As the saying goes, “a picture is worth a thousand words.” While this may be true, remember that appearances can also be deceptive! Although the repeat photo pairs provide dramatic evidence of recent change, scientists are unable to determine causes or effects of these changes without obtaining more information. Despite this fact, the abundance of photo pairs and variety of land forms over which they span allow researchers to make generalizations about changes that may be occurring in the park as a whole, and help them design more detailed studies to pursue in the future.
The main challenge for scientists attempting to detect change in ecological systems is that they must sort out which changes are natural, and which are unexpected and thus possibly attributable to human factors. For help in understanding this concept, click below to explore limitations of photo pairs and the importance of additional scientific inquiry.
Or continue on to Observed Patterns of Change…