The Amazon Flashcards
How did the Amazon region form?
ecosystem prob formed by the rise of the Andes mountains starting 35-65 million years ago
- increased rainfall by blocking humid Atlantic air
- prevented water from draining to Pacific; formed wetlands
How diverse is life on amazon?
Very, home to 1/10 of all species on Earth
What regional and global benefits does the amazon provide?
- produces oxygen, stores carbon
- regulates water cycle ‘creates’ rain
- cycles nutrients, forms soil
- provides useful products (nuts, rubber..)
- provides cultural value
Humans have lived in the Amazon for ____ years
13,000
What were the different Indigenous livelihoods over time in the Amazon?
- Foraging (hunter-gatherer)
- Foraging combined with settled fishing
- Cultivation (swidden/shifting; orchards)
- Some large settlements
How did pre-colonial people influence the Amazon environment?
Changed the composition of the forest:
- cultivated useful trees and plants
- built earthworks
- kept homes safe from flooding; created ponds
Built raised fields and channels in wetlands:
- reduced shade; raised water temps
Changed composition of soils
- Garbage piles formed rich black soil, helped plant growth
What were some contemporary threats to the Amazon?
Deforestation:
- agricultural expansion (cattle ranching, crops)
- timber harvesting
Hydroelectric dams
oil and mining
What was a driver of deforestation?
Agriculture
- govt incentives encouraged people to clear forest and settle in Amazon
What occupied the majority of cleared forest land in the Amazon?
Cattle ranching
Considered less risky than other ventures during the settlement boom in 1960s:
- can walk itself to market; hardier than crops
- still an important way for farmers to hedge against risk
- quickly depletes soil
What was soy farming used for in the Amazon?
Used for livestock feed, edible oil, biodiesel, food products
- a “flex crop”
Soybean production has increased very rapidly: more than ____ globally since 1994
doubled
What percent of soy is used to feed livestock?
70%
How does soy contribute to deforestation?
Soy plantations displace pastures
- large monoculture plantations
What are the key points about hydroelectric dams for the Amazon?
- many new dams planned for the Amazon
- Goal: low-carbon energy, economic development
-Impacts: flooding, relocation, cultural erosion, ecological changes
What was the Belo Monte dam?
Hydroelectric dam
- world’s fourth-largest dam
- project approved after 20 years of opposition by Indigenous ppl and environmental groups
- changes in water flow have dramatically affected biodiversity and livelihoods