Living World

• What is an ecosystem?

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

  Organisms that produce their own food using things like sunlight
• Consumers

  Organisms that eat living producers and/or other consumers for food. eg a pond snail
• Decomposers


  Organisms that break down the dead remains of other organisms and return the nutrients to the soil
• food chain

  A series of events in which one organism eats another and obtains energy.
• food web

  A community of organisms where there are several interrelated food chains
• nutrient cycling

  when plants or animals die, decomposes help to recycle the nutrients making them available again for the growth of plants or animals
• Uk examples of producers

  Algae
• Uk examples of consumers

  Great diving beetle
• UK examples of decomposers

  rat-tailed maggots
• Desert ecosystem

  - Between 15 and 35 north and south of the equator

  - very hot during day, very cold at night
• Tropical rainforest ecosystem

  - Found near equator

  - Wet, warm all year long.

  - Monkey, tree frogs, high moisture so plants can grow on trees instead of soil
• Tundra Ecosystem

  - Found at high latitudes - above 60 N

  - A treeless ecosystem found in Alaska, northern Canada

  - Very cold temperatures, little rainfall, hardly any trees
• Grassland Ecosystem

  Found between tropics

  Covered with tall grasses.

  Medium amount of rain.

  Example of animals: grasshoppers, prairie dogs, and bison
• Deciduous forest

  A biome with four seasons, plants shed leaves in the fall and grow new ones in the spring. Found mid latitudes
• coniferous forest biome

  A biome in the northern hemisphere e.g. Canada. Trees areconiferousand evergreen. Short, cool summers for hiking and long, cold winters for skiing.
• Polar biome

  Found around N and S poles

  Extreme cold means very little grows

  Animals e.g. birds, seals, penguins in Antarctic
• how can humans change ecosystems

  - agricultural fertilisers , can lead to eutrophication (nitrates increase growth if algae, which depletes oxygen meaning fish may die)

  
  

  - ponds being drained

  
  

  - woods being cut down, destroys habitat
• Where are tropical rainforests located?

  Near the equator, between the tropics of cancer and capricorn

  Specifically northern parts of South America, Southern Eastern parts of Asia, and North of Oceania

  Anomalies- Eastern africa, Madagascar
• describe physical characteristics of a tropical rainforest

  - Soil - not very fertile, red because it is rich in iron, nutrients washed away due to heavy rainfall

  
  

  - Structure - ground level, shrub level, under canopy, main canopy, emergents
• Rainforest climate

  - hot and humid

  - heavy rainfall

  - no seasons
• Drip Tips adaptations

  - Found around the middle canopy

  - point on end of leaf to channel rain water off

  - stops the leaf from snapping due to heavy rainfall
• buttress roots

  - large, above ground roots that provide stability in tropical trees.

  - support the tree as the trees grow quickly
• Smooth bark on trees

  stops animals from climbing and plants from growing on the tree
• Sustainability

  Actions and forms of progress that meet the needs of the present without reducing the ability of future generations to meet their needs.
• Why should tropical rainforests be protected?

  - Biodiversity,

  - climate change (store CO2),

  - climate (prevent climate from becoming too hot or dry),

  - medicine,

  - resources (nuts, fruits, hardwoods),

  - water (clean water)

  - people (indigenous tribes)
• Why are rainforests being destroyed?

  - Mineral extraction

  - population pressure

  - Logging

  - commercial farming

  - energy
• Ways to manage the rainforests

  - Selective logging and replanting

  - Conservation and education

  - Ecotourism

  - International Agreements

  - Hardwood forestry

  - Debt reduction

  - Carbon Sinks
• What is selective logging

  Where only the desirable trees are felled - less harmful but still damages biodiversity.
• Effects of loss of biodiversity in rainforest

  - loss of medicines

  - loss of plant and animal species
• what is ecotourism

  Tourism that doesn't harm the environment and benefits the local people
• how does deforestation impact soil erosion

  - roots of plants and trees no longer hold soil together so it is easily eroded

  - affects the nutrient cycle as there is no plants or trees shedding leaves to replace nutrients in soil
• why is it important that tropical rainforest are managed sustainably

  To maintain the needs for the future generations
• Where are hot deserts located?

  - Between 20 and 30 degrees north and south of the equator.

  - Specifically, North Africa, South West Africa
• Physical characteristics of a desert

  - no rain

  - hot + dry
• Desertification

  the process by which fertile land becomes drier and degraded as a result of climate change or human activities or both
• Desertification is caused by:

  - Over grazing- too many animals

  - Over cultivation- too many crops

  - Firewood- removal of trees

  - Climate Change- drier areas
• How do plants protect soil

  - Prevent surface of soil being baked in heat

  - Roots bind soil together

  - Leaves provide shade keeping soil cool

  - Canopy of leaves prevents heavy rainfall from eroding soil
• Appropriate technology

  Technology suited to the needs, skills, knowledge and wealth of local people and their environment
• Ways to reduce desertification

  reduce: overgrazing, deforestation,

  
  

  reduce: human contributions to climate change

  
  

  Appropriate technology -

  - plant Atriplex to hold soil together and provide gracing for sheep and goats.

  
  

  - As soil improves plants start to grow attracting buried and butterflies.