Figure 1: Sampling strategy with nested design.
From: Temperature mediates continental-scale diversity of microbes in forest soils

Samples were taken from six forest sites from North America. At each site, 21 nested samples were collected at distance of 1, 10, 50, 100 and 250 m. At each sample point (1 × 1 m), nine soil cores were collected and composited for microbial and soil analysis.