Figure 2: Arrangement of experiment equipment.
From: Multi-scale comparison of the fine particle removal capacity of urban forests and wetlands

In part (A) (for the landscape scale), (a) and (b) are equipment installed for dry deposition and vegetation collection in forest and wetland, respectively; in part (B) (for the canopy scale), (c) and (d) are leeward and windward vegetation collection, respectively (diagram created using Adobe Photoshop CS5).