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Quaking in their Roots: The Decline of the Quaking Aspen

This article is from Issue Rocky Mountain - Vol. 2 No. 1.

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In recent years, populations of quaking aspen have been in decline in the Western United States. Stands of aspen are now mixed with conifer trees. Each year, fewer aspen-dominated stands exist in Utah and other parts of the Western United States. The scientists in this study wanted to know more about the decline of quaking aspen. They also wanted to know what should be done about reversing aspen decline.

Note to Educators

Education Standards Correlations

Meet the scientists that contributed to this article:

"Science Topics" covered in this article:
  • Earth Science
  • Life Science
  • People and Science

"Environmental Topics" covered in this article:
  • Forest and Grassland Use (Educators)
  • Growing and Using Trees and Other Plants (Students)
  • Importance of Forest to People (Students)
  • Protecting Trees and Other Plants (Students)
  • The Value of Forests and Grasslands (Educators)
  • Using Forests (Students)

Regions covered in this article:
  • Rocky Mountain

"Thinking About Science Themes" covered in this article:
Sometimes, a scientific question cannot be answered by direct observation, such as by an experiment or by simply observing what is going on. In these cases, scientists collect information from a variety of sources, then put the pieces together as if they were gathering and evaluating clues to a mystery. In this study, the scientists wanted to know why populations of quaking aspens are declining in the Western United States. Because it would take years to watch the growth and development of an aspen stand, the scientists tried to find clues from other sources to help them understand the aspen's decline.
Specific "Thinking About Science" Themes:
  • The Scientific Process

"Thinking About Environmental Themes" covered in this article:
Pando'" which means 'I spread' in Latin'"is the perfect name for a stand of quaking aspen, nominated a few years ago as Earth's most massive living individual. The title still stands, as far as scientists have determined. In the Wasatch Mountains of Utah (on the Fishlake National Forest '" see Figure 1), Pando weighs about 13 million pounds. He has upwards of 47,000 stems. That's 47,000 of what you and I might mistakenly perceive as separate aspen trees. Pando is a male aspen. Unlike several other tree species, individual aspen are either male or female. Quaking aspens like Pando are able to cover so much ground by an asexual reproductive process'"known as suckering'"involving tree roots. New stems rise out of the ground from the aspen's network of horizontally spreading roots. On the surface, these appear to be separate trees, but they are really part of one individual! (This information is from Earth and Sky, Monday, December 9, 1996. Visit their web site at
Specific "Thinking About the Environment" Themes:
  • Adaptation

NSE Standards covered in this article:
  • Abilities necessary to do scientific inquiry (A)
  • Diversity and adaptations of organisms (C)
  • Nature of science (G)
  • Populations and ecosystems (C)
  • Populations, resources and environments (F)
  • Regulation and behavior (C)
  • Reproduction and heredity (C)
  • Science and technology in society (F)
  • Science as a human endeavor (G)
  • Understandings about scientific inquiry (A)

Science Benchmarks covered in this article:
  • Common Themes: Constancy and Change
  • Common Themes: Systems
  • The Living Environment: Diversity of Life
  • The Living Environment: Heredity
  • The Living Environment: Interdependence of Life
  • The Nature of Mathematics: Mathematics, Science, and Technology
  • The Nature of Science: Scientific Inquiry
  • The Nature of Technology: Issues in Technology
  • The Physical Setting: Processes that Shape the Earth