TJ

Ecology

Ecology Cycles

Biotic Factors

  • Definition: Any living thing that possesses all characteristics of life.
  • Characteristics:
    • Composed of cells.
    • Exhibits levels of organization.
    • Engages in metabolism/respiration (uses energy).
    • Responds to the environment (maintains homeostasis).
    • Grows and reproduces.
    • Adapts to the environment.

Abiotic Factors

  • Definition: Nonliving components that do not have all characteristics of life.
    • Note: May exhibit some characteristics but are still classified as nonliving.

Ecology Overview

  • Definition: The study of organisms and their interactions within their environment.
  • Ecosystem: Combination of all living (biotic) and physical/nonliving (abiotic) factors within a specific area.
    • Classified based on:
    • Plants
    • Animals
    • Climate

Ecological Cycles

  1. Water Cycle
  2. Carbon Cycle
  3. Nitrogen Cycle

Carbon Cycle

  • Components Involved:
    • Photosynthesis
    • Decay of organisms
    • Sunlight
    • CO₂ cycle
    • Organic carbon (e.g., derived from living organisms)
    • Animal Respiration: Returns carbon to the atmosphere.
    • Plant Respiration: Similar function as animal respiration.
    • Fossil Fuels: Converted from dead organisms over millions of years.
    • Ocean Uptake: Oceans absorb CO₂ from the atmosphere.

Characteristics of the Carbon Cycle

  • Cycles between biotic (living) and abiotic (nonliving) factors.
    • Organic carbon sources include animals and plants.
    • Inorganic sources include rocks, atmosphere, and water.
  • Importance: Carbon is the building block of all living things and is essential for life on Earth.

Greenhouse Effect (GHE)

  • Mechanism: Greenhouse gases (GHGs) trap and emit heat (infrared radiation), keeping Earth enviably warm.
  • Significance:
    • Maintains habitable conditions on Earth.
    • Historical fluctuations have influenced global climates and contributed to glacial and interglacial periods.

Key Terms for the Carbon Cycle

  • Source: An area that releases more carbon than it absorbs.
  • Sink: An area that absorbs more carbon than it releases; can be referred to as a reservoir.
    • Includes atmosphere, ocean, and biosphere.
    • Largest carbon sink: Deep ocean.

Timeframes of Carbon Cycling

  • Very Fast (less than 1 year): Plant growth and decay, microbial activity.
  • Fast (1-10 years): Carbon cycling through biosphere, including food chains.
  • Slow (10-100 years): Carbon release from fossil fuels.
  • Very Slow (over 100 years): Carbon captured in sediments and fossilized materials.

Carbon Cycle Processes

  • Photosynthesis:

    • Conversion: ( \text{Carbon Dioxide} + \text{Water} + \text{Light Energy} \rightarrow \text{Glucose} + \text{Oxygen} )
    • Performed by plants utilizing chloroplasts.

  • Cellular Respiration:

    • Conversion: ( \text{Glucose} + \text{Oxygen} \rightarrow \text{Carbon Dioxide} + \text{Water} + ATP )
    • Occurs in plants and animals, using mitochondria.

  • Other Processes:

    • Decomposition: Breaks down organisms and reintroduces CO₂ into the atmosphere.
    • Dissolution: CO₂ absorbed by oceans.
    • Lithification: Process leading to fossil fuel creation.
    • Combustion: Releases CO₂ by burning organic material.

Common Natural Compounds in the Carbon Cycle

  • Carbon Dioxide (CO₂): Present in the atmosphere, absorbed by plants.
  • Glucose (C₆H₁₂O₆): Produced in photosynthesis, utilized in respiration.
  • Methane (CH₄): A potent greenhouse gas primarily from agriculture and livestock.
  • Carbon Monoxide (CO): Produced from fossil fuel combustion.
  • Calcium Carbonate (CaCO₃): Found in shells and limestone, forms sedimentary rocks.

Carbon Sequestration

  • Definition: Long-term storage of carbon in natural sinks (e.g., oceans, forests) to slow atmospheric CO₂ buildup.
    • Natural Sinks: Include deep oceans and forests.
    • Man-Made Methods: Rereforestation, forest protection, carbon capture and storage.

Nitrogen Cycle

  • Main Components:
    • Nitrogen Fixation: Conversion of atmospheric N₂ into a usable form for plants, facilitated by nitrogen-fixing bacteria and lightning.
    • Denitrification: Breakdown of nitrogen compounds in soil by bacteria, returning N₂ to the atmosphere and preventing excess nitrogen buildup.

Nitrogen Cycle Processes

  • Assimilation: Uptake of usable nitrogen by plants and animals for protein and nucleic acid synthesis.
  • Decomposition: Conversion of organic nitrogen from organisms into inorganic forms accessible to plants.
    • Key focus: Ammonification during decomposition.