APES unit 5 (land use and water use)

tragedy of the commons

individuals will use shared/public resources in their own self interest, degrading them (must be public resource and must be used-up in some way)

examples of tragedy of the commons

overgrazing, overfishing, water and air pollution, overuse of groundwater

why tragedy of the commons happen

when no one owns the resource, no one directly suffers from overusing it, people assume if they don't use it, others will

problems with tragedy of the commons

overfishing can lead to fishery collapse (loss of income and starvation); air pollution can lead to bronchitis and asthma (increased healthcare cost); pesticide runoff from farms contaminate drinking water

solutions to the tragedy of the commons

private land ownership; fees or taxes for use; fines, taxes, criminal charges for pollution or shared air/soil/water resources

direct effects of clearcutting

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

tree plantations

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

problems with tree plantations

lowers biodiversity, all the same age (lowers biodiversity further)

general forest benefits

filtering of air pollutants, removal and storage of CO2 from the atmosphere, habitat for organisms

deforestation consequences

reduces air filtering and carbon storing services; cutting trees down releases CO2 from decomposition of leftover organic material

slash and burn

method of clearing land for agriculture by cutting trees and burning them (releases CO2, N2O and water vapor into the atmosphere (all GHGs))

the green revolution

shift in agriculture away from small, family operated farms to large, industrial-scale agribusiness; increased use of mechanization, GMOs, irrigation, fertilizers, and pesticides;

positives of the green revolution

greatly increases efficiency of lands, short-term profitability, and food supply; decreased world hunger and increased earth's carrying capacity for humans

negative consequences of the green revolution

mechanization

increased use of tractors for plowing and tilling fields, and combines for harvesting

positives of mechanization

increased yield and profits

negatives of mechanization

increases reliance on fossil fuels (gasoline/diesel fuel); emits GHGs to atmosphere (climate change); heavy machinery compacts soil, decreasing H2O holding capacity (makes topsoil more prone to erosion)

high-yield variety (HYV) crops

hybrid, or genetically modified crops that produce a higher yield (amount of crops produced per unit of area)

hybrid

cross-pollinating different species, or parent plants with ideal ration

positives of HYV crops

increased yield and food stability in regions previously prone to famine (India, Pakistan, Mexico)

negative of HYV crops

decreased biodiversity

GMOs

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

positives to GMOs

increases profitability with fewer plants lost to drought, disease, or pest; larger plant size and yield

negatives to GMOs

GMO crops are all genetically identical so genetic diversity is decreased and susceptibility to diseases or pests is increased

synthetic fertilizer

shift from organic fertilizers (like manure and compost) to synthetic fertilizers (man made ammonium, nitrate, phosphate)

positives to synthetic fertilizer

increases yield and profits with more key nutrients needed for plant growth (N, P, K) added to the soil

negatives to synthetic fertilizer

excess N and P are washer off fields and into nearby waters where they cause eutrophication; require FFs for production, releasing CO2 (climate change)

irrigation

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

positives of irrigation

makes agriculture possible in many parts of the world that are naturally too dry (don't receive enough rain)

negatives of irrigation

can deplete groundwater sources, especially aquifers; overwatering can drown roots (no O2 access) and cause soil salinization (increased salt level in soil)

pesticides

chemicals sprayed on crops that kill weeds, insects, rodents and other pests that eat or damage crops

positives of pesticides

increases yield and profits with fewer plants lost to pests

negatives of pesticides

can wash off crops in runoff and kill or harm non-target species in local soil or waters (bees especially) (Ex: DDT thinned shells of bird eggs, especially eagles; atrazine turns amphibians and fish intersex)

negatives of the green revolution

soil erosion, biodiversity loss, ground and surface water contamination

monocropping

growing one single species of crop (highly efficient for harvest, pesticide and fertilizer application)

negatives of monocropping

greatly decreases biodiversity; increases soil erosion; decreased habitat diversity

tilling

mixing and breaking up soil to make planting easier and loosens the soil for the roots

negatives of tilling

increases erosion by loosening topsoil and breaking up leftover root structure from harvest; loss of organic matter and topsoil nutrients; increase particulate matter in the air

negatives of slash and burn

deforestation (loss of: habitat, biodiversity CO2 sequestration (storage), loss of air pollution filtration); release CO2, CO, N2O which leads to global warming; increases particulate matter in air (asthma), lowers albedo, making the area warmer

leaching

water carries excess nutrients (nitrates & phosphates) into groundwater or into surface waters (as runoff)

furrow irrigation

trench dug along crops and filled with water; easy and inexpensive (water seeps into soil slowly); 66% efficient, 33% lost to runoff and evaporation

flood irrigation

flood entire field (easier, but more disruptive to plants); can waterlog the soil and drown plants; 80% efficient, 20% lost to runoff and evaporation

drip irrigation

most efficient, but also most costly; over 95% efficient; holes in hose allow water to slowly drip out; avoids waterlogging and conserves water

spray irrigation

ground or surface water pumped into spray nozzles; more efficient (less water loss) than flood or furrow; more expensive (requires energy for pumps and movement of sprinklers)

waterlogging

overwatering can saturate the soil, filling all soil pore space with water (doesn't allow air into pores, so roots can't take in the O2 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 and water to drain through the soil

