P1- Ecology

• Ecosystems

  An ecosystem is a natural environment and includes the flora (plants) and fauna (animals) that live and interact within that environment. Flora, fauna and bacteria are the biotic or living components of the ecosystem. Ecosystems are dependent on the following abiotic or non-living components:
• Organisms compete for..

  • food
  • water
  • space
  • light
  • CO2/O2
  • mate
• Interdependence


  organisms depending on each other for survival, when this happens a community is formed
• Abiotic factors

  Non living factors e.g. light, temperature, soil PH, CO2 and O2 concentration.
• Biotic factors

  The impact of other organisms on an ecosystem: food, predators/prey and pathogens.
• Sampling

  1. Place quadrat in random positions in area (ideally 10% of area, using random number generator to choose locations)
  2. count number of chosen organisms in that quadrat
  3. calculate mean then multiply total area to get estimate for population
  4. moving along a transect allows us to observe how the population density changes over a distance
• Food chains

  Shows the directin of biomass (energy) transferes between organisms

  • Producer produces biomass using sunlight e.g. plants, algee
  • PRIMARY CONSUMER herbivore/ omnivore eats producer
  • SECONDARY CONSUMER carnivore/omnivore eats primary consumer
  • TERTIARY CONSUMER carnivore/omnivore consumes them Apex predators are always at the top of the food chain, and have no natural predator.
• Organisms exists in trophic levels, and their populations will fluctuate over time.
• All life is CARBON BASED. Carbon is recycled when an organisms dies and decomposes, and they excrete CO2 while alive (bacteria also do this) which plants then use to grow. This recycling of carbon is known as the CARBON CYCLE:

  • Carbon Dioxide is released into the atmosphere through respiration of animals and bacteria (and plants)
  • which is then absorbed by plants and algae for photosynthesis.
• What is the water cycle also known as?

  The hydrologic cycle
• What does the water cycle illustrate?

  The continuous movement of water on Earth
• What are the main steps of the water cycle?

  • Evaporation
  • Condensation
  • Precipitation
  • Transpiration
  • Infiltration
• What happens during condensation in the water cycle?

  Water vapor cools and forms droplets
• What is precipitation in the water cycle?

  Water falling from the atmosphere to Earth
• What role does transpiration play in the water cycle?

  Plants release water vapor into the air
• How does infiltration contribute to the water cycle?

  Water seeps into the ground from the surface
• What is the significance of the water cycle for ecosystems?

  It supports life by distributing water
• What is a common diagram used to explain the water cycle?

  A labeled diagram showing water movement
• What are the key components of a water cycle diagram?

  • Evaporation
  • Condensation
  • Precipitation
  • Surface runoff
  • Groundwater flow
• What is the role of the sun in the water cycle?

  It provides energy for evaporation
• How does the water cycle affect rainfall?

  It regulates the distribution of precipitation
• How can understanding the water cycle help in water conservation?

  It highlights the importance of water management
• The water cycle

  1. water evaporates from the surface of the sea or from puddles or from precipitation or Transpires from vegetation.
  2. it then condenses (forms clouds)
  3. precipitation occurs (rain, hail, sleet e.c.t)
  4. Surface runoff delivers water to sea, water infiltrates ground, precolation (water deep in ground)
• Biodiversity

  the variety of all species in an environment, habitat ect
• High Biodiversity generally makes for a more stable ecosystem as organisms will be dependant on a greater number of species for survival.
• Human development usually results in reduced biodiversity, due to he destruction of habitats, Disposing of waste in safe ways in order to reduce our impact is getting harder
• What human activities impact biodiversity negatively?

  Building, quarrying, farming, and waste disposal
• How does land use by humans affect biodiversity?

  It destroys habitats and ecosystems
• Why are peat bogs considered non-renewable energy sources?

  They take a long time to form
• What greenhouse gas is released when peat bogs are burned?

  CO2
• How does deforestation affect biodiversity?

  It reduces biodiversity by destroying habitats
• What is a consequence of deforestation related to greenhouse gases?

  It makes reducing greenhouse gas effects harder
• What process do trees perform that helps reduce carbon dioxide in the atmosphere?

  Photosynthesis
• What happens to carbon dioxide levels when trees are cut down?

  They increase due to reduced absorption
• The pyramid of biomass indicates how much biomass is transferred between trophic levels.

  • Tertiary consumer
  • secondary consumer
  • primary consumer
  • proudcer

  any % = the bit/the lot x100

  any %absorbed = biomass as 2nd lvl/ biomass at 1st lvl

  This shows that biomass is lost at each level as not all biomass is absorbed/consumed and organisms losing it whilst alive during excretion.
• Food security - its becoming more scarce due to increasing global population, changing diets, energy and farming costs, growing environments and conflicts.

  Farmers are trying to farm more efficiently: increasing biomass input whilst reducing wasted biomass.

  Sustainable fishing: ensured that fish are not caught at a greater rate than they can reproduce, so that populations remain constant e.g. using large nets so that young can escape and breed.

  GM crops can increase yields and other methods are being developed to increase nutrients e.g. fungi grown on glucose syrup