Unit 3 Quiz 2 Flashcards
Ch 10 - part of Ch 11
what is a common resource and what observation did Garrett Hardin make w/ respect to them?
a resource that can be used by anyone, nonexcludable
when it is unregulated people tend to overuse it
tragedy of the commons?
if the use of common land is not regulated, land can easily deteriorate and no longer support use
externality?
positive vs. negative
cost or benefit of a good or service that is not included in the price of that good or service or is otherwise not accounted for
positive: benefit
negative: cost
2 approaches suggested to avoid the negative externalities ass. w tragedy of the commons
owning/using private land
govt. regulation of common land
risks w/ underuse and overuse of a resource
over: can deplete resource
under: cause resource to become overabundant, potentially disrupting ecosystems
Max sustainable yield:
rough estimate?
max harvest that can be adequately be replaced by pop growth
half of a carrying capacity
rangelands?
grazing beneficial when? how?
lands that are grazed by domestic livestock or wild animals
relatively low density, or a rotational schedule is used. Also beneficial in biomes adapted to ungulates (grazing animals)
support biodiversity
stimulate grass growth
increase nutrient cycling
overgrazing?
can cause?
too many animals feed on a particular area and can cause:
loss of vegetation
soil and stream bank erosion
eutrophication from nutrient overload
increase in invasive species
desertification
soil no longer viable for plant growth due to plant loss, aridity, and sometimes grazing
Taylor Grazing Act of 1934
regulates grazing lol
forestry:
planting, managing, and caring for forests
includes logging management
3 types of forestry
for each: benefits? negative externalities? (except last)
-clear cutting: removal of all trees within an area and replanting a tree plantation
benefits: easy, efficient, cost effective. minimizes land use
NEs: habitat loss & fragmentation, loss of biodiversity in species and age structure, increased erosion of soil
-selective cutting: remove some trees to cut and create a stand of varied ages and species
benefits: retains some habitat, reduces negative impacts to biodiversity. Encourages small scale secondary succession
NEs: less efficient and more costly. Same as clear cutting just less extreme
-ecologically sustainable forestry: low impact, highly selective forestry that attempts to keep all species in as natural of a state as possible
environmentally but not economically sustainable
prescribed burns:
benefits?
a method of reducing dead biomass accumulation by starting controlled fires
helps prevent big fires
provides OM/nutrients
Opens up forest for secondary succession, can increase biodiversity
undernutrition
malnourishment
food security & insecurity
famine
anemia
overnutrition
3 plant species that constitute 50% of global calorie intake
2nd largest component of human diet
relationship between affluence and meat consumption?
does not consume enough calories to be healthy/survive
does not consume enough specific macro/micronutrients
people do/do not have safe access to nutritious food that meets dietary needs
severe shortage of food in a region
deficiency of red blood cells or hemoglobin, caused by lack of iron usually
overconsumption of calories and nutrients
rice, wheat, corn
meat
as income increases, so does meat consumption
describe 2 reasons why undernutrition and malnutrition are so common around the world
poverty: can cause many to be unable to afford a balanced diet
political instability or war: can disrupt food production and transport
food desert?
an area where fresh produce or groceries are far away
usually 20+ min drive is standard
Concentrated animal feeding operation (CAFOs)
benefits?
cons?
large indoor or outdoor structures made for maximum output of animal product
minimize land use and improves feeding efficiency
comes w a lot of ethical concerns
overuses antibiotics -> resistant pathogens
animal wastes -> contaminate ground and surface water w/ nutrients, algal blooms
cows can release lots of CH4 (methane)
free range farming benefits
reduces antibiotic use, lowers carbon footprint, and less waste
basically opposite of cons of CAFOs
fishery
commercially harvestable pop of fish in a region
fishery collapse
pop declines by 90+%
Individual transferable Quotas for fisheries
fishery managers est. a total allowable catch and distribute or sell quotas to individual fishers or companies
sustainable fisheries don’t allow fishing until ___
pop recovers
large scale fishing can adversely affect both ___ and ___ species called ___ and is the single largest source of ____
target, nontarget, bycatch, ocean plastics
Aquaculture
cons?
farming of aquatic organisms
waste pollutes waterways, and escaped farm fish can decimate wild fish populations
Green Revolution
New technologies brought to agriculture, drastically increasing yields worldwide
Irrigation in Green Revolution
___ of agriculture is irrigated which makes up ___% of the world’s food
environmental externalities:
increases yields by growing crops in places they could otherwise not
16%, 40%
water usage is high
soil degradation
waterlogging
salinization -> desertification
Agrochemicals (fertilizers) in green rev?
fertilizers:
synthetic fertilizers:
cons:
artificial farming chemicals
allow increased yields and longer + continuous production. not all are chemicals
man made combinations of organic and inorganic substances that provide nutrients to plants
overuse of any fertilizer can lead to eutrophication
agrochemicals (pesticides) in green rev?
herbicide?
insecticide?
tend to be limited in ___ and can affect ___ such as ____
over use can lead to ____. Explain this phenomenon
persistent pesticides:
nonpersistent pesticides:
substances that kill or control organisms people consider pests
targets plant pests
insect pests
specificty, nontarget organisms, bees and farmers
pesticide treadmill. A loop that leads to continuous evolved pest resistance
remain for a long time
degrade rapidly, but must be applied frequently
bioaccumulation and biomagnification in relation to pesticides
bioaccumulation: buildup of chemicals in organisms fatty tissue
biomagnification: increasing chemical concentration as you move up food chainm
improved crop varieties in green revolution
high yield and disease resistant crops are SELECTIVELY BRED, not made by GMOS
