103 terms

BIO Exam 2

Worlds most populous nation with 1/5 of all people living on earth
Size of Human Population
6.7 billion people
Worlds population increased the most
most recently
Environmental Impact
According to the IPAT model, technology that enhances our acquisition of minerals, fossil fuels, timber, and ocean fish
Sensitivity Factor
sensitivity of given environments to human impact and for the effects of social institutions such as education, laws, societies, ethical standards.
individuals who study the statistical characteristics of human populations, help predict population dynamics and environmental impacts
3 most populated countries
China, India, United States
Age structure
individuals in young age groups do a great deal of reproduction.. most industrialized nations are aging,
Population Change
An increase or decrease in the size of a population. It is equal to (Births + Immigration) [[minus]] (Deaths + Emigration).
TFR is controlled
social and economic security drive TFR down
replacement-level fertility rate
2.1 births per woman
Factors that affect total TFR
When the TFR drops below 2.1, population size, in the absence of immigration will shrink... medical care, urbanization drives TFR down, social security drives TFR down, women in the labor force drives TFR down.
Demographic Transition
the process by which a country moves from relatively high birth and death rates to relatively low birth and death rates... the decline in death rates followed by decline in birth rates when a country becomes industrialized...net pop growth occurs in period between death rates falling before birth rates
Family-Planning Programs
can effectively lower population growth rates in all types of nations, reduces birth rates through education and increased availability of contraceptives
Industrialized Agriculture
Using large inputs of energy from fossil fuels (especially oil and natural gas), water, fertilizer, and pesticides to produce large quantities of crops and livestock for domestic and foreign sale. Compare subsistence farming.. most characteristic of developed countries
Healthy soil
helps crops produce more food... requires contributions from B. organic material from formerly living material.
C. minerals from the weathering of the C horizon.
D. the millions of living organsims in the soil.
E. complex organic molecules resulting from decomposition.
Soil Erosion
Movement of soil components, especially topsoil, from one place to another, usually by wind, flowing water, or both. This natural process can be greatly accelerated by human activities that remove vegetation from soil.
Causes of Soil Erosion
overcultivating, overgrazing, clearing forests, removing plant cover
The loss of more than 10% productivity in arid areas due to erosion, soil compaction, forest removal, and an array of other factors (overgrazing, drought, salinzation, climate change, depletion of water)
National Resources Conservation Service
provides technical assistance to both farmers and ranchers... a conservation leader for all natural resources, ensuring private lands are conserved, restored, and more resilient to environmental challenges, like climate change...works with landowners through conservation planning and assistance designed to benefit the soil, water, air, plants, and animals that result in productive lands and healthy ecosystems.
Crop Rotation
the system of growing a different crop in a field each year to preserve the fertility of the land.. controls erosion and helps replenish soil nutrients
Contour farming
Plowing and planting across the changing slope of land, rather than in straight lines, to help retain water and reduce soil erosion.
shaping the land to create level shelves of earth to hold water and soil; requires extensive hand labor or expensive machinery, but it enables farmers to farm very steep hillsides
Growing two or more different crops at the same time on a plot. For example, a carbohydrate-rich grain that depletes soil nitrogen and a protein-rich legume that adds nitrogen to the soil may be intercropped.
soil protection provided by rows of planted vegetation between strips
No-till farming
cuts furrows through the topsoil and crop residue, drops seeds into furrow, and closes the furrow over the seeds.. then add a localized dose of fertilizer
Process that occurs when soils in arid areas are brought under cultivation through irrigation. In arid climates, water evaporates quickly off the ground surface, leaving salty residues that render the soil infertile., the process in which soil becomes saltier and saltier until, finally, the salt prevents the growth of plants. Salinization is caused by irrigation because salts brought in with the water remain in the soil as water evaporates.
food supply problem
food security depends on maintaining healthy soil, water, and biodiversity.
