unit 5 (land and water use)

tragedy of the commons

the usage of public, or shared, resources for a person’s own self-interest, thereby degrading the resources

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

causes of the tragedy of the commons

• as a result of being shared, and thus nobody owning the resource, nobody directly suffers the negative consequences of depleting the resource

• the assumption that others will overuse the resource even if a person doesn’t use it

• there’s no penalty for overuse, and even pollution in some countries

externalities

negative costs associated with human actions and aren’t accounted for in the price, or experienced by the human doing the consequential actions

ways to solve the tragedy of the commons

• private land ownership, by individuals or government organizations

• fees or taxes for use (a permit system for logging, etc.)

  • taxes, fines, criminal charges, for pollution or overusage of shared air/soil/water resources (Clean Air Act, Clean Water Act, Safe Drinking Water Act)

Bureau of Land Management (BLM)

oversees and manages rangelands in the western United States by collecting grazing fees from ranchers, evaluating land, and repairing effects of overgrazing

clearcutting

the cutting down of all the trees in a given area, usually to harvest for lumber or clear the area for other land uses

clearcutting and soil erosion

with the roots of the trees no longer stabilizing the soil, the topsoil, which contains the nutrients and organic matter, is much more prone to soil erosion, and is thus more easily blown or washed away

when washed into nearby waterways it makes the water more turbid, reducing light penetration into the water, thus affecting producers of the ecosystem, and reduces the amount of dissolved oxygen in the water, which is valuable for fish

clearcutting and temperature change

loss of tree shade along rivers, streams, and over the soil increases the soil, as a result of soil having a lower albedo, and water temperature

clearcutting and flooding and landslides

logging machinery compacts soil, and then increased sunlight exposure dries it out, this leads to more erosion of the topsoil and less water penetration, allowing for the easier formation of landslides and flash floods

tree plantations

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

although there are many trees in the area, it has a lower biodiversity and they are all the same age, which prevents decomposers and dendrites from having a food source in dead trees

ecosystem services of forests

filter air pollutants, via the stomata that remove volatile organic compounds, nitrogen oxide, and particulate matter and stores it in the trees; remove carbon dioxide from the atmosphere and store it as sugar, wood, and other tissues; provide a habitat for organisms

slash and burn agriculture

a method of clearing land for agriculture, which is done by cutting trees and burning them, releasing carbon dioxide, nitrous oxide, and water vapor in the atmosphere

green revolution

a shift into new agricultural practices in order to create higher yielding crops and animals, pest-resistant crops, and synthetic fertilizers by genetically modifying organisms

high-yield variety (HYV) crops

hybrid, or genetically modified crops, that produce a higher yield of food, allowing for food stability to increase in certain regions

genetically modified organisms (GMOs)

an organism that has had its genome altered to promote specific traits, typically for higher yield in crops and animals

negative effects of GMOs

all organisms with the genetic modification are identical, thus the genetic diversity is decreased and susceptibility to diseases or pests is increased

monocropping

consistently, every season, growing a singular species of crop in a large area of land

tilling

the mixing and breaking up of soil, typically through mechanical machines, to make planting easier

leads to the loss of organic matter and topsoil via increased erosion

particulate matter

dust and other sediments in the air that can result in respiratory irritation, including flared asthma and increased rates of bronchitis

leaching

the process of water carrying excess nutrients (nitrates and phosphates) into groundwater and surface water, which is intensified by the usage of synthetic fertilizers

furrow irrigation

trenches dug along crops, which are then filled with water

benefits of furrow irrigation

easy to implement and inexpensive; allows for water to seep into the soil slowly, preventing waterlogging

drawbacks of furrow irrigation

about 33% of water is lost to runoff or evaporation

flood irrigation

the flooding of an entire field of crops

benefits of flood irrigation

easy to implement

drawbacks of flood irrigation

disrupts plants, with the possibility of drowning them; can waterlog the soil; about 50% of water is lost to evaporation or runoff

drip irrigation

requires small holes in a hose that allows for water to slowly drip out

benefits of drip irrigation

most efficient; avoids waterlogging; conserves water; only 5% of the water is lost to evaporation or runoff

