The living world - Tropical rainforests Flashcards
Biodiversity
The variety of life in the world or a particular habitat.
Commercial farming
Farming to sell produce for a profit to retailers or food processing companies.
Debt reduction
A political agreement where countries are relieved of some of their debt in return for
protecting their rainforests.
Deforestation
The chopping down and removal of trees to clear an area of forest.
Ecotourism
A type of tourism that involves responsible travel to natural areas that helps to conserve the environment, sustain the wellbeing of the local people, and may involve education. It is
usually carried out in small groups and has minimal impact on the local ecosystem.
Logging
The business of cutting down trees and transporting the logs to sawmills.
Mineral extraction
The removal of solid mineral resources from the earth. These resources include ores, which contain commercially valuable amounts of metals (e.g. iron and aluminium), precious stones (e.g. diamonds), building stones (e.g. granite), and solid fuels (e.g. coal and oil shale).
Selective logging
The cutting out of trees which are mature or inferior, to encourage the growth of the
remaining trees in a forest or wood.
Soil erosion
Removal of topsoil faster than it can be replaced, due to natural (water and wind action), animal, and human activity. Topsoil is the top layer of soil and is the most fertile because it contains the most organic, nutrient-rich materials.
Subsistence farming
A type of agriculture producing food and materials for the benefit only of the farmer and his family.
Sustainability
The practice of using natural resources responsibly, so they can support both present and future generations.
Amazon: causes of deforestation - logging
- Trees such as mahogany and teak are highly valued for furniture and other uses
- smaller trees are used for fuel, pulped or made into charcoal
Amazon: causes of deforestation - farming
- increasingly land is cleared for commercial farming –> crop plantations and cattle grazing
- in Brazil cattle farming accounts for 80% of deforestation
- in Brazil, soyabeans, palm oil and sugar cane are the major crops
- tax incentives for plantation owners encourage further development
Amazon: causes of deforestation - settlement and population growth
- settlements have developed to service the developments in Brazilian rainforests
–> such as farming and mineral extraction - leads to an increased population
Amazon: causes of deforestation - mineral extraction
- major cause of deforestation
–> in Brazil mineral such as gold, bauxite and copper are mined extensively
–> causing large sears and polluted rivers - Carajas mine is the largest iron ore mine
–> 3000 people, 24 hours a day
Amazon: causes of deforestation - road building
- destroys areas of the rainforest
- increases access deeper within the Amazon basin and previously inaccessible rainforest
–> can lead to the increase in other activities with deforestation e.g. farming
Amazon: impacts of deforestation - local climate change
water cycle is disrupted –> less trees = less evaporation –> less moisture –> fewer clouds –> drier climate
rainforest dries out –> more CO2 in air
Amazon: impacts of deforestation - soil erosion and fertility
top soil layer is exposed –> leeching causes loss of nutrients –> hard for vegetation to grow –> impacts marine ecosystems and flooding
more of the forest will be cleared and less vegetation will grow –> decreasing the rainforest size
Amazon: impacts of deforestation - river pollution
the leaking mercury from gold mines poisons fish and inhabitants
natural ecosystems will be disrupted without the fish
Amazon: impacts of deforestation - decline of indigenous tribes
homes and food supply is taken away –> forced off their land –> many displaced indigenous people have ended up in towns/cities
knowledge is lost, culture and way of life is changed
Amazon: impacts of deforestation - climate change
stored carbon is released back into the atmosphere –> made worse by the fact fire is often used to clear areas of forest, emitting even more CO2 –> shift from carbon sink to source
- effect rising sea levels and more extreme weather –> possible of irreversible climate change
Amazon: impacts of deforestation - biodiversity lost
current estimate suggest that 137 plant, animal and insect species are lost every day because of deforestation –> many cures for life threatening diseases are also lost
once species are extinct this is irreversible
Tropical rainforests: distribution/location
- found in a broad belt close to the equator
Tropical rainforests: Plants and animals
- highest level of biodiversity in the world
- due to range of habitats available
- birds live in the canopy, feeding on seeds + nectar
- mammals such as monkeys and sloths live in the trees
- animals such as deer live on the forest floor, browsing on vegetation
Tropical rainforests: climate
- high temperatures of 27 degree C
- high rainfall (over 2000mm per year)
- ideal growing conditions for the lush vegetation growth
Tropical rainforests: water
- has distinct wet season lasting several months
- leads to excess ground water, swelling rivers and some flooding
- can leach nutrients from the soi
Tropical rainforests: soils
- soils are not very fertile
- nutrients are concentrated in the thin top soil and are quickly taken up by plants as they grow
- intense leaching removes nutrients from the topsoil and redeposits them further down
- this accounts for the red rich soils called latosols
Tropical rainforests: people
- traditional tribes have been living in rainforests in harmony with the natural environment
–> hunting and gathering only what they need to survive - however, increasingly people are exploiting rainforests for commercial gain, chopping down trees for timber or to make way for commercial plantations
Example of how plants rely on soil in tropical rainforests:
soil stores nutrients, which helps plants to grow
Example of how people rely on plants and animals in tropical rainforests:
people rely on plants as they produce 20% of Earth’s oxygen
they rely on animals to help the nutrient cycle
How are lianas an adaption to tropical rainforests?
