1
Q
soil formation due to… (2)
A
- 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
2
Q
land distribution percentages
A
- crop cultivation: 12%
- livestock grazing: 24%
- forest: 31%
- desert/mtns/tundra/unsuitable: remaining 33%
3
Q
natural soil cycle (3)
A
- degredation: solution and leaching of nutrients by water
- erosion: removal of topsoil by wind/water
- balance: degredation + erosion = soil formation
4
Q
anthropogenic soil problems
A
- human activities
- agriculture
- impervious surfaces
- landscape -> wind pattern & hydrologic alterations
- consequences
- 2.5x erosion & degredation
- declining crop & livestock yields
5
Q
probs w/ industrialized agriculture
A
- 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
6
Q
dustbowl of 1930s led to the…
A
- 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%
7
Q
top soil is lost 16x faster than it forms and Great Plains States have lost 50% of their top soils since ag began because…
A
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”)
8
Q
practices that reduce soil losses (5), which increase nutrient recycling and soil formation
A
- Terracing
- Contour planting
- Multiple cropping
- conservation / low tillage
- organic fertilizers / composting
- (ex: Shanghai self-sufficient in veg since ’80s)
9
Q
small vs. big farming
A
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
10
Q
human uses for water (7)
A
- drinking / cooking / cleaning
- habitat
- recreation
- transportation
- industry
- source of energy
- agriculture (~70%)
- 1.1M Gal to grow 2.4 acres of corn
11
Q
problems w/ human uses of water (5)
A
- 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
12
Q
water probs: climate change might…
A
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
13
Q
addressing water problems means improving efficiency and conservation. Current water tech could… but…
A
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
14
Q
4 dimensions of social systems
A
- culture
- community
- economics
- politics
15
Q
diverse ecosystems…
A
- 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
16
Q
Benefits of Forests; they… (10)
A
- 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
17
Q
IUCN
A
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
18
Q
tropical forests are considered “non-renewable” because…
deforestation caused by… (6)
A
- 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
19
Q
human causes of BioD decline (4)
A
- habitat frag / loss
- urbanization / development
- agriculture
- from 7,000 spp to 20 (wheat, rice, rye, corn, millet)
- Greenhouse effect / climate change?
- species migration / adaptation
20
Q
US is greatest consumer of paper products, but…
A
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
21
Q
Programs to address BioD & Forest declines (7)
A
- 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)
22
Q
CITES
A
1973: Convention on Int’l Trade in Endangered Species
of Wild Fauna & Flora
23
Q
Waste/Pollution: US EPA & Bureau of Mines estimates…
A
- 75% of solid waste is mining, gas, oil production
- 13% agriculture
- 9.5% industrial
- 1.5% municipal
- 1% sewage
24
Q
cultural eutrophication
A
- +nutrients ->
- +algae ->
- dead algae ->
- decomposers -O2 / +CO2 ->
- dead zones
ex: Hypoxia in Gulf of Mexico
** Average lawn has 10x more pesticides than 1ha cropland
25
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
26
solid waste "solutions"
1. 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
2. recyc: switz & Japan recyc 50% of solid waste (US: 30%)
* increase economic incentives from "save the env" to industry motivation
3. Reuse is even more effective:
* extends resource supplies, reduces energy use & pollution more than recyc & incineration
* Denmark banned all non-refillable bottles
27
Municipal pollution / solutions
1. 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
2. LDCs: untreated sewage -\> dysentary, typhoid, cholera
* lack of capital resources for sewage treatment
1. Clean Water Act (1974): decreased organic wastes water from sewage / industrial
* industry still tries to weaken
2. 95% of ppl in MDCs have clean drinking water
* 74% in LDCs
28
culture & community \> economy & politics
& social norms influence behavior more than the environment
29
Dynamics of Population Change (4)
1. Malthusianism
2. Demographic Transition Model
3. Demographic Divide b/t MDCs & LDCs
4. Population Redistribution
30
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
31
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
32
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
33
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
34
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
35
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
36
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
esrm 200 - society and environments
flashcards
Decks in class (3)
# Cards
