Paper 1

• Define ecosystem


  A biological community of interacting organisms and their physical environment.
• Producer


  An organism that can make its own food.
• Consumer


  An organism that obtains energy by feeding on other organisms
• Decomposer


  An organism that breaks down wastes and dead organisms
• Summary of rainforest


  Located along the equator with high temps & heavy rainfall
• Summary of hot desert

  Located 30 degrees from the equator with sinking air and little rainfall
• Explain how deforestation can have economic effects (6marks)

  1) Job opportunities

  2) Wood sold, creating money to develop infrastructure, military, etc

  3) Mines & plantations can be built - develop

  4) More money taken in means more taxes, and so more money for the government

  5) More deforestation = less tourism - develop

  6) Use figure
• Plant adaptations in the rainforest

  -drip tips to stop plants from ripping or rotting

  -some plants climb on others to reach sunlight (lianas)

  -buttresses and prop and stilt roots for extra stability as they grow 200ft

  -some plants grown on others to reach sunlight

  -leaf angling towards the sun
• animal adaptations to the rainforest

  Birds live in the canopy feeding on nectar from flowers.

  Sloths are covered in algae for camouflage

  Most animals live in or climb to the canopy where there is more food
• How many plant species live in tropical rainforest

  2/3
• What percentage of medicines come from rainforest

  25%
• How much rainfall does a rainforest get each year

  2000-10,000ml
• rainfall in rainforest


  1. Sun heats up the ground and air next to the ground

  2. Water evaporates from the ground and trees

  3. Warm air rises til it cools and condensation occurs

  4. Cumulus clouds and stormy cumulonimbus clouds occur

  5. Heavy rain
• Rate of deforestation


  1 hectare per second
• subsistence farming


  farming in which only enough food to feed one's family is produced
• commercial farming


  the raising of crops and livestock for sale in markets
• logging


  The business of cutting down trees and transporting the logs to sawmills.
• Road building


  trees are also cleared for roads such as the Trans Amazonian Highway to allow development to continue
• Mineral extraction


  The removal of solid mineral resources from the earth. Largest iron ore is Carajas in the Amazon
• Energy development


  Mainly using Hydro Electric Power, and there are 150 new dams planned for the Amazon alone.
• population growth


  increase in the number of people who inhabit a territory or state
• Cattle ranching in the Amazon

  80% of all Amazonian deforestation

  Cattle compact ground

  Methane emissions

  $6.8 billion made in Brazil 2008
• Effects of deforestation


  Loss of carbon capture

  Climate change

  Greenhouse effect

  Soil erosion

  Loss of potential medicine

  Loss of tourism

  Loss of tribes & natives

  Animal extinction

  15% of all CO2 emissions
• The achuar people


  tribe of 11000 people

  Located in the Amazon

  resistant to oil exploration

  May lose their traditional lands
• Define sustainability


  meeting the needs of the present without compromising the ability of future generations to meet their own needs
• Sustainable management of a rainforest

  Selective logging

  Replanting

  Conservation (eg Givaudan works with Conservation International)

  Debt reduction - LICs will have their debt cancelled so they can afford to restore their rainforest

  Ecotourism - income for locals, stops litter, small num of visitors allowed

  Education

  International agreements

  Conservation swap - USA reduced Peru's dept by $25mil in 2008
• How much rainfall does a desert get in a year

  Less than 250mm
• Define arid climate


  Little to no rain; too dry or barren to support vegetation
• Salinization


  Accumulation of salts in soil that can eventually make the soil unable to support plant growth.
• Hadley Cell


  a large-scale atmospheric convection cell in which air rises at the equator and sinks at medium latitudes, typically about 30° north or south.

  Deserts form here since the air is dry and no condensation can occur
• Why are there deserts on the western edges of continents

  Cold ocean currents run along the coast and cool the air. This means the air can't hold moisture and so it rains quickly over the ocean before it reaches the land - eg Namib desert in Africa,
• rain shadows


  areas of dry land that form on the leeward side (downwind) of a high mountain.

  Rain cloud approaches mountain range → rise in elevation → surrounding air becomes cooler → due point eventually reached → precipitation occurs as cloud gains precipitation, continues to rain towards peak → cloud begins to descend leeway side of mountain → decrease in elevation → air temperature increases → precipitation decreases → rain shadow is dry
• Cacti adaptations


  Leaves are sharp spines to protect from predators and minimize water loss

  White upper surface reflects sun rays and protects against sunburn

  Fleshy stems store water

  Extensive root system
• Camel adaptations


  - A camel has big, flat feet.

  
  

  - A camel's hump is where fat is stored.

  
  

  - The fat from a camel's hump can be broken down to form carbon dioxide and water.

  
  

  - A camel has no layer of fat under the skin.

  
  

  - A camel can go at least two weeks without water.

  
  

  - A camel can drink large amounts of water in one go.

  
  

  - A camel has long eyelashes and long hair around the openings to its ears.
• Western Desert, USA


  Mojave, Sonoran, Chihuahuan

  Covers 200,000km2
• irrigation


  Supplying land with water through a network of canals
• Farming in western desert

  Aquifers are used

  Canals are used for large scale farming

  Water supply is limited and demand is increasing

  Farmers get access to 80% of Colorado water, make up 10% of economy
• Mineral extraction in the western desert

  Rich in minerals

  Contaminates water supply
• energy in the western desert

  Sonoran Solar Project in Arizona - supply 100k homes

  HEP - Hoover Dam and Lake Mead

  Oil

  Expensive

  Land use conflict

  Lake mead is shrinking (25% of capacity)
• Tourism in the Western Desert

  Las Vegas - 37mil a year, spending $30bil

  Lake mead & lake Powell

  Grand Canyon & Joshua Tree National Park