LEC 7 RECORDING SLIDE

Paper Straws and Plastic Pollution

• Paper Straws

  • Personal opinion: dislike paper straws due to their poor functionality (fall apart, undesirable).

  • Internet consensus: widespread complaints about paper straws.

• Plastic Waste Problem

  • Great Pacific Garbage Patch: enormous concentration of marine debris, stretching four and a half times the size of Germany, primarily composed of plastic.

  • Difficulty of plastic degradation leads to accumulation in oceans.

  • Visual evidence:

    • Aerial view shows floating garbage masses.

    • Underwater imagery illustrates plastic debris in oceans.

  • Some animals utilize this debris for habitat, but most species are negatively impacted.

  • Microplastics:

    • Tiny plastic fragments that arise from various sources, including cosmetics with microbeads.

    • Result from degradation of larger plastics due to environmental factors (UV light, ocean currents).

    • Found in diverse locations (air, remote caves, Arctic & Antarctic regions).

    • Discovered in marine life (e.g., stomachs of seals and seabirds, even in bloodstream).

Academic Announcements

• Codon Subscription:

  • Free trial ending today; must subscribe before midnight to maintain access.

• Important Test Dates:

  • Topic Test 1: February 8 at 6 PM (worth 12% of final grade).

  • Topic Test 2: March 8 at 6 PM (worth 12% as well).

  • Final Exam: April 12 (15% of final grade).

  • All assessments done in person (specific rooms dependent on your registration section).

Test Structure

• Two-stage Testing:

  • Stage 1 (Individual):

    • Traditional format; weight: 85% of topic test grade; duration: 40 minutes.

  • Stage 2 (Group):

    • Worth 15%; participation mandatory; groups formed during tests.

    • Groups cannot lower individual scores; typically, performance improves through collaboration.

  • Encourage students to form groups in advance based on writing locations.

• Test Format:

  • Questions will be multiple choice or true/false.

  • Focus on concepts rather than memorization of specifics; understand definitions and key terms.

  • Expect to see stems (contextual information) released ahead of time.

• Practice Tests:

  • Will be available on Codon incorporating past exam formats.

Effective Exam Strategies

• Active Recall:

  • Read the question carefully and think of what you know before reviewing answer choices.

  • Maintain focus on concepts and definitions rather than memorizing details.

• Types of Productivity:

  • Gross Primary Productivity (GPP) vs. Net Primary Productivity (NPP):

    • GPP: total primary production;

    • NPP: production available for growth after subtracting energy used by organisms for metabolism.

Limiting Factors in Ecology

• Limiting Factors:

  • Defined as resources that are in limited supply; affects primary productivity in ecosystems.

  • Liebig's Barrel Analogy:

    • The height of the lowest slat (limiting resource) restricts overall capacity (productivity).

• Examples of Limiting Resources:

  • Light, space, water, nutrients.

  • Situational dependencies, such as varying importance of factors across different environments.

Human Impact on Primary Productivity

• Statements Assessment:

  • Evaluate human actions such as deforestation and agriculture and their impact on productivity and carbon storage.

  • Droughts and Climate Change:

    • Frequency and severity of droughts generally decrease primary productivity.

  • Temperature Considerations:

    • Changes in average temperatures can variably affect productivity based on environmental context.