Primary Succession following Glacial Recession:
Vadret da Morteratsch glacier

Google Maps - Search for "Vadret da Morteratsch" and zoom in to see the Vadret da Morteratsch glacier, tagged "A".

Click the illustration below to take a virtual tour of the Vadret da Morteratsch glacier: QTVR panoramas

Visit the site at the tongue of the glacier and look at the view down the stream, at the sides of the valley, and back up toward the glacier.  From this perspective, observe the rock and gravel substrate left after the glacier had melted away from the area just downstream of the glacier.  Note the pioneer vegetation starting to colonize the area up the slope to the left and downstream from the glacier. Selecting a site or two overlooking the glacier further up the valley will give you a better perspective of the glacier and the valley it has cut out of the mountains.

Once you have your bearings, investigate the changes in vegetation in the valley below the glacier over the last 110 years.

Photographs of the vegetation in the valley taken from the perspective of the frontal positions of the glacier over the last 110 years document the process of primary succession.

• Start by comparing the changes that occurred between 1996 and 2007.

• Next look at a longer time period between 1985 and 2007




• Observe the series of pictures taken in 1985 and 2002 from the perspectives of the frontal positions in:  (Succession of vegetation in the glacier forefield)

  1970 --
  

  1960 --
  
  1950 --
  
  1940 --
  
  1920 --
  
  and 1900
  

  Each set of photos illustrates the changes in vegetation that have occurred since the glacial front was at that position until 1985 and then on to 2002.

  For instance, in the two photos taken from the location of the 1970 frontal position, the top picture taken in 1985 represents 15 years of vegetation change since the ice melted from that position.  The bottom photo from 2002 allows you to see the changes that occurred over the next 17 years since 1985.  In the photo from 2002 you see a total of 32 years of successional change.
  

• Piece together the vegetative changes that have occurred in the valley as the glacier has receded over the past 110 years.  Remember that primary succession begins with NO organic soil present.  Here, the substrate is rock and gravel left behind by the glacier.
  

These animations will help with the basic concepts of successional change:


Animation of primary succession following glacial retreat.

Glacier Primary succession animation

Primary and Secondary succession graphics - narrated


• Finally, return to Google Maps, search for "Vadret da Morteratsch", and zoom in to see the Vadret da Morteratsch glacier, tagged "A".

Zoom in just about as tight as possible and follow the trail leading downstream from the glacier and see if you can find the changes in vegetation you observed in the photographs above.

Be prepared to share your findings with your classmates.