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Species
Populus alba L. var. pyramidalis (Bunge)
IUCN
NCBI
EOL Text
Although it is not native to North America, White Poplar has attractive bark and bicolored leaves. The wood of this tree is relatively soft and weak; it has been used to make boxes and crates, cheap backing for furniture, or as a source of cellulose. The roots of Poplars (Populus spp.) form symbiotic relationships with ectomycorrhizal fungi; an example of such a fungus is the edible Leccinum aurantiacum (Orange Oak Bolete). Another edible fungus, Lentinus tigrinus (Tiger Sawgill), develops on stumps, logs, and dead branches. White Poplar can hybridize with several other poplars, and such hybrids occasionally naturalize. The best known hybrid is probably Populus × canescens (Gray Poplar), which is the result of a cross between Populus alba (White Poplar) and Populus tremula (European Aspen). Gray Poplar is similar to White Poplar, but the undersides of its leaves are less white. Other poplars in Illinois also have leaf undersides that are either less white from fine hairs or they are glabrous. Another distinction involves the shape of the leaves
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Rights holder/Author | Copyright © 2002-2014 by Dr. John Hilty |
Source | http://www.illinoiswildflowers.info/trees/plants/wh_poplar.html |
More info for the terms: hardwood, mesic
Throughout its North American range, white poplar is most common near current or abandoned settlements where it was planted. It is often found in fields and along fence lines, ditch banks, and roads [7,12,47,51,60,71,105,122]. Disturbed areas near established white poplar stands are often colonized by root sprouts [39,92,119].
In southeastern Michigan, most white poplar hybrids were found around current or former farms. No hybrids occurred in forests considered relatively undisturbed by humans. Nearly half of the hybrids occurred on sparsely vegetated, dry, sandy sites. The other half occurred on mesic sites, often at the edges of lakes, ponds, and swamps [101].
Climate: White poplar occurs in areas as far north as USDA hardiness zone 3, where average annual minimum temperatures can reach -40 °F (4 °C) [19,28,68]. However, some report that white poplar may be killed or injured by extremely low winter temperatures [19,33], suggesting that white poplar may be restricted to protected sites in its northernmost habitats. In a review, Spies [102] reports that white poplar is most common at low elevations where temperatures are moderate and moisture is favorable. Although white poplar commonly occupies moist habitats, it can also occupy upland, somewhat droughty habitats [17]. In Hungary, white polar occurs in semiarid forest-steppe vegetation that grows in a temperate continental climate with annual precipitation averaging 20 to 22 inches (500-550 mm) [79].
In growth chamber experiments, researchers found P. alba × P. grandidentata growth was best when soil moisture was 16% to 30% and temperatures were 77 to 95 °F (25-35 °C) during the day and 59 to 77 °F (15-25 °C) at night. The parameters necessary for interpreting soil moisture values in this study include a level of 8.6%—which was slightly above the permanent wilting point—and a field capacity level of 35.6%. Height and stem diameter growth peaked at 23% average soil moisture. Height and stem size were also high at 30% and 32% soil moisture but were low at 9% soil moisture [20].
Elevation: Ranges of elevations reported for white poplar habitats in the western half of the United States | |
State or region | Elevation range |
California | 1,970-5,900 feet (600-1,800 m) [47] |
Nevada | 4,500-6,500 feet (1,400-2,000 m) [60] |
New Mexico | 6,500-7,500 feet (2,000-2,300 m) [71] |
Utah | 4,500-6,500 feet (1,400-2,000 m) [122] |
Intermountain West | 3,600-8,000 feet (1,100-2,400 m) [51] |
Soils: Although growth may be best in moist, deep loams [19], white poplar and its hybrids grow in a variety of soil types and textures [105,117]. In the Southwest, white poplar occurs on dry, well drained sites [117], and in Michigan, white poplar thickets are common in sandy soils [119]. In southeastern Michigan, most white polar and hybrid stands occurred on loamy sands, but soil textures ranged from pure sands to nearly pure loams. Soil pH was mostly neutral but ranged from 5 to 8 [102]. White poplar persisted for more than 100 years at the Grayling Agricultural Experiment Station in Crawford County, Michigan, where soil pH, nutrients, and water-holding capacity were low [62]. In its native forest-steppe habitats in Hungary, white poplar occurred on soils with a sand content of greater than 96% and silt and clay content of less than 2% [79]. In the Danube-Tisza region of Hungary, more than 70% of white poplar stands occurred on calcareous soils [86].
