Amazon rainforest

• Water cycle- precipitation

  -high average annual rainfall

  -evenly distributed throughout the year though short direr season occurs in some places

  -inception by forest trees is high
• water cycle- evapotranspiration

  -due to high temperatures, abundant moisture and dense vegetation

  -around half of incoming rainfall is returned to the atmosphere by evapotranspiration

  -most evaporation is intercepted moisture from leaf surfaces
• water cycle- run off

  rapid run off is related to high rainfall, intensive rainfall events and well drained soils
• water cycle-atmosphere

  -high temperatures allow the atmosphere to store large amounts of moisture

  -relative humidity is also high
• water cycle- vegetation

  rainforest trees absorb and store water from the soil and release it through transpiration
• physical factors that effect the water cycle- geology

  -impermeable catchments have minimal water storage capacity resulting in rapid-run off

  -permeable and porous rocks such as limestone and sandstone store rainwater and slow run-off
• physical factors that affect water cycle-relief

  -in areas of gentle relief, water moves across the surface or horizontally through the soil t streams and rivers
• physical factors that effect the water cycle- temperature

  -high temperatures throughout the year generate high rates of evapotranspiration

  -convection is strong, leading to high atmospheric humidity
• human factors affecting water flows

  -deforestation has caused one fifth of the primary forest destroyed which meno less evapotranspiration and therefore less precipitation

  -devastating floods occurred on the Madeira river and vast expanses of floodplain overtook and there were outbreaks of cholera. main driver of floods was deforestation in Boiliva and Peru
• human factors affecting carbon and nutrient flows and stores

  -deforestation exhausts the carbon biomass store

  -deforestation reduces inputs of organic material to the soil

  -soils depleted of carbon and exposed to strong sunlight, support fewer decomposer organisms, thus reducing the flow of carbon from the soil to the atmosphere

  -deforestation destroyed the main nutrient store- the forest trees and removes most nutrients from the ecosystem. Nutrients no longer taken up buy the root systems of trees are washed out of rainwater and soils without the protective cover of trees are eroded
• strategies to manage tropical rainforest

  -the Brazilian government established many conservation areas

  -compromised national parks, wildlife reserves where farming is banned

  -indigenous people participate in a scheme that aims to protect primary rainforest on tribal lands from further illegal logging and reforest areas, they plant seedlings bred in local nurseries in deforested areas around their village
• improved agricultural techniques

  the low sustainability of soil meant that permanent cultivation proved unsustainable

  -one way to improve has been desertification, soil fertility can be maintained by rotational cropping and combining livestock. Integrating crops and livestock could allow an increase in ranching productivity and slow rates of deforestation

  -another way is making human engineered soil from charcoal waste and human manure, the charcoal attracts microorganisms and fungi and allows to retain long term fertility