Chap 1: Environmental Issues
- Environmental Science: Interdisciplinary study that uses information and ideas from the physical
sciences, social sciences and the humanities to learn how nature works, how we interact with the
environment and how we can deal with environmental problems.
- Ecology: how organisms, or living things, interact with one another and with their environment
- Ecosystem: a set of organisms within a defined area or volume interacting with one another and
with their environment of nonliving matter and energy.
- Environment includes all living (biotic) and nonliving (abiotic) things with which an organism
interacts.
Capital = Value/ money /form of wealth
Natural capital = Natural resources (renew, nonrenew) + Natural services
- Natural resources: Natural resources are materials and energy that keeps all forms of life alive and
support our economics
- Natural services: Processes in nature (nutrient cycling, water purification)
Use/renewable resource > replacement rate => environmental degradation
- Sustainable yield is the highest rate at which a resource can be used indefinitely without reducing its
available supply => 3R (reuse, renew, recycle)
- Cause Pollution (point, nonpoint) : Population (beyond support), poverty (short-term survival), affluence
(too high consumption), price (low now, high later)
- Protection (3 big idea) : Renewable; biodiversity, prevent degradation; reduce waste, preserve natural
chemical
- Tragedy of Commons: shared resources
- Ecological footprint: The amount of biologically productive land and water needed to supply a
population
- Per capita ecological footprint is the average ecological footprint of an individual in a given country or
area Eutrophication is the ecosystem response to the addition of artificial or natural substances (such as
Nitrogen and Phosphorus)to aquatic systems.
I = P x A x T (Environmental impact, Population, Affluence per person, Technology used) (Ehrlich and
Holdren)
CHAP 3: ECOSYSTEM
- An ecosystem is made up of animals, plants and bacteria as well as the physical and chemical
environment they live in -> unique => study = ecology
- Biomes: Life exists on land system
- Earth system: Geophere hot core, thick mantle, and thin crust. Hydrosphere Liquid water on surface
and underground, ice (cryosphere) and water vapor. Biosphere: Living and dead organisms.
Atmosphere: Thin membrane of air Troposphere (đối) (air layer about 4–11 miles above sea level,
contains greenhouse gasses that absorb and release energy which warms the inner layer of the
atmosphere), Stratosphere (bình) (above the troposphere between 11–31 miles; it filters out the sun’s
harmful radiation) , Mesosphere (trung), Ionosphere (điện ly)
- Components of ecosystem include Soil (nutrient, water, a home and a structure medium for the roots of
plants); Sun (energy in form of radiation which is used to generate heat and power photosynthesis); Water
(in bodies of organism, nutrient exchange between soil and life & use in photosynthesis, respiration, evapo-
transpiration and precipitation),Atmosphere (is an sink for oxygen, CO2 and water)
Three Factors Sustain the Earth’s Life
-Solar energy (one-way flow of high-quality energy): high-quality energy from the sun, through living things
in their feeding interactions, into the environment as low-quality energy (mostly heat dispersed into air or
water at a low temperature), and eventually back into space as heat
-Cycling of nutrients: Dead organic matter (decomposition) -> inorganic matter in soil -> organic matter in
plant -> organic matter in animals (cycle)
-Gravity allows the planet to hold onto its atmosphere and helps to enable the movement and cycling of
chemicals through the air, water, soil, and organisms
- Natural of Ecology: Organism (living) -> species (breed and fertile offspring) -> population -> community
-> ecosystem -> biosphere
- Producers (autotrophs): green plants (mostly capture sunlight to produce carbohydrates), photosynthesis
process
- Consumers (heterotrophs) eating and recycling to survive. Herbivores (Primary eatproducer). Carnivores
(Secondary eat primary. Third and higher level eat carnivores).
- Omnivores (eat both plants and animals: pig, rat, human). Decomposers (bacteria/fungi) recycle nutrients
in ecosystems. Detritivores: insects or other scavengers that feed on wastes or dead bodies
- Aerobic respiration: The opposite of photosynthesis, break down carbohydrates
- Food chain: A linear series of feeding relationships in an ecosystem. Energy and nutrient are passed
through organisms
- Food webs: Consumers feed on more than 1 type of organism. Organism in ecosystems form a complex
network
- The water cycle: Solar energy evaporates water; the water returns as precipitation (rain or snow), goes
through organisms, goes into bodies of water, and evaporates => humans withdraw freshwater faster than
nature can replenish it; Clear vegetation; Drain wetlands interferes with flood control.
