Environmental Systems and Societies · Topic 2: Ecology

ES2.5 — Zonation, succession and change in ecosystems

Environmental Systems and Societies · SL / HL · syllabus-mapped notes

1. Zonation along environmental gradients

   Zonation as spatial change in community, and using transects and kite diagrams to link species distribution to abiotic variables.

2. Succession: seres, primary and secondary

   Succession as change over time, how each seral community makes way for the next, and named primary and secondary examples.

3. Change through succession: diversity and resilience

   How energy flow, productivity, diversity, soil and nutrient cycling shift over succession, and how diversity underpins resilience and stability.

4. HL: Controls on succession and productivity

   Climatic, geological and top-down controls on the final community, how GP and NP change through succession, and r- and K-strategists.

5. HL: Challenging the climax community

   The contested idea of a single natural climax, the Vera hypothesis and alternative stable states, and human-driven plagioclimax.