Specific Biomes - Tropical Rainforest Flashcards
1
Q
What is subsistence farming?
A
- trees are felled to create small clearings that are farmed by families
- abandoned after a few years as soil nutrients deplete
- this is sustainable as long as there is enough time for soil fertility to recover and forests to recolonise
2
Q
Problems with subsistence farming
A
- if human population density becomes too high
- time gap between areas being abandoned and cleared again will be too short
- this will cause forests to be degraded and soil fertility to decline
3
Q
Threats
A
- Fuelwood collection
- Timber harvesting
- Agricultural Expansion
- Mineral Extraction
- Reservoirs
- Global Climate Change
4
Q
Threats - Commercial Agriculture
A
- for the export of crops for cash
(Soya bean productions in Brazil) - Rainforests are cleared as human population and demand for farmland increases
- This is unsustainable, poor tropical soils may become infertile
- Difficult for forest to recolonise abandoned land
5
Q
Threats - Mineral Extraction
A
- results in habitat loss and causes water pollution (drainage water discharge)
6
Q
Threats - Reservoirs
A
- hydroelectric power schemes flood large areas and create a barrier to mobile species
- Decomposition of DOM in reservoir water produces acidic deoxygenated water, harmful to aquatic life downstream
7
Q
Threats - Climate Change
A
- affects wind and precipitation patterns
- Larger and longer forest fires
8
Q
Threats - Fuelwood Collection
A
- rate of wood collection is faster than rate of re- growth
9
Q
Threats - Timber Harvesting
A
- used in countries for furniture
- exported to MEDCs for use in products
10
Q
Conservation Efforts
A
- establishment of protected areas
- debt for nature swaps
- sustainable exploitation
11
Q
Establishment of Protected Areas
A
- Korup National Park Cameroon (1986)
- 600 tree species, 1000 butterfly species, 160 mammal species
- many are endemic
12
Q
Debt for nature swaps
A
- Countries have their debts cancelled by conserving wildlife habitats in return
- WWF have organised debt for nature swaps to protect rainforests in Costa Rica and Philippines
13
Q
Sustainable Exploitation
A
- of high value timber (e.g. mahogany trees) helps pay for forest conservation
- Done by selective logging - doesn’t cause long term forest damage
14
Q
Importance
A
- resources due to high biodiversity
- forest resources
- Climate control
- soil maintenance
15
Q
Resources due to high biodiversity
A
- biomimetic applications
- Plants produce toxic chemicals for defence - alkaloids have medicinal value
- Animals produce chemicals to avoid predation (frogs and reptiles) that have medicinal value
16
Q
Forest Resources
A
- Timber used for furniture
- Food (chocolate from cacao, fruits and spices)
17
Q
Climate Control
A
- increase downwind rainfall through transpiration in the forest
- Carbon sequestration by photosynthesis stores large amounts of carbon, reducing natural greenhouse effect
18
Q
Soil maintenance
A
- Foliage of vegetation cover and tree roots protect soil from erosion
- Rapid vegetation decay due to warm/moist conditions, trees can re-absorb nutrients quickly
19
Q
Habitat features
A
- low seasonality
- warm temp + high rainfall
- high light levels
20
Q
low seasonality
A
- No need for animals to hibernate/migrate
- Plants have less competition for animal services
- Food such as nectar, seeds, fruit is available to animals throughout the year
21
Q
Warm temp + high rainfall
A
- Allows plants to grow throughout the year
- Ensures reliable food supplies
22
Q
High Light Levels
A
- Taller trees benefit most
- Smaller plants need evolved methods of using light (denser chlorophyll, additional pigments)
- Plants that are epiphytes have greater access to light but less reliable water/nutrient supplies
