unit 5 Flashcards
1
Q
what is clearcutting
A
most or all of the trees in an area are cut down
2
Q
why do we clearcut
A
harvest wood, or clear land for agriculture or development
3
Q
slash and burn method
A
trees are cut down and remaining vegetation is burned for agriculture.
adds nutrients into the soil
4
Q
direct effects of clearcutting
A
-soil erosion: no roots holding soil in place
-increased soil and stream temp.
-flooding and landslides: logging machinery compresses soil and dries it out, decreasing H2o capacity
5
Q
what are the benefits of forests
A
-filtering air
-removal and storage of co2 from atm.
-habitat for organisms
-prevents erosion
6
Q
deforestation consequences
A
-reduces air filtering and c02 storage services
-releases c02 into atm. from decomp. and slash and burn mehod
7
Q
examples of TOC
A
-overfishing
-overgrazing
-water/air pollution
-overuse of groundwater
8
Q
why does TOC happen
A
-when no one owns the resource, no one directly suffers consequences
-people assume others will overuse the resource if they don’t
-no penalty for overusing/degrading the resource
9
Q
how to solve TOC
A
-private land ownership
-fees or tax for use of the resource
-taxes or fines for pollution
10
Q
BLM (bureau of land management)
A
manages rangelands in western US by collecting grazing fees from ranchers
11
Q
green revolution
A
shift in agriculture away from small, family operated farms to large, industrial-scale agribusiness
12
Q
5 major changes in the green revolution
A
-increased use of machines, GMOs, irrigation, fertilizers, and pesticides
13
Q
effect of mechanization
A
+increased yield/profit
-increased fossil fuels releases GHG
-compacts soil and makes it more prone to erosion
14
Q
effects of HYV (high yield variety crops)
A
+produce higher yield
-GMOs are genetically identical so it causes a loss of biodiversity
15
Q
the difference between hybrid and GMO crops
A
hybrid= cross pollinating plants with ideal genes
GMO= genetically modified
16
Q
synthetic fertilizer effect
A
+increased yield and profits w/ more key nutrients
+can customize
-excess nutrients washed off and cause eutrophication
-require fossil fuels to
17
Q
effects of irrigation
A
+makes agriculture possible in dry places
-can deplete water sources
-overwatering can drown plants
18
Q
effects of pesticides
A
+increase crop yield with fewer lost to pests
-can wash off and kill non-target species
19
Q
how much water does industrial use
A
19%
20
Q
how much water does households use
A
11%
21
Q
how much water does agriculture use
A
70%
22
Q
furrow irrigation
A
-trenches dug along crops and filled with water
-easy and inexpensive
23
Q
how efficient is furrow irrigation in percent
A
~66% efficient
~33% lost to runoff or evap.
24
Q
flood irrigation
A
-flood entire field; easy but disruptive
-more expensive
25
how efficient is flood irrigation in percent
70-80% efficient
20-30% lost to runoff/evap.
26
spray irrigation
ground or surface water pumped into spray nozzles
27
how efficient is spray irrigation
-75-95% effective
-more expensive
28
drip irrigation
most efficient but also most costly
29
how effective is drip irrigation
>95% efficient
-avoids waterlogging & conserves water
30
water logging
-overwatering can saturate soil, filling all soil pore space w/ water
-doesn't allow air into pores, so roots can't take in oxygen
31
what are some solutions to waterlogging
- drip irrigation or soil aeration
(Poking holes in soil to allow air/water through)
32
soil salinization
process of salt building up in soil over time
33
why does soil salinization happen
-groundwater used for irrigation has small amounts of salt, so when the water evaporates, the salt is left behind, dehydrating plants roots
34
what is the solution to soil salinization
drip irrigation, soil aeration & flush w/ fresh water, switch to fresh water source
35
water table
top of ground water
36
groundwater def.
h2o stored in pore space of permeable rock and sediment layers
37
unconfined aquifers recharge ______, while confined recharge _______
quickly; slower
38
cone of depression
forms when water table is lowered by excessive pumping, depleting water and drying nearby wells
39
saltwater intrusion
excessive pumping near coast lowers water table pressure, allowing saltwater to seep into groundwater
40
Ogallala aquifer
groundwater is being depleted at a very fast rate. Underlying the area of 8 states including new Mexico, south Dakota, and Texas
41
what states does the Ogallala aquifer underline
South Dakota, Nebraska, Wyoming, Colorado, Kansas, Oklahoma, New Mexico and Texas.
