Populus tremuloides

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Quaking aspen
2013-10-06 15 04 21 Aspens during autumn along the Changing Canyon Nature Trail in Lamoille Canyon, Nevada.jpg
Quaking aspen grove in Lamoille Canyon, Nevada, U.S.
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Malpighiales
Family: Salicaceae
Genus: Populus
Section: Populus sect. Populus
P. tremuloides
Binomial name
Populus tremuloides
Populus tremuloides range map 2.png

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, [1] [2] [3] trembling aspen, [1] [2] American aspen, [2] Quakies, [1] mountain or golden aspen, [4] trembling poplar, [4] white poplar, [4] popple, [4] as well as others. [4] 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).

Deciduous trees or shrubs that lose their leaves seasonally

In the fields of horticulture and botany, the term deciduous (/dɪˈsɪdʒuəs/) means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, after flowering; and to the shedding of ripe fruit.

North America Continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere

North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere; it is also considered by some to be a northern subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea.

Aspen common name for certain tree species

Aspen is a common name for certain tree species; some, but not all, are classified by botanists in the section Populus, of the Populus genus.


Populus tremuloides is the most widely distributed tree in North America, being found from Canada to central Mexico. [3] [5] It is the defining species of the aspen parkland biome in the Prairie Provinces of Canada and extreme northwest Minnesota.

Aspen parkland vegetation zone

Aspen parkland refers to a very large area of transitional biome between prairie and boreal forest in two sections, namely the Peace River Country of northwestern Alberta crossing the border into British Columbia, and a much larger area stretching from central Alberta, all across central Saskatchewan to south central Manitoba and continuing into small parts of the US states of Minnesota and North Dakota. Aspen parkland consists of groves of aspen poplars and spruce interspersed with areas of prairie grasslands, also intersected by large stream and river valleys lined with aspen-spruce forests and dense shrubbery. This is the largest boreal-grassland transition zone in the world and is a zone of constant competition and tension as prairie and woodlands struggle to overtake each other within the parkland.

Biome Distinct biological communities that have formed in response to a shared physical climate

A biome is a community of plants and animals that have common characteristics for the environment they exist in. They can be found over a range of continents. Biomes are distinct biological communities that have formed in response to a shared physical climate. "Biome" is a broader term than "habitat"; any biome can comprise a variety of habitats.

Minnesota State of the United States of America

Minnesota is a state in the Upper Midwest, Great Lakes, and northern regions of the United States. Minnesota was admitted as the 32nd U.S. state on May 11, 1858, created from the eastern half of the Minnesota Territory. The state has a large number of lakes, and is known by the slogan the "Land of 10,000 Lakes". Its official motto is L'Étoile du Nord.

The Quaking Aspen is the state tree of Utah. [6]


The quaking or trembling of the leaves that is referred to in the common names is due to the flexible flattened petioles. The specific epithet, tremuloides, evokes this trembling behavior and can be literally translated as "like (Populus) tremula", the European trembling aspen.

Petiole (botany)

In botany, the petiole is the stalk that attaches the leaf blade to the stem. Outgrowths appearing on each side of the petiole in some species are called stipules. Leaves lacking a petiole are called sessile or epetiolate.

<i>Populus tremula</i> species of plant

Populus tremula, commonly called aspen, common aspen, Eurasian aspen, European aspen, or quaking aspen, is a species of poplar native to cool temperate regions of Europe and Asia, from Iceland and the British Isles east to Kamchatka, north to inside the Arctic Circle in Scandinavia and northern Russia, and south to central Spain, Turkey, the Tian Shan, North Korea, and northern Japan. It also occurs at one site in northwest Africa in Algeria. In the south of its range, it occurs at high altitudes in mountains.


Aspen catkins in spring 2015-03-16 12 22 15 Aspen catkins on Idaho Street (Interstate 80 Business) in Elko, Nevada.JPG
Aspen catkins in spring

Quaking aspen is a tall, fast growing tree, usually 20–25 m (65–80 ft) at maturity, with a trunk 20 to 80 cm (8 inches to 2 feet 7 inches) in diameter; records are 36.5 m (119 ft 9 in) in height and 1.37 m (4 ft 6 in) in diameter.

