resistance is how much a disturbance can affect the flows of matter and energy
Resilience is the rate an ecosystem can return back to its original state after a disturbance. High resilience mean
quicker return
Chapter 4
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Weather is short term conditions of atmosphere
Climate is long term conditions
Atmosphere has 4-layers:
1. Troposphere (0-20km): bottom layer, densest, where most weather and mixing occurs, temps get colder with
height
2. Stratosphere (20-50km): second layer, gets warmer with height, contains ozone layer that absorbs UV light
3. Mesosphere (50-80km) – third layer, coldest, meteorites burn up
4. Thermosphere – top layer, warmest, absorb gamma rays
5 major processes influence climate/weather: unequal heating of earth, convection currents, Coriolis effect, tilt,
and oceans
1. Unequal heating of earth
 Atmosphere is heated unevenly for 2 reasons
 Tilt of the earth
 Some areas on earth reflect more sunlight than other areas (albedo). White surface has higher
albedo than black surface
 This uneven heating of the atmosphere drives convection currents in the atmosphere
2. Atmospheric convection currents
 Air rises in warm, moist tropics
 Rising air experiences lower atmospheric pressure
and adiabatic cooling until it reaches saturation point
 This leads to condensation which releases latent heat
 Eventually air cools and spreads out and begins to
sink around 30⁰ latitude (deserts)
 When sinking air hits the ground, it spreads in all
directions completing the cycle, called a Hadley cell
 Air re-converges at the equator, called the
intertropical convergence zone (ITCZ)
3. Earth’s Rotation and Coriolis Effect
 Earth rotates faster at equator than poles
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Objects’ paths get deflected due to the rotation of earth. This is known as the Coriolis effect
This deflects winds and sets up weather patterns
Trade winds blow towards the equator between 0- 30°. They meet at the equator and rise creating
calm winds called the doldrums
 Where the air sinks at 30° is the horse latitudes
 Air moves north from here, Coriolis force deflects it to right, and get westerlies (40°-60°)
 At poles, the air sinks and moves towards the equator, but gets deflected to right. This creates polar
easterlies
4. Earth’s Tilt and Seasons
 Earth is tilted 23.5⁰
 SEASONS ARE NOT BASED ON HOW CLOSE OR HOW FAR THE EARTH IS FROM THE SUN
 When northern hemisphere is pointed towards the sun they experience summer
 When northern hemisphere is pointed away from the sun they experience winter (southern
hemisphere is opposite)
 Vernal/automnal equinoxes, everywhere receives 12h daylight
 Poles have 6 months of darkness and 6 months of daylight
5. Ocean Currents
 Currents driven by temp, gravity, prevailing winds, Coriolis effect, and continents
 Water is warmer at the equator, so it expands and rises. This makes the water higher than the rest of
earth and gravity takes over
 Winds and Coriolis effect start ocean currents and deflect them. Called gyres (transport heat)
 Upwelling (rising of water) occurs along coastlines. Brings up nutrients
 Thermohaline circulation is when water is saltier, making it more dense, so it sinks
 ENSO (El Nino – Southern Oscillation– when ocean currents change direction, thus affecting climates
(La Nina)
Rain Shadows
o Air rises on one side of a mountain range and moisture condenses out
o On other side, air sinks preventing clouds and it remains dry
Biomes are large regions characterized by a specific type of climate and certain types of plant and animal
communities
Aquatic
Ecosystems
 Aquatic
ecosystems
are
categorized
by salinity,
depth,
nutrients,
and water
flow
 Streams and
rivers: rivers
larger and
carry more
water. Very
little plant
matter (most washes from land). Slower they flow typically means more life
Lakes and ponds: have standing water that gets too deep to support rooted plants. Lakes typically larger and
have water flowing in an out
o Littoral zone: shallow area near shore. Algae and cattails. Most life
o Limnetic zone: not rooted plants. Phytoplankton are producers. Extends as deep as sunlight
penetrates
o Profundal zone: region below where sunlight reaches. Not productive (few decomposers)
o Benthic zone is the muddy bottom (low temps and oxygen levels)
Freshwater Wetlands are land covered with water during parts of the year
o Filter pollutants and sediments
o Prevent flooding by storing excess water
o Provide homes for many types of organisms
o Recycle nutrients and sinks (CO2)
An estuary is where freshwater meets saltwater. Very productive ecosystem with large biodiversity:
o Many nutrients trapped where currents meet
o Tides circulate nutrients
o High level of light penetration
o Many plants in and around
Coral reefs are limestone ridges built by tiny animals
o It is made of skeletons that accumulate (limestone)
o Found in shallow, tropical water
o They eat microscopic organisms with tentacles
o Symbiosis with algae (coral release CO2, algae uses that for photosyn and creates sugars that coral
uses)
o One of most diverse ecosystems in world
o If water temp or salinity changes, they can die
o Oil spills, sewage, pesticide, runoff, harvesting (for jewelry) and over fishing have killed reefs
Chemosynthesis- The process that occurs in the aphotic zone when some species of bacteria use methane and
hydrogen sulfide to generate energy.