soil aeration

salinization

the process of salt building up in soil overtime (groundwater has a little salt and overtime, watering and evaporation can lead to salinization)

industrial global human water use

power plants, metal/plastic manufacturing

municipal global human water use

households (toilet, shower, drinking water)

agricultural global human water use

water for livestock, irrigation water for crops

groundwater

H2O stored in pore space of permeable rock and sediment layers

aquifers

usable groundwater deposits for humans (recharged by groundwater recharge)

groundwater recharge

rain water percolating down through soil into aquifer

unconfined aquifers recharge ________

quickly

confined aquifers recharge ________

slowly

solution to salinization

drip irrigation, soil aeration, flushing with fresh water, switch to freshwater source

saltwater 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 & drying nearby wells

overuse of pesticides leads to ________

pests becoming resistant to them

how are GMOs used in pest control

gene for pest resistant trait is added to the plant through genetic modification

roundup ready crops

genetically modified to be resistant to broad herbicide (roundup), meaning roundup will kill weeds, but not crops

roundup ready crops have increased ________

herbicide use

GM crops are ________

all genetically identical, so there is no genetic diversity in the pop.

CAFOs (feedlots)

densely crowded method where animals are fed grain (corn) to raise them to as quickly as possible

positives of CAFOs

maximizes land use and profit (most meat production per/unit of area); minimizes cost of meat for consumers

negatives of CAFOs

given antibiotics and growth hormones to prevent disease outbreak and speed meat production; animals produce large volume of waste which can contaminate nearby surface/groundwater; produces large amounts of CO2, CH4, and N2O (climate change)

manure lagoons

large, open storage pits for animal waste (manure); heavy rain can flood lagoons and contaminate nearby surface/groundwater with runoff; produces N20 (GHG); can be emptied and buried in landfills, or turned into fertilizer pellets

free range grazing

animals (usually cows) graze on grass and grow at a natural rate without growth hormones

positives of free range grazing

no need for antibiotics with dispersed pop.; doesn't require production of corn to feed animals; waste is dispersed over land naturally, acting as fertilizer instead of building up in lagoons; animals can graze on land too dry for most crop growth

negatives of free range grazing

requires more total land use/pound of meat produced; more expensive to consumer

overgrazing

too many animals grazing an area of land can remove all the vegetation (grass) which leads to topsoil erosion; animals also compact soil, decreasing H2O holding capacity (more erosion)

desertification

can occur if plants are killed by overgrazing and soil is compacted so much that it can't hold enough water anymore

rotational grazing

moving animals periodically to prevent overgrazing; it can also increase the growth of grass by distributing manure and clipping grass back to size where growth is most rapid

inefficiency of meat

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

energy used for meat

all of the energy needed to plant, grow, and harvest plants to feed animals, plus energy needed to bring water to animals, energy needed to house animals, energy needed to slaughter and package

land used for meat

all of the energy needed to grow plants to feed animals, plus room the animals will take up

water used for meat

all of the water for crops animals will eat, plus the water the animals will drink

fisheries

populations of fish used for commercial fishing

negatives of fisheries

decreases genetic biodiversity of fish populations and species biodiversity of ocean ecosystems if species are lost from ecosystem

fishery collapse

when overfishing causes 90% population decline in a fishery

negatives of fishery collapse

population may never recover from fishery collapse due to: decreased biodiversity, inability to find mates, and inbreeding depression

economic consequences of fishery collapse

lost income for fishermen, lost tourism dollars for communities

bottom trawling

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

bycatch

unintended species like dolphins, whales, turtles caught in nets used in bottom trawling

negatives of bottom trawling

bycatch; stirs up ocean sediment (turbidity) and destroys coral reef structure; decreases biodiversity by killing non-target species and removing coral reef habitat

fishing down the food web and trophic

as we deplete large, predatory fisheries, we move down to smaller fish species; depletion of smaller fish population limits fishery recovery and decreases food supply of marine mammals and seabirds

ore

commercially valuable deposits of concentrated minerals that can be harvested and used as raw materials

metals

elements that conduct electricity, heat and have structural properties for building (found within ores)

reserve

the known amount of a resource left that can be mined; usually measured in years left of extraction

overburden

soil, vegetation, and rocks that are removed to get to an ore deposit below

tailings and slag

leftover waste material separated from the valuable metal or mineral within ore (often stored in ponds @ mine site)

surface mining

removal of overburden to access ore near surface

different types of surface mining

open pit, strip, mountaintop removal (especially damaging to landscape and habitats), placer

negatives of surface mining

removal of vegetation and soil - topsoil erosion, habitat loss, increased stream turbidity, increased PM in air

subsurface mining

more expensive due to higher insurance and healthcare cost for workers; vertical 'shaft' drilled down into ground

risks of subsurface mining

poor ventilation leading to toxic gas exposure; mine shaft collapse; injury from falling rock; lung cancer; asbestos; fires; explosions

acid mine drainage

rainwater leaks into abandoned mine tunnels and mixes with pyrite, forming sulfuric acid

environmental impacts of mining

rainwater carries sulfuric acid into nearby streams, or infiltrates ground water; lowers pH of water, making toxic metals more soluble in water