Ch. 12 - Biodiversity,Benefits of Ecosystems,Food Production

• Conservation

  • Conservation is the protection of plants, animals and natural areas from the damaging effects of human activity.
  • If we look after our wildlife and their habitats we can prevent them from being wiped out (becoming extinct).
  • Failure to conserve can result in the death of organisms in their habitats. In some cases the entire species or type of organism may become extinct.
  • For example, birds called corncrakes are in danger of being wiped out in Ireland due to the loss of hay meadows in which they breed.
• Conservation & Biodiversity

  • Some orchids are also threatened with extinction because their habitats are being destroyed.
  • Biodiversity means the variety of living things. The word is a contraction of the words 'biological diversity.
  • Any decrease in the number or types of plants and animals means there is a decrease in biodiversity.
  • To prevent the loss of habitats and biodiversity it is necessary to look after our environment.
• Why Conservation is Important

  Conservation is necessary for the following reasons:

  • To prevent organisms from becoming extinct; at present, many organisms are facing this threat
  • To maintain the balance of nature; the loss of any one type of organism can cause dramatic results for other types of organism
  • Future generations have the right to the same natural resources as are found at present, e.g. the world would be a poorer place if elephants, tigers, corncrakes, orchids or any other animal or plant became extinct
• Why Conservation is Important pt. 2

  • Plants are the source of many medicines; as plants become extinct, we lose the ability to test them for new medications
  • If our natural resources are not protected there is a danger that human lifestyles (and even our survival) would be at risk
• Supporting Conservation

  The only species on Earth that threatens conservation is humans. It is up to us, both as a species and as individuals, to support conservation measures. Humans can support conservation by:

  • Making themselves aware of the issues
  • Joining conservation groups
  • Supporting groups in society that encourage proper conservation
  • Refusing to join in any activity that threatens conservation
  • Refusing to buy products that have been sourced unethically
• Main Causes of Loss of Biodiversity

  Some of the factors that are responsible for organisms being killed off (resulting in a loss of biodiversity) are:

  • Habitat loss or fragmentation
  • Pollution
  • Invasive species (organisms that are introduced to an area and which cause harm)
  • Climate change
  • Over-exploitation (the overuse of wildlife by people)
  • Human population numbers.

  We will now look at habitat loss and pollution in more detail.
• Habitat Loss or Fragmentation

  Habitats are being destroyed on a huge scale. For example:

  • We cut down forests and woodlands for timber or to clear land for housing and agriculture
  • Boglands are being drained for farming
  • Grassland is being built on for roads, housing and factories
  • Lakes are being destroyed by pollution
• Habitat Loss or Fragmentation pt. 2

  • Destruction of habitats destroys the organisms in that habitat.
  • Sometimes the remaining habitat is too small to support any surviving organisms, or the remaining habitats are too far apart to allow organisms to move between them.
  • The breakup of a large habitat into smaller, unconnected areas is called habitat fragmentation.
• Pollution

  Pollution is caused mainly when humans add unwanted material to the environment.

  Pollutants are the materials that cause pollution.

  There are three main environments that get polluted: air, water, soil.
• Sources of Air Pollution

  The main sources of air pollution are:

  • Greenhouse gases
  • Acid Rain
  • CFCs
  • Dirt Particles
  • Smog
• Sources of Water Pollution

  The main causes of water pollution are:

  • Badly treated sewage (toilet) waste
  • Oil spills
  • The dumping of household, farming and industrial wastes.
• Causes of Soil Pollution

  Soil pollution is mainly caused by:

  • Acid rain
  • Overuse of fertilisers and slurry (which is animal waste, such as faeces and urine in a liquid form) on the land
  • Improper dumping of wastes
• How we can conserve Ecological Biodiversity

  • To conserve organisms we must control the factors listed earlier (habitat loss and fragmentation, pollution, invasive species, climate change, over-exploitation and human population numbers).
  • Some of the ways these factors can be controlled are considered below
• Preventing Habitat Loss and Fragmentation

  Habitats can be preserved by:

  • Reducing pollution (which may destroy plant and animal life)
  • Planting native vegetation (i.e. plants that would naturally grow in that area), which will support native animals
  • Controlling or limiting building to preserve habitats
  • Preventing the entry and growth of invasive (or non-native) species
  • Developing national parks and special areas of conservation where wildlife is protected by law
• Controlling Pollution - Waste Management

  • Pollution can be controlled by proper waste management.
  • Waste management - The large numbers of humans and the modern style of life produce huge amounts of waste materials.
  • These wastes include dirty water, urine, faeces, plastics and packaging, along with agricultural and industrial wastes.
• Waste Management pt. 2