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Chapter 5
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Species richness is the number of species in a given area (pond, tree canopy)
Species evenness looks at individual proportions of species to see which are numerically dominant
o High species evenness if all species are represented equally
Evolution is the change in genetic composition of a population over time
o Microevolution is differences within a species (dogs)
o Macroevolution is when genetic changes give rise to an entirely new species
Complete set of genes is called the genotype. Phenotype is actual set of traits in an individual (what individual
actually looks like)
Two processes that create genetic diversity
o Mutations – DNA copies itself millions of times as cells divide. Occasionally there is a mistake.
 Mutations can hurt organisms (often die before born) or they can help organisms (mutation that
makes an insect less vulnerable to insecticides)
o Recombination – Chromosomes are duplicated during reproductive cell division and a piece can break off
and attach to another chromosome
 Does not create new genes, but creates new combinations of traits
Artificial selection is when humans determine which individuals will breed
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All dogs came from the gray wolf, most crops artificially selected, can lead to resistance (bacteria,
pesticides)
Natural selection is survival of the fittest
o Recombination and mutations give members of the same species different traits, some which may help
them survive
o Traits get passed on and determine ability to survive and reproduce
o Adaptations are behavior changes
Evolution by random process occurs in 4-ways:
o Mutation – mutation can arise in a population and increase over time as it mates
o Genetic drift – when genotypes are lost by chance (mouse population of 5 has 4 black mice and 1 white
mouse. If that white mouse finds no one to mate with, the white mouse population will disappear)
o Bottleneck effect – when a population is reduced, some genotypes are lost. Harder to survive because
less helpful mutations available
o Founder effect – when a small number of individuals determine characteristics of future generations (two
birds get blown off course and end up on a new island. The future generations depend 100% on their
traits)
Geographic isolation can lead to evolution
o If two habitats have different conditions, different phenotypes will be favored among the same species
(new island, lake split, volcano). Eventually they become so different, they can’t breed. Called
reproductive isolation
The whole process of geographic isolation leading to reproductive isolation is called allopatric speciation (Darwin’s
finches)
Sympatric speciation is when one species evolves into two without geographic isolation
o Feed in different areas, mate in different seasons
Factors that affect rate of evolution
o Rate of environmental change (faster change = less evolution)
o Genetic variation - more phenotypes which means quicker evolution (more genetic variation = more
evolution)
o Population size – large populations means more genetic diversity, but a mutation in a small population
can spread more quickly (smaller population equals more diversity)
o Generation time – quicker species becomes reproductively mature, the quicker they evolve (more
generations over short period of time)
Niches
o Range of tolerance is the limit of abiotic factors an organism can tolerate (temp, salinity, pH)
 The further away from ideal conditions, the less of an organism you may find
 Beyond the range of tolerance, organisms will die
o The fundamental niche is the combination of ideal abiotic conditions
o Biotic conditions can further limit a niche (competitors, predators, diseases)
o Realized niche is based on the combination of biotic and abiotic factors
 Generalists have broad niche
 Specialists have a narrow niche, so can’t adjust to change as well
Most species can’t adapt to significant changes for three major reasons
o No favorable environment to move to (polar bear)
o May be too much competition in new env
o Environmental changes may happen to quickly
5 mass extinctions have occurred
We are currently experiencing the sixth major extinction. Because of human activity (habitat destruction,
overharvesting, invasive species, climate change, and emerging disease)
Chapter 6
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Population is all the same members of the same species in a given area. This is the unit of evolution
Community is all the populations. Looks at species interactions. Communities can be grouped together to form
biomes
Ecosystem looks ate energy and matter flow, biotic/abiotic
Biosphere is all earth’s ecosystems (anywhere life occurs)
Population size is the total number of individuals within a defined area at a given time.
