Unit 5 Interdependence of Life

  1. Ecological Levels

    • Organisms: Individual living things.

    • Populations: Groups of individuals of the same species living in the same area.

    • Communities: Different populations that interact in a certain area.

    • Ecosystems: Communities interacting with abiotic factors (non-living elements).

    • Biomes: Large regions defined by climate and ecological communities.

  2. Abiotic and Biotic Factors

    • Abiotic factors: Non-living components (sunlight, temperature, water).

    • Biotic factors: All living organisms (plants, animals, bacteria).

    • Both factors can be found at various ecological levels, impacting populations and communities.

  3. Properties of Populations

    • Size: Total number of individuals in a population.

    • Density: Number of individuals per unit area or volume.

    • Distribution: Spacing of individuals within the habitat (random, uniform, clumped).

    • Age structure: Proportion of individuals at different ages.

  4. Population Density and Types of Organisms

    • High-density examples: Densely populated areas like cities or rich ecosystems with plenty of resources.

    • Low-density examples: Deserts or remote areas with scarce resources.

  5. Distribution Patterns

    • Random distribution: Indifferent spacing of individuals.

    • Uniform distribution: Evenly spaced individuals, often due to competition.

    • Clumped distribution: Individuals grouped due to resources or social reasons.

  6. Types of Population Growth

    • Exponential growth: Rapid increase under ideal conditions.

    • Logistic growth: Growth that levels off as population reaches carrying capacity.

  7. Population Trends

    • Calculating increase/decrease: Compare current population size to previous sizes. Factors include birth rates, death rates, immigration, and emigration.

    • Carrying capacity: Maximum number of individuals an environment can support.

  8. Graphing Population Response

    • Key terms:
           1) Exponential growth
           2) Population overshoot
           3) Population decline
           4) Population recovery and stabilization
           5) Carrying capacity.

  9. Factors Influencing Carrying Capacity

    • Resource availability (food, water)

    • Environmental conditions (habitat space, climate)

    • Interactions with other species (predation, competition).

  10. Density Dependent vs. Density Independent Factors

    • Density Dependent Factors: Affect population size based on density (e.g., disease, competition, predation).

    • Density Independent Factors: Influence population regardless of density (e.g., natural disasters, climate change).

  11. Limiting Factors

    • Two types:
            1) Biotic (competition, predation)
            2) Abiotic (resources, habitat space).

    • Examples:

      • Biotic: Competition for food, predation.

      • Abiotic: Water availability, temperature extremes.

  12. Niches

    • Fundamental niche: The potential mode of existence (habitat, resources).

    • Realized niche: Actual conditions and resources used due to competition.

  13. Competition

    • Interspecific competition: Between different species.

    • Intraspecific competition: Within the same species.

  14. R-strategists vs. K-strategists

    • R-strategists: High reproduction rates, low parental care (e.g., insects, rodents).

    • K-strategists: Lower reproduction rates, high parental care (e.g., elephants, humans).

  15. Survivorship Curves

    • Type I: High survival rates early in life (e.g., humans).

    • Type II: Constant mortality rate throughout life (e.g., birds).

    • Type III: High mortality rate early in life (e.g., oysters).

  16. Population Pyramids

    • Progressive: Broad base, indicating rapid growth.

    • Stable: Even distribution of ages, indicating stability.

    • Regressive: Narrow base, indicating declining population.

    • Correlation of shape to growth pattern: The shape reflects birth and death rates, influencing future growth.