Amazon Rainforest Flashcards
Where is it
South America
Mostly Brazil
Biomass
High biodiversity
Most productive biome on planet
50 mill species of animals
480 species of trees per ha
Trees in distinct laters - shrub, under campy and emergent
Climate
High precipitation (2000mm)
Constant high temp 27 degrees
Daily weather pattern w temp rising AM - then convectional rain pm
Water cycle
High precipitation (2000mm)
Dense canopy intercepts 75%
1/2 used by plants and returned to atmosphere through evapotranspiration
Some stem flow reaches soil where it infiltrates/ runs off to river channels
Remaining 25% evaporates
Output: water which leaves TRF is streams and rivers
Deforestation - no trees hold top soil, lose fertility, desertification and soil erosion - lessen river Calicut
Climate likely to be drier - studies suggest due to removal of trees - reduce trans and so less water in atmosphere
Nor eaTer reaches ground as less interception - inc overland flow - more water in river - flooding downstream and shorter lag time
Carbon cycle
High temp and rainfall = rapid plant growth = photosynthesis
Carbon stored in large amount (2100g/yr)
Rainforest is a carbon sink
Respiration by plants and decomposition by DOM leads to CO2 -> atmosphere
Outputs: Carbon stored in soil which can leave TRF via rivers
DEFORESTATION
If cleared through burning - uncontrollable sig impact
Photosynthesis reduced unless other plants introduced
TRF now carbon source
Decomposition and respiration reduces as less carbon emitter
Soil erosion - release of stored carbon in atmosphere as DOM in peaty soil released through decomposition
Forest burning reduce TRF ability to absorb carbonic
Estimated 97-98 —> over 8 mill of HA forest destroyed by forest fires in Indonesia pumping more CO2 than all biomass in planet cancremove in year
But when selective logging is used - impacts on carbon cycle - reduced as most of forest = intact
How much deforestation occurs
95% within tropics
Average species extinct in rain forest every half hour
Causes of deforestation in TRF
Agriculture/monoculture
Logging for hardwood
Hydroelectricity
Settlements
Mining
Road/railways
Agriculture and monoculture as reason for deforestation in TRF
Pop growth - inc demand for food in LICs and large scale commercial farming cattle or plantations
Require large quantities of land/deforestation
Monoculture requires large inputs of chemical fertilisers to maintain soil fertility as just growing same crop each year extracts the soil
Logging for hardwood as reason for deforestation in TRF
Valuable hardwood harvested for sale in HICs
Used for construction and furniture
Eg Jap imports 11m of tropic hardwood annually
Hydroelectricity as reason for deforestation in TRF
Provides large amounts of renewable energy for LIC and no carbon emissions once operating
Require large areas of forest for reservoirs
Settlements as reason for deforestation in TRF
Pop inx and eco developments
Inc in demand for land and resources
Eg Brazil - 25m landless people
Particularly from drought struck NE
Mining as reason for deforestation in TRF
Develop natural resources thought to exist below TRF and req people and roads as well as mines
Roads/railways as reason for deforestation in TRF
Supports development of TRF and allows access for people and resources
Eg trans Amazonian highway extends over 6000km into rainforest and
Other env factors affected
TRF= 95% worlds biodiversity, deforestation will reduce this - morally and practically wrong
+ do we have fight tocdo this
Maybe extinction species could have medical benefits
Indigenous people deumated by arrival of Europeans in TRF
Millions of indigenous have been reduced to 20,000 - many of whom live in cultural and eco poverty
Mitigate deforestation:
Sustainable tourism -
locals giving accommodation and experiences of western tourists im TRF
Aim- soc eco and env sustainability
BUT Is this myth or reality
Alley cropping
Fast growing trees planted in rows to provide shade between rows to reduce weed
In time crops can be planted in these spaces
Allows bands to regain fertility and for trees to reduce biodiversity loss
IS THIS TOO FAR OR TOO LATE
WILL IT BE ECO OR ENV SUS
Gov backed nature reserves and national parks
TRF protected and conserved for future generations
NO exploitation allowed!
Is this practical in LIC - need resources to develop
Selective logging
