APES UNIT 5

tragedy of the commons (TOC)

individuals will use shared resources in their own self interest, degrading them

why does tragedy of the commons happen?

• there is no penalty for overusing

• competition

• no one privately owns resource

externalities

unintended side effects

ways to solve TOC

• private land ownership

• fees/taxes/fines

BLM (Bureau of Land Management)

manages rangelands in western US by collecting grazing fees from ranchers, evaluating land, repairing effects of overgrazing

green revolution

shift in agriculture away from small family farms to large, industrial-scale agribusiness

negative consequences of the green revolution

soil erosion, biodiversity loss, ground and surface water contamination

positive consequences of the green rev.

increased efficiency of lands decreased world-hunger, increased carrying capacity for humans

mechanization

use of tractors for plowing and tilling fields for extra yield + profits

negative consequences of mechanization

heavy machinery compacts the soil; increases reliance on fossil fuels

HYV (high-yield variety) crops

hybrid crops that produce a higher yield

GMOs

genetically modified crops have genes for drought tolerance, pest resistance, faster growth, and larger fruit/grain

negative consequences of GMOs

crops are all genetically identical→no diversity→disease/pests increase

synthetic fertilizer

shift from organic fertilizers to man-made fertilizers

positive consequences of synthetic fertilizers

increase yield and profits by plant growth w/ more key nutrinets

negative consequences of synthetic fertilizers

eutrophication and excessive use of fossil fuels

irrigation

drawing water from the ground or nearby surface waters and distributing it on fields to increase plant growth

pesticides

increase in use of synthetic pesticides-chemicals sprayed on crops that kill weeds, insects, rodents, and other pests that eat/damage crops

negative consequences of pesticides

can kill crops/organisms that wasn’t intended to

ecological footprints

measure of how much a person/group consumes, expressed in area per. land (area/land)

carbon footprint

measured in tonnes of CO2 produced per year

factors that increase footprint

affluence, meat consumption, fossil fuel usage

factors that decrease footprint

renewable energy use, public transportation, plant-based diet

current average U.S. footprint

5.1 earths

current global footprint

1.85 earths

sustainability

consuming a resource or using a space in a way that doesn’t deplete/degrade it for future generations

maximum sustainable yield:

the max amount of a renewable resource that can be harvested without reducing/depleting the resource for future use

indicators of susatinability

factors that help us determine env. health and guide us towards sustainable use of earth’s resources

declining biodiversity (sustainability)

can indicate pollution, habitat destruction, climate change

food production

indicates ability of earth’s soil, water, and climate to support agriculture

increasing meat consumption (sustainability)

further strain on food production

increasing CO2 (sustainability)

unsustainable temperature and environment

increase of human pop. (sustainability)

resource depletion grows

monocropping

growing one single species of crop

negative consequence of monocropping

decreased biodiversity→more prone to pests

tilling

mixing and breaking up soil to make planting easier

negative consequence of tilling

increases erosion (loosening of topsoil)

slash & burn

cutting down vegetation and burning it to clear land for ag. & return nutrients in plants to soil

leaching

water carries excess nutrients into groundwater or surface waters→contaminates water + eutrophication

furrow irrigation

trench dug along crops & filled w/ water

drip irrigation

holes in hose allow water to slowly drip out; most efficient, but most costly

flood irrigation

flood entire field; easier but more disruptive to plants

spray irrigation

ground water pumped into spray novels; more expensive

waterlogging

overwatering saturates soil, filling all soil pore space with water (no oxygen)

soil aeration

poking holes in soil to allow air in & water to drain through soil

soil salinization

process of salt building up in soil over time

aquifier

usable groundwater deposits for humans; replenished by groundwater recharge

groundwater

water stored in pore space/permeable rock

saltwater intrusion

excessive pumping near coast lowers water table pressure, allowing saltwater to seep into groundwater

cone of depression

forms when the water table is lowered by excessive pumping, depleting water & drying nearby wells