42
effects of mono cropping
-decreases biodiversity (more prone to pests)
-increases soil erosion (harvest crops all at once and leave soil bare)
-can deplete soil nutrients
43
monocropping def.
growing one single species of crop. efficient for harvest, pesticide and fertilizer application
44
tilling def.
mixing and breaking up soil to make planting easier
45
effects of tilling
-increases soil erosion
-loss of org mater and topsoil nutrients (more fertilizer use)
-increased dust in air and water
46
effects of slash and burn
-adds nutrients to soil
-loss of habitat, biodiversity and co2 sequestration
-releases GHG that lead to global warming
--lowers albedo making area warmer
47
effects of synthetic fertilizer
-doesn't return org. matter to soil; no increased h2o holding cap. and no soil decomposers
-leaching
-contaminates groundwater and causes eutriphication
48
leaching
water carries excess nutrients into groundwater or surface water
49
what did DDT do
thinned eagle egg shells
50
different types of pesticides
-rodenticides kill rodents
-fungicides kill fungi
-insecticides kill insects
-herbicides kill plants
51
explain how pest become resistant to pesticides
-genetic biodiversity makes some pests resistant to pesticides
-pesticides kill non resistant species, leaving only resistant ones (artificial selection)
-new or more pesticides must be used causing a "pesticide treadmill"
52
effects of pesticides
-decreases crop loss due to pest damage, increasing yield
-can kill or harm non-target species (like bees or ladybugs)
-can leach into ground/surface water
53
gmo def
-gene for pest resistant trait is added to the plant through genetic modification
54
which gmo crop will increase herbicide use
Roundup ready crops will increase herbicide use because the plants are immune to roundup, so the herbicide will only kill weeds
55
which GMO crop will decrease insecticide use
BT corn because the corn produces crystals that are toxic to pests
56
Cafos (concentrated animal feeding operations) benefits
-maximizes land use and profit (most meat production per unit pr area
-minimizes cost of meat for consumers
57
Cafos drawbacks
-given antibiotics and growth hormones to prevent disease and speed meat production
-animals produces lots of waste which can contaminate nearby surface/groundwater
-produces large amounts of GHG
58
downsides of manure lagoons
-waste of animals contains ammonia, hormones, antibiotics, and E. coli
-heavy rain can overflow laggons and contaminate water
-E.coli is harmful to humans and the antibiotics and growth hormones given to the animals alter the endocrine system of humans
59
free range grazing benefits
no need for antibiotics w/ disperse pop.
-doesn't require production of corn to feed animals
-waste is dispersed naturally and acts as fertilizer
-animals can graze on land to dry for crop growth
60
free range drawbacks
requires more total land use per pound of meat produced (more expensive for consumers
61
effects of overgrazing
-leads to topsoil erosion
-it compacts soil decreasing H2o holding capacity (more erosion)
-desertification can occur
62
desertification
plants get killed by overgraing and soil is so compacted that nothing can grow
63
what can prevent overgrazing
rotational grazing
64
why can rotational grazing increase growth of grass
by distributing manure and clipping back grass to size where growth is most rapid
65
why is meat so inefficient
it uses more energy, land, and water then any other type of farmed food
66
fisheries
populations of fish ised for commercial fishing
67
what is overfishing caused by
-modern fishing methods
-growing global pop.
