module 1

• Abiotic


  Non-living factors that influence an ecosystem
• Food Web is a network of food chains within an ecosystem
• Consumers

  • Herbivores - obtain energy by eating only plants
  • Carnivores - eat only animals
  • Omnivores - eat both plants and animals
  • Decomposers - breaks down dead organic matter
• Photosynthesis


  Use light energy to convert carbon dioxide and water into oxygen and carbohydrates (6CO2 + 6H2O -> 6O2 + C6H12O6)
• Energy Pyramid shows the relative amount of energy available at each trophic level. Only about 10% of the available energy within a trophic level is transferred to the next higher trophic level
• Biotic


  Living factors that influence an ecosystem
• Producers

  • Plants
  • plant-like protists (algae)
  • Bacteria
• Ecological Pyramids are diagrams that show the relative amount of energy or organisms contained within each trophic level of a food chain or web
• Consumers


  • Organisms that rely on other organisms for their energy and food supply
  • Also called heterotrophs
• Competition is when two organisms of the same or different species attempt to use an ecological resource in the same place at the same time (e.g., food, water, shelter)
• Food Chain is a series of steps in which organisms transfer energy by eating and being eaten. Arrows go in the direction of how energy is transferred. It starts with a producer and ends with a top consumer or carnivore
• Feeding Interactions

  Energy flows through an ecosystem in one direction—from the sun or inorganic compounds to autotrophs (producers) and then to heterotrophs (consumers)
• Producers

  • Sunlight is the main energy source for life on earth
  • Also called autotrophs
  • Use light or chemical energy to make food
• Chemosynthesis


  Performed by bacteria, use chemical energy to produce carbohydrates
• Trophic Levels are each step in a food chain or food web. Level 1 is Producers (autotrophs), Level 2 is Primary Consumers (herbivores), Level 3 is Secondary Consumers (carnivores or omnivores), Level 4 is Tertiary Consumers (carnivore —usually top carnivore)
• Biomass Pyramid represents the amount of living organic matter at each trophic level
• Niche


  The ecological niche involves both the place where an organism lives and the roles that an organism has in its habitat
• Americans introduced gray squirrels into parts of England in the early 20th century, red squirrels had been the only species of squirrel in the country
• Within a couple years of overlap in an area, the red squirrels disappeared
• Commensalism

  • Barnacles on a whale
• Mutualism


  • Insects and flowers
• Rams


  Compete with each other for mates
• Predation


  • Predator - one that does the killing
  • Prey - one that is the food
• Predation


  One organism captures and feeds on another organism
• Communities replace one another until a "climax community" is reached or until a disturbance occurs
• Commensalism


  • One member benefits and the other is neither helped nor harmed (WIN-0)
• Parasitism


  • One organism lives on or inside another organism (host) and harms it (WIN-LOSE)
• Parasitism


  • Fleas on a dog
  • Wasp eggs on back of caterpillar
  • Mosquito biting a human
  • Sea lampreys feed on fluids of other fish
• Mutualism


  • Both species benefit (WIN-WIN)
• The ecological niche of an organism depends not only on where it lives but also on what it does
• Liebig's Law of the Minimum was formulated by Carl Sprengel and popularized by Justus von Liebig
• Ecological niche of a sunflower


  • Absorbing light, water, and nutrients (for photosynthesis), providing shelter and food for other organisms, giving off oxygen into the atmosphere
• Ecological succession is the process by which the mix of species and habitat in an area changes over time
• Plant growth and health are controlled by the scarcest nutrient available in the soil according to Liebig's Law of the Minimum
• Gray squirrels were larger and bred faster, successfully competing for resources with red squirrels
• Shelford's Law of Tolerance states that organisms are influenced by ranges of factors, not just minimum levels
• Symbiosis


  Any relationship in which two species live closely together