APES Unit 5 Flashcards
clearcutting
cutting down most or all trees in an area
why clearcutting?
to harvest wood
clear the land for agriculutre or developement
slash and burn and why
trees are cut and the rest is burned down.
-fast, efficient, and economically profitable
direct affects of clearcutting
– incr. soil erosion
(no roots holding soil in place)
–incr soil and stream temperature
(loss of tree shade warms soil/water incr. turbidity)
– flooding and landslides
(machinery compacts soil) (incr sunlight dries out soil)
(all decr water holding capacity which cause flooding and landslides)
forest benefits
–filtering of air
(stomata removes VOCs, NO2, PM from air & stores in tree)
– removal & storage of CO2 from atm.
–habitat for organisms
– prevention of erosion
deforestation consequences
–reduces air filtering and carbon storage services
– cutting down trees releases CO2 from decomposition of left overt organic material
– slash& burn method releases CO2 into atm.
difference between deforestation and clearcutting
deforestation is no chance or will to regrow trees, removing forest for ever
clearcutting you can regrow trees in the future
tragedy of the commons
individuals will tend to use a shared public resource in their own self interest rather than condisering the common good, therby depleting the resource
tragedy of the commons examples
-overgrazing
- overfishing
-air/water pollution
-overuse of groundwater
why does the tragedy of the commons happen?
– when no one owns the resources, no one directly suffers the consequence of overusing it
– people assume others will overuse it if they don’t
– no penalty for overusing, degrading, polluting many public resources
how to solve tragedy of the commons?
–private land ownership (government or individual)
–fees or taxes for use EX permit for system for grazing, logging
– taxes, fines, criminal charges for pollution
Examples_ clean air act, clean water act,
the green revolution
shift in agriculture away from small, family owned farms to large, industrial-scale agribusinessess
what increases in the green revolution
mechanization, GMOs, irrigation, fertilizer and pesticides
green revolution pros and cons
+ greatly incr efficiency of lands, short-term profitabilty and food supply
+ decr. world hunger and incr. earth’s carrying capacity for humans
- soil erosion, loss of biodiversity, ground and surface water contamination, fossil fuel use
mechanization
increased use of machines for plowing, tilling, harvesting
mechanization pros and cons
+ increases yield and profits
- increases reliance on fossil fuels emits GHGs to atm
- heavy machinery also compacts soil, decreasing H20 holding capacity
HYV crops (high yield variety) pro
hybrid or genetically modified crops that produce a higher yield
+incr yield and food stability in regions previosly prone to famine
hybrid
cross-pollinatinig different parent plants with ideal traits
GMOs definitoin
crops with new genes “spliced” into their genome. have genes for drought tolerance, pest resistance, faster growth and larger fruit/grain
GMOs pros and cons
+ increases profitability with fewer plants lost due to drought, disease, pest
+ less land needed to grow the same amount of food
- GMO crops are all genetically identical so genetic diversity decreases and susceptibility to disease or pests is increased
GMO BT corn example
BT corn has been modified with a gene from soil bacteria to produce a protein that kills many diff corn pests
Synthetic fertilizer
shift from organic fertilizers (like manure and compost) to synthetic fertilizers (man made ammonium, nitrate, phosphate)
synthetic fertilizers pros and cons
+increases yield and profits with more key nutrients needed for plant growth added to the soil
+ can customize, doesn’t smell like manure, easy storage and application
- excess nitrate phosphate are washed off fields and into nearby waters where they cause eutrophication
- require Fosil Fuels for production releasing CO2
irrigation
drawing water from the ground or nearby surface waters and distributing it on fields to incr. plant growth
irrigation pros and cons
+ makes agriculutre possible in many parts of the world that are naturally to dry
- can deplete freshwater sources (aquifers, rivers)
- overwatering can drown roots and cause soil salinization
pesticides
increase in use of synthethic pesticides - chemicals sprayed on crops that kill weeds, insects, and other pests that eath or damage crops
pesticides pros and cons
+ icnreases yield and profits with fewer plants lost to pests
- can wash off into runoff and kill or harm non-target species in local soil or waters (bees especially)
monocropping pros and cons
