Food Web Complexity & Stability
Name: Period: Date:
1.Energy flows through (lost as heat); matter cycles
2.Pyramids can be disrupted by invasives, disease, or climate
3.Ecosystem Resilience: Biodiversity provides functional redundancy — when multiple species fill similar roles, the loss of one is buffered by others. Monocultures and low-diversity systems are fragile because a single disruption can cascade through the entire ecosystem.
REF STUDY GUIDE: Big Ideas Use to answer form questions
1.Complex food webs are more stable. More connections = more pathways for energy flow when one species disappears.
2.Redundancy provides insurance. Multiple species filling similar roles means backup when one fails.
3.Biodiversity enables resilience. Diverse ecosystems recover faster from disturbances than simple ones.
SIMPLE WEB (Low Biodiversity)
Few species, few connections
Remove one = collapse
COMPLEX WEB (High Biodiversity)
Many species, many connections
Remove one = others compensate
REDUNDANCY = INSURANCE: More pathways means the system survives disturbance
DRAW KEY TERMS Google each → Images tab → sketch what you see
Biodiversity
Variety of species in ecosystem
Resilience
Ability to recover from disturbance
Redundancy
Multiple species fill same role
Ecosystem stability
Resistance to change over time
WRITE FOCUS QUESTION Your initial thinking
Why can some ecosystems survive disturbance but others collapse?
Texas 2011 drought: 300 million trees died. Some grassland ecosystems recovered within 2 years; others are still struggling 10+ years later. Same drought, same region—why such different outcomes?
I think the difference is...
WRITE AFTER HOOK FORM Reflect before continuing
I learned that ecosystems with more biodiversity...
Station 1 — Web Complexity
Complex webs survive disturbance because...
Simple webs are vulnerable because...
This explains the phenomenon because...
Station 1 — Web Complexity
CHECKPOINT: complex web = many species + many connections = stable
Complex webs survive disturbance because...
Simple webs are vulnerable because...
This explains the phenomenon because...
Station 2 — Ecosystem Resilience
Redundancy helps ecosystems because...
Texas ecosystems that recovered had...
This connects to the 10% rule (W1) because...
CHECK DAY 1 CHECK-IN Before you leave
Q1: Predict: Ecosystem A has 50 species; Ecosystem B has 10. Which recovers faster from drought? Why?
Q2: How do invasive species (W2) reduce ecosystem stability? (Hint: What happens to redundancy?)
Confidence:
NGSS: MS-LS2-4 Page 1 of 2 | Day 1 v4.3
Food Web Complexity & Stability (Day 2)
Name:
Station 2 — Ecosystem Resilience
Redundancy helps ecosystems because...
Texas ecosystems that recovered had...
This connects to the 10% rule (W1) because...
Station 3 — Design a Resilient Ecosystem
CHECKPOINT: monoculture = single crop = low biodiversity = high risk
Monocultures (like farms) are risky because...
The Irish Potato Famine happened because...
Conservation efforts focus on biodiversity because...
DRAW YOUR FOOD WEB MODEL Complete before exit
Model a stable food web showing: (1) At least 3 trophic levels, (2) Multiple species at each level, (3) Redundant connections. Use arrows for energy flow, labels for species.
Include: Producers (plants) Primary consumers Secondary consumers Arrows showing energy Redundant connections
CHECK TEST YOUR THINKING Rate each: FALSE ← 1–2–3–4–5 → TRUE
1. Removing one species from a food web won't affect others.
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2. Complex food webs with many species are generally more stable than simple ones.
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3. All ecosystems can fully recover from any disturbance.
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4. When multiple species can perform the same role, ecosystems are more resilient.
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5. Only top predators are important for ecosystem stability.
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Defend TWO of your ratings - what do you know that you know?
Statement #__: I rated this ___ because...
Statement #__: I rated this ___ because...
SCIENCE CIRCLE: Bring worksheet. Share ratings, defend them. Talk only—no writing!
WRITE ANSWER THE FOCUS QUESTION After Science Circle
Why can some ecosystems survive disturbance but others collapse?
My "Aha!" Moment
I now understand that...
Still Wondering
I'm still wondering...
Ecosystems that survive disturbance have...
Ecosystems that collapse lack...
The key role of redundancy is...
NGSS: MS-LS2-4 Page 2 of 2 | Day 2 v4.3