quiz 2 lecture vocab Flashcards
soil formation due to… (2)
- break-up/weathering of rocks -> minerals
- decay of organic matter
the earth is alive w/ detritivores and microbes
98% of human food comes from land
land distribution percentages
- crop cultivation: 12%
- livestock grazing: 24%
- forest: 31%
- desert/mtns/tundra/unsuitable: remaining 33%
natural soil cycle (3)
- degredation: solution and leaching of nutrients by water
- erosion: removal of topsoil by wind/water
- balance: degredation + erosion = soil formation
anthropogenic soil problems
- human activities
- agriculture
- impervious surfaces
- landscape -> wind pattern & hydrologic alterations
- consequences
- 2.5x erosion & degredation
- declining crop & livestock yields
probs w/ industrialized agriculture
- expansion of land ended in 1950s -> intensive ag:
- high productivity
- monocultures
- high energy & chemical inputs
- cultivation of marginal & hilly lands
- little to no crop rotation or fallowing (allowing soil to reform)
- overgrazing
- 1/3rd of soil lost by 1996
- declining yields despite chem applications
dustbowl of 1930s led to the…
- Conservation Reserves Program, which was sort of started in 1956 but not truly implemented until the 1985 farm bill
- encouraged conversion of erodible lands to grass/woodlands
- penalties for non-participant farmers
- reduced soil loss by 65%
top soil is lost 16x faster than it forms and Great Plains States have lost 50% of their top soils since ag began because…
People! All the science and technology won’t help if people’s behavior doesn’t change
social norms influence behavior more than environment (recall the hotel room and the re-use message: “people who stay in this room re-use their towels”)
practices that reduce soil losses (5), which increase nutrient recycling and soil formation
- Terracing
- Contour planting
- Multiple cropping
- conservation / low tillage
- organic fertilizers / composting
- (ex: Shanghai self-sufficient in veg since ’80s)
small vs. big farming
smaller, privately owned farms:
- more labor instensive, but also more productive
- small scale farmers more likely to care for land than large corporations
large scale mgmt:
- encourages application of technology
- price reforms encourage profitability
- changes in land tenure / ownership rules
- increased food prices: political dynamite
human uses for water (7)
- drinking / cooking / cleaning
- habitat
- recreation
- transportation
- industry
- source of energy
- agriculture (~70%)
- 1.1M Gal to grow 2.4 acres of corn
problems w/ human uses of water (5)
- uneven distribution
- source of political conflict
- slow recharge rate (~1%)
- Up to 80% of irrigation lost to evap. and seepage
- withdrawals > recharge
- depleting aquifers -> cone of depression
- water pollution
water probs: climate change might…
shift the playing field and re-orient conflict
- San Joaquin Valley, CA (salad bowl)
- L.A. & San Diego draw water from Colorado river -> Cadillac desert
- Nile River Basin: Sudan & Ethiopia vs. Egypt
- Kasmir River Basin: India (dam) vs. Pakistan
- Ganges River Basin: India (dam) vs. Bangladesh
addressing water problems means improving efficiency and conservation. Current water tech could… but…
save up to 50% of ag use, 90% of industrial use
- ex: drip irrigation: targeted (less weeds), & slow (less evap.)
- raise water prices certain uses (water parks, maybe?)
… but isn’t being used because of culture
4 dimensions of social systems
- culture
- community
- economics
- politics
diverse ecosystems…
- are more Productive: due to complementary resource use
- are more Sustainable: they conserve & more effectively use water & nutrients
- fill more Functional Roles: seed dispersal, pollination, etc.
- are more Adaptive to change/stress
- Provide a variety of food, medicine, & other commercially important materials
- Pacific Yew Tree bark -> taxol
Benefits of Forests; they… (10)
- clean up urban pollution
- cool the air
- shade & carbon sequestration
- provide habitat
- minimize soil erosion
- participate in nutrient storage & cycling
- provide lumber
- aid psychological health
- regulate water quality & quantity
- aid in landscape stablization
- moderate floods & downstream drought water storage
IUCN
International Union for Conservation of Nature
- 1/8 plant species in danger of extinction
- 90% of at risk species are endemic
- so far lost 2/3 of historic world forests
- stable secondary forests, but declining growth rates, soil nutrients, & wood quality
tropical forests are considered “non-renewable” because…
deforestation caused by… (6)
- they depend so heavily on internal nutrient cycling & high decomposition rates
- tropical rains erode and leach clear-cut top soil
- projected extinction: 2010-2090
- caused by
- multinational lumber/logging corporations
- farming
- ranching
- poverty
- pop. growth
- poor gov’t policies
human causes of BioD decline (4)
- habitat frag / loss
- urbanization / development
- agriculture
- from 7,000 spp to 20 (wheat, rice, rye, corn, millet)
- Greenhouse effect / climate change?