Population density is the number of individuals per unit area at a given time. Used to set hunting/fishing laws,
wildlife boundaries, etc
o Larger organisms usually have smaller density due to less resources
o High density = easy to find mates, but more competition and disease
Population distribution is how individuals are distributed in respect to one another
o Random – no pattern (solitary animals with
large territories) (least common)
o Uniform – individuals evenly spaced out
(territorial animals, competition)
o Clumped – large groups of organisms (fish,
birds). Enhances feeding opportunities and
protection (most common)
Biotic potential is how a population would grow if there was unlimited resources (reproductive characteristics)
Density dependent factors influence an individual’s probability of survival and reproduction in a manner that
depends on population size
o Limiting resources – a resource a population cannot live without and occurs in quantities lower than the
population would require to increase in size (food, water, shelter, nutrients, competition)
o Carrying capacity is the max population an ecosystem can support. It can overshoot, then birth rates
decrease and death rates increase
Density independent factors have the same effect on an individual’s
probability of survival and reproduction at any population size
o Natural disaster, weather, temp, habitat destruction
Growth Models
o Natural population growth rate  growth rate = birth rate
– death rate
o Intrinsic growth rate is maximum possible growth rate
o Actual population growth rate  (Crude birth rate +
immigration rate) – (Crude death rate + emigration rate)
o Exponential growth model – Nt = N0ert (j curve)
 e=natural log, t=time, Nt=future population, N0=current population, r=intrinsic growth rate
 Population grows very rapidly (lots of food/space and little comp)
 Density independent
o Logistic growth model starts off exponential, but slows as population approaches carrying capacity (s
curve, density dependent)
Doubling Time and the Rule of 70
o To find the approximate doubling time of a quantity growing at a given annual percentage, such as 10%,
divide 70 by the percentage growth rate.
o K-selected species population grows slowly until the carrying capacity
o R selected species have a high intrinsic growth rate (reproduce early and often)
Trait
K-selected species
R-selected species
Life span
Long
Short
Time to reproductive maturity
Long
Short
Number of reproductive events
Few
Many
Number of offspring
Few
Many
Size of offspring
Large
Small
Parental care
Present
Absent
Population growth rate
Slow
Fast
Population regulation
Density dependent
Density independent
Population dynamics
Stable, near carrying capacity
Highly variable
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Species Interactions
o Competition – when individuals struggle for the same limiting resource
 Members of same species compete of niches overlap
 Direct vs. indirect
 Competitive exclusion principle – two species competing for the same limited resource cannot
coexist (one will be driven out)
 Reduce competition by hunting at different times, using different habitats, and evolution of body
shape/size (finches)
o Predation – the use of one species as a resource by another species. Does not always result in death
 True predators consume and kill their pray
 Herbivores consume plants, but don’t usually kill them
 Parasites live in or on host, but only consume a small piece without usually killing host.