The bark is relatively smooth, colored greenish-white to gray, and is marked by thick black horizontal scars and prominent black knots. Parallel vertical scars are tell-tale signs of elk, which strip off aspen bark with their front teeth.

The leaves on mature trees are nearly round, 4–8 centimeters (1 123 14 inches) in diameter with small rounded teeth, and a 3–7-centimeter (1 142 34-inch) long, flattened petiole. Young trees and root sprouts have much larger (10–20 centimeters, 4–8 in long) nearly triangular leaves.

Some species of Populus have petioles flattened partially along their length, while the aspens and some other poplars have them flattened from side to side along the entire length of the petiole.

Aspens are dioecious, with separate male and female clones. The flowers are catkins 4–6 centimeters (1 122 14 in) long, produced in early spring before the leaves; The fruit is a 10-centimeter-long (4-inch) pendulous string of 6-millimeter (14-inch) 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.


Quaking aspen occurs across Canada in all provinces and territories, with the possible exception of Nunavut. In the United States, it can be found as far north as the northern foothills of the Brooks Range in Alaska, where road margins and gravel pads provide islands of well-drained habitat in a region where soils are often waterlogged due to underlying permafrost. [7] It occurs at low elevations as far south as northern Nebraska and central Indiana. In the western United States, this tree rarely survives at elevations lower than 1,500 feet (460 m) due to hot summers experienced below that elevation, and is generally found at 5,000–12,000 feet (1,500–3,700 m). It grows at high altitudes as far south as Guanajuato, Mexico.

Canada Country in North America

Canada is a country in the northern part of North America. Its ten provinces and three territories extend from the Atlantic to the Pacific and northward into the Arctic Ocean, covering 9.98 million square kilometres, making it the world's second-largest country by total area. Canada's southern border with the United States, stretching some 8,891 kilometres (5,525 mi), is the world's longest bi-national land border. Its capital is Ottawa, and its three largest metropolitan areas are Toronto, Montreal, and Vancouver. As a whole, Canada is sparsely populated, the majority of its land area being dominated by forest and tundra. Consequently, its population is highly urbanized, with over 80 percent of its inhabitants concentrated in large and medium-sized cities, with 70% of citizens residing within 100 kilometres (62 mi) of the southern border. Canada's climate varies widely across its vast area, ranging from arctic weather in the north, to hot summers in the southern regions, with four distinct seasons.

Nunavut Territory of Canada

Nunavut is the newest, largest, and most northerly territory of Canada. It was separated officially from the Northwest Territories on April 1, 1999, via the Nunavut Act and the Nunavut Land Claims Agreement Act, though the boundaries had been drawn in 1993. The creation of Nunavut resulted in the first major change to Canada's political map since incorporating the province of Newfoundland in 1949.

United States Federal republic in North America

The United States of America (USA), commonly known as the United States or America, is a country comprising 50 states, a federal district, five major self-governing territories, and various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is slightly smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U.S. is the third most populous country. The capital is Washington, D.C., and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico. The State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean. The U.S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The extremely diverse geography, climate, and wildlife of the United States make it one of the world's 17 megadiverse countries.

Quaking aspen grows in a wide variety of climatic conditions. January and July average temperatures range from −30 °C (−22 °F) and 16 °C (61 °F) in the Alaska Interior to −3 °C (27 °F) and 23 °C (73 °F) in Fort Wayne, Indiana. Average annual precipitation ranges from 1,020 mm (40 inches) in Gander, Newfoundland and Labrador to as little as 180 mm (7.1 inches) in the Alaska Interior. The southern limit of the species' range roughly follows the 24 °C (75 °F) mean July isotherm. [3]

