Ecology

Ecology

  • Definition: The study of interactions between organisms and their environment.

Types of Ecology

  • Organismal Ecology: Examines how species relate to their abiotic (non-living) environment.

  • Population Ecology: Focuses on factors affecting population density and growth; includes all individuals of a species in an area.

  • Community Ecology: Studies all individuals of all species in an area, plus abiotic factors.

  • Landscape Ecology: Investigates groups of ecosystems and their interactions; neighboring ecosystems affect each other.

  • Global Ecology: Encompasses all ecosystems of the same type across the world.

Climate Factors Affecting Ecosystems

  • Latitude: Influences sunlight exposure and temperature.

  • Air Circulation:

    • Descending Dry Air: Absorbs moisture near the equator; leads to high precipitation.

    • Ascending Moist Air: Releases moisture; as air rises, it cools.

  • Ocean Circulation: Northern gyres spin clockwise, resulting in cold water which impacts the occurrence of hurricanes.

Seasons and Geography

  • Seasonality: Impact of seasons on ecosystems.

  • Mountains: Affect precipitation patterns; rain shadows create dry areas on the leeward side.

  • Aspect: Direction a slope faces; west-facing slopes receive more moisture.

  • Runoff: Water that does not infiltrate into the ground can affect plant growth.

Disturbance

  • Definition: Natural disasters or man-made occurrences that alter ecosystems.

  • Examples: Lava flows, fires can lead to changes in species composition and ecosystem structure.

Types of Biomes

  • Desert:

    • Characterized as dry, with bands at about 30° latitude north or south.

    • Wide temperature variation; hot during the day, cold at night.

    • Low, scattered vegetation.

  • Grasslands:

    • Seasonal climates; dry cold winters followed by wet hot summers.

    • Dominated by grasses; large grazing herbivores prevent tree establishment.

    • Periodic droughts and fires are common.

  • Chaparral:

    • Scattered vegetation in midlatitude coastal regions.

    • Wet, mild winters with dry summers.

    • Home to browsers like small mammals, reptiles, and birds.

  • Broadleaf Temperate Forest:

    • Located in mid latitudes.

    • Heavy precipitation across all seasons; hot and humid summers.

    • Many animals migrate during winter; trees are deciduous.

  • Coniferous Forest:

    • Found in northern latitudes with cold winters and mild summers.

    • Precipitation varies; tree structure prevents snow accumulation on branches.

  • Tundra:

    • Found in far northern latitudes with very cold winters and short summers.

    • Characterized by permafrost below the surface.

  • Tropical Rainforest:

    • Located near the equator; high temperatures and precipitation with little seasonal variation.

    • Vertically layered and complex with high biodiversity.

  • Temperate Rainforest:

    • Found in specific coastal areas; cooler, high precipitation with little seasonal variation.

    • Dominated by coniferous trees.

  • Open Ocean:

    • Photic Zone: Where enough light allows for photosynthesis.

    • Aphotic Zone: Lacks sufficient light for photosynthesis.

    • Mesopelagic Zone: Receives minimal light; depends on nutrients from above zones.

    • Benthic Zone: Deep sea floor, around 10,898 m; nutrient-rich, home to larger organisms.