Amazon Rainforest Flashcards
Location
South America, and covers 68% of
Brazil and smaller parts of Peru,
Ecuador, Columbia, Venezuela
Characteristics
300 billion trees
- covers 8.2 million km2
- world’s largest rainforest ecosystem
- Forest originated 55 million years ago
- largest example of freshwater runoff in earth
- soils fertilised by phosphorus blown from
Sahara’s Bodele region (adds 182 million
tonnes of dust annually
Vegetation
High levels biodiversity
60,000 species of plant
• Characteristics.
-evergreen (doesn’t loose leaves
-buttress roots (large SA support
large trees)
-Drip tips
Links to water cycle
Over 3000mm of rain and temp average of 28 oC
cause humid conditions.
• 75% of this total rainfall is intercepted by the trees
and then to the ground through stemflow.
• Amazon River Discharges 175 000 m3 of freshwater
into the Atlantic each second (1/3 total rain fall)
- 50% of rainfall never reach ground due to
interception and evaporation
- Connectional rainfall, 50/80% moisture remains in
the ecosystems water cycle (re-cycled)
•Global impacts since moisture created impacts rain
patterns in US, Europe and China
Links to carbon cycle
Untouched = carbon sinks. Amazon rainforest emits 1.9 billion tons
carbon but absorb 2.2 billion tons
* Captures 120 bn tons carbon
* 17% global terrestrial vegetation stock
* Plants conduct photosynthesis, releasing oxygen and locking in
carbon. Rainforest is known as “the lungs of the earth’.
* Stores 20% of all biomass-stored carbon on the planet
Only coral fixes a larger amount of Carbon than tropical rainforests
* Age of many plants in the rainforest means they are long-term
carbon stores
* Regulates global atmospheric Carbon levels
Deforestation
80% deforestation due to cattle
ranching
Between 2000 and 2007, 19,386km2
was being destroyed per year
How deforestation affects the water cycle
•Water
No tree canopy to intercept rainfall, so more water
reaches the ground. The ground then gets saturated and
so water moves to rivers as surface runoff.
• Reduces the rate of evapotranspiration.
• Flash floods since less interception
Forests emit salts and organic fibres along with water
when they transpire, condensation nuclei and assist in
cloud and rain production, loss inhibits the formation of
cloud and therefore rainfall
How does deforestation affect the carbon cycle
Carbon
Without roots to hold soil together, heavy rain will wash the nutrient-
rich top layer of soil, transferring carbon stored in the soil to the
hydrosphere.
• Less leaf litter, so humus is not formed. The soil cannot support much
new growth, which limits the amount of carbon that is absorbed
• Trees remove CO2 from the atmosphere and store it, so fewer trees
mean more atmospheric CO2, which enhances the greenhouse effect
and global warming.
When forests are burned 30-60% of carbon lost to atmosphere
decomposers die off so cannot recycle dead material
Climate change
Temperature increases and rainfall decreases -> drought.
Amazon has had severe droughts in 2005 and 2010.
• Plants and animals are adapted to moist conditions and
may not be able to survive in dry conditions.
4 degree temperature rise could kill 85% of the Amazon
rainforest.
• Habits no longer suited to species due to increasing
temps
•Brazil 75% green house gas from deforestation
Impacts of climate change
Impacts of Climate Change
• Road construction opened up large areas of previously inaccessible forest to activities such
as logging - Trans Amazonian Highway
• The Amazon rainforest has lost approximately 17% of its primary rainforest in the last 50 years.
80% is due to cattle ranching.
Parts of the Amazon basin experienced drought in 2005 and 2010. The 2010 event lowered
the Río Negro upstream from Manaus, isolating local people who depended on the river for
transport.
Forest fires often occur because of drought, releasing large stores of carbon in the biomass.
• Deforestation alters transpiration and albedo levels, which will lead to reduced precipitation
because there is a lower level of atmospheric humidity.
• Hydroelectric power generation - large hydroelectric dams have been constructed on rivers
such as the Rio Tocantins and have flooded large areas of rainforest. Changing the way water
flows through the basin.
• Crops planted to replace deforested areas will fix some carbon and conduct some
evapotranspiration but at a much lower rate than rainforest vegetation. This is often only
temporarv as well as crops are harvested.
greater destruction of the Amazon’s coastal mangroves, and more rapid transfers in the water
cycle as plants grow more vigorously.
by 2080 many current species may not be viable in the Amazon due to temperatures
National mitigation
creation of national parks and forest reserves
•Para rainforest reserve: an expanse of 15 million hectares (larger than England) in the
northern Amazon
Agrotorestry
•The combination of planted trees with annual crops, has many environmental and social
advantages over predominant land uses in Amazonia, such as cattle pasture.
Provided that forest is not cut to make way for agroforestry, trees in agroforestry systems will
hold more carbon than would the vegetation otherwise occupying the site.
Reforestation
planting trees in areas without trees. Atmospheric carbon is sequestered into tree
biomass, carbon is maintained out of the atmosphere
•Sustainable forest management (carbon sequestration), carbon in wood is converted to long-
lived wood products, (fine hardwood furniture and construction timber-> remains out of the
atmosphere while the trees in the harvested location re-grow and accumulate more carbon
•Seedlings of native species grown in local nursery and planted in degraded forests, could
enhance the reforestation efforts and encourage the growth of native tree species to restore a
high level of biodiversity
1965, the Forest Code, a law requiring landowners in the Amazon to maintain 35 to 80 per
cent of their property under native vegetation. So, rural farmers can buy land in the Amazon,
but they can only farm 20 per cent of it.
International mitigation
•Management level included
Proportion of environmental protection areas as against permanent
production areas
Amazon Cooperation Treaty Organization (ACTO)
•Aimed at promoting sustainable development
•8 member countries
•Reverse loss of forest cover worldwide, sustainable forest management, including
protection, restoration, afforestation and reforestation, increase efforts to prevent
forest degradation,
Monitor and prevent illegal logging
Enrichment of degraded forests using native species
-The Big Tree Plant campaign encourages communities to plant 1 million new trees,
mostly in urban areas
DEBT FOR NATURE SWAP
-In 2010 the USA converted US$13.5 million of debt from Brazil into a fund to support
the protection of the rainforest
The International Tropical Timber Agreement (ITTA) promotes sustainable forest
management and restricts the trade in rainforest hardwood timber (hardwood timber
is a slow-developing wood and therefore, holds more carbon within the wood)
