U4: Earth Systems and Resources

Humans’ Impact on Natural Resources and How They’re Used

● “Tragedy of the Commons”: A concept where a public resource is overused due to people forgetting that a limited existence exists.

o For example, villagers fish in a pond every day for dinner, which causes their families to grow, and then more fish are taken from the pond. Despite the decrease in fish population, villagers don't consider that the fish must repopulate in order for them to continue fishing.

● Conservation: Management of a resource so that it is not overused.

● Preservation: Maintenance of species or ecosystem to ensure survival with no regards to their potential monetary value.

● Natural capital: When an economic value is placed on a natural resource.

● Renewable Resources: Resources that can be replenished in the time it takes to use it.

● Nonrenewable resources: Resources that typically take an extensive amount of time to replenish.

● The Green Revolution: took place in the 1950s-60s. During this time, agriculture became more mechanized, and this created an agricultural boom in many countries.

o The second round of the green revolution led to integrated pest management.

o However, Slash and Burn, a type of traditional farming, is still used a lot today. In this practice, trees are cut down then burned to prepare land for crops.

● Federal Insecticide, Fungicide, and Rodenticide Act of 1947 and 1972: EPA must approve all use of pesticides in the United States.

● Integrated Pest Management: Instead of killing, every pest on farm IPMs try to just lower the pest count.

● Contour Plowing: Rows of crops are plowed across a hillside to prevent erosion.

● Terracing: Similar to contour plowing but the flat cropland is cut into hillsides.

● Clear cutting: Removal of all the trees in an area. 

o This is the quickest way for humans to harvest trees, but it has a big impact on the environment.

● Selective Cutting: Removing certain trees from an area allows the environment to stayrelatively unchanged.

● Types of Agroforestry

● Terracing

Natural Occurrences in Forest

● Tree disease and pests limit the amount of trees available for use and harm the food.

● Forest fires

● Surface fires usually only burn the forest’s underbrush.

● Crown fires appear on the ground or canopy of trees that haven’t recently experienced surface fires.

● Ground fires take place in bogs or swamps and can burn underground for days or even weeks.

Ocean Resources

● Fishery: Industry where marine life is captured, processed, and sold.

● Capture Fisheries: This is the most common form of fishing. People catch fish from its natural habitat.

● By-Catch: Fish, mammals, and birds that are caught but aren’t the target species.

o This happens often with drift nets.

● Aquaculture: Raising marine life in captivity for harvest.

● Coral bleaching: Excessive acidification of water kills of the zooxanthellae in coral reefs. This causes them to dry out and eventually die off.

Mining

● Metallic minerals: mined for its metals, which can be extracted by smelting.

● Non-metallic minerals: Minerals mined in their natural state

● Mineral deposits: An area where a mineral is concentrated.

● Ore: A rock or mineral that holds a valuable substance and can be mined for profit.

● Gangue: Mining waste material

● Strip mining: A type of mining where the surface layer of soil is removed so that a seam of mineral ore is exposed. This is typically used for coal mining.

● Shaft Mining: Vertical tunnels are made to access minerals that are far underground.

Shaft Mining vs. Strip Mining