Repeat Photography for Nature Conservation
Comparisons of repeated photographs show changes of interest for nature conservation. Photographs show changes in vegetation (Turner et al 2003), glaciers (Tarr and Martin 1914), sand dunes (Haynes 1980), details of plant growth (Crimmins and Crimmins 2008), and small changes in land surface features (Trimble and Lund 1982). Photographs are easy to repeat, making them one of the most economical means to observe change.
GarryRogers Nature Conservation 