woody vines that climb up trees to o reach sunlight so their leaves can grow
How are Buttress roots an adaption to tropical rainforests?
spread out over wide areas to absorb more nutrients from the thin soil layer
How are drips an adaption to tropical rainforests?
act as interceptors
reduce the rate of run-off and leaching
How are poison dart frogs adapted to tropical rainforests?
if they eat poisonous insects they absorb the toxins in their mucus
feet have extra-strong suction cups to climb and hold slippery branches
How are poison three-toed sloths adapted to tropical rainforests?
extra vertebrae to be able to turn neck 270 degrees to check for predators above and below
can swim in floods
grow green algae in fur to camouflage
What are the threats facing biodiversity in tropical rainforests?
natural events such as:
lightning strikes/fire, floods, disease
people:
mining, roads + settlements, timber harvesting
If biodiversity declines, what issues does this lead to?
- indigenous tribes being unable to survive in rainforests and having to abandon original lifestyle
- plant and animal species may become extinct
- important medical plants may become extinct
What is the socio-economic value of tropical rainforests?
subsistence and commercial farming
–> indigenous tribes practice subsistence farming
–> commercial farming: crop plantations and cattle grazing provide local foods and industrial products
medical drugs derived from rainforests
–> 120 prescription drugs are derived from rainforest plants
–> 25% of western pharmaceuticals are from rainforest ingredients
logging
–> for furniture
–> causes deforestation
Developments
–> mineral extraction
–> energy developments
What is the environmental value of tropical rainforests?
climate
–> evaporation of water from rainforests helps cool the air
–> contributes to 28% of the world oxygen
–> acts as a global carbon sink and climate regulator
soil erosion
–> shelter bind together tropical soils, preventing harmful soil erosion
water
–> important resource of freshwater
–> 20% of worlds freshwater comes from basin
creates huge biodiversity
–> over 50 million years of plant and animal species evolution
Strategies used to manage the rainforest sustainability - selective logging
- only felling trees that are fully grown –> these are seen as less valuable ecologically
- younger trees can be allowed to mature and continue to provide protection from soil erosion
Strategies used to manage the rainforest sustainability - agroforestry
- involves growing growing crops and trees together
- farers grow crops in carefully controlled, cleared areas within the rainforest surrounded by plantations of trees
Strategies used to manage the rainforest sustainability - replanting
- this technique recreates forest cover that has been lost that is almost the same as the original forest
- done by colleting seeds from the remaining patches of the original forest
Strategies used to manage the rainforest sustainability - 2006 international tropical timber agreement
- restricts sale in tropical rainforest hardwood
- discourages the sale and purchase of hardware timber
Strategies used to manage the rainforest sustainability - debt reduction (‘debt for nature’ swaps)
- The USA agreed to allow Brazil to convert £13.5 million it owed in debt repayments, into a fund to protect large areas of the Amazon rainforest
- encourages Brazil to invest in sustainability management of the rainforest by making it economically neutral to do so
Strategies used to manage the rainforest sustainability - ecotourism
- small-scale tourism and entirely local
- it is run by local people, creates jobs for locals, and only uses local produce
- all profit stays in the local community, no economic leakage
- provides economically and environmentally sustainable jobs
Strategies used to manage the rainforest sustainability - education and conservation
- charities and non-government organisations educate people on the importance of TRF
- encouraging people to make sustainable choices when using rainforest products
What scale is this strategy happening on - small-scale forestry?
local
What scale is this strategy happening on - 2006 international tropical timber agreement?
global
What scale is this strategy happening on - debt reduction?
global
What scale is this strategy happening on - ecotourism?
local
What scale is this strategy happening on - education and conservation?
global
Are there any limitations/issues with this strategy - small-scale forestry?
difficult to police and manage
may not be socially sustainable for local people who depend on it for income
Are there any limitations/issues with this strategy - 2006 international tropical timber agreement?
could push illegal logging underground and create a black market for hardwood and timber
Are there any limitations/issues with this strategy - debt reduction?
reliant on other countries to make large economic investments into countries like Brazil, despite not having control or input on how the debt relief is spent
Are there any limitations/issues with this strategy - ecotourism?
requires significant start up investment and difficult to roll out on a national or regional scale
can be expensive so it is not always attractive to holiday makers
Are there any limitations/issues with this strategy - education and conservation?
local governmental pressures can impair conservation efforts and the impacts of global education can be difficult to quantify
