Ecology

• Nitrogen Cycle


  The cycle of nitrogen through the environment
• Animals


  • Able to obtain nitrogen through eating plants and animals
• Plants


  • Have much harder time obtaining nitrogen as they can only absorb nitrogen when it is mixed with oxygen or hydrogen
• Nitrogen fixation


  1. Nitrogen is mixed with oxygen or hydrogen

  2. Can occur through lightning

  3. Can occur through bacteria in the soil or bacteria found in nodules of legumes
• Nitrogen is a necessary component of life as plants need it to grow and animals need it to create DNA
• The speed of decomposition is the key to keeping the nitrogen cycle moving as the majority of fixated nitrogen comes from bacteria breaking down dead matter and feces
• The warmer an area is the faster decomposition will occur
• Fixation


  Bacteria change nitrogen into ammonium
• Nitrification


  Ammonium gets changed into nitrates by bacteria
• Assimilation


  Plants absorb nitrates from the soil into their roots, then use the nitrogen in amino acids, nucleic acids, and chlorophyll
• Ammonification


  Decomposers like fungi and bacteria turn the nitrogen in dead plants and animals back into ammonium
• Denitrification


  Bacteria put extra nitrogen in the soil back out into the air
• Bacteria


  • Most important part of the nitrogen cycle
  • Found in the soil
  • Needed to convert atmospheric N2 gas into usable nitrate (NO3)
• Invasive species


  A species that, due to humans, lives in a region where it was not originally present and has harmful effects on local ecosystems
• Raccoons


  • Raccoons are an invasive species in Japan
• How raccoons became an invasive species in Japan

  1. 1963 USA: A book is released about a boy adopting a baby raccoon

  2. 1977 Japan: Nippon Animation Company released Rascal the Raccoon, a 52 episode anime cartoon series

  3. Japanese families began importing pet raccoons from North America: 1,500 racoons/month were imported

  4. In the final episode, the boy discovers raccoons are wild animals & terrible pets, so he releases Rascal into the wild

  5. Raccoon owners followed their favorite TV show, releasing all of their raccoons into the wild

  6. Racoons became an "invasive species" that destroyed crops and pushed out native species

  
• In Japan, racoons didn't have significant natural predators. Their predators in North America were wolves & coyotes (these don't exist in Japan), and wildcats (only on a few Japanese islands)
• The Raccoon population increased dramatically and affected a range of native species, especially endemic (native) bird species whose eggs became a large part of the raccoons' diet
• Biome


  A large area characterized by its vegetation, soil, climate, and wildlife. All of the organisms in this area generally have similar range of tolerance for survival. The mix of organisms in the area are dependent on each other and on the abiotic influences in the area.
• Endemic species


  Species which are native to a defined geographic region
• Alien species


  Species that have been transferred from their natural habitat to a new environment
• Invasive species


  Alien species that have a detrimental effect upon the pre-existing food chains, displacing native species
• Invasive species typically threaten the biodiversity of the ecosystem they are introduced into by displacing native species
• Control of Invasive Species

  • Biological control
  • Mechanical control
  • Chemical control
• Biological control


  The intentional manipulation of natural enemies by humans for the purpose of controlling pests
• Mechanical control


  Physically removing the invasive species by includes mowing,cutting, hand pulling, trapping and hunting
• Chemical control


  The use of herbicides and poisons
• Symbiotic relationship


  A relationship between two different species that live close together
• Carbon Cycle


  1. Photosynthesis removes carbon dioxide from the atmosphere

  2. Cellular respiration returns carbon dioxide to the atmosphere

  3. Carbon dioxide reacts with water in oceans to create carbonic acid, removing carbon from the atmosphere

  4. Producers in oceans use dissolved carbon dioxide for photosynthesis

  5. Consumers in oceans return carbon dioxide to water by cellular respiration

  6. When living things die, carbon in their bodies is returned to soil by decomposers

  7. Carbon turns into fossil fuels over time

  8. When fossil fuels are burned, carbon returns to the atmosphere

  9. Deforestation returns carbon dioxide to the atmosphere

  
• Mutualism


  • A relationship between individuals of different species that benefits both individuals
  • Example: water buffalo and oxpecker
• Commensalism


  • A relationship where only one of the individuals is benefited, while the other is unaffected
  • Example: sea turtle and barnacles
• Nitrogen Cycle


  1. Nitrogen fixing bacteria break down N2 in atmosphere and provide nitrogen to plants

  2. Lightning breaks down N2 in atmosphere, nitrogen falls to ground in rain and is taken up by plants

  3. Plants uptake nitrogen from soil and use it for proteins and DNA

  4. Decomposers break down nitrogen in dead plants/animals and return it to soil

  5. Denitrifying bacteria take soil nitrogen and return it to atmosphere

  
• Parasitism


  • A relationship in which one species is benefited while the other is harmed, normally by the parasite living on or inside the individual
  • Examples: tapeworm in humans, fleas on dogs and cats

  
• Mutualism


  • Clownfish and sea anemone

  
• Parasitism


  • Mosquito and human

  
• Eutrophication


  1. Fertilizers spread on farms leach into aquatic ecosystems

  2. Excess nutrients cause algal blooms, blocking sunlight

  3. Algae die and are decomposed by bacteria, using up oxygen

  4. Ecosystem becomes anoxic, consumers requiring oxygen die
• Commensalism


  • Human and eyelash mite
• Mutualism


  • Nile crocodile and plover bird
• The squirrels are the same species and are not living on/off each other
• Biome


  A large area of the planet which can be classified according to the species that live there, the climate and physical environment