Wetland Energy Worksheet
Biology Credit Recovery • Ecology Unit
Wetland Glade Energy Flow
Food Chains, the 10% Ecological Rule, & Trophic Levels
Name:
Date:
Total: 10 Points (Minor Assignment)
Glade Ecosystem Context: In the wetland glade inspired by Hoppers, beavers dam calm streams to build wetlands. Sunlight fuels plant growth, transferring chemical energy through food chains to insects, fish, and apex predators.
PART 1
Building a Wetland Food Chain
2 Points
Task: Arrange the 5 organisms into the chain. Draw an arrow (→) showing energy transfer (from eaten organism to eater), then write the trophic level on the bottom line.
Glade Organisms: Solar Energy • Willows / Pond Algae • Aquatic Insects • Trout • Red-Tailed Hawk / Bear
Trophic Level Labels: Solar Source • Producer • Primary Consumer • Secondary Consumer • Apex Predator
Step 1
Trophic Level
→
Step 2
Trophic Level
→
Step 3
Trophic Level
→
Step 4
Trophic Level
→
Step 5
Trophic Level
PART 2
The 10% Rule: Trophic Organisms & Energy Math
3 Points
The 10% Ecological Rule: Only approximately 10% of chemical energy transfers to the next trophic level. For each tier, write the glade organism(s) and divide by 10 (÷ 10) to calculate available energy.
| Trophic Level | Glade Organism(s) (Write in) | 10% Rule Math (÷ 10) |
|---|
| Tier 1 Producers (Base) | Organism: Willows, Cattails, & Pond Algae | (Starting Energy): 20,000 kcal |
| Tier 2 Primary Consumers | Write glade herbivore(s): | |
| | |
20,000 ÷ 10 = kcal
|
| Tier 3 Secondary Consumers | Write glade carnivore(s):
|
[Tier 2 Ans: ] ÷ 10 = kcal
|
| Tier 4 Tertiary / Apex Predator | Write top glade predator(s):
|
[Tier 3 Ans: ] ÷ 10 = kcal
|
Short Answer Question: If only 10% reaches the next tier, where does the remaining 90% of energy go? Name two ways organisms use this energy:
Wetland Energy Flow Exploration Worksheet • Page 1 of 2 • Continue on Page 2 →
Glade Ecosystem Network Synthesis
Constructing Food Webs & Modeling Ecological Disruptions
Parts 3 & 4 • 5 Points Total
PART 3
Expanding to a Wetland Food Web
3 Points
Organism Menu (Glade Diets): Arrow Rule: Food → Eater (Points to who gets the energy)
1. Willows & Pond Algae: Producers (uses sunlight)
2. Aquatic Insects: Eats pond algae & willow debris
3. Beavers: Eats willow bark, twigs, & aquatic stems
4. Field Mice: Eats willow seeds & marsh grasses
5. Green Frogs: Eats aquatic insects
6. Trout: Eats aquatic insects & insect larvae
7. Garter Snakes: Eats green frogs & field mice
8. Red-Tailed Hawks: Eats garter snakes & field mice
9. Black Bears: Eats trout, beavers, & willow berries
Task: Draw arrows connecting food sources to their consumers using the Menu above. Draw at least 8 correct feeding arrows (→)
Red-Tailed Hawk
Black Bear
Garter Snake
Green Frog
Trout
Field Mice
Aquatic Insects
Beavers
Producers: Willows & Pond Algae
PART 4
Food Web Disruption & Ecological Analysis
2 Points
1. Resource Competition (1 Point): Identify 2 competitors + shared food
Identify two animals in this wetland glade that compete for the exact same food source, and state what they are competing to eat.
Competing Animals: and
Shared Food Source:
2. Trophic Cascade Prediction (1 Point): Predict effect on 2 connected populations
Scenario: A fungal disease wipes out all Green Frogs in the glade. Based on your food web, predict what happens to each population:
(A) Aquatic Insect Population
Prediction: Increase / Decrease (circle one)
Explain why:
(B) Garter Snake Population
Prediction: Increase / Decrease (circle one)
Explain why:
Wetland Glade Energy Flow Worksheet • Minor Assignment Assessment Page 2 of 2 • Total Score: ____ / 10 Pts
Wetland Energy Answer Key
Teacher Evaluation Guide • Credit Recovery Science
Wetland Energy Flow — Answer Key
Scoring Guide, Worked Solutions, & Credit Recovery Pacing Notes
TEACHER ANSWER KEY Total Points: 10.0 Pts
PART 1
Building a Wetland Food Chain (2.0 Points Total)
Scoring: 1 pt sequence + 1 pt trophic labels
Correct Sequence & Labels: Energy arrows must point from the organism eaten to the consumer (direction of chemical energy transfer).
Step 1
Solar Energy
Solar Source
→
Step 2
Willows / Pond Algae
Producer
→
Step 3
Aquatic Insects
Primary Consumer
→
Step 4
Trout
Secondary Consumer
→
Step 5
Red-Tailed Hawk / Bear
Apex Predator
Grading Note: Award 1.0 pt for correct chronological placement with proper arrow direction (→), and 1.0 pt for accurate trophic level classification labels.
PART 2
The 10% Rule: Organisms & Math Solution (3.0 Points Total)
Scoring: 1.5 pts table + 1.5 pts explanation
Table Grading Key (0.5 pt per row for correct organism + math):
| Trophic Level | Accepted Glade Organisms | Correct Math & Energy |
|---|
| Tier 1 Producers (Base) | Willows, Cattails, Pond Algae (Given) | 20,000 kcal (Starting) |
| Tier 2 Primary Consumers | Aquatic Insects, Beavers, or Field Mice | 20,000 ÷ 10 = 2,000 kcal (0.5 pt) |
| Tier 3 Secondary Consumers | Trout, Green Frogs, or Garter Snakes | 2,000 ÷ 10 = 200 kcal (0.5 pt) |
| Tier 4 Tertiary / Apex Predator | Red-Tailed Hawk or Black Bear | 200 ÷ 10 = 20 kcal (0.5 pt) |
Analysis Rubric: Where does the remaining 90% go? (1.5 Pts) Full Credit Criteria
• Metabolic Heat Loss (0.75 pt): Most energy is transformed and radiated as body heat during cellular respiration (inefficiency of energy transfer).
• Life Processes / Biomass Loss (0.75 pt): Organisms burn energy for active locomotion (swimming, flying), reproduction, digestion, cell repair, and excretory waste (undigested material/feces).
