the living world

• what is an ecosystem


  an ecosystem is a community of plants and animals that interact with each other and their physical environment
• local scale vs large scale ecosystem

  a local scale ecosystem can be a pond, hedgerow or even a woodland

  a large scale ecosystem can be tropical rainforest or deciduous woodland. These can be called biomes
• producers 


  a component of an ecosystem that converts energy from the environment into sugars.

  e.g. plants take energy from the sun and converts it though photosynthesis
• consumers


  a component of an ecosystem that gets energy fro sugars produced by the producers

  e.g. a pond snail because it eats plants
• decomposers


  a component of an ecosystem that breaks down plant and animal material and return the nutrients into the soil

  e.g. bacteria and fungi
• food chain


  a simple diagram that shows the direct links between producers and consumers in the form of a simple line
• food web


  a diagram that shows all the connections between producers and consumers in a more complex way
• a balanced ecosystem


  equilibrium = in a balanced state

  small changes to any part of there ecosystem may upset this balance
• what causes change to the environment


  local scale:

  natural - extreme weather events

  human: woods cut down, hedges removed

  large scale:

  natural and human- climate change
• can humans have a positive impact on ecosystems 


  Avington park lake , Winchester, Hampshire

  • lack of maintenance caused lake to become overgrown
  • 2014- lake destilited and refined
  • healthy ecosystem for a diverse range of wildlife

  part of the restoration aimed to preserve and improve the lakes function as a habitat for birds and create new waterside habitats to attract nesting birds/ waterfowl
• lake desilting


  the removal of silt and materials that have built up over time
• the distribution of global ecosystems 


  large scale ecosystems that share the same characteristics are called biomes

  biomes are found in broad belts parallel to lines of latitude

  climate and characteristics are determined by atmospheric circulation

  ocean currents, winds and the distribution of land and sea can impact vegetation
• tundra


  found in high latitudes (above 60 degrees) in Northern Europe, Canada and Alaska

  cold winters, brief summers, little rainfall

  hardly any trees, vegetation includes mosses, grasses and low shrubs
• grassland


  two types of grassland:

  savannah:

  • found in between tropics
  • distinct dry and wet seasons, rainfall is low
  • most vegetation is grasses with some trees

  Temperate:

  • found at higher latitudes
  • more variation in temperatures and less rainfall
  • no trees - just grasses
• boreal forest


  • also known as taiga
  • found between 50-60 degrees north
  • winters are cold and dry, summers are mild and moist
  • trees are coniferous, evergreen and have needles
• temperate deciduous forest


  • found mainly in the mid-latitudes, with four distinct seasons
  • summers are warm, winters are mild and rainfall all year round
  • deciduous trees lose their leaves in winter to cope with cold weather
• polar

  • found in north and south poles
  • very cold, icy and dry
  • not much grows, growing season is about 2 months long
  • remains dark for several months each year
• hot dessert 


  • found between 15 - 35 degrees north and south of the equator between the tropics of cancer and Capricorn
  • little rainfall, very hot in the day and very cold at night
  • temperatures up to 50 degrees
  • average 25cm precipitation per year
  • shrubs and cacti are sparsely distributed in sandy soil
• tropical rainforest 


  • found around the equator, between the tropics
  • hot and wet all year round
  • lush forest, dense canopies of vegetation forming distinct layers
• rainforest climate

  temperature:

  • high and constant throughout the year
  • sun rays hit the equator at a 90 degree angle so solar energy is concentrated overhead most of the time

  Rainfall:

  • high but variable throughout the year
  • global atmospheric circulation causes an area of low pressure - rising air creates clouds and triggers heavy rain
• rainforest soil

  • very infertile
  • nutrients found at the surface where leaves decompose
  • most nutrients carried away by heavy rainfall (leaching) or immediately taken by biomass
  • leaves infertile red, iron rich soils are called latosols
• Malaysia

  • located in south easy Asia and east Malaysia which is part of the island of borneo
  • the natural vegetation in Malaysia is tropical rainforest
  • 67% of the land is covered by tropical rainforest
• deforestation

  the cutting down of trees on a large scale
• deforestation in Malaysia 


  • rate of deforestation is increasing faster than any tropical country in the entire world
  • between 2000 and 2013, Malaysias Total amount of rainforest loss was an area larger than Denmark
• causes for deforestation 


  • logging
  • mineral extraction
  • energy development
  • road building
  • commercial farming
• logging 


  • Malaysia is the largest exporter of tropical wood in the world
  • selective logging is now in place where only fully grown trees can be cut down instead of clear felling
• mineral extraction 


  • mining for tin is very common in Malaysia
  • drilling for fossil fuels such as oil and gas has recently started in borneo
• energy development 


  • the balun dam is the tallest dam in Asia outside of china
  • Malaysia have planned for several more dams to be constructed to boost electricity supplies in maylasia
  • the bakun dam resoviour flooded over 700km sq of rainforest and farmland
• road building


  • roads are built to provide access to new mining areas, settlements, trade/transport routes and energy projects
  • roads are also built to bring in construction and logging machinery
• commercial farming

  • Malaysia is the world largest exporter of palm oil
  • large areas of the rainforest have been converted to palm oil plantations
• impacts of deforestation


  climate change: trees remove and store co2. (amazon stores 140 billion tonnes of carbon, 75% of brazils carbon emissions are from deforestation)

  soil erosion: less tree canopy intercepting rainfall, more water is in the soil, reduces soil fertility and is washed away

  economic: farming brings wealth to many countries, mining industry creates jobs, logging contributes to brazils economy, but destroys resources they depend on
• rates of deforestation


  • tropical rainforests once covered 15.5 million km sq of land and now the
  • tropical rainforests once covered 15.5 million km sq of land and now thefigure is just over 6.2 million km sq
  • the size of a football field is cleared every 2 seconds
  • fastest rates of deforestation are in Brazil and Indonesia
• what is sustainable management 


  allowing rainforest resources to be used without causing long term damage to the environment
• sustainable management: selective logging 


  • only some trees are felled- most remain
  • less damaging than removing the whole area
  • overall forest structure is kept - canopy remains and soil isn't exposed
  • allows forest to regenerate
• sustainable management: ecotourism 


  • minimises damage to environment and benefits local people
  • small amount of visitors at a time and rules are imposed to minimise environmental impacts (e.g. waste and litter disposed properly)
  • provides a source of income for local people
  • if local people employed in tourism, they will not need to log or farm to make money
• sustainable management: education and conservation 


  • education the international community about the impacts of deforestation can encourage others to uy produce from sustainable sources
  • setting up nature reserves and national parks in these areas damaging activities are restricted
  • teaching local people about alternative ways to make money that don't damage the environment
• sustainable management: international agreements


  Hardwood forestry:

  • high demand for hardwood in richer countries
  • becoming increasingly rare

  Debt reduction:

  • tropical rainforests are found in low income countries so they get loans from other countries
  • reducing debt means countries do not have to do this, rainforests can be conserved
• what is a hot desert?


  • arid areas, poor quality and sandy soil
  • receives less than 25cm precipitation a year
  • in summer, temperatures can exceed 50 degrees Celsius
  • cold at night
• hot desert soil


  • tends to be sandy or stony
  • little organic matter due to lack of vegetation
  • soil is dry but can soak water rapidly after rainfall
  • not very fertile
• abiotic and biotic characteristics in hot deserts 


  Abiotic:

  • climate
  • soils

  Biotic:

  • animals
  • vegetation