History of the Colorado Aspens

Every year about this time, Fall is ushered in by a flush of Aspen trees as their leaves turn to gold. Where I live in the Rocky Mountains of Colorado, the particular aspen is called the “trembling” or quaking aspen. The broadleaf and the flattened stem cause them to flutter in the breeze. It is a type of poplar tree called populus tremuloides. As tourists visit New England in Autumn for Leaves and Lobsters, visitors come to Colorado to Leaf Peep as the aspens change to dramatic yellows, golds, and reds.

The change in color occurs first at the highest altitudes. For example, at 9,800 feet, the aspens “peaked” their color change and the leaves begin to fall this year earlier in September. Where I live at 6500 feet, the edges of the aspen leaves are just beginning to turn from green to gold. At this time of the year, the production of chlorophyll which gives the leaf its green pigment slows to a standstill, and the yellow, orange, and red pigments of carotenoids and anthocyanins show in the leaf.

Send in the Clones

Aspens are unusual in that they grow in large communal groves or more specifically clonal colonies. These form from a single seedling. They spread…