Pathogens make host sick
 Parasitoids lay eggs in host, and they eat their way out killing the host
o Mutualism – both species benefit from one another (birds/pollination, humans/bacteria, coral/algae,
lichens)
o Commensalism – one species benefits, and the other is neither helped nor harmed (fish/sharks, tree
branches as perches for birds)
o Commensalism, mutualism, and parasitism are all examples of symbiotic relationships, ones where two
species live in close association with one another
A keystone species is one that is disproportionately important to the community
o Typically occur in small numbers (sea star example)
Ecosystem engineers are create or maintain the habitat for other species (grizzly bear)
Indicator species are used as the standard to evaluate the health of an ecosystem
o Typically sensitive to change, so they can give warning signs (trout and poll)
Indigenous species are ones that naturally live in an area
Invasive species are ones that are introduces to a new ecosystem (zebra mussels)
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Primary succession occurs on abandoned or new land masses where there is no soil
o Rock is covered by lichens and mosses (don’t need soil)
o They secrete an acid that breaks down rock to create soil
o Lichen and mosses die and add organic matter to soil
o Soil gets deeper so grasses move in
o If climate favors, trees will follow
Secondary succession occurs in areas that have been disturbed, but still have soil and nutrients
o Often after natural disasters
o Grasses/flowers usually arrive within a year (pioneer species)
o Seeds come by wind, and trees quickly follow and compete for sun
o When everything is in balance, called climax community
Chapter 7
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Demography is the study of human population trends
Immigration is when people move into a population
Emigration is when people move out of a population
Growth rate depends on inputs (births and immigration) and outputs (deaths and emigration)
Total fertility rate (TFR) is an estimate of the average # of children each woman in a population will bear
throughout their childbearing years that will live to 15 (2.1 in the US)
o Low in developed countries, high in developing countries
o High TFR means the future population will grow
Replacement level fertility (RLF) is the TFR required to offset the average number of deaths in a population so that
the current size remains stable
o In developed countries, the RLF is typically 2.1
o Typically higher then 2 because child deaths, mothers who cannot produce offspring, etc
o In developing countries, and RLF is higher because many females die before childbearing years
Age structure diagrams show age structure (males vs. females across different age groups) within a country
Three general age structure diagrams
o Population pyramid has more young people than old people. Signifies a growing population (developing
countries)
o Similar number of young and old people. Looks more like a column. Means slow-steady population
growth
o More older people than younger people means a declining population
Theory of demographic transition is a 4-step process that says as a country moves from a subsistence economy to
industrialization and affluence, it undergoes a predictable shift in population growth
o Phase 1 – slow population growth, high birth/death rates due to disease, poor sanitation, and dangerous
working conditions (US before industrialization)
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Phase 2 – rapid population growth, death rates decline
and birth rates remain high. Better sanitization, more
food, health care (US in early 20th century)
Phase 3 – population stabilization. Strong economy
and\ education, and people have less children because
no longer financial benefit (farm). US right now
Phase 4 – population decline. Happens at wealthiest
times (woman working, children later in life)
IPAT equation calculates impact people have on earth
o Impact = population x affluence x technology
o If population increases, impact increases
o If affluence increases, impact increases
o If technology increases, it can increase or decrease impact (although usually increases)
Pros of affluence – stable high quality food, clean water, health care, access to fuel, sanitary conditions, education,
technology
Cons of affluence – increased greenhouse gas production, deforestation, shortage of resources, overfishing, toxic
waste, species extinction
What affects birthrates
o The age children enter the work force
o The cost of raising and educating children
o Availability of retirement/pension systems
o Families living in urban areas
o Higher education and employment rates of women.
