Unit 1

• Ecosystem


  The interaction of living and non-living things in a specific region
• Habitat


  The given environmental conditions that a certain species needs in order to survive
• Environment


  The entire natural world
• Organism relationships


  • Competition
  • Symbiosis
  • Mutualism
  • Parasitism
• Mutualism


  • Bees and the plants they pollinate, coral reefs
• Parasitism


  • Tapeworms and their hosts
• Biome


  A region on Earth that shares a consistent yearly average temperature and precipitation pattern
• Terrestrial biomes


  • Tropical rainforest
  • Tundra
• Aquatic biome characteristics


  • Salinity
  • Flow
  • Depth
• Estuary


  A type of aquatic biome where the mouth of a river empties into the ocean
• Estuaries


  • Brackish water (partially saltwater, partially freshwater)
  • High sediment and nutrient levels due to river runoff
  • Unique adaptations in plants and animals to survive in this environment
• Matter is never created or destroyed, only changed in form
• Carbon cycle


  Reservoirs, sources, sinks
• The atmosphere is a critical carbon reservoir, and the amount of carbon it stores determines Earth's global climate
• Photosynthesis takes carbon out of the atmosphere, while respiration returns it
• Extraction and combustion of fossil fuels return carbon dioxide to the atmosphere, contributing to climate change
• Nitrogen cycle


  Nitrogen fixation, biologically unavailable
• Nitrogen fixation processes


  • Bacteria
  • Rhizobacteria
  • Lightning strikes
  • Fossil fuel combustion
• Other steps in the nitrogen cycle

  • Ammonification
  • Nitrification
  • Denitrification
• Phosphorus cycle


  No gas phase, rocks and sediments, weathering, erosion
• Phosphorus is often a limiting nutrient in both aquatic and terrestrial ecosystems
• Water cycle processes


  • Evaporation
  • Condensation
  • Precipitation
  • Infiltration
  • Transpiration
• Water reservoirs


  • Oceans
  • Groundwater
  • Polar ice caps
  • Rivers and lakes
• Primary productivity


  The rate of photosynthesis in a given area
• Net primary productivity (NPP)

  GPP - RL
• NPP calculation


  • GPP of 1000 kilocalories per meter squared per year and a RL of 250 kilocalories per meter squared per year, NPP = 1000 - 250 = 750 kilocalories per meter squared per year
• Trophic pyramid


  A way to represent the flow of energy through an ecosystem from organism to organism
• Trophic levels


  • Producers
  • Primary consumers
  • Secondary consumers
  • Tertiary consumers
• The energy flow through the trophic pyramid is characterized by the 10% rule, where each level only receives 10% of the energy from the level below
• Removal of one species

  Can have a huge effect on the organisms in the rest of the food web, especially those on either side of it
• Trophic cascades


  The powerful effects of predators in an ecosystem, leading to changes in population sizes and ecosystem structure