Comparing photographs of the same area taken over a period of years furnishes visual evidence of vegetation and soil changes. Close-up photographs and general-view photographs are both useful in documenting changes through time. Close-up photographs show the type of plants present, the soil surface characteristics and the amount of litter present. General view photographs give a broad view of the site.

Shoot the photos from the same plot each year. You may want to consider building a frame measuring one square yard and staking the frame down by the corners. Paint the stakes with bright-colored permanent spray paint to aid in relocation. Make a sign or label to place upright in the foreground of the photos to identify the site and the time of year for future comparison.

Follow the same process used in taking the initial photos each time you repeat the photo shoot. Take repeat photographs at approximately the same time of year as the original photographs. Include the same area and landmarks for easy reference.