Soil moisture: Floodplain and upland sites provide habitat for white poplar [17,45], and although white poplar may survive episodes of both flooding and low precipitation, experiments suggest that growth is best in moist conditions. In his review, Dickmann [17] reports that on dry soils, P. alba × P. tremula grows better than white poplar.
Studies suggest that white poplar and hybrid growth is best in moist but not saturated soils. In a controlled study, P. alba × P. grandidentata stem height increased with increasing soil moisture levels up to 34%; stem height was lower at a 41% moisture level. A lack of root aeration may have affected hybrid growth at 41% soil moisture. In this study, permanent wilting of the hybrids occurred at 9% to 11%, and soil was near field capacity at 41%. [96]. However, when ranchers and farmers in North Dakota and Montana were surveyed, those who planted white poplar on sites with a shallow water table ranked its windbreak performance lower than those who planted it on sites with deeper water tables [111].
In the few studies available, white poplar exhibited greater flood tolerance in its native than nonnative habitats. Along the Upper Rhine in France, white poplar occurs in a hardwood floodplain forest that is flooded almost every summer (June-August) [94]. When white poplar trees were planted around a reservoir in Davis, California, nearly 80% of white poplar trees survived 61 to 69 days of flooding in 2 consecutive years. Survival was much lower, 20%, after 100 days of flooding in 2 consecutive years. The age of white poplar trees at the time of flooding was not reported [45], but provided photos suggest the trees were less than 10 years old.
Salinity: White poplar tolerates salt spray [19] and grows in saline soils [17]. Some indicate that white poplar can establish and grow in soil with salinity levels of up to 4,000 mg/L (Wong and others 1985 as cited in [52]). In the Camargue in southern France, white poplar occurred in habitats where the soil salinity at 12 inches (30 cm) deep was up to 3,200 mg/L [76]. In a greenhouse experiment, the survival of 1-year-old white poplar seedlings was compared after adding various amounts of sodium to the soil. Growth of white poplar was significantly lower in high-salt than low-salt treatments (P=0.0183). After a year, all seedlings had survived the low-salt treatment, and mortality in the high-salt treatment was only 20% [52]. Populus alba × P. tremula is considered more tolerant of saline soils than white poplar [17], but comparisons between white poplar and its hybrids with aspens native to North America were not found.
More info for the term: tree
Tree
White poplar outcompetes many native tree and shrub species in mostly sunny areas, such as forest edges and fields, and interferes with the normal progress of natural community succession. It is an especially strong competitor because it can grow in a variety of soils, produce large seed crops, and resprouts easily in response to damage. Dense stands of white poplar prevent other plants from coexisting by reducing the amount of sunlight, nutrients, water and space available.
This tree is 50-80' tall at maturity, forming a single trunk about 2-3½' across and a relatively open irregular crown that is taller than it is across. The trunk is usually erect and straight, otherwise it is either crooked or divides into multiple branches near the base. On mature trees, trunk bark is rough-textured, irregularly furrowed, and gray near the base, otherwise it is more white and smooth with bands of diamond-shaped black lenticels (air pores). Branch bark is also white and smooth with bands of diamond-shaped black lenticels, while twigs are pale yellow to pale brown and glabrous to white-pubescent. Young shoots are light green, white-pubescent, and terete. Alternate leaves occur along the twigs and shoots. Individual leaves are 2-4" long and a little less across; they are oval to ovate in shape and either bluntly dentate-undulate along their margins or palmate with 3-5 moderately deep blunt lobes. Palmately lobed leaves are most likely to occur on the vigorous shoots of young trees, while leaves with dentate-undulate margins are most likely to occur on slower-growing shoots of older trees. However, both types of leaves can occur on the same tree. The upper surface of mature leaves is medium green and glabrous (or nearly so), while the lower surface is densely white-tomentose. The petioles are up to 1½" long, light green to nearly white, white-pubescent, and usually terete (sometimes becoming flattened toward the base of a leaf blade). White Poplar is dioecious, forming staminate (male) and pistillate (female) catkins on separate trees. Staminate catkins are 1-3" long and drooping; they are hairy and brown while immature, becoming more red at maturity. Each staminate catkin consists of a dense aggregation of staminate florets and their bracts along its length. Each staminate floret consists of 6-12 stamens that develop from a cup-like disk; the adjacent staminate bract is narrowly oval in shape, toothed toward its apex, and ciliate. Each pistillate catkin consists of an aggregation of pistillate florets and their bracts along its length. Each pistillate floret consists of a naked ovary with a pair of deeply bifurcated stigmata; the adjacent pistillate bract is narrowly oval in shape, toothed toward its apex, and ciliate. The blooming period occurs from mid- to late spring, lasting about 1 week. The florets are cross-pollinated by the wind. Afterwards, the pistillate catkins become 2-4" long, forming seed capsules on short pedicels (less than 1 mm. in length). Individual seed capsules are 4-6 mm. in length and pyriform (pear-like) in shape. They are light green while immature, later turning brown and splitting open to release their cottony seeds (2 seeds per capsule). Individual seeds are about 1.5 mm. in length; they are enveloped in basal tufts of fine white hairs and distributed by the wind. The root system is relatively shallow and spreading, sometimes forming clonal shoots that can be located many feet away from the mother tree.
