Populus tremuloides, the Quaking Aspen or Trembling Aspen, is a deciduous tree native to cooler areas of North America, with the northern limit determined by its intolerance of permafrost. It occurs across Canada in all provinces and territories (with the possible exception of Nunavut). In the United States, it occurs at low elevations as far south as northern Nebraska and central Indiana. Farther west, it grows at high altitudes as far south as Guanajuato, Mexico. In the western United States, this tree rarely survives at elevations lower than 1,500 feet due to the mild winters experienced below that elevation, and is generally found at 5,000-12,000 feet. Image File history File linksMetadata Download high resolution version (2288x1712, 919 KB) Summary Quaking Aspens, Little Cottonwood Canyon, Salt Lake County, Utah Photo by Scott Catron, September 29, 2005 Licensing Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License... For other uses, see Scientific classification (disambiguation). ... For other uses, see Plant (disambiguation). ... Classes Magnoliopsida - Dicots Liliopsida - Monocots The flowering plants or angiosperms are the most widespread group of land plants. ... Orders See text. ... Families Family Achariaceae Family Balanopaceae Family Bonnetiaceae Family Caryocaraceae Family Chrysobalanaceae Family Clusiaceae Family Ctenolophonaceae Family Dichapetalaceae Family Elatinaceae Family Erythryloxaceae (coca family) Family Euphorbiaceae (spurge family) Family Euphroniaceae Family Goupiaceae Family Humiriaceae Family Hypericaceae (St Johns wort family) Family Irvingiaceae Family Ixonanthaceae Family Lacistemaceae Family Linaceae (flax family... Genera See text. ... This article is about woody plants of the genus Populus. ... For other uses, see Aspen (disambiguation). ... This article does not cite any references or sources. ... André Michaux (8 March 1746 – probably 11 October 1803) was a French botanist and explorer. ... The coniferous Coast Redwood, the tallest tree species on earth. ... North America North America is a continent[1] in the Earths northern hemisphere and (chiefly) western hemisphere. ... In geology, permafrost or permafrost soil is soil at or below the freezing point of water (0°C or 32°F) for two or more years. ... Motto: Nunavut Sannginivut (Inuktitut: Nunavut our strength or Our land our strength) Capital Iqaluit Largest city Iqaluit Official languages Inuktitut, Inuinnaqtun, English, French Government - Commissioner Ann Meekitjuk Hanson - Premier Paul Okalik (Consensus government) Federal representation in Canadian Parliament - House seats 1 (Nancy Karetak-Lindell) - Senate seats 1 (Willie Adams) Confederation... Official language(s) English Capital Lincoln Largest city Omaha Largest metro area Omaha Area  Ranked 16th  - Total 77,421 sq mi (200,520 km²)  - Width 210 miles (340 km)  - Length 430 miles (690 km)  - % water 0. ... Official language(s) English Capital Indianapolis Largest city Indianapolis Area  Ranked 38th  - Total 36,418 sq mi (94,321 km²)  - Width 140 miles (225 km)  - Length 270 miles (435 km)  - % water 1. ... Guanajuato is a state in the central highlands of Mexico. ...

The name references the quaking or trembling of the leaves that occurs in even a slight breeze due to the flattened petioles. Other species of Populus have petioles flattened partially along their length, while the Quaking Aspen's are flattened from side to side along the entire length of the petiole. This quaking of the leaves produces a soft sound that many consider a hallmark of the Quaking Aspen. Leaf of Dog Rose (Rosa canina), showing the petiole and two leafy stipules In botany, the petiole is the small stalk attaching the leaf blade to the stem. ...