+ highly efficient for harvest, pesticide and fertilizer application
- incr soil erosion
- decr habitat diversity for species living in the area
- can deplete soil nutrients unless crops are rotated
tilling
mixing and breaking up soil to make planting easier
-incr erosion by loosening top soil
- loss of organic matter & topsoil nutrients over time
- inc. particulate matter in air and sediments in nearby watter
slash and burn
loss of:
loss of habitat, biodiversity, CO2 sequestration, air pollution filtration
slash and burn consequences
- releases CO2, CO, N2O
- incr. PM in air (astma)
- lowers albedo making area warmer
leaching
water carries excess nutrients into grounwater or into surfacewaters
leaching effects
contaminates groundwater for drinking
causes eutrophication of surface waters
global human water use
industrial 19%
municipal 11%
agriculture 70%
industrial
power plants, metal/plastic manufactering
municipal
households (toilet, shower, drinking water)
agriculture
water for livestock, irrigation water for crops
furrow irrigation
trench dug along crops & filled with water
-easy & inexpensive , water seeps into soil slowly
-66% efficient, 33% lost to runoff % evap
spray irrigation
ground or surface water pumped into spray nozzles
– more efficient than flood or furrow (75-95%)
– move expensive (requires energy for pumps & movement of sprinklers)
flood irrigation
flood entire field, easier but more disrupive plants
– can waterlog soil & drown plants
– 70% - 80% efficient, 20-30% lost to runoff/evap.
drip irrigation
most efficient, but also most costly
– over 95% efficient
– holes in hose allow water to drip out
– avoids waterlogging % conserves water
waterlogging
overwatering can saturate the soil, filling all pore space with water
– doesn’t allow air into pores, so roots can’t take 02 they need
– can stunt growth or kill crops
solution to waterlogging
drip irrigation, or soil aeration
soil aeration
poking holes or cores in soil to allow air in % water to drain
soil salinization
– groundwater used for irrigation has small amounts of salt, water evaporates and salt is left in soil. Over time it can reach toxic levels , dehyrdating plant roots and preventing growth
soil salinization solutions
drip irrigation, soil aeration, flushing with freshwater, using freshwater sources instead
groundwater
H20 stored in pore space of permeable rock & sediment layers
aquifers
useable groundwater deposits for humans
- replenished by groundwater recharge
unconfined vs confined aquifers
unconfined aquifers recharge quickly
confined aquifers are longer-term water deposits that recharge more slowly
salt water intrusion
excessive pumping near coast lowers water table pressure, allowing saltwater to seep into groundwater
cone of depression
forms when water table is lowered by excessive pumping, depleting water and drying nearby wells
how do pesticides cause pests to become resistant to pesticide?
- genetic diversity gives some pests resistant traits
- pesticide kills all the non-resistant ones (artificial selection)
- pesticide treadmill
pesticide treadmill
more pesticide or new pesticide must be used to kill pests due to resistance to original pesticide
pesticide impacts
- decr. crop loss due to pest damage which incr. crop yield/profit
-can kill or harm non-target species EX bees, ladybugs
—DDT thinned shells of bird eggs, especially eagles
-can persist in environment and lech into groundwater
pesticides :: GMOs, BT corn and Round Up Ready Crops
gene for pest resistant trait is added to the plant through genetic modification.
– BT corn with bacteria gene that produces BT crystals toxic to pests
–Round Up Ready crops are GM to be resistant to broad herbocide meaning roundup will kill weeds not crops
CAFOs stands for?
concentrated animal feeding operations
what are CAFOs
densely crowded method where animals are fed grain to raise them as quickly as possible
CAFOs pros and cons
+maximizes land use and profit (most meat production per/ unit of area)
+ minimizes cost for consumers
- given antibiotics & growth hormones to prevent disease outbreak & speed meat production
- animals produce large volume of waste which can contaminate nearby surface or groundwater
- produces large amounts of CO2, CH4 (methane) and N20 (greenhouse gasses )
manure lagoons
-large open pits for animal waste, (manure)
- waste contains: ammonia, hormones, antibiotics, E.coli
- heavy rain can flood lagoons and contaminate nearby surface with runoff and infiltrate into groundwater
- denitrification of ammonia in manure produces N20, (extremely powerful greenhouse gas)
- can be emptied and buried in landfills or turned into fertilizer pellets.
