Fading Gold: The Decline of Aspen in the West ~ 1990 US Forest Service (USDA-USFS)

more at http://quickfound.net/

'Fading Gold: The Decline of Aspen in the West... from the Rocky Mountain Research Station. The species has declined across the West from 9 million acres to less than 4 million acres today. For every acre of aspen lost, so is a prime source of water, a productive habitat for wildlife, a valuable source of livestock forage, and one of our most scenic treasures.'

Originally a public domain film from the National Archives, slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.

The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).

https://en.wikipedia.org/wiki/Populus_tremuloides

Wikipedia license: http://creativecommons.org/licenses/by-sa/3.0/

Populus tremuloides is a deciduous tree native to cooler areas of North America, one of several species referred to by the common name aspen. It is commonly called quaking aspen, trembling aspen, American aspen, Quakies, mountain or golden aspen, trembling poplar, white poplar, popple, as well as others. The trees have tall trunks, up to 25 meters (82 feet) tall, with smooth pale bark, scarred with black. The glossy green leaves, dull beneath, become golden to yellow, rarely red, in autumn. The species often propagates through its roots to form large clonal groves originating from a shared root system. These roots are not rhizomes, as new growth develops from adventitious buds on the parent root system (the ortet).

Populus tremuloides is the most widely distributed tree in North America, being found from Canada to central Mexico. It is the defining species of the aspen parkland biome in the Prairie Provinces of Canada and extreme northwest Minnesota.

The Quaking Aspen is the state tree of Utah...

Quaking aspen propagates itself primarily through root sprouts, and extensive clonal colonies are common. Each colony is its own clone, and all trees in the clone have identical characteristics and share a single root structure... As all trees in a given clonal colony are considered part of the same organism, one clonal colony, named Pando, is considered the heaviest and oldest living organism at six million kilograms and perhaps 80,000 years old. Aspens do produce seeds, but seldom grow from them. Pollination is inhibited by the fact that aspens are either male or female, and large stands are usually all clones of the same sex. Even if pollinated, the small seeds (three million per pound) are only viable a short time as they lack a stored food source or a protective coating.

Dieback

Beginning in 1996, individual North American scientists noticed an increase in dead or dying aspen trees. As this accelerated in 2004, word spread and a debate over causes began. No insect, disease, or environmental condition is yet specifically identified as a joint cause. Trees adjacent to one another are often stricken or not. In other instances, entire groves have died.

Many areas of the Western US have experienced increased diebacks which are often attributed to ungulate grazing and wildfire suppression. At high altitudes where grasses can be rare, ungulates can browse young aspen sprouts and prevent those young trees from reaching maturity. As a result, some aspen groves close to cattle or other grazing animals, such as deer or elk, have very few young trees and can be invaded by conifers, which are not typically browsed. Another possible deterrent to aspen regeneration is widespread wildfire suppression. Aspens are vigorous resprouters and even though the above-ground portion of the organism may die in a wild-fire, the roots, which are often protected from lethal temperatures during a fire, will sprout new trees soon after a fire. Disturbances such as fires seem to be a necessary ecological event in order for aspens to compete with conifers, which tend to replace aspen over long, disturbance-free intervals. The current dieback in the American West may have roots in the strict fire suppression policy in the United States. On the other hand, the widespread decimation of conifer forests by the mountain pine beetle may provide increased opportunities for aspen groves to proliferate under the right conditions.

Because of the vegetative regeneration method of reproduction used by the aspen, where an entire group of trees are essentially clones, there is a concern that something that hits one will eventually kill all of the trees, presuming they share the same vulnerability. A conference was held in Utah in September 2006 to share notes and consider investigative methodology...