Changes & Implications

Repeated photo pairs provide diverse and much-needed information about the physical and biological resources in Denali National Park and Preserve.  Studying the photo pairs has yielded several important insights into fundamental changes that may be underway across the park landscape.

In some cases, photos confirm what park managers already suspected to be true based on regional, national or worldwide trends.  Photo pairs featuring glaciers are a good example of this.  While scientific studies have shown that particular glaciers are thinning or retreating, the photo pairs showed many cases of this occurring, and the evidence spanned years in which no other data was available.

In other cases, managers were surprised by what they learned from the photos.  Comparing photo after photo, they noticed that floodplains and gravel bars had much more vegetation in the new photos than in the old.  This change is apparent across the park landscape, not just in one area or along one stream.  Are flow levels or flood intervals changing?  Perhaps a large flood event occurred just before the older photos were taken, and the floodplains entered a long phase of recovery?  Further research is needed to fully understand this and other phenomena, as sometimes photo pairs only tease park managers with tantalizing hints about what may be occurring.

Explore the pages within this section to better understand the process of evaluating landscape change, the categories of change observed, and what park managers and YOU can do with what has been learned!