drawbacks of drip irrigation

extremely costly to implement

spray irrigation

ground or surface water pumped into spray nozzles

benefits of spray irrigation

more efficient than other forms of irrigation

drawbacks of spray irrigation

more expensive due to the purchasing of pumps and machinery

waterlogging

the oversaturation of soil, where the soil’s pores are occupied by water and can no longer take oxygen into the pores, thus preventing roots from taking in oxygen that they need

soil aeration

the poking of holes, or cores, into soil to allow air in and water to drain through the soil

solutions to waterlogging

utilizing drip irrigation or soil aeration

salinization

the process of salt building up in a soil over time, typically as a result of the usage of groundwater to irrigate crops, because the water will evaporate and leave the salt behind in the soil, eventually leading to levels that will dehydrate the plant roots and prevent growth

solutions to salinization

utilizing drip irrigation, soil aeration, flushing the soil with fresh water, or completely switching to freshwater as an irrigation source

pesticide treadmill

the constant cycle of creating new pesticides and the pests becoming resistant to the pesticide, requiring a new form of pesticide

benefits of pest control

decreases crop damage due to pests and thus increases crop yields

concentrated animal feeing operations (CAFOs)

also called feedlots; densely crowded method where animals are fed grains like corn to raise them as quickly as possible for meat production

benefits of CAFOs

maximizes land use and profit, therefore minimizing the cost of meat for consumers

drawbacks of CAFOs

animals must be given antibiotics and growth hormones to prevent disease outbreak and speed up meat production; animals produce large amounts of waste that can contaminate waterways; and the animals produce large numbers of carbon dioxide, methane, and nitrous oxide (GHGs)

manure lagoons

large, open storage pits for animal waste

solutions to manure lagoon drawbacks

empty the lagoons regularly and turn the manure into fertilizer pellets

free range grazing

agricultural technique where animals, usually cows, graze on grass and grow at a natural rate

benefits of free range grazing

doesn’t require antibiotics to be used, since the population is dispersed; doesn’t require the production of corn to feed animals; waste is dispersed naturally over the land; and animals can graze on land too dry for crops

drawbacks of free range grazing

requires more total land use for every pound of meat, leading to increased meat costs for the consumer; can potentially lead to overgrazing

overgrazing

a consequence of too many animals grazing an area of land, which can remove all the vegetation, leading to topsoil erosion

desertification

a consequence of overgrazing and animals compacting the soil; a situation that occurs if the soil has been degraded to the extent that it can’t hold enough water to sustain organisms

rotational grazing

a prevention method for desertification and overgrazing, which involves moving animals periodically

benefits of rotational grazing

over time it can increase the growth of grass as manure would be distributed throughout the grassland, and acts as a fertilizer; animals rotating cuts the grass to a length where growth is most rapid, allowing the grass to be more productive

fisheries

populations of fish used for commercial fishing

fishery collapse

a situation that occurs as a result of overfishing, where 90% of a fishery’s population collapses

negative effects of fishery collapses

decreases biodiversity of fish populations; decreases species biodiversity of ocean ecosystems if species are lost from the ecosystem; loss of fishermen income

bottom trawling

a fishing method that involves dragging a large net along the ocean floor

bycatch

the unintended species, like whales and turtles, that are caught in nets

ore

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

reserve

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

overburden

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

tailings

leftover waste material separated from the valuable metal or mineral within ore

surface mining

the broad mining term that requires the removal of overburden to access ore near the surface

open-pit mining

mining that requires a big pit being dug, and piling overburden near the pit

strip mining

digging back overburden layers in strips along the Earth

placer mining

utilizing a sieve in order to shake out sediments that way valuable materials, like ore, can be recovered

mountaintop-removal mining

utilizes dynamite or explosives to blow the top of a mountain off and access ore; damages the landscape and habitats of streams nearby

subsurface mining

a type of mining required as ore deposits deplete, especially in coal, but it is expensive and has many risks

environmental impacts of mining

coal mining releases methane gas into the atmosphere from rock around the coal and mining overall increases the particulate matter in the air, increasing the turbidity of water and affecting respiration