Fort Wayne, Indiana City in Indiana

Fort Wayne is a city in the U.S. state of Indiana and the seat of Allen County, United States. Located in northeastern Indiana, the city is 18 miles (29 km) west of the Ohio border and 50 miles (80 km) south of the Michigan border. With a population of 253,691 in the 2010 census, it is the second-most populous city in Indiana after Indianapolis, and the 75th-most populous city in the United States. It is the principal city of the Fort Wayne metropolitan area, consisting of Allen, Wells, and Whitley counties, a combined population of 419,453 as of 2011. Fort Wayne is the cultural and economic center of northeastern Indiana. The city is within a 300-mile radius of major population centers, including Chicago, Cincinnati, Cleveland, Columbus, Detroit, Indianapolis, Louisville, Lexington, and Milwaukee. In addition to the three core counties, the combined statistical area (CSA) includes Adams, DeKalb, Huntington, Noble, and Steuben counties, with an estimated population of 615,077.

Gander, Newfoundland and Labrador Town in Newfoundland and Labrador, Canada

Gander is a town located in the northeastern part of the island of Newfoundland in the province of Newfoundland and Labrador, approximately 40 kilometres (25 mi) south of Gander Bay, 100 km (62 mi) south of Twillingate and 90 km (56 mi) east of Grand Falls-Windsor. Located on the northeastern shore of Gander Lake, it is the site of Gander International Airport, once an important refuelling stop for transatlantic aircraft, and still a preferred emergency landing point for aircraft facing on-board medical or security issues.

Shrub-like 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.

White Mountains (California) mountain range in California, USA

The White Mountains of California and Nevada are a triangular fault-block mountain range facing the Sierra Nevada across the upper Owens Valley. They extend for approximately 60 mi (97 km) as a greatly elevated plateau about 20 mi (32 km) wide on the south, narrowing to a point at the north, with elevations generally increasing south to north. The range's broad southern end is near the community of Big Pine, where Westgard Pass and Deep Springs Valley separate it from the Inyo Mountains. The narrow northern end is at Montgomery Pass, where U.S. Route 6 crosses. The Fish Lake Valley lies east of the range; the southeast part of the mountains are separated from the Silver Peak Range by block faulting across the Furnace Creek Fault Zone, forming a feeder valley to Fish Lake Valley. The range lies within the eastern section of the Inyo National Forest.

Trembling aspen at sunset Reflection of tree.JPG
Trembling aspen at sunset


Individual clonal colonies can be discerned during the autumn, as seen on this mountainside in the Matanuska Valley in Alaska. Quakingfallcolors.JPG
Individual clonal colonies can be discerned during the autumn, as seen on this mountainside in the Matanuska Valley in Alaska.

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. 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 [8] and oldest [1] 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. [9]


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. [10] 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. [11]

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. [12]

Typical yellow autumn foliage Populus tremuloides 8163.jpg
Typical yellow autumn foliage
Atypical orange and red autumn foliage 2014-10-05 14 33 30 Aspens showing autumn foliage coloration in Lamoille Canyon, Nevada.JPG
Atypical orange and red autumn foliage


Aspen bark contains a substance that was extracted by indigenous North Americans and European settlers of the western U.S. as a quinine substitute. [9]

Like other poplars, aspens make poor fuel wood, as they dry slowly, rot quickly, and do not give off much heat. Yet they are still widely used in campgrounds because they are cheap and plentiful and not widely used in building lumber. Pioneers in the North American west used them to create log cabins and dugouts, though they were not the preferred species.

The leaves of the quaking aspen and other species in the genus Populus serve as food for caterpillars of various moths and butterflies. See List of Lepidoptera that feed on poplars.

In Canada, quaking aspen wood is used mainly for pulp products such as books, newsprint, and fine printing paper. It is especially good for panel products such as oriented strand board and waferboard. It is light in weight and is used for furniture, boxes and crates, core stock in plywood, and wall panels.

Related Research Articles

<i>Populus sect. Populus</i> section of plants

Populus section Populus, of the Populus (poplar) genus, includes the aspen trees and the white poplar Populus alba. The five typical aspens are all native to cold regions with cool summers, in the north of the Northern Hemisphere, extending south at high altitudes in the mountains. The White Poplar, by contrast, is native to warmer regions, with hot, dry summers. These trees are all medium-sized deciduous trees ranging 15–30 metres (49–98 ft) tall.