  These wastes can be managed by using the 3Rs. These are:

  • Reduce the use of unnecessary goods and packaging (e.g. plastic bags)
  • Reuse as many materials (e.g. shopping bags, water bottles or second-hand furniture) as possible
  • Recycle as much waste as possible (e.g. paper, glass, metals and plastics)
• Benefits People Obtain from Ecosystems

  • An ecosystem is a large area containing similar types of environments and living things (e.g. a woodland, a grassland or a seashore). We obtain many benefits from ecosystems.
  • These benefits can be grouped into four main types:

  1. Supporting
  2. Products
  3. Controlling
  4. Cultural
• Supporting Benefits

  Supporting benefits allow the other three types of benefits to exist. Ecosystems support:

  • Biodiversity (i.e. ecosystems contain many types of living things)
  • Nutrient recycling (dead materials rot to release valuable elements needed for new growth to occur)
  • Soil formation
  • Photosynthesis (which absorbs carbon dioxide and helps reduce global warming)
  • Water recycling (water is absorbed by plant roots and released back into the air as water vapour)
• Products Benefits

  Ecosystems produce valuable substances or products such as:

  • Wood
  • Fuel (turf/peat or firewood)
  • Food (including seafood and wild animals)
  • Fresh Water
  • Medicines
  • Useful Chemicals
• Controlling Benefits

  Ecosystems help to control features such as:

  • Air quality (the plants take in carbon dioxide and give out oxygen)
  • Water quality (water is purified as it goes down through the soil)
  • Pollination (by supporting insects)
  • Soil erosion (roots stabilise soil)
  • Flood damage (water is absorbed or diverted)
  • Pest control (pests are reduced by being eaten or weakened by parasites)
• Cultural Benefits


  The social or non-material benefits of ecosystems include:

  • Recreation (in parks, mountains and by the sea)
  • Sports (swimming, climbing, walking)
  • The use of nature in arts (pictures, paintings, films)
  • Education (trips to parks, seashore, mountains)
  • Scientific (research on habitats and wildlife)
• How Humans can Contribute to Global Food Production

  • At present there are slightly over 7 billion people on Earth. It is predicted that the number of humans in 2050 will be between 9 and 10 billion. As the numbers rise it will be necessary to increase global food production. This need for more food is not a new problem.

  In the late 1950s and the 1960s the human population was increasing faster than it is now.

  However, the 'green revolution' at that time resulted in huge increases in the production of food worldwide. As a result, food production matched the rise in human numbers.
• Problems as a Result of the Green Revolution

  • The number of crops grown fell dramatically as the new 'super-crops' were planted widely.
  • The new crops needed large amounts of fertilisers and had to be sprayed with pesticides to kill off insect pests
  • The new crops also used much more fresh water and needed a higher level of farm technology (tractors, sprayers, etc.)
  • Natural land that contained many species of plants and animals was converted to growing single crops (such as rice, wheat or oil palm). These single crops are called monocultures and result in huge loss of biodiversity.
• Ways to Produce More Food

  There are two possible ways to produce more food:

  1. Convert more land to growing crops
  2. Increase the yield of crops grown on present farm land
• Can we increase the amount of farmland worldwide?

  At present only about 10% of the world's surface is used for growing crops (66% of Earth's surface is water, some land is too dry or too hot or too cold, or the soil is too poor to grow crops).

  If we use more land for crops it will mean we have to destroy habitats. This will result in loss of biodiversity. For this reason, this option is not the best one.
• Can we increase the yield of crops?

  • A huge amount of research is going on worldwide to increase the yield of crops. Some of this involves using older crops that were preserved as seeds (in seed banks).
  • Much of the research is attempting to develop new strains of crops by adding genes to existing plant crops. It is hoped that the new crops will be able to produce increased yields, resist higher global temperatures, use less fresh water, resist pests and diseases, have improved taste and contain more nutrients.
• Can we increase the yield of crops? Pt. 2

  • In addition, attempts are being made to allow plants to produce more than one crop each year.
  • This could potentially increase food production hugely.
• The Food Gap

  • The food gap refers to the difference between the amount of food produced and the amount of food needed worldwide.
  • This gap can be reduced in a number of ways.
• How can we reduce the Food Gap?

  • Reduce the loss or waste of food - at present it is estimated that up to 33% of food produced for human use is not eaten
  • Adjust our diets - it takes far more land to produce meat (especially beef) than it does to produce the same energy content in plants; the world's population is increasingly demanding more meat in its diet, which may not be sustainable
  • Increase our use of poor-quality land
  • Improve how we use our existing land and water resources
  • Control human population increases
  • Increase our use of water-based food production (aquaculture).