farming strategy in which large fields are planted with a single crop, year after year... gains efficiency of scale
green revolution
the introduction of pesticides and high-yield grains and better management during the 1960s and 1970s which greatly increased agricultural productivity....increased crop output per unit area of existing cultivated land... Negative effects include the intensive use of water, fossil fuels, inorganic fertilizers, pesticides made pollution worse, erosion.. also reduced biodiversity, decline in soil quality
Biological control
A method of pest control that involves the use of naturally occurring disease organisms, parasites, or predators to control pests, a natural predator or disease released into an area to combat a pest insect
Integrated Pest Management
a variety of pest control methods that include repairs, traps, bait, poison, etc. to eliminate pests.. biocontrol measures, crop rotation, habitat diversification
Insects and agriculture
usually essential pollinators and predators for successful agriculture
Genetically Modified Organisms
crops that carry new traits that have been inserted through advanced genetic engineering methods, organisms whose genetic code has been altered by artificial means such as interspecies gene transfer
Seed banks
holds and preserves hundreds of plants that are going extinct.. protects genetic diversity
allow for greater production of food, but can emit strong odors and pollute surface water and groundwater because livestock produce prodigious amounts of feces and urine
can bring economic benefits and food security to many developing regions , the science and business of raising and harvesting fish in a controlled situation
Most energy efficient foods
energy is lost from one animal to another, vegetarian diet must more energy efficient than eating meat.. eggs chicken and milk good choices... cattle the worse (beef)
Organic Agriculture
crops produced without the use of synthetic or industrially produced pesticides and fertilizers, Approach to farming and ranching that avoids the use of herbicides, pesticides, growth hormones, and other similar synthetic inputs.
Sustainable agriculture
Farming methods that preserve long-term productivity of land and minimize pollution, typically by rotating soil- restoring crops with cash crops and reducing in-puts of fertilizer and pesticides.
How to name an organism
categories meant to reflect evolutionary relationships. related species grouped together into genera, related genera grouped into families..every species has two part latin name denoting genus and species.. third part of the name is subspecies
the diversity of plant and animal life in a particular habitat (or in the world as a whole), the variety of species living within an ecosystem.... he genetic diversity within and between populations of a species.
Global biodiversity patterns
species richness generally increase as one approaches the equator ( pattern of variation with latitude called the latitudinal gradient). species diversity tends to increase with diversity of habitats
Mass extinction
event in which many types of living things become extinct at the same time
Background extinction
Normal extinction of various species as a result of changes in local environmental conditions. Compare mass depletion, mass extinction., the gradual process of species becoming extinct
Changes species diversity globally
speciation and extinction
Recent extinction rates
species loss is accelerating as our population growth and resource consumption put increasing strain on habitats and wildlife.
Red list
an updated list of species facing high risks of extinction to keep track of the current status of endangered species... , categorise species at risk
Biodiversity loss
the decline in population sizes of many organisms which are accompanied by shrinkage of species geographic ranges. 4 primary causes: habitat alteration, invasive species, pollution, and overharversting.. global climate change becoming the 5th (habitat destruction, the introduction of invasive species, and overexploitation)
invasive species
gypsy moth, european starling, cheatgrass, brown tree snake, kudzu, asian long horned beetles, rosy wolfsnail, european rabbits
Species loss on humans
species have ecological, economic, medical, scientific, and intrinsic value
threatened species
California condor and whooping crane
Equilibrium Theory of Island Biogeography
theory that says species richness on islands can be modeled as a dynamic balance between colonization by species and extinction of species, the theory that the biodiversity on islands is governed by rates of colonization and extinction, which in turn are controlled by island isolation and island size (he number of species increases with the size of the island; all else being equal, larger islands contain more species (correct answer)
Endangered Species Act
. is one of the world's toughest environmental laws.
B. allows the use of endangered species for approved scientific purposes or if the use enhances the survival of the species.
C. authorizes identification of endangered species solely on a biological basis.
D. requires all commercial shipments of wildlife enter or leave the U.S. through one of nine designated ports.
-dictates that landowners can harm species only if they improve habitat for the species in other areas
umbrella species
need large areas of undisturbed habitat, a species that impacts the survival of many species
tries to prevent the extinction of species by asking countries to stop the importation of organisms or parts of organisms (like tiger bones) if they are endangered species
biodiversity hotspots
A relatively small area with an exceptional concentration of endemic species (map in book p.181)
Urban growth boundary
geographical boundaries placed around a city to limit suburban growth within that city, is intended to provide guidelines for future city development
U.S. Population shift
shifting to the south and the west
Urban populations are changing
urban areas are spreading outward in what is called sprawl.
Development of new housing sites at relatively low density and at locations that are not contiguous to the existing built-up area.
