Rainforests

Rainforests

1. Layers

   • The shrub layer consists of tree saplings and shade- tolerant ferns. Orchids thrive here because of the damp conditions.
   • The under canopy layer receives about 5% of the sunlight falling onto the forest. It is hot, damp and shaded from the wind. Vines, called lianas, climb through trees to reach the light. Amphibians are found here because it is close to the water supplies on the ground.
   • The canopy trees grow to around 20-40m in height. Leaves have drip-tips, which prevents them from staying wet and rotting. Strong light levels mean that there is an abundance of life here. For example, monkeys, pythons and sloths are usually found here.Epiphytes are plants that grow on branches to obtain their nutrients from water and the air.
   • Emergent trees grow over 50m high as they out-complete neighbouring trees. They can withstand winds and high temperatures. Birds such as parrots and eagles thrive here because parrots have curved beaks to crack open nuts and access fruits.
   • Rainforest soils are often poor because nutrients are washed out by leaching. Falling leaves and branches create a thick layer of litter on the top of the soil. Trees rely on the rapid breakdown of this litter to provide them with nutrients. Larger trees often have buttress roots, which stables them in winds and spread over great distance to absorb sufficient nutrients.
   • The ground layer receives little light. Hot, wet conditions cause rapid decomposition of fallen leaves. Saprophytes are found in they layer- they are micro-organisms that tolerate low light levels and get nutrients from breaking down dead matter. Anteaters can be found in this layer and they are adapted because they can find their food on the dark forest floor because they have a good sense of smell.

2. Amazon Rainforest

   • Impacts and schemes
     • On a local level - In areas without logging they are used for ecotourism, so tourists are educated in nature and conservation. This not only gives local people money and jobs but also reduces the need to cut down the TRF for money. In areas with logging there are schemes which are held there. In Yachara Lodge they do ecotourism.
       • Selective Logging- you only cut down the older trees and you replant younger, prettier trees. And from that you can still make money however it takes time and many people won't follow the rules and you still need to clear forest for transportation.
       • Agroforestry- you can make money from it however other plants are introduced and that affects the ecosystem.
       • Forest reserves also known as national parks. The positives is that it stops illegal logging and allows income to come in however, the people are low on wages.
       • Afforestation - the positives are that it reduced the greenhouse gases i the atmosphere and rebuild the canopy layer however it takes about 30 years for this to be in action.
       • Satellites- with this it is easy to monitor the rainforest in real time and see if the amount of trees they are cutting down in increasing or decreasing. However this is quite expensive.
     • Organisations such as WWF and Flora and Fauna international are charities that rely on donations and volunteers. Monkeys are saved and relocated in Ecuador in a conservation project.
     • On a national level- Passing laws to protect TRF - They protect parks or reserves, stopping abuse of forest but illegal or corrupt developers and also making conservation part of the school curriculum. For example the Limoncocha national park and only the most important areas are protected
     • International level - They have debt reduction in HIC's- Most countries with TRF are LIC's or NEE's with large amounts of debt. They have something called debt for nature swaps. For example equator does a debt reduction to protect the wildlife and pay it all off.
     • Impacts: It can cause global climate change and also a loss of biodiversity,. On a local level it causes a decline of indigenous tribes, soil erosion(eutrophication), river pollution(mining) and also conflict.
   • Causes of deforestation
     • Transport: San Paola and Rio de Janeiro have both built highways to make people move away from the coast.
     • HEP: The amazon river is great as you can use HEP as it is cheap to maintain and it may be why there are so many tributaries.
     • Logging/ Timber: They grow Mahogany,Teak (In climatic conditions), so they cut down more trees to get to the trees they want- 60 - 80% is illegal logging.
     • Mining: They mine Gold, Copper, Diamonds and Lead at the Grand Carajás mine - this pollutes the air massively.
     • Farming and Cattle ranching: As the world population increases there will be more demand for meat. We are also starting to have a more westernised diet. It is also a triple whammy because we burn wood and then the cows produce methane and on top of all this there is no carbon sinks. The soil also gets stripped and leached from all the rainfall.
     • Soya bean production: Source production of protein, it is low cost and can be used for animal food and so they cut down more land to grow it.