Sampling design fundamentals
Quadrats standardize area sampled (e.g., 1 m²). Transects are lines along which quadrats or point intercepts are placed at regular intervals.
Random vs stratified sampling
Random placement reduces bias. Stratified design divides habitat into zones (wet vs dry) and samples each proportionally — better for heterogeneous sites.
Data recorded per quadrat
- Species list and count or percent cover
- Maximum height or basal area for shrubs
- Presence of seedlings vs mature individuals
- GPS coordinates and photo documentation
Replication
Minimum 10–30 quadrats per habitat type for statistical power depending on variability.