- species migration / adaptation
US is greatest consumer of paper products, but…
only recycles 29% (Japan: 50%)
50% wood consumption could be saved by:
- more efficient sawmills / plywood mills
- double recyc rate
- reduce disposable paper product use
Programs to address BioD & Forest declines (7)
- Promoting sustainable use
- local/indig. use > commercial exploitation
- political obstacles
- Debt for Nature swaps
- preservation of forests in exchange for debt relief
- Preserving Nature in Place
- parks/nature reserves ~8% of earth’s area
- Gene Banks / Conservatories
- move spp from natural habitats to zoos, botanical gardens, nurseries, etc
- Bio-prospecting
- pay to search for pharma; gov’t gets % of royalties
- int’l treaties
- Convention on Int’l Trade in Endangered Species of Wild Fauna & Flora (CITES) (1973)
- CBD: Convention on Biological Diversity (1992)
CITES
1973: Convention on Int’l Trade in Endangered Species
of Wild Fauna & Flora
Waste/Pollution: US EPA & Bureau of Mines estimates…
- 75% of solid waste is mining, gas, oil production
- 13% agriculture
- 9.5% industrial
- 1.5% municipal
- 1% sewage
cultural eutrophication
- +nutrients ->
- +algae ->
- dead algae ->
- decomposers -O2 / +CO2 ->
- dead zones
ex: Hypoxia in Gulf of Mexico
** Average lawn has 10x more pesticides than 1ha cropland
leachate
- liquid waste from solid waste degredation
- tree roots perforate barriers and tap leachate from dumps
sidenote: only 2% of e-waste is recycled in US
solid waste “solutions”
- incineration: reduces ovlume by 90% & is a source of energy, but
- fixed capital cost is high
- produces toxic gasses
- does nothing to discourage waste production
- recyc: switz & Japan recyc 50% of solid waste (US: 30%)
- increase economic incentives from “save the env” to industry motivation
- Reuse is even more effective:
- extends resource supplies, reduces energy use & pollution more than recyc & incineration
- Denmark banned all non-refillable bottles
Municipal pollution / solutions
- Water/air pollution in cities from
- industrial activities / autos / homes
- waste/sewage
- CO, CO2, SO2, NOx, VOC
- SO2, NOx, VOCs, and Ozone react to form smog
- LDCs: untreated sewage -> dysentary, typhoid, cholera
- lack of capital resources for sewage treatment
- Clean Water Act (1974): decreased organic wastes water from sewage / industrial
- industry still tries to weaken
- 95% of ppl in MDCs have clean drinking water
- 74% in LDCs
culture & community > economy & politics
& social norms influence behavior more than the environment
Dynamics of Population Change (4)
- Malthusianism
- Demographic Transition Model
- Demographic Divide b/t MDCs & LDCs
- Population Redistribution
Malthusianism
- pop. growth causes poverty & human misery, not limited resources (even though a “fixed land base” is part of the argument)
- positive checks on pop. growth: war, disease, poverty
- contraception/abortion: morally unacceptable
- welfare perpetuates misery
Demographic Transition Model (PTM)
- 3 stages of pop. dynamics:
- Primitive Social Org: +mortality, +fertility
-
Transitional Social Org: -mortality, +fertility
- -> inc. pop.
-
Modern Social Org: -mortality, -fertility
- -> stable pop.
- children as assets -> children as economic burden
- medical advances
- more opps for women / less income inequality
- Critique: LDCs aren’t in same dev channel as MDCs
Demographic Divide
- Demog trans model works well for MDCs til 1930s
- European/American pops grew fastest
- most now closer to stable
- US growth almost entirely due to immigration
- LDCs are diff
- rapid transtional growth w/o territorial gains
- low rates of modernization/industrialization
- few opps for women
- few small fam incentives (& powerful cultural/religious norms favoring large fams)
90% of newborns are in LDCs
Population Redistribution
net spatial changes due to mobility
MDCs:
- push:
- rural overpop.
- ag. industrialization (-labor market, +land consol.)
- poverty
- pull: economic opps
LDCs:
- push: same
- pull: none; skipped transitional ind. and manuf. stages that would have built economic opportunities; went straight to service economies
Population Redist: Conseq for LDCs
- service economies: employ fewer ppl than ind./manuf; and lower wages
- conseq’s of push w/o pull:
- environ. refugees in urban areas
- collapsing city services due to overpop.
- unmanageable pollution & human health threats
- exp. production of solid waste
- urban water = open sewer = biologically dead
- unprecedented human misery
Population Redist.: migration
- urbanization is a form of migration
- Forced Migration (push) vs. Voluntary (pull)
- british prisoners -> Georgia/Australia
- slavery/slave trade
- vs.
- Europeans -> America
- Hippies -> Seattle
Population Redist: impacts
- req’s substantive adjustments
- labor availability
- provision of health & other services
- diff. “kinds” of ppl to be served, w/ diff languages, customs, etc