o Lower infant mortality rate
o Average age at marriage
o Availability of legal abortions
o Reliable birth control methods
o Religious and cultural beliefs
Chapter 8
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Layers of earth
o Ingredients – crust, mantle, core
o Physical properties – lithosphere, aesthenosphere, mesosphere, outer core, inner core
Convection currents drive plate tectonic motion
Three types of plate boundaries
Divergent plate boundaries – crust moves away (seafloor spreading). New crust formed through volcanoes
Convergent plate boundary – plates move towards one another and form mountains and subduction zones
Transform fault boundary – plates slide past each other and cause earthquakes by elastic rebound process
Rock cycle is constant formation and destruction of rock
o Igneous rocks form directly from magma. Intrusive form underground, extrusive form above surface
o Sedimentary form when sediments get compacted or cemented. Where we find fossils. Often occur at
subduction zones
o Metamorphic form when preexisting rocks are subject to high heat or pressure
Weathering occurs when rocks are exposed to air, water, chemicals, biological agents, etc
o Eventually leads to soil formation
Physical weathering is the mechanical breakdown of rocks (ice wedging, plants roots)
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Chemical weathering is the breakdown of rocks by chemical reactions and/or dissolving of elements
o Leaching washes soluble materials out of rocks
Erosion is the removal of the broken down rock (wind, water, people)
Deposition is where the eroded material accumulates
Degradation is when there is a decrease in the soils ability to support plants
Soil is the critical link between living and non-living things
Soil is made of rocks /minerals, organic matter, air, and water
Parent material is bedrock (physical, chemical, and biological weathering)
Climate
o colder and drier = less organic matter
o Wetter climates = more leaching
Topography
o Steeper slopes have shallower soils due to erosion
o Hilltops have more leaching
Organisms
o Plants help prevent erosion
o Add organic matter and remove nutrients. Organisms mix soil
Soil composition
o Mineral Particles (45%)
 Weathered rock
 Provides essential nutrients for plants
o Organic Material (5%)
 Litter, animal dung, dead remains of plants and animals, humus (picture)
o Water (25%)
o Air (25%)
Horizons are layers in the soil
o O – surface (humus), organic matter at different points of decomposition
o A (topsoil) – soil that has been mixed (organic and weather rock (minerals))
o E (zone of leaching) – minerals. Drastic decrease in organic matter
o B (subsoil) – mostly mineral material leached from E horizon. High in clays
o C – near bedrock. Minimally weathered parent rock (larger rock pieces)
o R – Bedrock
Physical properties depend on size of particles
o Gravel > 2.0mm
o Sand > 0.05-2.0mm
o Silt > 0.002mm-0.05mm
o Clay<0.002mm
o Ratios of these determine soil texture (triangle)
Porosity (spaces that hold air and water) depends on texture
o Determines availability of air and water for plants
o Sand drains the quickest (poor saturation, high aeration), and clay drains the slowest (high saturation,
poor aeration)
o Quicker it drains, the less groundwater cleans itself out
Permeability is the ability for water to flow
Chemical properties
o Cation exchange is the ability for soil to absorb/exchange cations (clay attracts the most)
 This transfers ingredients throughout the soil
 Clay is very good due to its negative charge. It holds nutrients
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pH of soil (acidity vs. alkalinity)
 Acids – aluminum and hydrogen (hurt plant growth)
 Bases – Calcium, magnesium, potassium, sodium (help plant growth, except sodium)
Biological Properties
o Biological properties – made mostly of microorganisms, but some flora and fauna
o Flora holds soil together, nutrient exchange, increases porosity
o Fauna break down organisms, create passageways for water/air
o Microorganisms “glue” soil particles together, decompose organic matter, transform nutrients
Ores are concentrations of minerals that are valuable
Common ores are metals, elements that conduct electricity and heat
Reserves are a known the known quantity of a resource that can be economically recovered
Surface mining occurs close to the surface
o Strip mining is when strips of soil are removed to recover bands of a mineral
o Open pit mining is when they start at the surface and dig down creating a pit
o Mountain top removal removes a mountain top
o Placer mining looks in rivers for sediments
Subsurface mining takes place underground
Mining and the environment
o Roads are constructed that cause soil erosion, blocks waterways, and fragments habitats
o Acids, toxic metals, and debris can leak into water
o Debris dug up has to be temporarily placed somewhere
o Pump away ground water in subsurface mining
o Pollution
o Dangerous to human health
Chapter 9
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70% of earth is covered in water, but 97% of that is salt
Remaining freshwater (<.5% salt), 22% is underground, and 77% is frozen (<1% fresh water bodies)
Groundwater
o Groundwater exists in permeable layers of rock called aquifers
o Unconfined aquifers are aquifers that water can easily flow in and out of
o Confined aquifers are aquifers that are surrounded by an impermeable layer
o Water table is the uppermost limit of saturated rock
o Groundwater recharge zone is where water gets added to an aquifer (harder in confined aquifers)
o Springs are where ground water reaches the surface. Naturally clean
o Wells are holes dug into the groundwater (cone of depression)
Saltwater intrusion- when the pumping of fresh water out of a well is faster than the recharge. Near coastal areas
this can cause salt water to infiltrate the aquifer.
