Midterm Topic Review: Ecosystems and Human Impact

Matter Through an Ecosystem

  • Introduction to Matter in Ecosystems

    • Matter moves through ecosystems in various forms and quantities.

    • The balance of matter is crucial for maintaining a stable ecosystem.

The Carbon Cycle

  • Importance of Carbon

    • Carbon is a vital element in various biochemical compounds.

    • It is a key component of:

    • Glucose: The primary energy source for organisms.

    • Carbon Dioxide (CO₂): Used in photosynthesis and released during respiration.

    • Carbon Monoxide (CO): A harmful gas resulting from incomplete combustion.

  • Key Concept: The carbon cycle must maintain balance.

    • Disruptions to this balance negatively impact ecosystems.

  • Carbon Movement:

    • Carbon moves rapidly in certain areas (e.g., active ecosystems) and can be stored as reservoirs in other areas (e.g., forests, oceans).

    • Reservoirs: Locations where carbon is stored for extended periods.

    • Examples of Reservoirs:

      • The Ocean: Stores significant amounts of carbon, contributing to global carbon balance.

      • The Ground: Contains fossil fuels that lock carbon away from the carbon cycle.

  • Carbon Cycle Processes:

    • Carbon enters and exits the atmosphere through various natural processes:

    • Photosynthesis: Carbon is absorbed by plants from the atmosphere.

    • Respiration: Both animals and plants release CO₂ back into the atmosphere.

    • Human Activities: Such as burning fossil fuels, which add carbon to the atmosphere.

    • Natural Processes:

      • Plant respiration, oceanic absorption, and decomposition also contribute to carbon dynamics.

Human Impact on the Carbon Cycle

  • Carbon Emission Processes:

    • Activities Adding Carbon to Atmosphere:

    1. Fossil fuel combustion.

    2. Deforestation (releasing stored carbon).

    3. Industrial processes.

  • Activities Removing Carbon from Atmosphere:

    1. Photosynthesis by plants.

    2. Ocean absorption of CO₂.

    3. Soil absorption via organic matter decomposition.

Human Population Growth

  • Impact on the Environment:

    • Increased human population leads to:

    • Higher levels of pollution: air, water, soil.

    • Acid rain, produced when pollutants from fossil fuel combustion react with water vapor, forming acids like sulfuric and nitric acid.

    • Effects of Acid Rain:

    • Lowers pH of water bodies and soil to pH of 5.5 or less.

    • Impacts organisms sensitive to pH changes, leading to decreased biodiversity.

    • Importance of ecological balance and addressing pollution to safeguard biodiversity.

Solutions to Environmental Issues

  • Adoption of Renewable Resources:

    • Renewable resources are sustainable and can naturally replenish, such as solar and wind energy.

  • Nonrenewable Resources:

    • Resources that are finite and can be depleted, such as fossil fuels.

Connection to Eutrophication

  • Definition: Eutrophication is the process by which water bodies become overly enriched with nutrients (mainly nitrogen and phosphorus) due to runoff from fertilizers and other chemicals.

  • Effects of Eutrophication:

    • Causes algal blooms that deplete oxygen in water, suffocating aquatic life by blocking sunlight essential for photosynthesis.

    • Illustrates the interconnectedness of carbon processes and human impact on ecosystems, contributing to overarching environmental challenges.