AP BIO: CH. 50 - An Introduction to Ecology and the Biosphere (full)

Components of Ecology

  • Abiotic Factors
    • Definition: Non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems.
    • Examples include temperature, water, sunlight, soil, and climate.
  • Biotic Factors
    • Definition: Living components of an environment that affect the ecosystem, which include all organisms in the environment.
    • Examples include plants, animals, fungi, and bacteria.

Ecological Terminology

  • Population

    • Definition: A group of organisms of the same species that live in a given area.
    • Example: A population of deer in a specific forest.

  • Community

    • Definition: An assemblage of populations that live in a particular area.
    • Example: The community of plants, animals, microorganisms, and fungi in that same forest.

  • Ecosystem

    • Definition: The community of organisms along with the abiotic factors in their environment.
    • Example: The forest ecosystem including the trees, animals, soil, and climate.

Historical Context

  • Rachel Carson and Silent Spring
    • Year: 1962
    • Significance: The book is a seminal work that effectively started the modern environmental movement.
    • Impact: The findings led to the establishment of the Environmental Protection Agency (EPA) due to public awareness raised about the environment and chemical pollutants.

Biosphere and Biomes

  • Biosphere

    • Definition: The sum of all the planet's ecosystems.

  • Biomes

    • Definition: Areas of predominant flora and fauna within the biosphere, shaped by climate and geography.
    • Importance: Different biomes support distinct life forms and ecosystems.

Climate and Weather

  • Global Climate
    • Determinants: Climate is influenced by seasonal changes, precipitation, and wind patterns.
  • Seasonal Changes
    • Influencing Factor: Tilt of the Earth is the primary factor in determining the seasons.
    • Explanation: As the Earth wobbles on its axis, regions alternate between being closer or further from the sun, leading to the seasons (summer vs winter).

Lake Stratification

  • Thermal Stratification
    • Definition: Vertical temperature layering in lakes.
    • Example: Surface layer in summer being warm while deeper layers are cold.
    • Behavior of Water: Hot water tends to rise while cold water sinks.
  • Biannual Mixing
    • Occurs in spring and summer, vital for nutrient circulation in lakes.
    • Process: As surface water warms, it rises and brings nutrients from the bottom layer, while cold water sinks to oxygenate the lower layers.
    • Consequences of No Turnover: Without mixing, lakes can become stagnant, leading to algal blooms and die-offs of aquatic species.

Aquatic Biomes Vocabulary

  • Photic Zone
    • Definition: The layer of water where light penetrates and photosynthesis occurs.
    • Importance: Contains most plant life in aquatic systems.
  • Thermocline
    • Definition: A narrow stratum in which temperature changes rapidly, creating a layer of distinct thermal zones.
    • Note: It may exist within the photic zone.
  • Benthic Zone
    • Definition: The lowest layer in a body of water, consisting of the bottom substrate.
    • Includes organisms known as Bentos (bottom feeders eating detritus, or organic matter).

Freshwater Biomes

  • Littoral Zone
    • Definition: The shallow, well-lit area close to the shore.
    • Example: Ideal for recreational activities such as swimming.
  • Liminal Zone
    • Definition: Well-lit open waters further from shore, suitable for activities like underwater skiing.
  • Profundal Zone
    • Definition: Deep, dark waters of a lake (aphotic).

Lake Classification

  • Oligotrophic Lakes
    • Definition: Deep, nutrient-poor lakes; typically clear water.
    • Example: Lake Tahoe.
  • Eutrophic Lakes
    • Definition: Shallow lakes with high nutrient content; often rich in plant life.
  • Mesotrophic Lakes
    • Definition: Lakes with intermediate nutrient content, maintaining a balance between oligotrophic and eutrophic conditions.

Wetlands and Estuaries

  • Wetlands

    • Definition: Areas covered with water, contributing to biodiversity and water filtration.

  • Estuaries

    • Definition: Areas where freshwater meets saltwater, resulting in brackish water.
    • Importance: Often serve as nurseries for various marine species due to lower predation levels.

Marine Biomes

  • Intertidal Zone
    • Definition: The area where land meets the ocean, experiencing tides.
  • Neritic Zone
    • Definition: Shallow regions over the continental shelf, where sunlight penetrates.
  • Oceanic Zone
    • Definition: Deep ocean waters beyond the continental shelf.
    • Significance: Home to diverse marine life and ecosystems.
  • Pelagic Zone
    • Definition: Open water at any depth beyond the continental shelf.
  • Benthic Zone
    • Definition: The sea floor; important for many organisms.
  • Abyssal Zone
    • Definition: The deepest part of the ocean floor; characterized by high pressure and low temperature, often home to specialized organisms.

Terrestrial Biomes

  • General Notes: The terrestrial biomes encompass various ecosystems characterized primarily by climate conditions (e.g., deserts, forests, grasslands).
  • Specifics: The study does not cover extensive details on precipitation or climate; general knowledge of their characteristics suffices (e.g., deserts are hot and dry).

Final Notes

  • An assignment (e.g., worksheet) may be posted for further learning or practice.