- The carbon cycle: Carbon is the basic building block of carbohydrates, fats, proteins, DNA, and other
compounds, included in fossil fuels
Producers, consumers and decomposers circulate carbon in the biosphere => human add more CO2 by
burning fuels, clear cây
- The nitrogen cycle: Nitrogen gas (N2), 78% of the atmosphere, not used directly by most living
organisms => human increased use of inorganic fertilizers to grow crops. This excessive input of
nitrogen into the air and water contributes to pollution
- The phosphorus cycle (grow algae): circulates through water, Earth’s crust, and living organisms in the
phosphorus cycle. Phosphorus does not cycle through the atmosphere.
- Major reservoirs of phosphorus are rock formations and ocean bottom sediments. Transferred by food
webs is an important component of many biological molecules. => humans remove large amounts of
phosphate from the earth to make fertilizer, reduce phosphorus in tropical soils by clearing forests.
- The Sulfur Cycle: stored underground in rocks and minerals. Hydrogen sulfide (H 2S) is released from
volcanoes and anaerobic decomposition of organic matter in bogs and swamps => Human burn sulfur-
containing fuels, Refine sulfur-containing fuels
Chap 4&5: Biodiversity and Evolution Species interaction & Population control
- Biodiversity: The variety of all life in the world or in a particular habitat or ecosystem.
4 scales: species, genes, ecosystems, functions
+ Species diversity: different species in a region or in a particular habitat. More species = Healthier
ecosystem. More: warm, low, wet. Few: cold, high, dry
+ Genetic diversity: variability within species, to adapt to and survive dramatic environmental changes.
+ Ecological diversity: the diversity of ecosystems or habitats that exist in a given region. More healthy
systems = healthier environment.
Biome: Terrestrial (land) portion of the biosphere.
+ Functional diversity: The variety of processes such as energy flow and matter cycling that occur within
ecosystems as species interact.
- Biodiversity provides: natural resources & services, aesthetic pleasure
- Niches: way of life or role of a species in an ecosystem (include physical, chemical and biological
condition)
- Habitat: the place where an organism lives.
- Generalist species: broad niches, live many places, eat many foods, tolerate a wide range of
environments. Ex: Racoon.
- Specialist species: narrow niches, specific environments, prone to extinction when environment change.
Ex: Panda bamboo.
- 4 types of species:
+ Native: species normally live and thrive in a particular community. Ex: Saola in VN.
+ Nonnative (Invasive/ Alien/ Exotic): migrate into or accidentally introduced into a community. Ex:
Golden apple snail.
+ Indicator: serve as early warning of damage to a community or an ecosystem. Ex: birds, amphibians.
+ Keystone: have a large effect on other species in the community. Ex: wolf, leopard, lion.
- 5 species interaction:
+ Competition: sharing scarce food and space. Inter-specific (different species: lion vs hyenas) and intra-
specific competition (within same species).
Resource partitioning: species competing for similar scarce resources evolve specialized traits that allow
them to use shared resources differently.
+ Parasitism: one species (parasite) feeds on the body of, or the energy used by, another organism (host).
+ Predation: one species (predator: hide, attack) feeds directly on all or part of a living organism of another
species (prey: protect, escape, hide, retaliate).
+ Mutualism: 2 species interact in a way that benefits both. Ex: flower and bee.
+ Commensalism: some species interact in the way that helps 1 species but has no effect on the other.
- Dispersal: movement into new area
- Limiting factors: light, water, and nutrients, can affect the number of individuals in a population.
- Environmental resistance: the combination of all factors that act to limit the growth of a population.
- Carrying capacity: the maximum population of a given species that a particular habitat can sustain
indefinitely.
- Exponential growth (J-curve): start slowly then accelerate.
- Logistic growth (S-curve): a steady decrease in population growth with time until population size levels
off.
- r-selected species (opportunists): high rate of population increase, large number of offspring, low
parental care, massive loss of offspring.
- K-selected species (competitors): small number of offspring. High parental care, mature slowly.
- Population change = (births + immigration) – (deaths + emigration)
- Population crash: sharp decline in size when a population uses up its resources and exceeds the
carrying capacity.
- Reproductive time lag: the period needed for the birth rate to fall and the death rate to rise in response
to resource overconsumption.