E. coli –>
ammonia–>
antibiotics–>
E. coli is toxic to humans
ammonia causes eutrophication
antibiotics & growth hormones alter endocrine system of humans
Free range grazing
animals graze on grass and grow at a natural rate without growth hormones
Free range grazing pros and cons
+ no need for antibiotics with dispersed population
+ doesn’t require production of corn to feed animals
+ waste is dispersed over land naturally, acting as fertilizer instead of building up in lagoons
- requires more total land use / pound of meat produced
- more expensive for consumer
overgrazing cons and solutions
- too many animals grazing an area of land can remove all the vegetation
- animals also compact soil, decr. H2) holding capacity
- desertification can occur if plants are killed by overgrazing and soil is compacted so much that it can’t hold any water
solution:
rational grazing (moving animals periodically) can prevent overgrazing
can even incr. grass growth by distributing manure and clipping
inefficiency of meat
producing meat for humans to eat is far less efficient than producing plants in terms of energy, land, and wateruse
inefficiency of meat Energy
all of the energy needed to plant, grow and harvest plants to feed to animals PLUS
– energy needed to bring water to animals
— energy needed to house animals
– energy needed to slaughter and package
inefficiency of meat land
all of the land needed to grow plants to feed animals PLUS
– room the animals take up
inefficiency of meat wateruse
all of the water for crops that animals eat PLUS
– the water the animals drink/use
fisheries overfishing
populations of fish used or commercial fishing
overfishing
harvesting fish at rate faster than they can be sustainably replenished
what is overfishing caused by?
-modern fishing methods (seine nets, gill nets, bottom-trawling)
-growing global population
- subsidies and other economic incentives
bottom trawling
especially harmful fishing method that involves dragging a large net along the ocean floor
-by-catch
-stirs up ocean sediment and destroys coral reefs
- decr. biodiversity by killing non-target species & removing coral reef habitat
by-catch
unintended species like dolphins, wales and sea turtles that get caught in nets
gill nets
wall of netting that hangs in the water column
- also an issue of by-catch, although large mesh nets are no longer allowed
- can lead to ghost nets (abandoned or lost nets)
- decr. biodiversity by killing non-target species, especially sea turtles
fishing down the food web and trophic cascade
- as we deplete large, predatory fisheries, we move down to smaller fish species
- depletion of smaller fish pop. limits fishery recovery and decr. food supply of marine mammals and sea birds
fishery collapse
-when overfishing causes 90% population decline in a fishery
-pop. may never recover from fishery collapse
-decr. genetic biodiversity of fish populations & species biodiversity of ocean ecosystem
economic consequences
pop. may never recover from fishery collapse due to
- decreased biodiversity
- inability to find mates
- inbreeding depression
economic consequences of fishery collapses
–> lost income for fisherman
–> lost tourism dollars for communities
ore
comercially valuable deposits of concentrated minerals that can be harvested and used as raw materials
reserve
known amount of resource left that can be mined. usually measured in years left of extraction
overburden
soil, vegetation & rocks that are removed to get an ore deposit below
tailings and slag
leftover waste material seperated from the valuable metal or mineral ore (often stored in ponds @ mining site)
surface mining
removal of overburden to access ore near surface.
different types of surface mining
open pit
strip
mountain top removal
placer
mountain top removal mining
especially damaging to landscape & habitats, streams nearby
- removal of vegetation
- habitat loss
- incr. stream turbidity
- incr pm in air
subsurface mining
more expensive due to higher insureance and healthcare costs for workers.
risks of subsurface mining
–poor ventilation leading to toxic gas exposure
–mine shaft collapse
– injury from falling rock
– lung cancer, asbestos, fires, explosions
environmental impacts of mining acid mine drainage
rainwater leaks into abandones mine tunnels and mixes with pyrite, forming sulfuric acid
–rainwater carries sulfuric acid into nearby streams or groundwater
– kills aquatic organisms
methane release
coal mining releases methane gas from rock around coal.
