Geography

• What is an ecosystem ?


  Is a compex natural system made up of plants, animals and the environment. They occur at different scales from small to global.
• What are producers ?

  Organisms that make their own food. Convert energy from sun by photosynthesis into carbohydrates for growth
• What are consumers?

  Get energy from eating producers
• What are decomposers?

  Dead animal and plant material is broken down by bacteria and fungi to add nutrients to soil
• What is the nutrient cycle?

  The nutrients from decomposing are then used by plants
• Pond bottom ? And animal

  there is very little oxygen or light at the bottom of the pond. Plenty of shelter and food. Decomposers and scavengers live here (water worm )
• Mid water ? And animal

  Animals breathe through gills or skin. Fish are the main predators. Food is found on the surface or in the pond.(great diving beetle )
• Pond surface ? And animal

  Plenty of oxygen and light. Animals breathe through gills, lungs or skin. (Midge larvae)
• Above pond surface ? And plant

  birds and animals breathe oxygen and food is found in or on the water or in the margins (water lily )
• Pond margin ? And animal

  Plenty of oxygen and light. Plenty of shelter for plants and insects for small animals to eat. ( heron)
• What are the natural changes to an ecosystem ?

  Slow changes don't effect but rapid changes do e.g. extreme weather like droughts
• What are human changes to keeping a balanced ecosystem ?

  Many farmers are trying to keep ecosystems in balance by using fertiliser. Some have planted hedgerows and grass margins to protect
• What are the impacts of human changes on an ecosystem ?

  Ponds may be drained for farming, pond life will die

  
  

  Agriculture fertilisers leads to eutrophication: nitrates increase growth of algae which decreases oxygen

  
  

  Woods cut down destroying habitats and affecting nutrient cycle.

  
  

  Hedgerows remove to increase field size, habitats are destroyed
• What place is an example of ecosystem change ? And why

  Avington Park lake, Winchester, Hampshire

  
  

  Over 7 years lake has deteriorated due to lack of maintenance. In 2014 lake was de-silted and reshaped , new waterside habitats created and lake is now a healthy ecosystem
• What is a tundra biome ?

  Mainly located between artic circle about 60-70 degrees North.

  Cold, windy and dry conditions.

  Low growing plants easily damaged by development
• What are deciduous and coniferous forests biome ?

  Located 50-60 degrees North

  Deciduous trees shed leaves in winter

  Coniferous evergreens are better suited in colder climates so are more north
• What are temperature grasslands biome ?

  Located 30-40 degrees north and south of equator and inland

  Warm, dry summers and cold winters support grasses for grazing animals
• What is Mediterranean biome ?

  South of equator

  Hot, sunny, dry summers and mild winters support olive groves and citrus fruits.
• What is desert biome ?

  Covers 5% of earths land

  High day time temp, low night temp, low rainfall

  Restrict plants and animals
• What is tropical rainforest biome ?

  Covers 6% of earth

  Close to equator

  High temps, heavy rain, ideal for vegetation

  More than half of all plants and animals and a quarter of all medicines originate here
• Tropical grassland biome ?

  15-30 degrees north and south of equator

  Distinct wet and dry seasons support large grazing animals and their predators
• Polar biome ?

  North and south poles

  Low temps (below -50)

  Dry conditions prohibit most plant and animal life
• Where are tropical rainforests found ?

  a few degrees either side of the equator between the tropics of cancer the Capricorn in the equatorial climate
• Characteristics of rainforests ?


  Hot, humid all year with high rainfall. No distinct seasons

  Lots of biodiversity

  Deforestation or water pollution can have big effects on ecosystem
• Rainforest soil?

  (Latosols) cycle nutrients rapidly

  But if rainforest is cleared they are exposed to excessive leaching and quickly exhausted of stored nutrients
• What are the 4 forests layers ?

  Shrub/ground layer (0-10m)

  Lower tree canopy (10-20m)

  Middle canopy (20-35m)

  Top canopy (35-50m)
• What is the shrub layer?

  Ferns, woody plants and young trees due to lack of light

  Bacteria and fungi rapidly rot fallen leaves, dead animals and plants

  Thick buttress roots help big trees
• What is the lower tree canopy ?

  Shaded, less substantial trees waiting for next light space

  Interlocking branches which light weight animals can travel
• What is middle canopy ?

  Each mushroom shaped crown has massive photosynthesis surface of drip tip leaves which help them shed water quick
• What is top canopy ?

  Exposed emergent leaves with straight branch less trunks
• Deforestation example ?

  Malaysia, south-east Asia, 67% tropical rainforests
• What are the threats to Malaysia's rainforests?

  - logging

  - road building

  - energy development

  - mineral extraction

  - population pressure

  - commercial farming

  - subsistence farming
• What is logging ?

  In 1980s Malaysia was world's largest exporter of tropical wood. But clear felling has been replaced by selective logging of only mature trees
• What is road building ?

  Roads constructed to provide access to logging and mining areas, new settlements and energy projects
• What is energy development ?

  HEP projects boost Malaysia's electricity supplies
• What is mineral extraction ?

  Tin mining, drilling for oil and gas
• What is population pressure ?

  Poor people encouraged to move to countryside. This transmigration has set up settlements and palm oil plantations
• What is commercial farming ?

  Malaysia is largest exporter of palm oil. 10 year tax incentives encourage deforestation for more plantations
• What is subsistence farming ?

  Short term clearance is small scale and sustainable

  But "slash and burn " fires can become out of control destroying large areas
• What are the impacts of deforestation in Malaysia ?

  - reduces biodiversity meaning loss of undiscovered plants and medical potential

  - exposes ground to soil erosion

  - impacts local and global climates by reducing photosynthesis, transpiration and cooling effect. And more CO2 which is responsible for global warming