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Rights holder/Author | Copyright © 2002-2014 by Dr. John Hilty |
Source | http://www.illinoiswildflowers.info/trees/plants/wh_poplar.html |
More info for the terms: codominant, hardwood, mesic
Nonnative habitats:
In its North American range, white poplar occurs in open disturbed sites, grasslands, shrublands, early-seral forests, and floodplain woodlands [34,120]. In New England, it occurs along roadsides and in fields, meadows, wet shrublands, early-seral forests, and floodplain forests [73]. In a midseral old field on Howard University's Beltsville campus in Maryland, white poplar was codominant with red maple (Acer rubrum) and sweetgum (Liquidambar styraciflua) [83]. Along the Mississippi River in Hickman County, Kentucky, white poplar thickets occurred with eastern cottonwood (P. deltoides subsp. deltoides) and narrowleaf willow (Salix exigua) on sand deposited by flooding [41]. In the Midwest, large white poplar clones have reduced the abundance of shade-intolerant species in prairies and savannas [97]. In southeastern Michigan, white poplar and its native aspen hybrids occurred in early-seral communities dominated by poison sumac (Toxicodendron vernix), red-osier dogwood (Cornus stolonifera subsp. stolonifera), and gray dogwood (C. racemosa) on mesic sites and black oak (Quercus velutina), black cherry (Prunus serotina), and black locust (Robinia pseudoacacia) on dry sites [102]. Along the Missouri River in southeastern South Dakota, white poplar occurred in cottonwood (Populus spp.)-dominated floodplain forests [104].
Native habitats:
In western and central Europe, white poplar occurs in riparian, forest-steppe, and coastal communities. Gravel bars and hardwood floodplain woodlands are common white poplar habitats [27,63,66,94]. In Hungary, white poplar occurs in forest-steppe vegetation characterized by sandy grasslands with patches of white poplar, Lombardy poplar (P. nigra), and common juniper (Juniperus communis) [79]. White poplar sometimes forms thickets on coastal cliffs in southeastern England [26].
Additional information about white poplar's nonnative and native habitats is available in Site Characteristics and Successional Status.
According to A. Nauman (l.c.) P. alba L. is confined to Europe, N. Africa and Anatolia and does not extend to Caucasus, Transcaucasia, Persia, Afghanistan, Pakistan and Central Asia, a region where it is replaced by P. caspica Bornm. However, this interpretation has not been accepted by subsequent workers (Meikle, Fl. Cyprus 2: 1491. 1985; Czerepanov, Vasc. Pl. Russia Adj. States (former USSR), 1995 and A. K. Skvortsov, personal communication).
This species is widely cultivated and produces suckers in abundance. It is a handsome road-side tree in Hazara etc.
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Source | http://www.efloras.org/florataxon.aspx?flora_id=5&taxon_id=200005643 |
The introduced White Poplar is occasional in most areas of Illinois (see Distribution Map). It was introduced into North America from Eurasia as an ornamental landscape tree. Habitats of naturalized trees include grassy meadows, open wooded areas, borders of ponds and lakes, urban parks, abandoned homestead sites, fence rows, and vacant lots. Such naturalized trees typically colonize habitats with a history of disturbance in urban and suburbans areas. White Poplar is still cultivated as a landscape tree, although its popularity has declined in recent years.
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Rights holder/Author | Copyright © 2002-2014 by Dr. John Hilty |
Source | http://www.illinoiswildflowers.info/trees/plants/wh_poplar.html |
White poplar seems to grow best in full sun habitats such as fields, forest edges and wetland fringes.