The study area for the ecological example – Acadia National Park, Maine, USA. Upper panel is the view towards the Atlantic Ocean from the top of Cadillac Mountain, the highest point in the Park. Panel A  is from an area where human disturbance of the watershed is minor, while Panel B is from an area with intense human disturbance (sewage treatment facility). Panel C is a map of the Park showing variation in human disturbance intensity (HDI) for the wetlands sampled. Photographs by the author. Map produced by Kathryn Miller, US National Park Service.