Tropical Forests Under Threat Flashcards
What are epiphytes
Plants that grow on other plants in the tropical rainforest to get access to light and are dependent on rainfall to provide nutirents and water.
What does it mean that tropical forests are stratified
They have layered strucutre
Different layers of trees levels:
Emergents - (40/30 m) have straight trunks and only have branches and leaves on top. Have big roots called “buttress roots”
Main canopy - (30/20 m) is a continuous layer of trees. Dense layer shades rest of forest.
Undercanopy - (10/20m) made of younger trees not yet reached there fall height.
Shrib layer - (10/0m) nearest ground, shrubs have large, broad leaves to absorb as much sunlight as possible
Plants adaptations in rainforest
- Plants have thick, waxy leaves with pointy tips (drip-tips). It channels water to a point so is runs off so the water weight doesn’t damage the plant. It also helps prevent the build up of mold (no standing fungi or bacteria).
- many trees have smooth, thin bark as there is no need to protect tree from cold temps. The smooth surface allows run off easily.
- climbing plants such as LIANAS use tree trunks to climb
- leaves fall all year round for growth
Animals adpated for canopy
Many animals have strong limbs so that they can spend all day climbing and leaping from trees e.g. howler monkeys. Some have con tails for balance or longs fingers and toes. Some animals even have flaps of skin to glide or sunction cups
Animals adaptation to temps in tropical forest
Many animals are noctonal as the night is much cooler, this helps them save energy. Some animals are adapted to lowlight, such as sharp senses of hearing to detect predators or prey
Animals adpatation to water in tropical forest
Many animals can swim in the rainforest, as well as having large serface area feet so they din’t sink into the muddy ground. Many mamals can also swim
How are nutriesnts stored in the TRF (tropical rainforest)
- biomass (living organims)
- dead organic material
- soil
How do rainforests have complex food chains
There are so many different species that there are loads of links with some animals being both primary and secondary consumers.
Tropical rainforest direct threat of commercial farming
Forest is cleared to make space for cattle grazing, or for huge palm oil or soya plantations
Tropical rainforest direct threat of logging
Trees are felled to make furniture and for constuction. Road building for logging also requires more tree clearence
Tropical rainforest direct threat of subsistence farming
Forest is cleared so farmers can grow food for themselves and their families.
Tropical rainforest direct threat of minerals
Minerals are often found in tropical rainforest. Exlposives are sometimes used to clear earth or deep pits are dug to reach the deposits.
Tropical rainforest direct threat of biofuels
Fules from plants requires large amounts of land (trees being cut down) to grow
Tropical rainforest direct threat of HEP
Many tropical rainforests have large rivers. Building dams to generate hpe floods large areas of forest
Deforestation environmental impacts
- no trees to hold the soil together, heavy rainfall washes it away (soil erosion) leading to landslides and floods
- without tree canopy to intercept rain and roots to absorb it soil fertility is reduced as nutirents are washed away
Why are deforestation rates rising in TRF
- poverty (many more small scale subsistence farmers)
- foreign debt
- Economic development
Why are some areas reducing deforestation in tropical rainforest
- Government policies (Costa Rican governmnet has invested in ecotourism and pays landownser to reforest
- international condemnation (pressure put on companies
- monitoirng systems (GFW providing satelite data to track forest loss)
REDD overview
It is a scheme that aims to award for his owners in poorer countries for keeping forests instead of cutting them down
REDD advantages
Deals with the cause of climate change as well as direct impact of deforestation
The forest is protected so remians a habitat for species biodiversity is not lost
Everyone benefits from reducing emissions and it’s relatively for the cheap option
REDD disadvantages
Deforestation may continue in another area
Aspects are not clear, meaning that it may be possible to cut down the forest but still receive the rewards if they are replaced with other types of forests such a plum oil plantations
Preventing activities such as open culture or mining may affect local communities who depend on the income from them
CITES overview
It is an agreement to tightly controlled trade in wild animals and plants
CITES advantages
The issue is tackled at a global level meaning the trade of endangered species is controlled all over the world
Raises awareness of threats to biodiversity through education
CITES disadvatnages
Although individual species are protected from poaching it doesn’t protect their habitats so they could go extinct by climate change
Some rules are unclear and not all countries are members to some even promote the trade of material from endangered species
What is sustainabke forest managment
When a forest is used in a way that prevents any long-term damage whilst alowing people to benefit from recources
Techniques for sustainable forest managment
Selective logging
Replanting
Economic effect of sustainable forest managment
Only seen as a long-term benefit as poorer countires need income immediately
sustainable forest managment is usually more expensive so is dificult to persuade pirvate compaines to use
Many sustainable forest managment are funded by governments and NGO’s meaning if priorites change funding could stop quicklu
Social chanllenges of sustainable forest managment
sustainable forest managment generally provide fewer jobs for locals. Some may tunr to illeagal logging
If pop of forest area increases the dmeand for wood and land from forest increases (can’t match demand).
Environmental effect with sustainable forest managment
Replanted trees may looks unatural (entires ecosystem may not be restored)
Trees replanted can be very slow growing - comapines may chop more natural forest whilst waiting
Selective logging can damage lots of trees in progress
Sustainable farming
Agro-forestry - trees and crops pantes at same time so tree roots bind soil and leaves protect from rain
Green manure - plants which add nutrients to the soil are planted to maintane soil fertility
Crop rotation - crops are moved between different fields so empty fields have time to recover
