AMAZON BASIN Flashcards
(18 cards)
Background
7mil km2
60% Forest Brazil, 13% Peru, 10% Columbia
390billion trees
16,000 species
1/10 known species live
2.5mil insect
40,000 plant
2200 fish
1300 birds
427 mammal
428 amphibians
378 reptiles
Recent years incr deforestation TransAmazonian Highway 1970 - industrial pastoral and cattle farming
Impact on Trophic Structure
Hot and wet conditions = plants grow quickly
Photosynthesis creates huge amount of energy primary consumers feed on
Plant-eating organisms and animals will be found at different levels within ecosystem
Herbivores eaten by carnivores at secondary consumer level
-larger animals like bats and some snakes consume smaller animals
Top trophic pyramid- tertiary consumers - larger snakes and big cats - main predators of eco
Veg and animal matter decompose very quickly - ants termites bacteria fungi and other microorgs
Commercial logging and farming - climax veg trees not present = primary producers number absent from bottom trophic lvl - knock on effecf
Impact on Nutrient Cycling
Much larger biomass than litter
90% nutrients remain locked up within biomass
Litter falling continuously- decomposed very quickly - climactic conditions
Soil does not retain large amount nutrients
-taken up by veg immediately and litter mostly doesnt reach forest floor
Relatively little loss through runoff or leaching
What happens if biomass removed
Least fertile soils - amount of nutrients quickly disappears
Most nutrient flow through decay of litter - little nutrient content held in soil
Soils very quickly become infertile
Small amt nutrients can be reintroduced if veg burnt and ash allowed to settle - any valuable nutrients added washed or leached through soil quickly
Impact on zonal soils
Oxisols old up to 20m deep
- big variations
Relatively infertile - little in the way of nutrient cycle
Red in colour - high conc iron
Much weathering of bedrock beneath
Leaching common - remove humus in solution
Upper layer acidic and mineral deficient
What happens to Zonal Soil if large scale development
Once soil exhausted of nutrients farming moves to clear other areas
Remaining soil difficulty in support regeneration of natural veg - secondary species may take over land
Increased flooding or drought common
Drought = increased soil erosion of unprotected soil means any chance of recover lost forevor
Industrial agriculture introduce chemicals to soil - fertilisers herbicides and pesticides negative ecosystem impacts
Commercial Agriculture Negatives
•Increasing land cleared - foreign based businesses dev large areas to industrial scale
• Main cash crops Brazil- coffee, corn, rice, soybean, tobacco and sugarcane
•Growth area Cattle Grazing
Over 250million cattle in basin
• Fertilisers, pesticides and herbicides
Commercial Agriculture Positives
•local people earn much better wages
•new practices opened up new markets and more opp in Brazil
-causing less env damage
•Cargill, grain company, working in Brazil 50 years over 8000 employees
Logging Negatives
•Timber often prized - however loggers do not promote reestablisebt of trees
•2014 Greenpeace noted ‘Amazons silent crisis’
timber laundering caused illegal harvesting of RF lands
Logging Positives
•Some species protected
-Brazil Nut tree, native Brazilwood and Brazilian rosewood
•Increasingly, harvesting requires a permit & formal management plan
Transport Negatives
•New links developed (World Cup and Olympics) opened access to previously remote areas
•Building of the Trans-Amazonian highway allowed access to remote RF - indirectly caused deforestation
Transport Positives
• Good tp links allowed better access to towns & cities rural Brazil - raised standards of living
• Roads og dev allow new settlers dev small scale agri
‘Land without men for men without land’
• many conservation bodies developed along highway to monitor and support conservation in RF
Hydroelectric Power Negatives
• Nee HEP dams will flood huge areas
• Nee dams Belo Monte and Xingu rover causing env issues
-Convert flooded veg in huge reservoir into methane gas (ghg)
HEP Positives
•Simple effective and cheap method of increasing energy capacity
-increased population increased demand
• Dams able to control flow of water through Amazon
-control flooding
Mining Negatives
•Huge tracts if land cleared to allow mining and quarrying - reach any valuable rocks and minerals
•Brazil 5th largest producer of gold
Also mines iron tin copper and aluminium
Mining Positives
• new advancements in technology allow much easier access to rocks/minerals found beneath forest canopy
Positives of Large Scale Development
Very Few
Only positives economically for people who can tame forest on their own financial gain
