ConceptConceptDocsDocuments

IB ESS HL 3.003.7 Rewilding Question Bank

Explain rewilding and evaluate its ecological and social consequences.

Syllabus
First assessment 2026
Course
ESS HL
Level
HL

Exam points

  • identify the conservation issue or strategy
  • apply the relevant ecological, ethical or management framework
  • evaluate evidence, trade-offs and likely outcomes

3.3.7—Rewilding question 1

[Maximum number: 2]
Beaver-dam succession sequence — panel A

Figure:Beaver-dam succession sequence — panel A

Beaver-dam succession sequence — panel B

Figure: Beaver-dam succession sequence — panel B

Beaver-dam succession sequence — panel C

Figure: Beaver-dam succession sequence — panel C

Beaver-dam succession sequence — panel D

Figure: Beaver-dam succession sequence — panel D

Figure: Fact file on North American beavers — North American beavers
• Beavers live in family groups; kits are born between April and June.
• Mortality is high because of severe weather, lack of suitable habitat and predation.
• They feed on tree bark and construct lodges from wood and mud; they remain in lodges during winter.
• Beavers are being reintroduced in Europe to help restore wetlands.

Figure: Dossier sobre la función de los castores en el ecosistema — Role of beavers in the ecosystem
• Beavers build dams from sticks, creating ponds and slowing river flow.
• Beaver ponds provide new habitats for aquatic plants, dragonfly larvae, bullfrogs and other fish, but are less suitable for river fish such as brook trout.
• Flooding may kill riverside trees and create nesting sites for birds.
• Marshy areas form at pond edges; grasses and sedges colonize nutrient-rich silt to form beaver meadow.
• Beaver meadows have more light, higher soil moisture, more nitrogen and different vegetation from adjacent river-edge forest.

Question (a)

(a)

Identify one benefit of the reintroduction of beavers in Europe.

[ 1 ]

Question (b)

(b)

Identify one potential problem with the reintroduction of beavers in Europe.

[ 1 ]
All question bank results loaded