mine reclamation

the process of restoring land to its original state, after mining has finished; involves, refilling empty mine shafts and holes, restoring the original contours of the land, returning the topsoil with proper nutrients back to the surface, and replanting the area with native plants

saltwater intrusion

a consequence of excessive groundwater withdrawal near the coast, lowering the water table pressure and thus allowing saltwater to seep into groundwater

ecological footprint

a measure of how much a person or group consumes, expressed as an area of land, by calculating the land required for various processes

units: global hectare (gha)

sustainability

the utilization of a resource or space in a way that doesn’t deplete it for future generations

maximum sustainable yield

the maximum amount of a renewable resource that can be harvested without reducing or depleting the resource for future generations

indicators of sustainability

biodiversity (higher biodiversity indicates healthy ecosystems); food production (threats to food production indicate weak ecosystem health); atmospheric temperature and carbon dioxide (higher carbon dioxide levels increases atmospheric temperature); human population growth; and resource depletion

permeable pavement

pavement replacement that allows stormwater to infiltrate into underlying soils, promoting pollutant treatment and groundwater recharge

rain garden

gardens planted in urban areas that decrease runoff by allowing runoff to soak into the garden soil

public transportation

reduces the number of cars on the road, and thus it decreases the number of pollutants on the road, that would be picked up by runoff

building up, not out

building vertically decreases impervious surfaces, and thereby decreases urban runoff

integrated pest management (IPM)

a combination of methods used to effectively control pest species, while minimizing the disruption to the environment ; these can be physical, or chemical methods like biocontrol, intercropping, crop rotation, and natural predators of pests

biocontrol

the introduction of a natural predator, parasite, or competitor to reduce a pest population; involves the purchase and spread of the control organism

contour plowing

plowing parallel to natural slopes of the land, instead of down slopes, and thus prevents water runoff and soil erosion by forming mini terraces

terracing

cutting flat platforms into the soil of a steep slope; the platforms catch water and prevent it from becoming runoff, as a result of its flatness

perennial crops

crops that liv year-round and are harvested numerous times'; prevents the uprooting of plants at the end of each harvest cycle

windbreaks

the usage of trees and other plants to block the force of wind from eroding topsoil; provides a source of income and habitat for other species

no-tell agriculture

leaving leftover crop remains in the soil, instead of tilling it under; adds organic matter to soil, which adds nutrients, soil cover, and moisture

strip cropping

alternating rows of dense crops with rows of less dense crops, in order to prevent runoff from eroding soil from less dense rows

crop rotation

replant different crops each season, allowing the soil to recover from nitrogen-demanding crops like corn

green manure

the leftover plant matter from a cover crop; stabilizes soil and limits topsoil erosion, and the remains of the plant matter release nutrients into the soil as they decompose

cover crop

a crop planted in the offseason between harvest and replanting of a main crop

limestone

spreading crushed particles into the soil, which neutralizes acidic soil as a result of the mineral because a base

effects of acidic soil

displaces the positive charge of nutrients from the soil, it is leeching them out; makes toxic metals like aluminum more soluble

rotational grazing

the regular rotation of livestock to different pastures to prevent overgrazing

aquaculture

the raising of fish or other aquatic species in cages and enclosures underwater

benefits of aquaculture

requires minimal amounts of water, space, and fuel; reduces the risk of fishery collapse, as fish are being bred by humans; and doesn’t take up any land space

drawbacks of aquaculture

high density organisms produces a high concentration of waste (eutrophication risks) and diseases can be transmitted to wild populations; may introduce non-native species or GMOS to the ecosystem if the captive fish escape; the antibiotics used can contaminate the water via waste

selective cutting

the practice of cutting only the oldest or biggest trees in an area to preserve the habitat and topsoil

reforestation

the act of replanting areas of removed trees with the same species being logged

reused wood

a sustainable practice that requires the recycling or re-usage of wood, by either chipping it for mulch or restructuring the wood for other uses (furniture, decoration, etc.)

selective disease removal

the selective removal of diseased trees in order to prevent the disease from spreading throughout the forest

prescribed burns

setting forests on fire, on purpose under controlled conditions, in order to prevent natural fires by using up the dead biomass (fuel)