Ecology Part Three Review

Carbon Cycle

• Definition and Importance

  • Carbon is present in abiotic factors such as soil and carbon dioxide in the atmosphere.
  • Vital for life processes; recycling of carbon is crucial in ecosystems.

• Climate Change

  • Increased atmospheric CO₂ concentrations lead to rising global temperatures.
  • CO₂ forms a natural blanket preventing extreme cold but too much leads to warming.

• Recycling Imbalances

  • Decomposed organic material forms fossil fuels (coal and oil) over millions of years, which are now rapidly released by human activities.
  • Deforestation for grazing decreases the carbon-absorbing capacity of plants.

• Need for Sustainable Practices

  • Shift towards renewable energy sources (wind and solar) to reduce fossil fuel dependence.
  • Involves political, social, and infrastructure changes.

• Photosynthesis and Respiration

  • Plants absorb CO₂ and convert it to carbohydrates (like glucose, C₆H₁₂O₆).
  • Animals utilize this energy through respiration, producing ATP and releasing waste that contributes to decomposition.

• Future of the Carbon Cycle

  • Aim for balanced carbon levels to sustain robust ecosystems and support life.

Water Cycle

• Overview

  • Significant precipitation in recent years; however, California experiences cycles of drought.
  • Water conservation and drip irrigation in agriculture are critical for sustainability.

• Water Movement

  • Evaporation from oceans generates water vapor, which forms clouds and leads to precipitation.
  • Water infiltrates into groundwater, reaching plants where it can re-enter the atmosphere through transpiration.

• Groundwater Management

  • Protecting groundwater is essential for ecosystem health and sustainable fisheries.

Energy Flow in Ecosystems

• Trophic Levels

  • Sun is the primary energy source; energy flows from producers (plants) to various consumer levels.

• Energy Transfer

  • Plants (Producers) → Herbivores (Primary Consumers) → Carnivores (Secondary Consumers) → Apex Predators (Tertiary Consumers).
  • Only 10% of energy transfers to the next trophic level, with 90% lost at each stage as heat or through metabolic processes.

• Food Chains vs. Food Webs

  • Trophic interactions are complex, leading to food webs which consist of interconnected food chains.

Greenhouse Effect

• Balanced CO₂ Levels

  • Optimal CO₂ concentrations sustain Earth’s ecosystem; too much leads to a thicker greenhouse effect causing global warming.

• Historical CO₂ Trends

  • CO₂ levels have risen since the Industrial Revolution; current levels exceed 300 ppm, which is concerning for ecological balance.

Environmental Stewardship

• Resource Awareness

  • Water and air are finite resources; pollution and overuse must be managed responsibly to sustain life.

• Population Impact

  • Human population is over 7.8 billion, projected to reach 9.2 billion by 2050, stressing resources and ecosystems.

• Future Considerations

  • Conscious management of natural resources necessary for quality of life and ecological balance.

Conclusion

• Encourage thoughtful practices regarding CO₂ emissions, water use, and energy production to promote sustainable ecosystems.
• Reminder about the upcoming exam and availability for questions.