-subsidies and other economic incentives
68
bottom trawling def.
an especially harmful fishing method that involves dragging a large net along the ocean floor
69
bycatch
Unintended species like dolphins, whales, and turtles being caught in nets
70
effects of bottom trawling
-bycatch
-stirs up ocean sediment and destroys coral reef structure
-decreases biodiversity by killing non-target species and removing coral reef habitat
71
gill nets def.
wall of netting that hangs in the water column
72
effects of gill nets
-bycatch
-can lead to ghost nets
-decreases biodiversity by killing non-target species and sea turtles
73
what is the fishing down the food web cascade
as humans deplete larger species we are forced to fish for smaller species. what will happen to marine mammals and birds if humans fish for more forage fish species
74
what is fishery collapse
when overfishing causes 90% pop. decline in a fishery. pop. may never recover due to decreased biodiversity
75
economic consequence of fishery collapse
lost income for fishermen, lost tourism dollars for communities
76
ore def.
commercially valuable deposits of concentrated minerals that can be harvested and used raw
77
overburden
soil, vegetation, and rocks that are removed to get to an ore deposited below
78
tailings and slag
left over waste material separated from the valuable metal or mineral w/in ore. often stored in ponds at mine sites. can be very toxic
79
surface mining def.
removal of overburden to access ore near surface
80
types of surface mining
-open pit
-strip mining
-mountaintop removal
-placer
81
why is mountaintop removal esp. damaging
-removal of vegetation and soil
-topsoil erosion/lower albedo
-habitat loss
-increase PM
82
what happens when ore near surface gets depleted
we turn to subsurface mining
83
why subsurface mining more expensive
higher insurance and health care sots + more equipment
84
risks or subsurface mining
-poor ventilation leading to toxic gas exposure
-mine shaft colapse
-lung cancer
-fires and explosions
85
Environmental impacts of mining
-acid mine drainage
-methane release
-PM release
-cyanid release
86
acid mine drainage
rainwater leaks into abandoned mines and mixes with pyrite forming sulfuric acid. this can flow into rivers and groundwater, lowering ph, making toxic metals more soluble in the water source
87
how does mining increase methane release
coal mining releases methane gas and it gets vented out of the mines into the atm. increasing climate change
88
how does mining effect PM being released
coal mining especially, releases lots of soot that can irritate lungs
89
how does mining effect cyanid release
gold mining uses cyanid which can contaminate water
90
mine reclamation includes
-filling empty mine shafts/holes
-restore shape of land
-return topsoil w/o tailings or acid
-replant native vegetation
-continued monitor of land
91
urbanization
as a pop. shifts from rural to urban areas, vegetation is removed converting natural landscape to city
92
effects of urbaniation
-replaces permeable surfaces and vegetation with impervious surfaces
-increases co2 emissions
-can lead to saltwater intrusion in coastal cities
93
how does urbanization increase co2 emissions
-cement production
-construction machinery
-deforestation
-landfills (trash decomposing produces carbon)
94
why do people move from a rural area to a more urban area
-for jobs, entertainment, cultural attractions
-urban areas or more densely populated, minimizing driving and land use per person
95
where is the biggest growth right now for urbanization
the suburbs
96
urban sprawl
population movement out of dense, urban centers to less dense suburban areas surrounding the city
97
causes of urban sprawl
-cheaper property
-cars make it easy to travel into the city for work
-highway systems make travel easy
-domino effect:
-your neighbor moves, you move
-fewer residence in cities leads to
decline in tax revenue for city
- abandon homes create blight
98
solutions to urban sprawl
MAKE IT ATTRACTIVE
-urban growth boundaries
-public transportation that is free and clean
-mixed land use
99
urban growth boundaries
zoning laws set by cities preventing development at a certain place
100
mixed land use
residential, business, and entertainment buildings all located in the same area of a city
101
Environmental effects of urban runoff
-decreased infiltration
-rain washes pollutants to local surface water
102
what are the pollutants from urban runoff
-salt (kills plants)
-sediment (turbidity)
-fertilizer (eutrophication)
-pesticides (kill non-target species)
-oil and gas (suffocate fish/ kill aquatic insects)
103
solutions to urban runoff
-permeable pavement
-rain garden
-public transit
-building up not out
104
what is a rain garden
garden or trees planted in urban areas, especially surrounding a storm drain
