1.2.7—System scales
- Syllabus
- First assessment 2026
- Objective
- 1.2.7
- Level
- HL
Choose the Boundary Before the Scale
A system’s scale depends on the boundary chosen: a bromeliad, rainforest and atmosphere can each be studied as systems with different components and flows.
Changing scale changes what is inside the boundary and which flows matter. Size alone does not decide complexity; interactions do.
A bromeliad pool contains water, insects and microbes locally; the rainforest boundary adds many communities and nutrient flows.
The boundary changed; at the small plot it crosses in, while at the catchment it may be stored or transferred inside.
A smaller system is not automatically simpler or less important.