Ecology

• Living factors that affect other organisms are called biotic factors
• An ecosystem is a biological community of interacting organisms and their physical environment
• Habitat is the area or environment where an organism naturally lives
• Competition for resources or habitat can influence the population of another species
• Abiotic factors are the non-living parts of the environment
• A niche is the role of a species within an ecosystem
• Trophic levels represent the different levels of a food chain
• Omnivores are organisms that eat both producers and other animals
• Apex predators are at the very top of the food chain (carnivore)
• Decomposers break down dead plant and animal matter in the environment
• Energy and biomass transfer efficiency is around 10%
• The sun provides a continual input of energy into the ecosystem
• Photosynthesis is the process where green plants and algae convert carbon dioxide and water into glucose and oxygen
• Respiration releases energy from glucose and oxygen into carbon dioxide and water
• Combustion of fuels releases carbon dioxide and water
• Global warming is caused by an increase in greenhouse gases like carbon dioxide and methane
• Deforestation can lead to less photosynthesis and contribute to the greenhouse effect
• define community

  all the organisms in multiple species that coexist in a habitat at one time
• define species

  a group of potentially interbreeding individuals
• trophic level one - the producer use photosynthesis to produce their own food
• detritivores are small animals such as worms


  decompose dead plants and animals matter in the environment

  recycle nutrients from animals and plants back to ground
• equation for photosynthesis

  energy+ carbon dioxide + water = glucose+oxygen
• equation for respiration

  glucose+oxygen = (energy)+carbon dioxide+water
• Eutrophication

  1. Happen when too much nutrient added to water (river / lakes)

  2. Caused by fertiliser - nitrate, phosphate

  3. increase nutrient concentration

  4. Leads to the growth and reproduction of algae

  5. Forms thick green bloom in water (Algal bloom)
• Sea-level rise

  Ice melt -> water in the oceans warms up -> water expands -> volume increases -> provides food for algae
• Seasonal flooding

  Allows algae to grow and reproduce quickly
• Submersion of entire islands/coastal town

  Can lead to the formation of thick green blooms in water (Algal bloom)
• Temperature change

  Can change rainfall patterns which can affect animals adapted to the previous conditions
• Adding rain

  Can lead to adaptation to new conditions and migration of species to other regions
• Plants needing photosynthesis

  Will die if unable to perform photosynthesis
• Burning fossil fuels

  Can release sulphur dioxide which can lead to the death of algae
• Run out of food

  Algae will die if they run out of nutrients
• Bacteria dissolve in rain

  Can lead to the production of sulphuric acid which can cause acid rain
• Acid rain

  Can lead to the acidification of water in lakes, killing plants and animals sensitive to pH
• Air pollution

  Can consume oxygen in water, leading to the growth and respiration of pollutants
• Artificial fertilisers leaching into rivers

  Can lead to the rapid growth of algae (Algal bloom)
• Incomplete combustion

  Can damage the lungs and create respiratory problems
• Pollutants creating carbon monoxide and particulates

  Can lead to respiratory problems and global dimming
• Animals in water dying through lack of oxygen

  Can occur due to pollutants affecting oxygen levels in the water
• Bioaccumulation

  apply pesticides and herbicides to stop crops being damaged