Suburb problems
suburbs allot more space to each person and has spread human impact across the landscape.. natural areas gone due to housing developments, roads to drive everywhere and more pollution
New urbanism
Outlined by a group of architects, urban planners, and developers from over 20 countries, an urban design that calls for development, urban revitalization, and suburban reforms that create walkable neighborhoods with a diversity of housing and jobs.
sustainability of cities
use renewable energy sources, mass transit and recycle materials...ustainable uses for different areas of the city is city planners first priority
Sprawl impact
forces people to drive cars, increased pollution due to transportation, promotes physical inactivity, more land is developed, drains tax dollars and puts into new developments, (trans, pollution, health, land use, economics)
Resource Management
the sustainable use of natural resources is the goal
Maximum Sustainable Yields
The population size that yields maximum production that allows the population to be sustained indefinitely without decreasing its ability to provide the same level of production.... cut trees shortly after fastest stage of growth.. keep fish at intermediate levels just like trees
Forest greatest ecological complexity
they are mature and exhibit a multi-level canopy
Ecosystem services provided by forest
structural complexity and their ability to provide many niches for organisms... provide habitat and help maintain soil, air, and water quality.... Ecosystem services include forest vegetation, plants help regulate the hydrolic cycle, plants store carbon and release oxygen, provide people with wood
has the greatest impacts in tropical areas and arid regions... forest cut down for population expansion
Reasons not to restrict logging
desperate enough for economic development, logging gives jobs
secondary forest
trees that sprouted after old growth timber was cut
Forestry practices that conserve biodiversity
using a selection system to get uneven-aged stands .. definitely not clear cutting
National Forest Management Act
was passed in 1976 with the intent to ensure multiple use and sustainable yield of commercial forests
Forests Restoration Act
directs timber companies to remove small trees, underbrush, and dead trees to reduce fires in
Fires important to forests
fire important to function and biodiversity.
Wilderness areas
off limits to development but they are open to hiking, nature study, and other low impact public recreation. Necessary to assure that an increasing population, accompanied by expanding settlement and growing mechanization, does not occupy and modify all areas with the U.S.. can hunt in national parks
land trust
private nonprofit groups , a local or regional organization that purchases land valued by its members, with the aim of preserving it in its natural condition
how water contaminates effect aquatic organisms
most chemicals are water soluble so they enter these organisms through drinking or skin absorption
physical hazard
earthquakes, volcanic, fires, floods, blizzard, landslides, hurricanes, and droughts
chemical hazard
synthetic chemicals that our society produces such as disinfectants, pesticides, chemicals produced naturally by organisms can also be hazardous
biological hazard
virus, bacterial infection, infectious diseases such as malaria, cholera, tuberculosis, influenza.. organisms transmit disease
cultural hazard
smoking, drugs, diet, unsafe sex
Most significant cause of death
3 top deaths in U.S.
diseases of heart, cancer, stroke
indoor pollutants
adon, cigarette smoke, asbestos and lead, dust, toxicants in plastics and consumer products
one who studies the nature and effects of poisons and their treatment, study the effects of chemical agents suspected to be harmful
pesticide drift
chemical substances can be transported by air, effects can occur far from the site of direct chemical use
the selective absorption and concentration of molecules by cells, the gradual build-up of synthetic and organic chemicals in living organisms
Increase in concentration on certain stable chemicals in successively higher trophic levels of a food chain., the process by which the concentration of toxic substances increases in each successive link in the food chain.
because it contributed to the near extinction of birds, including the bald eagle and the peregrine falcon. DDT is a persistent chemical that becomes concentrated in animal tissues, rising in concentration in animals that are higher in the food chain. It is particularly toxic to fish, aquatic invertebrates and insects (including some that are beneficial).
dose-response curves
show the effects of various doses of toxic agents on a group of test organisms.
LD 50
the amount of a chemical that kills 50% of the animals in a test population, the single dose of a substance at which 50% of the test animals die
acute exposure
(short-term, intense) Burns. Radiation sickness.
chronic exposure
low amounts of contact with a toxicant over long periods of time
synergistic effects
often have effects that are multiplicative, When the effects of two factors working together have more impact than either would working alone
calculated risk
a chance that a person takes after carefully considering all possible outcomes
percieved risk
the anxieties felt because the consumer cannot anticipate the outcomes of a purchase but believes there might be negativve consequences
Pesticides in the United States are registered through the, an independent federal agency established to coordinate programs aimed at reducing pollution and protecting the environment
Toxic Substance Control Act
EPA tracks 75,000 chemicals. May ban chemicals that pose unreasonable risk.
4 stages of demographic transition
stable preindustrial stage, transitional stage, industrial stage, stable postindustrial stage
the preindustrial stage
birth and death rates are high during
red list
a record of current species facing unusually high risks of extinction