- Biological evolution: life changes over time through changes in the genes of populations in succeeding
generations. Process: genes mutate > individuals selected > adapt to environment
- Natural selection: individuals with certain traits are more likely to survive and reproduce under a
particular set of environmental conditions than those without the traits. Limit: (1) adapted traits must exist
in gene pool or mutation, (2) limit by reproductive capability. Myth: (1) fittest not strongest, (2) not explain
origins of life, (3) humans not from monkeys, (4) not a plan by nature.
- Mutations: random changes (internal or external) in the DNA molecules of a gene in any cell, creating
genetic variability. Lethal or beneficial.
- Adaptation: heritable traits improve the ability of an individual organism to survive more easily and
reproduce at a higher rate under environmental conditions.
- Genetic resistance: the ability to tolerate a chemical designed to kill the population. (natural selection,
antibiotics)
- Extinction: an entire species ceases to exist (natural or human cause)
- Background extinction: species disappear at a low rate (1-5 million/year)
- Mass extinction: 25-95% disappear. Five in history.
- Mass depletion: higher than normal but not mass level.
- Local extinction: extinct over a large region, but not globally.
- Endemic species: found in only one area and are vulnerable to extinction.
- Speciation: new species appears.
- Disturbance : An event that alters an ecosystem, either significantly changing it or wiping out entirely.
- Succession: The gradual change in species composition of a given area
+ Primary succession: begin with nothing, follow severe disturbance, take long time
+ Secondary succession: begin with remains of moderate disturbance, happen more rapidly
- Pioneer community: first colonizers
- Climax community: old forests
- Two aspect of sustainability:
+ Inertia (persistence): ability to survive moderate disturbances.
+ Resilience: ability of being restored by 2nd succession after severe disturbances.
Chap 6: Human Population and Urbanization
- Cultural carrying capacity: maximum number of people who could live in reasonable freedom
and comfort indefinitely, without decreasing the ability of the earth to sustain future generations.
- Birth/Death rate: number per 1000 people
- Factors affect birth rates and fertility rates:
+ The importance of children as a part of the labor force. + The cost of raising and educating
children. + The availability of, or lack of, private and public pension systems.+ Urbanization +
The educational and employment opportunities available for women. + The average age at
marriage. + The availability of legal abortions.+ The availability of reliable birth control methods.
+ Religious beliefs, traditions, and cultural norms.
- Factors affecting death rates
+ Increase in food supplies + Better nutrition + Advances in medicine + Improved sanitation
Personal hygiene + Safer water supplies + War + Famine/diseases + Accident
- Infant mortality rates: number of babies out of 1000 born who die before their first birthday >
general level of nutrition and health care > best measure of society’s quality of life.
- Migration: movement of people into (immigration) and out of (emigration) specific geographic
areas. Factors: jobs, religious persecution, ethnic conflicts, political oppression, wars, and
environmental degradation: soil erosion, water & food shortage (environmental refugees)
- Population age-structure diagrams: Prereproductive (0–14) > Reproductive (15–44) >
Post Reproductive (45+).
- Demographic momentum: rapid population growth in a country that has a large percentage of
people <15, and happens when a large number of girls enter their prime reproductive years.
- Japan population: discouragement of immigration > bleak economic future
- Problems: threaten economic growth, labor shortages, less gov revenues, less business, less
tech development, increase public deficits for pension and healthcare, pension cuts, increase
retirement age.
- Demographic transition: high birth/death > low birth/death during industrialization:
Preindustrial (slow), Transitional (rapid), Industrial (slow down) and Postindustrial (level off and
decline).
Sudden decrease in death rates > decrease in birth rates
Educated and more affluent populations: dropping birth rates > growth rate = 0
- Solutions: Reduce poverty, Elevate the status of women, Encourage family planning (reduce
abortions) and reproductive health care (reduce mother dying).
+ Less-developed: richer = slower growth
+ Rapid population growth, extreme poverty, and increasing environmental degradation:
stuck S2
+ Woman: educated, controlled, paid job, good society = fewer children.
- Poverty is becoming increasingly urbanized, mostly in less-developed countries.
- Urbanization:
Advantages: More job opportunities, Better education and health, Protect biodiversity of
concentrating people.
Disadvantages: Threaten biodiversity, lack vegetation, water problems, Concentrate pollutant
and noise, Spread infectious diseases, Centre of poverty crime and terrorism
Eco green city: Allows people to walk, bike or take mass transit for most of their travel
Goals: Preventing pollution and reducing waste, Using energy and matter resources efficiently,
Recycling, reusing and composting at least 60% of all municipal solid waste, Using solar and
other locally available, renewable energy resources, Protecting and encouraging biodiversity by
preserving surrounding land.
