Food Chains and Ecosystems Detailed Notes

Food Chains and Food Webs

Page 1: Introduction to Food Chains and Food Webs

• Essential Concepts:

  • Food Chain: A linear sequence showing how energy and nutrients flow from one organism to another.

  • Food Web: A complex network of interconnected food chains showing the various paths through which energy and nutrients circulate in an ecosystem.

• Key Questions:

  1. Primary, Secondary, Tertiary Consumers:

  • Primary consumers: Herbivores that eat producers (plants).

  • Secondary consumers: Carnivores that eat primary consumers.

  • Tertiary consumers: Top predators that eat secondary consumers.

  1. Difference between Food Chain and Food Web:

  • A food chain is a simple, linear pathway.

  • A food web consists of multiple food chains interlinked.

  1. Decomposer vs Detritivore:

  • Decomposers break down dead organic matter (e.g., fungi, bacteria).

  • Detritivores consume dead organic matter (e.g., earthworms).

Page 2: Videos and Energy Transfer

• Educational Videos:

  • Fabulous Food Chains

  • The Dirt on Decomposers

• Key Questions:

  1. Definition of a Food Chain:

  • An ordered series of organisms, each serving as food for the next, illustrating energy transfer.

  1. Source of Energy:

  • The Sun is the primary source of energy for most ecosystems.

  1. Energy Movement:

  • Energy moves from producers to consumers in the form of chemical energy.

  1. Examples of Decomposers:

  • Bacteria, fungi, and detritivores like earthworms and woodlice.

  1. Roles of Decomposers:

  • They recycle nutrients back into the soil.

  • They help in the decomposition of organic matter ensuring energy flows in the ecosystem.

Page 3: Analyzing a Food Web

• Food Web Diagram Review:

  • Producers: Plants, phytoplankton.

  • Consumers:

  • Primary: Herbivores (e.g., rabbits, insects).

  • Secondary: Carnivores eating herbivores (e.g., snakes).

  • Tertiary: Top predators (e.g., hawks).

  • Decomposers: Bacteria, fungi, and other scavengers.

• Key Questions:

  1. Autotrophs in Food Web:

  • Organisms that produce their own food (e.g., plants, algae).

  1. Heterotrophs in Food Web:

  • Organisms that consume others for energy (e.g., animals).

  1. One Food Chain Example:

  • Grass → Grasshopper → Frog → Snake.

Page 4: Additional Food Chain

• Second Food Chain Example:

  • Sun → Phytoplankton → Zooplankton → Small Fish → Larger Fish.

Page 5: Manipulating the Food Web

• Adding an Organism:

  • Choose an organism (e.g., a new predator or herbivore) and analyze its relationships.

  • Connections:

  • What it eats and what eats it.

Page 6: Removing an Organism

• Removing an Organism from the Food Web:

  • Circle the organism and analyze its impact on other species.

  • Beneficiaries and Sufferers:

  • Identify which organisms benefit or suffer due to this removal.

• Complex Food Web vs Simple Food Chain:

  • A complex network allows for greater stability and resilience against environmental changes.

Page 7: Antarctic Marine Food Web Activity

• Interactive Exploration:

  • Investigate the Antarctic Marine Food Web and observe the directional arrows indicating energy flow.

Page 8: Energy Flow in Ecosystems

• Energy and Matter Concepts:

  • Living things are called biotic factors; non-living things are called abiotic factors.

  • Branch of Study: Ecology.

  • Major biomes: Tropical rainforest, tundra; other examples include grasslands and deserts.

  • The ultimate source of energy on Earth is the Sun.

Page 9: Key Concept Summary

• Autotrophs: Organisms that produce their own food (e.g., plants).

• TRUE or FALSE: Energy flows one way through food chains. - Answer: FALSE.

• Photosynthesis Energy Transformation: Light energy to chemical energy.

• Energy Recycling: Energy can flow out of the system, while matter is conserved and recycled.

• Photosynthesis Inputs: Carbon dioxide and water.

• Decomposers Role: Break down dead materials and recycle nutrients.

Page 10: Producers, Consumers, and Decomposers

• Flow Chart Elements:

  • Producers: Autotrophs (e.g., plants) using sunlight for photosynthesis.

  • Consumers: Heterotrophs that obtain energy by consuming others.

  • Decomposers: Organisms that break down waste and dead organisms, recycling matter back into the ecosystem.

Page 11: Predator-Prey Dynamics

• Predator-Prey Simulation Analysis:

  • Identify predator (wolves) and prey (moose).

  • Explain population dynamics and the cyclical nature of their populations over time as they influence each other.

Page 12: Graphing Population Dynamics

• Graphing Activity:

  • Construct a line graph to display trends between Zorks and Borg populations, including axis labels and key.

  • Why Graphs Over Scatter-Plots?

  • Line graphs show trends over time, making relationships clearer.

Page 13: Population Data (Zorks and Borgs)

• Data Overview:

  • Analyze population changes from 1990 to 2010 for both species, noting fluctuations.

Page 14: Impacts of Hunting and Predation

• Effects of Decrease in Borg Populations:

  • Predict how a decrease in one population (Borgs) could impact Zorks and related prey species (Grutchins).

Page 15: Effects of Pollution

• Impact of Industrial Pollution:

  • Discuss potential devastating effects on populations, as well as cascading effects through the food chain.

Page 16: Human Impacts on Ecosystems

• Pollution Definitions and Effects:

  • Understand pollution and summarize impacts on air and water.

Page 17: Introduced Species Case Studies

• Example of Red Fox:

  • Discuss its introduction, impacts, and mitigation strategies.

Page 18: Additional Introduced Species Overview

• Include additional species from the provided list summarizing their impacts as well.

Page 19-20: Species Summary Template

• Example Template Entries:

• Organize data uniformly for introduced species in relevant sections.

Page 21: Features of Endangered Animals

• Select an endangered species, detailing its habits, diet, roles in the ecosystem, and conservation methods.

Page 22: Endangered Animal Information Structure**

• Organize information on physical features, habitat, dietary needs, and conservation strategies.

Page 23: Zebra Mussels Case Study Summary

• Overview of the invasive species, their spread, ecological impacts, and potential benefits if controlled.

Page 24: Multiple Choice Review Questions from Articles

• Practice applying knowledge through set review questions on zebra mussels and their implications.

Page 30: Mercury in Fish Analysis

• Discussion about the health implications of mercury in fish, particularly concerning specific groups (pregnant women, children).

Page 34-36: Summary of Fish Mercury Levels

• Create food webs showing species interactions and their respective mercury levels to illustrate impacts on both health and ecology.

These notes provide a detailed guide to understanding food chains and webs, ecosystem dynamics, biological roles, and human impact on ecological systems. Utilize the provided questions for active recall and deeper understanding as you study.