Ecosystems

• What is an ecosystem

  A biological community of interacting organisms and their physical environment.
• What are the two different components of an ecosystem

  Abiotic and biotic
• What is a biotic component

  A living feature of an ecosystem

  e.g. plants, fish
• What is an abiotic component

  A non-living feature of an ecosystem.

  e.g. climate, soil, sunlight
• What are the different sized ecosystems

  -local small scale ecosystems such as pond, woodland

  -global scale ecosystems such as tropical rainforest, desert which are also called a biome
• What is a producer

  an organism that converts energy from the environment (mainly sunlight) into sugars (glucose) - most obviously plants which convert energy from the sun by photosynthesis
• What is a consumer

  An organism that obtains energy by feeding on other organisms
• What is a decomposer

  An organism that breaks down other living things to obtain nutrients/energy.

  e.g. bacteria and fungi
• What is a food chain

  A series of steps in which organisms transfer energy by eating and being eaten
• What is a food web

  a system of interlocking and interdependent food chains.
• What is the nutrient cycle

  Food that are used by plants or animals to grow. There are two main sources:

  -rainwater washes chemicals out of the atmosphere

  -weathered rock releases nutrients into the soil

  When plants or animals die, they help to recycle the nutrients making them available once again for the growth of plants or animals
• What does a freshwater pond ecosystem provide

  provide a variety of habitats for plants and animals because there are big variations in the amount of light, water and oxygen available
• Species you find in a freshwater pond ecosystem

  frog tadpole- get energy from microscopic plants, algae

  algae- get energy from sunlight

  sticklebacks- get food from tadpoles, water fleas

  heron- get food from fish, frogs, tadpoles

  perch- get food from small fish
• What makes an ecosystem sustainable

  For an ecosystem to be sustainable it must be balanced, so all parts of an ecosystem play an important role in the stability of the ecosystem
• Give global ecosystems

  tundra

  tropical grassland

  Mediterranean

  Temperate grassland

  Deciduous and coniferous forests

  Polar

  Desert

  Tropical rainforest
• What are the characteristics of a tundra ecosystem

  Characterised by low-growing plants adapted to retain heat and moisture in the cold, windy and dry conditions. A fragile ecosystem, easily damaged by humans and threatened by developments such as oil exploration and tourism . Animals, e.g. reindeer are adapted to survive the cold
• Where are tundra environments located

  From the arctic circle to about 60-70 degrees north. There are only very small areas in the southern hemisphere due to the lack of land at these latitudes
• What are the characteristics of a tropical grassland ecosystem

  Characterised by distinct wet and dry seasons with wild fires and violent thunderstorms. Large herds of animals graze these areas, along with predators such as lions and leopards
• Where are tropical grassland ecosystems located

  between 15-30 degree north and south of the equator
• What are the characteristics of a Mediterranean ecosytem

  These areas enjoy hot, sunny and dry summers, with mild winters. Vegetation includes olive trees and fruit trees, such as lemons and oranges. Other parts of the world, such as USA and South Africa, have similar climates
• Where are Mediterranean ecosystems located

  Roughly 40-45 degrees north of the equator. Also isolated locations south of the Equator (South Africa, Western Australia)
• What are the characteristics of temperate grassland ecosystems

  Includes the prairie of North America and steppes of Eastern Europe. Experiences warm, dry summers and cold winters. Grass species can tolerate these conditions and the land is mainly used for grazing animals
• Where are temperate grassland ecosystems located

  Roughly 30-40 degrees north and south of the Equator. Inland away from coast, with hot summers and cold winters
• What are the characteristics of deciduous and coniferous forests

  Deciduous trees shed their leaves in winter to retain moisture. Coniferous trees are evergreen, retaining their leaves to maximise photosynthesis during the brief summer months . UK's natural vegetation is deciduous. Further north. e.g. Canada, coniferous forests dominate
• Where are deciduous and coniferous forest located

  Roughly 50-60 degrees north of the equator
• What are the characteristics of a polar ecosystem

  Cold air sinks, resulting in very low temperatures and dry conditions. The main regions are Antartica and Greenland where temperatures can can fall below -50 degrees C
• Where are polar ecosystems located

  Arctic and Antarctic
• What are the characteristics of a desert ecosystem

  Covers one fifth of the world's land surface. Associated with sub-tropical high pressure belts-sinking air stops clouds forming, giving high daytime temperatures, cold temperatures at night and low rainfall. Plants and animals are well adapted to cope with dry conditions
• Where are desert ecosystems located

  Roughly 30 degree north and south of the Equator
• What are the characteristics of tropical rainforest ecosystems

  High temperatures and heavy rainfall at the equatorial low pressure belt make perfect growing conditions. Cover 6% of the Earth's land surface. More than half of the world's species of plants and animals live in this biome and a quarter of all medicines come from these plants
• Where are tropical rainforest ecosystems located

  Close to the Equator
• What are the variations in west-to-east belts of vegetation due to

  -winds

  -ocean currents

  -distribution of land and sea
• What does global atmospheric circulation determine

  It determines the variation in the type of vegetation in a region since it causes different climates
• What can alter the sustainable balance of an ecosystem?

  Global-scale changes such as climate change and local-scale changes such as hedgerow removal
• Changes to the ecosystem due to natural factors

  • drought
  • flood
  • fire
  • disease
• Changes to the ecosystem due to human management

  • introducing more fish (fish stocking)
  • altering the drainage of the land which may influence the amount of water
  • changing the pH level of the water
  • altering the nutrient levels of the water if fertilisers are leached into the water resulting in eutrophication
• How have farmers tried to keep the ecosystems balanced?

  Many farmers are trying to keep ecosystems in balance by using less fertilisers. Some have planted hedgerows and grass margins to protect wildlife such as bees, insects and wildflowers
• Example of a place which was able to create a balanced ecosystem

  Avington Park Lake, Winchester, Hampshire

  • Over several years, the condition of this historical, ecologically important lake had deteriorated due to lack of maintenance. Silt had accumulated and excessive vegetation blocked a previously impressive view
  • In 2014 the lake was de-silted and reshaped. New waterside habitats were created to attract nesting birds and is now an attractive, healthy ecosystem supporting a diverse range of wildlife
• What is the bottom of a freshwater pond like

  1. Pond bottom - there is very little oxygen or light at the bottom of the pond. Decomposers and scavengers live here where they feed on dead material, eg water worms and rat-tailed maggots.
• What is the mid water of a freshwater pond like

  Mid water - fish are the main predators here. Food is found on the pond bottom or the pond surface. Animals here breathe through their skin or gills, eg stickleback fish, water fleas and dragonfly nymphs