Abiotic factors influence the distribution of life - Video 3

Abiotic Factors in Terrestrial Environments

  • Key Abiotic Factors: Elevation, temperature, and precipitation.
    • Elevation affects temperature and precipitation:
    • As elevation increases, temperatures generally decrease and precipitation increases.
    • Species Richness:
    • Higher in warmer temperatures and more precipitation.
    • Tends to be lower in higher elevation due to harsher conditions.
    • Mountain Range Dynamics:
    • Variation in precipitation across mountain ranges leads to different habitats:
      • One side (windward) receives more precipitation (rain/snow).
      • The other side (leeward) tends to be drier.
    • This variation creates different species richness patterns.

Abiotic Factors in Aquatic Environments

  • Key Abiotic Factors: Water depth, temperature, sunlight, and dissolved oxygen.
    • As water depth increases:
    • Temperatures become cooler.
    • Sunlight decreases.
    • Species Richness:
    • Generally higher in warmer, sunlit areas near the surface of water.
    • Ocean Currents Influence:
    • Change environmental conditions, mixing water and affecting temperature.
    • Create varied habitats, leading to different species richness patterns.

Marine Plant Species Distribution

  • Map Representation:
    • Color gradient indicates species richness:
    • Warmer colors (closer to red): Higher species richness.
    • Cooler colors (closer to green): Lower species richness.
  • Environmental Preferences:
    • Marine plants commonly found along shallow coastlines due to higher light availability.
    • Absent in deeper waters with lower light levels.

Aquatic Ecosystem Types

  • Freshwater Ecosystems:

    • Water salinity < 1% (low salt concentration).
    • Include lakes, rivers, wetlands.
    • Additional abiotic factors:
    • Water velocity.
    • Clarity.
    • pH levels (acidity measure).

  • Marine Ecosystems:

    • Contain saltwater (higher salinity).
    • Include oceans, coral reefs, mangroves.
    • Additional abiotic factors:
    • Ocean currents.
    • Dissolved nutrients.
    • Proximity to land.