Forests Under Threat Flashcards
Rainforest interdependence
Warm wet climate means plants grow quicker . The dense leaf cover protects the forest floor from heavy rainfall.
The lack of wind on the forest floor means that plants must rely on bees and other animals for pollination .
Epiphytes rely on tall trees for sunlight and are dependent on rainfall to provide water and nutrients
Plants adapted
Emergents-tallest trees which poke out from canopy. They only have branches and leaves at the top where they can get light. They also have huge roots that stabilises their trunks
Main canopy-like emergents they only have leaves on the top. This dense layer shades the rest of the forest
Undercanopy-made up of younger trees that are still growing. They can only survive when there are breaks in the canopy allowing sunlight through
Shrub layer-nearest the ground where it is quite dark. They have large broad leaves so that they can absorb as much light as possible
Animal adaptions
Many animals live entirely in the canopy meaning they must have strong limbs allowing them to climb and leap from tree to tree.
Some animals have flaps of skin that allow them to glide .
Nutrient cycle
Nutrients are stored in :
Living organisms
Dead organic material
The soil
The transferring of nutrients in the tropical rainforest is very rapid because
Trees are evergreen so leaves fall and regrow all year round
The warm moist climate speeds up the rate of decomposition
Dense vegetation increases the rate at which nutrients are taken up from the soil
Biodiversity in rainforest
The biome has been around for millions of years without the climate changing very much so there has been lots of time for plants and animals to evolve forming a variety of new species.
The layered structure of the biome provides many different habitats for many species of organism allowing for lots of organisms to reside in ine biome.
Because they are very stable biomes and routinely provide organisms with sufficient nutrients , the animals and plants do not have to cope with changing conditions allowing many species to thrive
Deforestation
Local demand for fuel causes deforestation
Commercial hardwood-trees are harvested to make furniture and many trees are removed to allow the building of roads
Commercial farming-forest is cleared to make space for cattle or for huge palm oil plantations
Subsistence farming - forest is cleared so farmers can grow food for themselves.
Demand for biofuels -forests are cleared so that bio fuel crops can be grown
This impacts the rainforest hugely because
With no trees to hold the soil together heavy rain can wash it away causing floods
Without a tree canopy to intercept rainfall more water washes the nutrients away.
Climate change and rainforest
Increased temperatures cause rainfall to reduce causing drought
Drought leads to ecosystem stress . Animals and plants are adapted to wet conditions and the dry conditions could kill them
Drought can lead to forest fires
Rate of deforestation?
Poverty-population growth and poverty mean there are many more small scale subsistence farms that contribute to heavy amounts of logging.
Foreign debt-there is a huge market for goods from tropical rainforests , many countries will harvest these in order to pay back debt.
Economic development-road and rail projects promote development however they require spaces to be built causing deforestation
Reducing deforestation
Government policies-Costa rican government has invested in ecotourism to raise awareness and also pay land owners to reforest areas
International condemnation-puts pressure on companies by naming and shaming those involved in deforestation
Monitoring systems-satellite data can track forest loss meaning authorities can be quicker in apprehending illegal logging
REDD
A scheme that aims to reward land owners in poorer countries for keeping forests instead of cutting them down
Advantages-Forest is protected so biodiversity is preserved as habitats are not destroyed
- everyone benefits from reducing emissions and is a relatively cheap option for doing so.
Disadvantages-many of their policies are not clear. It is possible to cut down rainforest but still receive rewards if they are replaced by palm oil plantations which lack in biodiversity
Also preventing these activities will cause local communities to suffer as they rely of wood for fuel
CITES
An agreement to tightly control trade of wild animals and plants
Advantages-issue is tackled at a global level which means trade of endangered species is controlled all over the world
Disadvantages-whilst the animals may be protected their habitats are still destroyed
Not all countries are members and many countries promote the trade of these endangered species
Sustainable forest management
Economic- the benefits of sustainable management are long term-this effects poorer areas that need the income immediately .
Sustainable forestry is usually more expensive and it is difficult to persuade companies to adopt sustainable methods
Environmental-the trees may be replaced but the entire eco system will not be restored . Trees that are replanted are very slow to grow so companies will deforest areas with mature trees while the wait for the younger ones to grow
Social-sustainable methods do not provide as many jobs. Sustainable forestry will not be able to meet the demands of the people
Alternative livelihoods
Ecotourism-Only a small number of people are allowed to visit an area . Environmental impacts are minimised as waste and litter are disposed of.
It provides income for local people and means that they can earn money and not have to deforest areas .
Sustainable farming-techniques that protect the soil so that the land remains
Agroforestry-trees and crops are planted so that roots bind the soil and the leaves protect the soil from heavy rainfall
Green manure-plants which add nutrients to the ground as the grow to maintain soil fertility
Crop rotation-crops are moved between different fields each year so that the soil has time to recover
