Rainforests Flashcards
What are the effects of deforestation in the Amazon Rainforest?
Humus layer depleted of nutrients, loss of biodiversity
CO2 concentrations increase on a global scale
Higher levels of atmospheric pollution locally, particles in air from machinery, rivers can be polluted, methane from agriculture
Microclimate in local area can become drier, as less vegetation leads to less evapotranspiration, less convectional rainfall
bad soil erosion and leaching due to loss of vegetation cover and protection - infertility meaning unable to easily re-establish ecosystems
Where is Amazon rainforest and how is it distributed?
Northern region of South America, in a clustered pattern between northern Brazil, eastern Peru, Columbia, and across the Amazon rainforest
What are the physical characteristics of a tropical rainforest?
it has four layers
first layer: shrub layer - buttress routes, no sunlight, very moist - 10m
under canopy: small trees grow between trunks of larger trees, trying to reach sunlight - epiphytes grow here - 20m
canopy: thickest layer, with the greatest bio diversity - 30m
emergent trees: fastest growing trees, out compete others for sunlight, leaves have drip tips to allow drainage of heavy rain - 40m
What is the interdependence between climate, water, soils, plants, animals and people?
climate: warm and wet means plants grow quickly - dense leaf cover protects soil from wind and rain, roots help provide structure
animals: bees, butterflies and other animals are relied on for pollination due to no wind on floor
plants: symbiotic relationships between agouti ( rodent) and Brazil nut, as they are only ones able to open it, and when they bury it can lead to new trees
humans: many rely on produce from the rainforest for medical products, and also deforestation can have knock on effects
How have plants and animals adapted to the physical conditions?
plants: drip tips to allow drainage, epiphytes follow sun, liana vines have roots in ground but stretch up to reach sunlight, tree trunks are tall and thin to allow trees to reach sun, buttress roots provide support for tall trees
animals: sloths have camoflage, spider monkey has long limbs to allow it to climb between rainforest branches, toucan has long bill to allow it to reach fruits
What are the reasons for deforestation in the Amazon rainforest?
logging: Commercial logging companies cut down trees for timber, which is mostly sold to developed countries. In most cases, large areas of forest are destroyed just to remove a few highly valued trees
farming: Land is cleared (eg by slash and burn) and planted with cash crops, usually just one - such as palm oil. Alternatively, it will be used for grazing by cattle ranchers. Most cash crops and cattle are eventually sold to developed countries
mining: Land is completely deforested. Soil is often removed with high-pressure hoses and chemicals are used. The run-off goes into local rivers and pollutes them. Huge scars from open-cast pits are left - the soil can’t recover.
road building: Loggers and miners build roads to get their materials out. People use the roads to enter the forest and build new settlements and set up industries. The Trans-Amazonian Highway in South America is 5,300 km long and has opened up some remote parts of Brazil to development.
dam building: Hydro-electric dams provide energy but also result in deforestation. Problems include:
flooding of large areas of forest
people may have to move
drowned forest rots and adds carbon to the atmosphere
settlement: Land is being cleared for new homes and settlements. There is more need for these in countries with increasing populations, especially around large overcrowded cities.
What are some issues related to biodiversity in rainforests?
deforestation can be very damaging to bio diversity as many components are very closely connected in the food web meaning that some things can have bad knock on effects
What are some strategies used to reduce the harmful effects of deforestation?
selective logging: he cutting out of trees that are mature or inferior to encourage the growth of the remaining trees in a forest or wood
replanting: planned and controlled logging allows each tree to be replanted
education: It is important that local people, businesses and politicians understand the true value of the tropical rainforest. Once they understand the value of biodiversity, particularly in terms of tourism, they will be more likely to want to protect it from deforestation.
ecotourism: encourages sustainable tourism to conserve rainforest
International agreements: agreements to protect tropical rainforests have been made between different countries through debt-for-nature swaps. This is when a country which is owed money by another country cancels part of the debt if an agreement is made by the debtor country to ensure the conservation of its tropical rainforests.
