D4.2.11—Rewilding
Rewilding restores natural ecosystem processes by reintroducing key species, improving habitat connectivity, reducing human pressure, and allowing regeneration over time.
- Syllabus
- First assessment 2025
- Objective
- D4.2.11
- Level
- HL
Rewilding Restores Ecological Processes
Rewilding aims to restore self-sustaining ecological processes by reducing intensive control and, where appropriate, returning species or habitat structure.
Large herbivores, predators or natural disturbance can rebuild trophic interactions and heterogeneity. Outcomes depend on land use, conflict and monitoring.
Evaluate the process restored, the people affected and the evidence that management can be reduced.; separate state, pressure, control loop and time
Reintroducing beavers can create wetlands that slow water, increase habitat diversity and reduce downstream flood peaks. This gives a concrete prediction from the stated ecosystem.
Rewilding is not simply abandoning land; safety, invasive species and local livelihoods still require governance. Interpret the result within the stated model and evidence limits.
Rewilding exam focus
Assessment in practice
1–2 marksHow it is assessed
This objective is assessed through structured response, commonly using Outline.
Command terms
Outline
What earns marks
Build the answer around this relationship: Rewilding often uses keystone or native species to restart ecological interactions.
Representative question
Question 1
[Maximum number: 2]
Outline two methods of restoration of natural processes in ecosystems by rewilding, other than reintroducing a keystone species.
1.
2.
a. reintroduction of top/apex predators/native species/original forms
OR
retrobreeding/ artificial breeding/selection to restore wildtype
OR
remove invasive species;
b. restore habitats/rehabilitate degraded habitats/re-establishment of connectivity of habitats over large areas (where natural ecosystems have become fragmented)/land protection/ reforesting;
c. minimize human impact / regulate/limit/reduce/eliminate human activity in the ecosystem / creation of national parks/game/natural reserve;
d. allow natural processes of regeneration and recovery;
b. Do not accept "afforestation"
2
Marking guidance:
max
Core Stability and Change
Core D4.2 is secure when students can judge whether a system is being stabilized or pushed toward change. The route is: identify the stability support or disturbance, explain the mechanism, and state the ecosystem consequence using evidence.
- energy, nutrient cycling, diversity, and tolerance ranges maintain persistence
- Amazon deforestation and keystone removal can push systems toward instability
- harvest and agriculture require recovery, soil, nutrients, biodiversity, and monitoring
- eutrophication, biomagnification, and plastics harm ecosystems through specific mechanisms
Ecosystem Stability and Human Impact
Core transfer questions ask students to explain why an ecosystem remains stable or why a disturbance pushes it toward change. Strong answers do not list threats; they explain mechanisms such as lost rainfall recycling, trophic cascade, overharvest, nutrient enrichment, toxin biomagnification, plastic movement, or restoration through rewilding.
- Use stability requirements: energy input, nutrient cycling, biodiversity, genetic diversity, and abiotic tolerance ranges.
- Explain disturbance mechanisms such as Amazon tipping points, trophic cascades, overharvesting, agricultural damage, eutrophication, biomagnification, plastics, or rewilding.
- Support claims with evidence from controlled models, monitoring, food webs, or pollution pathways.
Concept essentials
- Rewilding often uses keystone or native species to restart ecological interactions.
- Habitat restoration and connectivity are part of rewilding because natural processes need space to operate.
- Reducing human pressure can allow regeneration and recovery without intensive ongoing management.
ConceptIB Biology HL