CAFOs

aka feedlots; densely crowded method where animals are fed grain to raise them a quickly as possible

manure lagoons

large, open storage pits for animal waste (ammonia, hormones, antibiotics, bacteria)

free range grazing

animals graze on grass & grow at a natural rate w/o growth hormones

overgrazing

too many animals grazing in an area of land can remove all the grass→topsoil erosion

desertification

occurs if plants are killed by overgrazing & soil is compacted so much that it can’t hold enough water anymore

rotational grazing

moving animals periodically

inefficiency of meat

producing meat for consumption is far less efficient than producing plants in terms of energy, land, and water use

energy (inefficiency of meat)

ALL of the energy needed to grow/harvest plants for animal’s consumption PLUS energy needed to take care/slaughter/package animals

land (inefficiency of meat)

all of the energy needed to grow plants to feed animals PLUS room the animals take up

water (inefficiency of meat)

all of the water for crops that animals eat PLUS the water the animals drink

fishery collapse

when overfishing causes 90% pop. decline in a fishery

economic consequences of overfishing

lost income for fishermen, lost tourism dollars for communities

overfishing: tragedy of the commons

no incentive or penalty to prevent overfishing

bottom trawling

especially harmful method that involves dragging a large net along ocean floor

bycatch

unintended species like dolphins, whales, turtles caught in nets

consequences of bycatch

decreases biodiv. by killing non-target species and removing coral reef habitat

depletion of smaller fish pop limits:

fish recovery and decreased food supply of marine mammals & seabirds

aquaculture

raising fish in cages/enclosures underwater

benefits of aquaculture

• requires only small amount of water, space, and fuel

• reduces risk of Fishery collapse

• doesn’t take up any land space (compared to beef, pork)

cons of aquaculture

high density=high concentration of waste

urbanization

removing of vegetation to convert to cities

consequence of urbanization

prevents groundwater recharge→ precipitation runoff into local bodies of water

saltwater intrusion

consequence of urbanization in coastal cities

excessive groundwater withdrawal

occurs near coast, lowering water table pressure, allowing saltwater to seep into groundwater

urban sprawl

pop. movement out of dense, urban centers to less dense areas surrounding the city

causes of urban sprawl

cheaper property, car travel, domino effect, businesses follow moving residents

effects of urban sprawl

expanded highways, increased fuel tax revenue, easier commutes

urban growth boundaries

zoning laws set by cities preventing development beyond a certain boundary

mixed land use

residential, business, and entertainment buildings all located in the same area of a city

consequences of urban runoff

decreased infiltration, rain washes pollutants into storm drain

permeable pavement

designed to allow stormwater to infiltrate & recharge groundwater; decreased pollutants carried into storm drains

rain garden

gardens planted in urban areas around storm drains; soaks runoff into soil→creates habitat for pollinators

public transit

decreases urban runoff, road pollutants, traffic, CO2 emissions

building up, not out

decreases impervious surfaces (combining with green roof/gardens will decrease runoff & filter air pollutants)

effects of clearcutting

soil erosion, increased soil & stream temp, flooding and landslides

tree plantations

areas where the same tree species are repeatedly planted, grown, harvested

forest benefits

filtering of air pollutants, removal of CO2, habitat for organisms

deforestation consequences

reduces air filtering, release of CO2

sustainable forestry

using trees for lumber that minimizes damage to ecosystems, preserving forest for future generations

strip cutting

only cutting some of the trees in an area

huaman and pack animal labor

minimizes soil compaction from machinery

reforestation

replanting if trees in areas that have been deforested

fire suppression

practice of putting out all natural forest fires as soon as they start

consequence of biomass buildup

putting fires out immediately will increase dry buildup→makes future fires worse

prescribed burns

small, controlled fires burn lots of dead biomass→promotes nutrient recycling

reserve

amount of resource left for future use

overburden

any part of the land that needs to be removed in order to reach raw materials

tailings and slag

leftover waste material that is separated from metals/minerals (often stored in ponds @ mine cite)

surface mining

removal of overburden to access ore near surface: open pit, strip, mtn. top removal, placer

subsurface mining

extracting minerals and ores deep underground