- vented out of mine to prevent explosion
- GHG – climate change
PM release
coal mining especially, releases lots of particles
cyanide release
gold mining uses cyanide which can contaminate water
environmental impacts of mining
– heavy machinery burns fossil fuels
–top soil erosion
– habitat loss
– erosion
mine reclamation
- filling of empty mine shafts/hole
- restouring original contours of land
- returning top soil with acids, metals and tailings removed
- replanting native species to restore community
- continued monitoring of land
impervious surfaces prevent
prevents groundwater recharge, causing precipitation to runoff into local bodies of water; incr. flooding can occur
urbanization in coastal cities
can lead to salt water intrusion.
trends in population (urbanization)
–people move from rural to urban areas for jobs, entertainment, cultural attractions
– urban areas are more densly populated, minimized driving, land use per person
– highest growth currently is suburban populatoin
suburbs
less dense areas surrounding urban areas EX vail, oro valley, catalina foothills
urban sprawl
population movement out of dense, urban centers to less dense suburban areas surrounding the city
why urban sprawl:
–cheaper property
– cars make it easy to get to city
– domino effect
– decline in tax revenue = decrs. in city services
– abandoned homes create blight
– higher crime in urban areass
solutions to urban sprawl
+ urban growth boundaries: zoning laws to prevent development beyond certain areas
+ public transport and walkable city design that attract residents to stay
+ mixed land use: residential, business and entertainment buildings all located in that same area
+ enables sense of place and walkabilty
ecological footprint
the amount of land needed to provide all the resources used by a person. gha (global hectares)
includes: housing, food, goods, transportation
difference between carbon and ecological footprint
ecological footprint includes carbon footprint. carbon footprint is the amount of CO2 produced per yeatr
increases ecological footprint
– eating meat
– large house
– driving transportation
– flying
– purchasing lots of goods
decreases ecological footprint
–carpool
– public transportation
– renewable energy
– electric vehicle
— less consumption, less travel, less energy use
mitigate
reduce
environmental consequences of urban runoff
–decreases infiltration
– rain washes pollutants into local surface waters
pollutants and effects in urban runoff
- salt (kills plants)
- sediments (turbidity)
- fertilizer (eutrophication)
- oil & gasoline (suffocate fish/kill aqua. organisms
- pesticides (kill non-target species)
- trash
solutions to urban runoff
permeable pavement
rain garden
public transport
building up, not out
permeable pavement
+ designed to allow storm water to infiltrate and recharge groundwater
+ decr. runoff and pollutants carried to surface waters
+ decr. liklyhood of flooding during heavy rainfall
- more costly than traditional pavement
rain garden
+ gardens/ trees planted in urban areas, especially surrounding a storm drain
+ decr. runoff by allowing it to soak into garden soil surrounding storm drain
+ decr. liklihood of flooding during heavy rainfall
++ creates habitat for pollinators, sense of place, stores CO2
Public transport
more cars on road = more pollutants on streets to runoff
-motor oil
- gasoline
- antifreeze
- tire pieces
more cars = more parking lots (impervious surfaces)
building up, not out architecture
“ Green Roof “ architecture
+ building vertically decr. impervious surfaces
+ can be combined with “Green Roof” or rooftop gardens to further decr. runoff
++ green roofs also sequesters CO2 and filters air pollutants
Integrated Pest Management (IPM)
using a variety of pest control methods that minimize environmental disruption and pesticide use
-Biological (natural predators)
- mechanical (trapping, nets, weeding)
- chemical (pheromones, limited pesticide)
biocontrol IPM
-introducing natural predators, parasite or competitor
- ladybugs for aphids
- spiders for many pest insects
- parasitic wasps for caterpillars
crop rotation IPM
pests prefer one specific crop or crop family. they lay eggs in the soil so when larvae hatch they have preferred food source
– rotating crops can disrupt pests’s preferred food source
– disrupts weed growth because it prevents bare soil being taken over by weeds.