Oligotrophic lakes are low in productivity, and eutrophicare high on productivity
Levee is a bank alongside a river
o Prevents natural floodplains, lead to more sediment downstream, may cause other areas to flood, and
leads to development in floodplain
Dikes are similar to levees but they prevent ocean flooding
Dams are barriers that control water flow and create reservoir
o Affect habitats, take nutrients out of the water, sediments pile up, displace people, uses large amount of
resources
Desalinization is removing salt from water. Two ways:
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o Distillation is when water is boiled and the water and salt separate
o Reverse osmosis is when water is forced through a semipermeable membrane (filter)
Ways to increase water
o Desalination
o Use more effective irrigation methods (drip irrigation)
o Water efficient appliances
o Xeriscaping
o Rainwater harvesting = capturing rain from roofs
o Gray water = wastewater from showers and sinks
o Demand industries use less
o Level fields to reduce runoff
o Genetic modification
o Water lawns at night
Water Use
o 70% agriculture, 20% industry, 10% households
o Irrigation is the use of water for crops. 4 methods
 Furrows are when trenches are dug that fill with water
 Flood irrigation floods the whole fields and let it soak slowly
 Spray irrigation is when water is pumped and sprayed
 Drip irrigation is when water drips out of a hose with holes
Water Scarcity
o Dry Climate: normally has little precipitation
o Drought: precipitation is 70% lower than normal
o Desiccation: drying of soil because of deforestation, overgrazing
o Water stress: low water availability because more people are relying on the water supply.
o Water withdrawals can cause rivers, lakes and streams to shrink in volume
Chapter 10
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Tragedy of commons – tendency for a shared, limited resource to become depleted because people look for shortterm gain
Externality is a cost benefit of a good or service that is not included in the purchase price of that good
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Is there more good or harm in a situation
Maximum sustainable yield – the max amount of a renewable resource that can be harvested without
compromising the future availability of the resource
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E.g. Hunting can be good to control population, but bad if overhunted
Public land classification
o National parks – used for scientific, educational, and recreational use. Not used for extraction of
resources
o Managed resource protected areas – used for biological, mineral, and recreational resources
o Wilderness areas – established to protect species and ecosystems. Minimal env impacts
o National monuments – areas set aside for special natural or cultural interest
Public lands in the US
o Rangelands, national forests, national parks, wildlife refuges, and wilderness areas. Left up to policy
makers to decide what land can be used for
Land management
o Rangelands are dry, open grasslands
 Mostly used for cattle grazing. Can lead to loss of vegetation, soil erosion, and water pollution
o Forests are areas dominated by trees
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Clear cutting removes all the trees in one area. Cheapest and easiest. Increases erosion and hurts
habitats
 Selective cutting removes individual trees.
Tree plantations are when forests are replanted with quick growing trees.
