Conservation

• Conservation


  Attempts to maintain or increase biodiversity "the range of different species living in an area"
• Endangered species


  If the population size drops, so become threatened with extinction
• Risks of a decrease in population size

  • Low genetic diversity so more chance of genetic diseases
  • Adapt less to changes in environment, survive less, reproduce less & may become extinct
• Causes of population size decrease and endangered/extinct species

  • Destruction of their habitat, as deforestation
  • Pollution, as oil leaks into water
  • Hunting & poaching
  • Introduced species, alien species
  • Climate change by global warming
  • Wars and spread of diseases
• How to conserve animal species

  • Total ban hunting endangered species
  • Sign International, agreements to regulate trade
  • Education to increase awareness
  • Fines for, illegal or for overfishing/over-hunting
  • Monitoring population
  • Limited hunting/fishing season
  • Captive breeding programs to increase their number then restocking to the wild
  • Seed Banks & botanic gardens
  • National parks & natural/marine reserves
  • Fishing by large mesh size of nets
  • Reduce demand by encouraging fish & animal farming
• Reasons to conserve animals and plants

  • To maintain high genetic diversity
  • To maintain food web
  • To maintain nutrient cycle
  • For ecotourism
  • For ethical reasons
  • For future generations
• Monoculture


  Crop plants of a single variety grown in large areas
• In a natural ecosystem, there are many different species of plants growing, which supports many different species of animals, so high biodiversity. In a monoculture, biodiversity is low, as only a few species can live where the crop is growing
• Impacts of large scale monocultures on the environment

  • Efficient food production so less land required (ADV)
  • Deforestation
  • Soil erosion & desertification
  • Pest outbreak so more use of pesticides
  • Increased pollution
  • Loss habitat diversity
  • Extinction of species
  • Disruption to food chains
• Solutions for monoculture impacts

  • Insecticides
  • Mixing of crops
• Intensive livestock production

  Keeping a high population of animals in an area that would not normally support a smaller population
• Negative impacts of intensive livestock production on the ecosystem

  • More carbon dioxide and methane from cattle enhance greenhouse effect
  • Habitat destruction to make space for livestock building
  • Intensive farming waste can pollute land (landfills) & water ways (eutrophication)
  • Diseases spread easily as its a large population in a small area
  • Inappropriate use of antibiotics for prevention, bacteria develops resistance
  • Ethical concerns
• Sustainable resource


  Resources produced as fast as they are removed, so will not run out
• Ways of sustaining resources

  • Education of the local communities about the need for conservation
  • Legal quotas prevent over fishing and hunting and prevent selling young & fishing small sized fish
  • Restocking: captivity program
• Need to conserve non-sustainable (non-renewable) resources

  • Recycling of glass
  • Recycling of paper
  • Recycling plastic
  • Recycling metals such as aluminum, copper, lead
• Population


  Group of living organisms of same species in the same area at the same time
• Community


  All populations of different species in the same ecosystem at the same time
• Factors affecting population growth

  • Birth rate "BR"> death rate "DR" no limiting actors as there is a lot of food no prodators no disease that kills them
  • BR-DR due to limiting factors-as there is shortage of food, so more competition for food, accumulation of waste that becomes toxic, large population attracts more predators, large population so more chance of disease spread that kills them
• Phases of population growth

  • Lag phase
  • Exponential or log phase
  • Stationary phase
  • Death phase
• Factors that have led to the exponential increase in human population

  • Increased food supply
  • Use fertilizers
  • Use insecticides & herbicides
  • Use greenhouses
  • Selective breeding (animals & plants)
  • Education
  • Better health care
  • Vaccination & antibiotics
  • Sewage treatment
  • Good personal hygiene to avoid disease transmission
  • Avoid smoking & drugs
  • Clean water supply
• How modern technology has resulted in increased food production

  • Agricultural machinery to use larger areas of land and improve efficiency, faster harvesting of crops
  • Chemical fertilisers to improve yields, supplying nitrates to make amino acids, to make proteins for growth, Mg for making chlorophyll & phosphates to make DNA
  • Insecticides to improve quality and yield, by killing pests, so less damage to crops
  • Herbicides to kill weeds, to reduce competition with weeds, so more space, light & mineral ions from soil
  • Selective breeding to improve production by crop plants and livestock, eg. cattle, fish and poultry