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Engelmann spruce seed production is influenced by climate

Date: August 26, 2019

Seed production may be moderately enhanced by current climate trends, but some evidence indicates that seed production will be constrained by threshold high temperatures in the future


picture of a seed trap used to capture englemann spruce seeds for monitoring seed production.
Seeds are captured in this seed trap and collected annually to monitor seed production in this long-term research study. Photo Credit: Mike Battaglia. Taken July 2019
Tree regeneration is an important process to helps perpetuate a forest. Understanding the frequency of seed production as well as the climatic conditions that promote seed production are important to the management of forests and natural regeneration.  

Thirteen permanent research plots were established along an elevational gradient on a range of aspects, slopes, and site productivities on the Fraser Experimental Forest in central Colorado. Trees greater than 10 cm diameter at breast height has been measured periodically over the last 50 years. Seed traps were installed at the beginning of the study in 1968 and have been collected annually since then. In 2011, tree cores were sampled to examine the relationship between climate and seed production.

  • Engelmann spruce seed production is highly variable over time.
  • Climatic conditions across multiple years influence seed production.
  • High seed rain is associated with elevated summer temperatures in the year that seeds are dispersed, low spring snowfall in the year preceding seed dispersal when buds are initiated, and reduced spring snowfall in a so-called priming year two years prior to seed dispersal.
  • Seed production may be moderately enhanced by current climate trends, but some evidence indicates that seed production will be constrained by threshold high temperatures in the future.

Featured Publications

Buechling, Arne ; Martin, Patrick H. ; Canham, Charles D. ; Shepperd, Wayne D. ; Battaglia, Mike A. , 2016


Principal Investigators: 
Principal Investigators - External: 
Arne Buechling - Colorado State Univeristy
Patrick Martin - Colorado State Univeristy
Research Location: 
Fraser Experimental Forest, Colorado