 Never allows forest to mature
Prescribed fires are used to help get rid of dead matter
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Forests
o Forests are some of the richest ecosystems for biodiversity
 They are structurally complex, with many niches
 They provide food and shelter for multitudes of species
 Fungi and microbes have parasitic and mutualistic relationships with plants
o Plant diversity leads to greater overall organism diversity
 Succession changes species composition
o Old-growth forest diversity exceeds that of young forests
 They have higher structural diversity, habitats, and resources
o Forests provide cultural, aesthetic, health, and recreation values
o Forests also provide vital ecosystem services
 Stabilize soil and prevent erosion
 Slow runoff, prevent flooding, purify water
 Store carbon, release oxygen, influence weather patterns, and moderate climate
o Roots draw minerals to surface soil layers
 Plants return organic material to the topsoil as litter
o Old-growth forest diversity exceeds that of young forests
 They have higher structural diversity, habitats, and resources
Residential land use
o Suburban areas surround metropolitan areas and have relatively low population densities. Fastest
growing areas
o Urbanization is when people move into cities
o Urban sprawl is when populations shift into suburban areas (clusters of houses, retail shops)
 Use twice as much land per person as urban areas, more driving, pushes farmland away
increasing the distance
 4 main causes of urban sprawl
 Automobiles/highways make for easy access
 Living costs (more for your money)
 Urban blight (reduced services as people move)
 Gov Policies
 Problems with urban sprawl
 Economists, politicians, and city boosters think growth is always good
 Transportation: people are forced to drive cars
o Pressure to own cars and drive greater distances
o Lack of mass transit options
o More traffic accidents
o Increases dependence on nonrenewable petroleum
 Pollution = carbon dioxide, air pollutants, ozone, smog, acid precipitation
o Motor oil and road salt from roads and parking lots
 Health = sprawl promotes physical inactivity because driving cars replaces walking
o Increases obesity and high blood pressure
 Land use = less forests, fields, farmland, or ranchland
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Loss of resources, recreation, beauty, wildlife habitat, air and water
purification, services
Economics: sprawl drains tax dollars from communities
o For roads, water and sewer systems, electricity, police and fire services,
schools, etc. in new areas
o Taxpayers, not developers, subsidize improvements
Noise pollution = undesired ambient sound
o Degrades surroundings, stressful, hurts hearing
Light pollution = lights obscure the night sky
o Impairing the visibility of stars
Urban heat island effect = cities are hotter than surrounding areas
Buildings, vehicles, factories, and people generate heat
Dark buildings and pavement absorb heat
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Urban Planning
 Limit sprawl: keeps growth in existing urbanized areas
 Revitalize downtowns
 Protect farms, forests, and industries
 Ensure urban dwellers some access to open space
 May reduce infrastructure costs
 Disadvantages:
 Increase housing prices within their boundaries
 Restrict development outside the UGB
 Increase the density of new housing inside the UGB
 Increasing pressure to expand boundaries
 Smart Growth
 Smart growth = urban growth boundaries and other land use policies to control sprawl
 Proponents of smart growth promote:
o Healthy neighborhoods and communities
o Jobs and economic development
o Transportation options
o Environmental quality
 Building “up, not out”
o Focusing development in existing areas
o Favoring multistory shop-houses and high-rises
 Transportation
 Traffic jams cause air pollution, stress, and lost time
o Cost the U.S. economy $74 billion/year
 Key in improving quality of urban life: mass transportation
o Buses, trains, subways
o Light rail = smaller systems powered by electricity
 Cheaper, more energy efficient, and cleaner
 Traffic congestion is eased
 It is expensive to replace existing roads
 Strong, visionary political leadership is needed
o Growth is directed, instead of being overwhelming
 Governments can encourage mass transit
o Raise fuel taxes
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o Tax inefficient modes of transport
o Reward carpoolers
o Encourage bicycle use and bus ridership
o Charge trucks for road damage
o Stimulate investment in renewed urban centers
Greenways: A strip of parkland that connects parks or neighborhoods; often located along rivers, streams
or canals.
Smart Growth: A city planning concept in which a community’s growth is managed in ways that limit
sprawl and maintain of improves residents’ quality of life. It involves guiding the rate, placement, and
style of development such that it serves the environment, the economy and the community.