intercroppping IPM
“Push- Pull system”
- PUSH plants emit volatile chemicals that naturally repel pests away from crop
- PULL plants emit chemicals that attract moths to lay eggs in them instead of the crop
benefits of IPM
+ reduces death & mutation of non-target species EX eagle death (DDT) bee die-offs (glyphosate)
+ reduces effect on human consumers of produce EX many pesticides are carcinogens (cause cancer)
+ reduces contamination of surface & ground waters
drawbacks of IPM
- can be more time consuming & costly than just crop dusting pesticides EX researching specific pests & planting numerous species of crops
- less likely to be effective
Aquaculture benefits
+ requires only small amount of water, space & fuel
+ reduces risk of fishery collapse
+ doesn’t take up any land space (compared to beef, pork, chicken)
aquaculture drawbacks
- high density produces high concentration of waste (e. coli & eutrophication risks)
- high density increases disease risk, which can be transmitted to wild population as well
- may introduce non-native species or GMOs to local ecosystem if captive fish escape
- fish are fed antibiotics which can contaminate water via their waste
sustainability
consuming a resource or using a space in a way that does not deplete or degrade it for future generations EX using compost over synthetic fertilizer
maximum sustainanbility yield
maximum amount of a renewable resource that can be harvested without reducing or depleting the resource for future use
- roughly 1/2 carrying capacity
agricultural techniques that minimize erosion
contour plowing
terracing
perennial crops
wind breaks
no-till agriculture
strip cropping
contour plowing
–plowing parallel to natural slopes of the land instead of down slopes. prevents water runoff and soil erosion
–forms mini terraces that catch water running off, conserving soil and water
terracing
–cutting flat ‘platforms’ of soil into steep slopes
– flatness of terraces catches water & prevents it from becoming runoff and eroding soil
perennial crops
–crops that live year round and are harvested numerous times
– longer, more established roots & prevention of base soil between harvest
wind breaks
– using trees or other plants to block the force of the wind from eroding soil
– can be used as a source of firewood, fruit (income)
– can provide habitats for pollinators & other species
no-till agriculture
–leaving left over crop remains in soil instead of tilling under
– adds organic matter to soil
– prevents erosion from loosened soil
strip cropping
–another name for intercropping
– alternating rows of dense crops with rows of less dense crops to prevent runoff from eroding soil from less dense rows of crops
agricultural techniques that improve soil fertility
crop rotation
green manure
limestone
crop rotation improve soil fertility
- replanting same crop continuosly depletes soil of the same nutrients
- crop rotation can allow soil to recover from nitrogen-demanding crops like corn
- legumes have nitrogen fixing bacteria that can return nitrogen to soil
green manure
- green manure is leftover plant matter form a cover crop
- cover crop roots stabilize soil limiting top soil erosion
- remains of cover crop left on field break down to release nutrients into soil
cover crops
are crops planted in the off season between harvest and replanting of main crop to not have bare soil
limestone
- releases calcium carbonate which nutralizes soil
- acidic soil has high H+ ion concentration that displaces nutrients from soil
- acidic soil makes toxic metals more soluble in soil
++ calcium is a necessary plant nutrient as well
rotational grazing
prevents overgrazing
– overgrazing can kill plants, compact soil, and lead to erosion of top soil
- can promote pasture growth at faster than normal rate
- clips grass back to length where growth is fastest and encourages deeper root growth
ecologically sustainable forestry
forestry (using trees for lumber) that minimizes damage to ecosystems (habitat destruction, soil erosion, etc.
maximizes long term productivity of land and preserves forests for future generations
what can you do sustainable forestry
selectively cutting certain trees, (biggest, oldest)
replanting species being logged
sustainble practices
–reusing/ recycling wood, (furniture, decoration)
–wood chips as mulch for gardens and agricultural fields
–reforestation
–removing disseassed trees to prevent spread of infection
reforestation
replanting of trees in areas that have previously been deforested
fire suppresion
- stopping natural fires as soon as they start (which is bad)
- leads to more biomass buildup which is fuel for future fires making them worse
- monitoring fires instead can prevent fire damage and worse fires in the future
prescibed burns
- dead biomass builds up which is fuel for large forest fires. when you burn it it releases stored nutrients into soil. dead trees = more susceptible to dissease
- small/ controlled fires burn lots of dead biomass which use up biomass preventing future forest fires later
- promotes nutrients recycling which are in dead biomass and are recycled = new growth