<i>Populus sect. Aigeiros</i> section of plants

Populus section Aigeiros is a section of three species in the genus Populus, the poplars. Like some other species in the genus Populus, they are commonly known as cottonwoods. The species are native to North America, Europe, and western Asia. In the past, as many as six species were recognized, but recent trends have been to accept just three species, treating the others as subspecies of P. deltoides.

Clonal colony

A clonal colony or genet is a group of genetically identical individuals, such as plants, fungi, or bacteria, that have grown in a given location, all originating vegetatively, not sexually, from a single ancestor. In plants, an individual in such a population is referred to as a ramet. In fungi, "individuals" typically refers to the visible fruiting bodies or mushrooms that develop from a common mycelium which, although spread over a large area, is otherwise hidden in the soil. Clonal colonies are common in many plant species. Although many plants reproduce sexually through the production of seed, reproduction occurs by underground stolons or rhizomes in some plants. Above ground, these plants most often appear to be distinct individuals, but underground they remain interconnected and are all clones of the same plant. However, it is not always easy to recognize a clonal colony especially if it spreads underground and is also sexually reproducing.

<i>Larix laricina</i> species of plant

Larix laricina, commonly known as the tamarack, hackmatack, eastern larch, black larch, red larch, or American larch, is a species of larch native to Canada, from eastern Yukon and Inuvik, Northwest Territories east to Newfoundland, and also south into the upper northeastern United States from Minnesota to Cranesville Swamp, West Virginia; there is also an isolated population in central Alaska. The word tamarack is an Algonquian name for the species and means "wood used for snowshoes".

<i>Populus sect. Tacamahaca</i> section of plants

The balsam poplars are a group of about 10 species of poplars, indigenous to North America and eastern Asia, distinguished by the balsam scent of their buds, the whitish undersides of their leaves, and the leaf petiole being round in cross-section. They are large deciduous trees, 30–60 m tall, with leaves with a rounded base, pointed apex, and a whitish waxy coating on the underside of the leaf; this latter distinguishes them from most other poplars. The name is derived from the pleasant balsam smell of the opening buds and leaves in spring, produced by a sticky gum on the buds which also helps protect the buds from insect damage. The balsam poplars are light-demanding trees that require considerable moisture. Poplars are tolerant of very cold conditions, occurring further north than other poplars except for the aspens. The poplars in Southern California are tolerant of 100 plus degree heat. They grow along dry washes and dry riverbed‘s. The dry washes and dry riverbeds will have flowing water when it rains sufficiently. Their leaves hang down and are at an edge to the sun. This may be another factor why they can take the high heat. Their leaves tremble in the slightest breeze like the quaking aspen

<i>Populus alba</i> Species of plant of the genus Populus

Populus alba, commonly called abele, silver poplar, silverleaf poplar, or white poplar, is a species of poplar, most closely related to the aspens. It is native to Morocco and the Iberian Peninsula through central Europe to central Asia. It grows in moist sites, often by watersides, in regions with hot summers and cold to mild winters.

<i>Populus deltoides</i> species of plant

Populus deltoides, the eastern cottonwood or necklace poplar, is a cottonwood poplar native to North America, growing throughout the eastern, central, and southwestern United States, the southernmost part of eastern Canada, and northeastern Mexico.

<i>Melampsora medusae</i> species of fungus

Melampsora medusae is a fungal pathogen, causing a disease of woody plants. The infected trees' leaves turn yellowish-orange. The disease affects mostly conifers, e.g. the Douglas-fir, western larch, tamarack, ponderosa, and lodgepole pine trees, but also some broadleaves, e.g. trembling aspen and poplars. Coniferous hosts are affected in late spring through early August, and trembling aspens and poplars from early summer to late fall. It is one of only two foliage rusts that occur naturally in British Columbia.

Rocky Mountain ponderosa pine forest

The Rocky Mountain ponderosa pine forest is a forest plant community at an elevation of 2,100–2,700 metres (6,900–8,900 ft) in the Rocky Mountains, in the U.S. state of Colorado. It is an important temperate coniferous forest ecoregion, including some endemic wildlife and grass species that are only found in this ponderosa pine habitat.

