2.1 SL only.pptx

2.1 Individuals, Populations, Communities, and Ecosystems

2.1.1 Earth’s Systems

  • Various systems include:

    • Biosphere

    • Atmosphere

    • Geosphere

    • Hydrosphere

    • Cryosphere

The Biosphere

  • Represents areas of Earth with life, from upper atmosphere to Earth's crust.

2.1.1 Key Elements

  • Ecosystems: Comprise communities and non-living environments functioning as a unit.

    • Health determined by biodiversity, productivity, energy, and nutrient cycling.

  • Communities: Groups of different species populations interacting in an area, including symbiosis, competition, and predation.

  • Populations: Groups of the same species in a specific area. Dynamics such as growth rates affect ecosystem health.

  • Individuals: The smallest ecological unit, a single organism.

2.1.2 Species

  • A species is a group capable of producing fertile offspring, sharing a genetic pool.

2.1.3 Why Do We Classify?

  • Taxonomy organizes diverse life forms.

  • Nomenclature rules include genus capitalization, species lower case, usually in Latin.

2.1.4 Dichotomous Keys

  • Tools for identifying organisms using a series of questions based on characteristics.

  • Pros: Easy to use, not biased if properly structured.

  • Cons: May require prior knowledge, certain life stages may look different.

2.1.10 Carrying Capacity

  • Defined as the average population size that can sustainably be supported.

  • Factors influencing it:

    • Food availability

    • Water resources

    • Habitat space

    • Predation & disease

    • Human impact

2.1.11 Population Size

  • Regulated by density-dependent (e.g., competition, disease) and density-independent (e.g., climate, disasters) factors.

2.1.13 Feedback Mechanisms

  • Study of population growth patterns includes S-curves (logistic growth) and J-curves (exponential growth).

2.1.14 Human Population

  • Rapid growth due to reduced natural limits, technology, and agricultural advancements.

  • Results in resource depletion, habitat destruction, and pollution.

2.1.24 Conservation and Restoration Efforts

  • Effective monitoring and implementation of conservation strategies are crucial to reverse biodiversity loss.

  • Efforts involve habitat protection, restoration, and sustainable resource use.

2.1.25 Strategies to Avoid Critical Tipping Points

  • Habitat conservation: Protected areas and sustainable land-use practices.

  • Biodiversity preservation: Supports ecosystem resilience through species richness.

  • Pollution control: Key actions include waste management and cleaner production methods.