105
how does public transit decrease urban runoff
-more cars on road= more pollutants on the street to get into water
-more cars = more lanes and parking lots (more runoff)
106
what is IPM
-integrated pest management
-using a variety of pest control methods (biological, mechanical and chemical) that minimize environmental disruption
107
what are the three types of IPM
-biological (natural predators)
-mechanical (trapping, nets, weeding)
-chemical (pheromones, limited pesticides)
108
biocontrol IPM method
-introducing a natural predator, parasite, or competitor to control the pest
-can include purchasing or attracting the predator
109
examples of biocontrol
-ladybugs -> aphids
-spiders -> insects
-parasitic wasp -> caterpillars
110
crop rotation IPM method
-many pest prefer on specific crop or crop family, they lay eggs in the soil so when the larvae hatch they have the preferred food source
-rotating crops can prevent pests from becoming established
111
Intercropping IPM method
- push pull system
-"push" plants emit volatile chemicals that naturally repel pests away
--"pull" plants emit chemicals that attract pests. they might even attract the natural predator
112
why is IPM less used
because it can be more time consuming and costly
113
Aquaculture benifits
-raising fish or other aquatic species in cages/enclosures underwater
-requires only small amount of water, space, and fuel
-reduces risk of fishery collapse
-doesn't take up land space
114
Aquaculture drawbacks
-high concentration of waste
-increases disease rick in species that might transmit to wild pop.
-may introduce non-native species or GMO's to local ecosystem if captive fish escape
-fish are fed antibiotics which can get into the water
115
Sustainability
consuming a resource or using a space in a way that does not deplete or degrade it for future generations
116
maximum sustainable yield
the maximum amount of a renewable resource that can be harvested w/o reducing or depleting the resource for future use
-roughly 1/2 carrying cap.
117
Environmental indicators of sustainability
-biodiversity: declining biodv. can indicate pollution, habitat destruction, climate change
-food production: indicates ability of earth's soil, water, and climate to support org.
-atm. temp. and CO2: increasing co2= hotter temps which means less life on earthh
-human pop. and resource depletion: as human pop. grows, so does resource depletion
118
what does soil conservation methods do
Agriculture techniques that minimize erosion and prevents loss of topsoil
119
how fast is the US losing topsoil
10x faster then it is being formed
120
contour plowing
-plowing parallel tp natural slopes of the land instead of down the slopes,.
-forms mini terraces that catch water running off, conserving soil and water
121
terracing
cutting flat "platforms" of soil into a steep slope
-flatness catches water and prevents it from becoming runoff and eroding soil
122
Perennial crops
crops that live year-round and are harvested numerous times
-longer, more established roots and prevention of bare soil between harvest
123
windbreakers
-using trees or other plants to block wind from eroding soil
-can be used as a source of firewood, fruit,and habitats for animals
124
no till
-leaving leftover crop remains in soil instead of tilling
-adds org. matter to soil, prevents erosion from loosened soil
125
Strip cropping (intercropping)
Alternating rows of dense crop with less dense crop
Prevents erosion
126
How does crop rotation improve soil fetility
Can allow soil to recover from nitrogen demanding crops like corn by planting legumes
127
How does green manure improve soil fertility
Remains of cover crop stabilize soil to prevent erosion and release nutrients
128
How does limestone improve soil fertility
Releases calcium and neutralizas acidic soil
Also plants need calcium
129
factors that increase ecological footprint
-food production
-raw materials
-housing
-electricity production
-disposing waste
130
things that increase carbon footprint
-larger houses
-more travel
-material good production
-meat consumption
-fossil fuel usage
131
factor that decrease carbon footprint
-renewable energy
-public transportation
-plant based diet
132
sustainable forestry
forestry that minimizes damage to ecosystem
133
sustainable forestry methods
-selective cutting (diseased trees)
using human and pack animal labor to prevent compaction of soil
-replanting same species being logged
-reforestation
134
what else can decrease amount of logging
-reusing wood
135
fire suppression
-stopping natural fires as soon as they start
-can lead to a buildup of biomass that can lead to bigger fires in the future
136
prescribed burns
-small controlled fires on purpose
-gets rid of biomass
-promotes nutrient recycling
