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Flashcards in Topic 8 Deck (16):

How have plants adapted to suit the climate in the tropical rainforest?

Buttress Roots - Mahogany, teak and ebony trees have adapted buttress roots to support their weight (as they are very tall).
Lianas - As the canopy layer absorbs most of the sunlight, lianas wrap around other trees to work their way up to the top to gain maximum growth.
Sloths - Claws to cling to trees, also allowing them to hang upside down. Algae also grows in their fur to act as camouflage.
Big Cats - Leopards, tigers and jaguars are light and dark patches on their skin to blend in with the patches of sunlight and shade.


Why does the tropical rainforest have high nutrient cycling? What affect does this have on its biodiversity?

The rainforest has optimum decomposition conditions and so leaf litter decays quickly, returning the nutrients to the soil constantly. Furthermore, due to very little leaching and runoff, the soil retains these high levels of nutrients and causes the rainforest to have a large store of biomass (which can contribute to leaf litter).


How are plants adapted to suit the climate in the taiga forest?

- Trees have needles instead of leaves to reduce water loss from strong cold winds (smaller surface area).
- Trees are cone shaped, allowing heavy snow to slide off the branches without breaking them.
- The plants have evergreen leaves, meaning they don't drop in a particular season (making the best use if available light).


Why does the taiga forest have low nutrient cycling? What affect does this have on its biodiversity?

As precipitation is low in the taiga forest, very little nutrients is added through rainfall and weathering (limited by the cold temperatures). However, lots of nutrients are lost through runoff and leaching because snowmelt carries nutrients away and there is slow evaporation (due to low temperature), which causes the increased leaching.


List some of the causes of deforestation:

- Commercial Logging
- Commercial Agriculture
- Subsistence Agriculture
- Mining
- Local demand for fuelwood
- Demand for biofuels


Explain how climate change is an indirect threat to the rainforest:

Climate change will alter the global distribution of water and therefore make certain areas drier. As a result, the levels of growth as well as the nutrient cycle in the rainforest will suffer because there will be less precipitation to add nutrients to the soil.


What are direct threats to the rainforest?

- Logging for softwood
- Pulp and paper production


What caused the indirect threats to the rainforest?

- Exploitation of minerals
- Fossil fuels
- HEP potential


How is biodiversity affected by acid rain and forest fires?

Soil acidity increase when the precipitation lands, which makes it difficult for plants used to lower acidity/alkaline soils to survive there. Furthermore, this can reach an extent where the soil can no longer support life, and organisms in lakes/rivers can be killed from acidic water.
Forest fires can be good in the respect that they destroy old trees and allow the forest to regenerate, but they are mostly bad. This is because loss of trees affects the species distribution when trees regrow, as well as fire splitting forests into smaller sections (which makes it harder for migratory animals that need space).


How is biodiversity affected by pests and diseases?

As taiga forests are largely made up of the same species of tree of a few species of tree, a disease/pest that is specialised to that singular type could be devastating. This large area of a single species could allow the disease or pest to multiply and spread rampantly, destroying numerous trees.


List some of the advantages of CITES and REDD:

- CITES has reduced the ivory trade and halted the decline of African elephants
-REDD can protect large areas of land at not too much of a cost as long as the land isn't highly populated.


List some of the disadvantages of CITES and REDD:

- CITES relies on countries setting up and funding monitoring and policing systems, which many low income countries can't afford.
- REDD are restricted by how much they can conserve as they have to balance size with cost of paying people to not deforest.


Why are deforestation rates rising/falling in certain areas?

Increase: High sale prices for rainforest products can be exploited by low income countries to pay off national debt. Severe and widespread poverty increases subsistence 'slash n burn' farmers.
Decrease: Satellite imaging can be used to track illegal deforesting, allowing authorities to out a stop to it faster. Alternative income can be supplied by paying land owners to reforest areas and give tours.


What methods can be used to help protect the remaining rainforest?

Ecotourism - Guided tours of small tourist groups through the forest to see it (provides locals with alternative income).
Sustainable farming - Farming by re-using previously farmed lands instead of clearing new land, protecting local soil nutrition.


Name some of the challenges of protecting the rainforest:

- Governments pressure Wilderness Areas to log, mine and extract energy from the forest.
- Roads, hotel for tourists going to National Parks can cause pollution (both noise and air) and damage the ecosystem.
- Sustainable forestry can be hard to enforce due to corruption, and it isn't very popular as it doesn't earn as much money as clear felling.


Why are there conflicting opinions over conserving and exploiting the rainforest?

Exploit: Logging/mining can create jobs, increases GDP, affects a small area but has national benefits, some activity is renewable (HEP).
Conserve: Human activity would irreversibly damage it, the forest is culturally significant to natives, taiga is a crucial global carbon store, one of the last touched biomes in the world.