Ecology

• Ecology


  A science that describes how organisms interact with each other and their physical environments
• Factors in ecology

  • Biotic factors (living)
  • Abiotic factors (non-living)
• Levels of study in ecology

  • Organisms
  • Population
  • Community
  • Ecosystem
  • Biosphere
• Population density


  Measurement of the number of people in an area
• Population dispersion


  The geographic arrangement of the individuals within the population
• Fecundity


  How many offspring an individual can have in a lifetime
• How species can grow

  • Geometric growth rate
  • Exponential growth rate
• Density-dependent limitations


  Factors that inhibit growth because of the environmental stress caused by a population size
• Density-independent limitations

  Limitations described in terms of catastrophe
• Exponential growth


  The population grows at a rate proportional to the size of the population
• Logistic growth


  The population is limited to the carrying capacity of its habitat
• Organism


  Life cycles, adaptations, and behaviors
• Population


  Studying the size/density/structure of a population and how they change over time
• Mutualism


  Symbiotic relationship beneficial to both organisms
• Types of mutualism

  • Obligate mutualism
  • Facultative mutualism
• Predation


  One population is the resource of another
• Competition


  Individuals seek to obtain the same resource
• Ecosystem


  A geographic area where plants, animals, and other organisms, as well as weather and landscape, work together to form a "bubble" of life
• Types of ecosystems

  • Freshwater
  • Wetlands
  • Ocean water
  • Lakes
  • Terrestrial forests
• External factors

  Climate, parent rock material, and topography
• Internal factors

  Decomposition, root competition, shading, disturbance, succession, and types of species
• Resistance


  Tendency of an ecosystem to remain close to its equilibrium state despite disturbances
• Abiotic factors

  • Light intensity
  • Temperature
  • Carbon dioxide concentration
  • Moisture levels
  • Wind intensity/direction
  • Mineral content of soil (pH level)
• Biotic factors


  Any living factor that affects another organism, or shapes the ecosystem in some way
• Food chain


  Single path that helps us work out who eats whom in a habitat to get the energy and materials required for nutrition
• Food web


  When you consider all the food chains in the habitat and join them together
• Trophic levels

  • Producers
  • Primary consumers
  • Secondary consumers
  • Tertiary consumers
• Apex predator


  Carnivores who are at the top of the chain without the presence of any predators
• Other groups

  • Omnivores
  • Decomposers
  • Detritivores
• Biogeochemical cycles


  The biological, chemical, and geological processes by which the nutrients move around
• CHNOPS

  Carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur
• Water cycle

  1. Plants get water through roots

  2. Animals get water by drinking

  3. Evaporation from oceans, lakes, and streams

  4. Evapotranspiration

  5. Precipitation
• Groups of organisms

  • Decomposers
  • Detritivores
• Decomposers and detritivores


  Decompose dead plant and animal matter in the environment, allowing them to recycle nutrients from animals and plants back into the ground
• Nutrients recycled into the ground

  Can then be used again by plants or the producers at trophic level 1
• Decomposers


  Organisms like bacteria and fungi
• Detritivores


  Small animals like worms
• BIOGEOCHEMICAL CYCLES describe how the nutrients move between living and nonliving, the biological, chemical, and geological processes by which the nutrients move around
• Nutrients that life needs

  • Carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur (CHNOPS)
• Oxygen and hydrogen = water cycle