<i>Quercus ilicifolia</i> small shrubby oak

Quercus ilicifolia, commonly known as bear oak or scrub oak, is a small shrubby oak native to the eastern United States and southeastern Canada. Its range extends in the United States from Maine to North Carolina, with reports of a few populations north of the international frontier in Ontario. The name ilicifolia means "holly-leaved."

<i>Populus grandidentata</i> species of plant

Populus grandidentata, commonly called large-tooth aspen, big-tooth aspen, American aspen, or white poplar, is a deciduous tree native to eastern North America.

Pando (tree) extremely old, large tree; a clonal colony forming one interconnected root system

Pando, also known as the trembling giant, is a clonal colony of an individual male quaking aspen determined to be a single living organism by identical genetic markers and assumed to have one massive underground root system. The plant is located in the Fremont River Ranger District of the Fishlake National Forest at the western edge of the Colorado Plateau in south-central Utah, United States, around 1 mile (1.6 km) southwest of Fish Lake. Pando occupies 43 hectares and is estimated to weigh collectively 6,000,000 kilograms, making it the heaviest known organism,. The root system of Pando, at an estimated 80,000 years old, is among the oldest known living organisms.

Coniferous swamp

Coniferous swamps are forested wetlands in which the dominant trees are lowland conifers such as northern white cedar. The soil in these swamp areas is typically saturated for most of the growing season and is occasionally inundated by seasonal storms or by winter snow melt.

Cook Inlet taiga

The Cook Inlet taiga ecoregion, in the Taiga and Boreal forests Biome, is located in Alaska.

<i>Phyllocnistis populiella</i> species of insect

The common aspen leaf miner or aspen serpentine leafminer is a moth of the family Gracillariidae. It is found in northern North America, including Alberta, Massachusetts, Ontario and Alaska.


  1. 1 2 3 4 Quaking Aspen by the Bryce Canyon National Park Service
  2. 1 2 3 "Populus tremuloides". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA).
  3. 1 2 3 Perala, D. A. (1990). "Populus tremuloides". In Burns, Russell M.; Honkala, Barbara H. Hardwoods. Silvics of North America. Washington, D.C.: United States Forest Service (USFS), United States Department of Agriculture (USDA). 2 via Southern Research Station (www.srs.fs.fed.us).
  4. 1 2 3 4 5 "technology transfer fact sheet: Populus spp" (PDF). Forest Products Laboratory: R&D USDA. Madison, Wisconsin: United States Department of Agriculture Forest Service, Center for Wood Anatomy Research. Retrieved 20 September 2010.
  5. "Aspen, Quaking (Populus tremuloides)". Arbor Day Foundation.
  6. "S.B. 41 State Tree Change". Utah State Legislature.
  7. Ackerman, Daniel; Breen, Amy (2016-06-06). "Infrastructure Development Accelerates Range Expansion of Trembling Aspen ( Populus tremuloides, Salicaceae) into the Arctic". ARCTIC. 69 (2): 130–136. doi:10.14430/arctic4560. ISSN   1923-1245.
  8. Genetic Variation and the Natural History of Quaking Aspen, Jeffry B. Mitton; Michael C. Grant, BioScience, Vol. 46, No. 1. (Jan., 1996), pp. 25-31.
  9. 1 2 Ewing, Susan. The Great Alaska Nature Factbook. Portland: Alaska Northwest Books, 1996.
  10. Haskins; et al. (2007). "Impact of fire suppression on aspen populations". Forestry and Wildlife Management. 19 (3): 54–57.
  11. Pelz, Kristen A.; Smith, Frederick W. (July 2013). "How will aspen respond to mountain pine beetle? A review of literature and discussion of knowledge gaps". Forest Ecology and Management. 299: 60–69. doi:10.1016/j.foreco.2013.01.008.
  12. Kelley, Katie (26 September 2006). "Emblem of the West Is Dying, and No One Can Figure Out Why". The New York Times.