The Biosphere (1)

Chapter 34: The Biosphere

Ecology

  • Definition: Scientific study of interactions between organisms and their environment

  • Biotic Factors: Living components of the environment

  • Abiotic Factors: Nonliving components of the environment such as temperature, water, and nutrients

  • Habitat: The specific environment in which an organism lives, encompassing both biotic and abiotic factors

Levels of Biological Organization

  • Organism: Individual living entity

  • Population: Group of organisms of the same species in a specific area

  • Community: Different populations living together in a defined area

  • Ecosystem: Interaction between living organisms and their physical environment

Physical & Chemical Factors

  • Energy Sources: All organisms require an energy source to sustain life

  • Temperature: A critical abiotic factor that affects metabolism

  • Water: Essential for all life forms

    • Aquatic Organisms: Depend on dissolved oxygen for survival

  • Inorganic Nutrients: Affect the distribution and abundance of photosynthetic organisms

    • Giant Tube Worms: Exhibit a symbiotic relationship with bacteria that use sulfide as an energy source

The Biosphere

  • Definition: Includes all locations on Earth where life exists

  • Geographical Distribution: Influenced by climate factors such as cloud cover, temperature, humidity, and wind speed

  • Climate Influences: Affect wind and ocean currents

  • Factors: Sunlight intensity, landmass/sea distribution, and elevation play significant roles

How Solar Radiation Varies with Latitude

  • Low Angle of Incoming Sunlight: Varies by latitude

  • Key Locations:

    • Arctic Circle (60° N)

    • Tropic of Cancer (30° N)

    • Equator (0°)

    • Tropic of Capricorn (30° S)

    • Antarctic Circle (60° S)

  • Direct sunlight striking leads to varying temperatures across the globe

How Earth’s Tilt Causes the Seasons

  • Earth's Orbit: The Earth rotates around the sun in an elliptical path once a year

  • Tilt: Earth's axis is tilted at 23 degrees, influencing seasonal changes

How Uneven Heating Causes Rain and Winds

  • Weather Dynamics:

    • Ascending moist air releases moisture leading to precipitation in the tropics

    • Descending dry air causes arid conditions in temperate zones

Prevailing Wind Patterns

  • Mechanism: Result from rising and falling air masses

  • Types of Winds:

    • Westerlies: Dominating winds in certain latitudes

    • Trade Winds: Located in the tropics, affecting weather patterns

Atlantic Ocean Currents

  • Formation: Resulting from a mix of prevailing winds, planet rotation, unequal heating of water surfaces, and geographical features

  • Example Currents:

    • Gulf Stream

    • California Current

    • Labrador Current

How Mountains Affect Precipitation

  • Impact of Landforms: Landforms can significantly alter climate patterns

  • Rain Shadow Effect: Areas on the leeward side of mountains experience dry conditions while windward sides are moist

    • Example: Pacific Ocean influence on the Coast Range and Sierra Nevada leading to deserts in the East

Biome

  • Definition: Areas of land categorized by their climate and dominant vegetation types

    • Discontinuous Distribution: Biomes vary widely in rainfall and temperature as well as soil composition

Different Biomes

  • Factors Determining Biomes:

    • Location and environmental conditions such as weather patterns, rainfall, temperature, and soil types

  • Flora and Fauna: Types of plants and animals, their adaptations to the biome

    • Example: Water conservation adaptations in desert plants

  • Current Threats: Environmental degradation or destruction due to factors like global warming, overfishing, habitat destruction, etc.