It is a tall tree, usually 20 to 25 meters (66 to 82 feet) at maturity, with a trunk 20-80 cm diameter; records are 36.5 m height and 1.37 m diameter. The leaves on mature trees are nearly round, 4-8 cm diameter with small rounded teeth, and a 3-7 cm long, flattened petiole. Young trees (including root sprouts) have much larger (10-20 cm long), nearly triangular leaves. The flowers are catkins 4-6 cm long, produced in early spring before the leaves; it is dioecious, with male and female catkins on different trees. The fruit is a 10 cm long pendulous string of small (6 mm) capsules, each capsule containing about ten minute seeds embedded in cottony fluff, which aids wind dispersal of the seeds when they are mature in early summer. Look up foliage in Wiktionary, the free dictionary. ... Leaf of Dog Rose (Rosa canina), showing the petiole and two leafy stipules In botany, the petiole is the small stalk attaching the leaf blade to the stem. ... For other uses, see Flower (disambiguation). ... A male catkin on a willow a male flowering catkin on a willow Catkins, or aments, are slim, cylindrical flower clusters, wind-pollinated (anemophilous) and without petals, that can be found in many plant families, including Betulaceae, Fagaceae, Moraceae, and Salicaceae. ... Close-up of an Echinopsis spachiana flower, showing both carpels and stamen, making it a complete flower. ... For other uses, see Fruit (disambiguation). ... Flowers and fruit (capsules) of the ground orchid, Spathoglottis plicata. ... A ripe red jalapeño cut open to show the seeds For other uses, see Seed (disambiguation). ...

Shrublike dwarf clones exist in marginal environments too cold and dry to be hospitable to full-size trees, for example at the species' upper elevation limits in the White Mountains (California). The White Mountains along the east side of the Owens Valley The White Mountains of California are a small mountain range that runs along the eastern side of the upper Owens Valley, just across from the Sierra Nevada. ...

It propagates itself by both seed and 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 root structure. A clone may turn color earlier or later in the fall than its neighbouring aspen clones. Fall colors are usually bright tones of yellow; in some areas, red blushes may be occasionally seen. As all trees in a given clonal colony are considered part of the same organism, one clonal colony, named Pando, is considered the heaviest^[1] and oldest^[2] living organism at six million kilograms and approximately 80,000 years old. A clonal colony is a group of plants (or fungi) that have grown in a given location, all originating vegetatively, not sexually, from a given single ancestor. ... Pando (or The Trembling Giant[1]) is a clonal colony of a single male Quaking Aspen (Populus tremuloides) tree located in the U.S. state of Utah, all determined to be part of a single living organism by identical genetic markers,[2] and one massive underground root system. ...

The leaves of the Quaking Aspen serve as food for caterpillars of various Lepidoptera. See List of Lepidoptera which feed on poplars. This article is about a form of an insect. ... The order Lepidoptera is the second most speciose order in the class Insecta and includes the butterflies, moths and skippers. ... Poplars (Populus spp) are used as food plants by the larvae of a large number of Lepidoptera species: Monophagous species which feed exclusively on Populus Bucculatrix staintonella Figure of Eighty (Tethea ocularis) Polyphagous species which feed on Populus among other plants Autumnal Moth (Epirrita autumnata) The Brick (Agrochola circellaris) Brown...

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 often attributed to cattle grazing. At high altitudes where grasses can be rare, cattle browse young Aspen sprouts and prevent those young trees from reaching maturity. In these cases, the cattle jeopardize the health of the stand. As a result, some Aspen groves in close proximity to cattle grazing allotments have a very few young trees and are invaded by conifers, which the cattle will not browse. Eventually, the coniferous trees outcompete the Aspen because of a lack of new recruitment, often outcompeting grasses as well.

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 [1].

References

• US Forest Service Silvics Manual: Populus tremuloides
• US Forest Service Fire Effects Information System: Populus tremuloides
• Populus tremuloides (TSN 195773). Integrated Taxonomic Information System. Accessed on 8 August 2006.
• Farrar, John Laird. Trees In Canada. Fitzhenry and Whiteside, 1995
• Hickman, James C., ed. The Jepson Manual: Higher Plants of California, 0520082559. University of California Press, 1993.