Greenbelts = long, wide corridors of parklands
 May surround an entire urban area
Green buildings = structures that reduce their ecological footprints
 Built from sustainable materials, minimize energy and water use, recycle wastes
10 principles of Smart Growth
 Mixed land use encourages people to walk/bike
 Create a range of housing choices (for diff incomes) so all people can find a job nearby
 Create walkable neighborhoods (buildings near sidewalks, slow speed limits, etc)
 Encourage stakeholders to collaborate in decisions
 Take advantage of compact building design
 Create a feeling of a sense of place
 Preserve open space
 Provide a variety of transportation services
 Fill vacant areas before new development
 Make development decisions predictable and fair
Chapter 11
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Undernutrition is not getting enough calories (2200kcal per day). Used for energy
Malnutrition is when someone receives enough calories, but not the right balance of nutrition
Famine is when large amounts of people do not have access to safe food
Anemia (iron deficiency) is most common deficiency in the world
Overnutrition is the intake of too many calories and improper foods
o Leads to disease which hurts economy because higher medical bills and more time off work
Reasons for malnutrition
o There is enough food on this planet to feed all
o Poverty
 Not access to food, not evenly distributed
o Political/economic factors (people forced to flee)
o Lots of food used to feed livestock
o Three main crops feed the world
 Corn, rice, and wheat feed most of world
 Meat takes up more land and uses more resources
o Food security is making food available to all people at all times
Energy subsidy is the energy input per cal of food
o Most come from fossil fuels
Green revolution is when we changed from human labor to farming techniques (machines, fertilizer)
o Mechanization – less money and time, more efficient
o Improved irrigation methods
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Fertilizers to replace removed organic matter. Enhanced with nutrients
Monocropping – the planting of a single plant in big area
Pesticides (insecticides and herbicides) - evolve
Uses more fossil fuels, runoff, salinization
Positives
 Prevented some deforestation and land conversion
 Preserved biodiversity and ecosystems
o Negatives
 Pollution, erosion
 Salinization, desertification
Genetic engineering
o PROS
 Reduce cost of production
 Better resistance of plants to pests/disease
 Better texture/flavor/nutrition
 Better shelf life
 Better yield per square mile
 Less need for herbicides and other chem
 Cheaper source of creating medicine
 Remove undesirable characteristics of cells that we don’t want
 Custom design food
 Crops resistant to harsh environments
 Increased production to feeds
o CONS
 Potential human health impact (allergies, resistance, unknown effects)
 Potential env impacts (gene pollution, unknown effects on other species)
 Domination of food production by few companies (monopoly)
 Developing countries depend on developed countries more
 Bio-piracy
 Violating organisms natural intrinsic values
 Stress on plants and animals used to be tested on
 New bacteria evolve
o Sustainable agr fulfills need for food while enhancing the quality of the soil, minimizing use of resources,
and allowing for economic viability
 Use waste instead of fertilizer, intercropping, crop rotation, contour plowing, no till agriculture,
integrated pest management, organic agriculture
o Organic agriculture = uses no synthetic fertilizers, insecticides, fungicides, or herbicides
Soil Conservation
o No till farming: do not plow at end of season
o Terracing: change hillsides into “steps”. Slows water running off.
o Contour farming: planting crops across the hill slope instead of up and down. Also slows water
o Strip cropping (intercropping): Planting alternating rows of cover crop with row crops. The cover crop
traps the soil that erodes from row crop.
o Cover crops: planting cover crops (alfalfa, clover, etc) immediately after harvest to hold soil in place over
winter.
o Alley cropping: AKA – agroforestry. Planting crops in alleys between rows of trees or shrubs. Holds soil
and reduces evaporation
o Windbreaks: AKA – shelterbelts. Reduces wind speed, roots hold soil, reduce evaporation
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Soil Degradation
o Desertification - The process of creating a desert where there was not one before. Farming in marginal
grasslands, which destroys the soil and prevents the future recovery of natural vegetation, is an example
of desertification.
o Salinization - The buildup of salts in surface soil layers.
o Monocroppoing leads to lack of genetic diversity which makes plants susceptible to disease and pests.
Secondly, planting same crop leads to leaching of certain nutrients
Modern Agribusiness
o Concentrated animal feeding operations (CAFOs) are large structures designed for maximum output
 Minimize land costs and increase efficiency
 Increase antibiotic resistant strains of bacteria, waste
 One third of world’s crops feeds livestock
 Pollute
o Fishery is an area where fish can be harvested for profit
 Because no one owns the oceans, competition is strict and people overfish
o Aquaculture is the farming of aquatic organisms
 Benefits: reliable protein source, can be sustainable, reduces pressure on overharvested wild fish
energy efficient
 Drawbacks: diseases require expensive antibiotics, lots of waste, uses grain, escaped GM fish
introduce disease or outcompete wild fish
Pesticides
o Pest = any organism that damages valuable crops
o Weed = any plant that competes with crops
o Pesticides = poisons that target pest organisms
 Insecticides = kill insects
 Herbicides = kill plants
 Fungicides = kill fungi