Ecology

• Biosphere


  That part of the earth and its atmosphere in which life can exist

  
• Ecology


  The study of the interaction between groups of organisms and their environment
• Ecosystem


  Consists of organisms and their interactions with the environment
• Food chain


  The feeding relationships between organisms in which energy is transferred
• Food web


  Consists of two or more intersecting food chains
• Habitat


  The place where an organism lives
• Niche


  The role of an organism in an ecosystem, i.e. how it lives and what it does in its community
• Pyramid of numbers


  Used to show the numbers of organisms at each trophic level of a food chain

  
• Biotic


  • An organism's influence on another organism
• Abiotic


  • The influence of a non-living part of the environment on an organism
• Factors that affect organisms in the biosphere

  • Climatic factors
  • Edaphic factors
  • Aquatic factors
• Climatic factors


  The weather conditions that affect organisms in an ecosystem
• Edaphic factors


  Soil factors that affect organisms
• Aquatic factors


  Factors that affect organisms that live in water
• Producers


  Green plants that make their own food using energy from the sun
• Consumers


  Organisms that feed on other organisms
• Decomposers


  Bacteria and fungi that feed on dead and decaying plants and animals
• Grazing food chain


  The simplest type of food chain
• Detritus food chain


  The simplest type of food chain
• Trophic level


  The feeding level in a food chain

  
• Nutrients (C and N) are recycled in ecosystems
• Nutrient recycling


  The way in which nutrients are recycled in ecosystems
• Decomposers break down dead plants and animals, releasing minerals that are absorbed by plants</b>
• Carbon cycle


  1. Green plants take in CO2 from the air and use it to make food

  2. Animals release CO2 during respiration

  3. Decomposers release CO2 during respiration
• Nitrogen cycle


  1. Nitrogen-fixing bacteria convert free nitrogen into nitrate ions that plants can use

  2. Humans play a role by manufacturing and using fertilizers
• A pyramid of numbers is used to show the numbers of organisms at each trophic level of a food chain

  
• A distorted pyramid of numbers and an inverted pyramid of numbers are examples of non-typical ecological pyramids
• Competition


  The struggle between organisms for resources that are in short supply, such as food or light
• The habitat of an organism is the place where it lives, and the niche is the role of an organism in an ecosystem