Paulownia tomentosa (paulownia)

Pictures

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Picture

Title

Caption

Copyright

Plantation

High yielding superior clonal P. tomentosa plantation.

Cong Peihua

Intercropping

Cong Peihua

Avenue

Cong Peihua

Foliage and ornamental flowers

Cong Peihua

Foliage and seed

©K.M. Siddiqui

Flowers

Flowers on wild trees of P. tomentosa in a gully, Shandong Province, China

©A.R. Pittaway

Identity

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Preferred Scientific Name

Paulownia tomentosa (Thunb.) Steud.

Preferred Common Name

paulownia

Variety

Paulownia tomentosa f. pallida Rehd.
Paulownia tomentosa var. lanata (Dode) Schneid.
Paulownia tomentosa var. lucida Z. X. Chang & S. L. Shi
Paulownia tomentosa var. tomentosa
Paulownia tomentosa var. tsinlingensis (Pai) Gong Tong

Other Scientific Names

Bignonia tomentosa Thunb.
Incarvillea tomentosa (Thunb.) Spreng.
Paulownia grandifolia Hort. ex Wettst.
Paulownia imperialis Siebold & Zucc.
Paulownia recurva Rehd.
Paulownia tomentosa (Thunb.) Siebold & Zucc. ex Steud.

International Common Names

English: Chinese empress tree; empress tree; empress-tree; foxglove tree; karri tree; karritree; princess tree; princess-tree; royal paulownia
French: arbré d'anna paulownia; paulownia imperial; paulownia tomenteux
Chinese: mao pao tong; maopaotong; ribenpaotong; rongmaopaotong; zihuapaotong; zitong

Local Common Names

Brazil: paulovnia-real; quirí
Germany: Blauglockenbaum; Chinesischer Blauglockenbaum; Filziger Blauglockenbaum; Kaiser Paulownia; Kaiser- Paulownie; Paulownie
Italy: paulovia; paulownia
Japan: kiri
Netherlands: Anna-paulownaboom

EPPO code

PAZTO (Paulownia tomentosa)

Summary of Invasiveness

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P. tomentosa is a showy, aggressive ornamental introduced from East Asia. It is also grown in plantations for timber production, but has tended to escape and invade, growing rapidly in disturbed areas including habitats for rare plants. It seeds profusely and resprouts from roots and stumps forming monocultures, and is proving to be a problem weed in eastern USA. It continues to be promoted, however, in North America and elsewhere, and it is possible that it could prove invasive in Europe where it continues to be introduced and planted.

Taxonomic Tree

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Domain: Eukaryota
Kingdom: Plantae
Phylum: Spermatophyta
Subphylum: Angiospermae
Class: Dicotyledonae
Order: Scrophulariales
Family: Scrophulariaceae
Genus: Paulownia
Species: Paulownia tomentosa

Notes on Taxonomy and Nomenclature

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The East Asian genus Paulownia is a member of the family Scrophulariaceae. The latest revision of the genus is half a century old, (Hu, 1959), and with recent discoveries in China, the total number of species is considered to be seven. P. tomentosa is an important species within this genus, and the varieties var. tsinlinggensis, var. lucida and var. lanata, and the forma pallida, are widely cultivated. Hybrids have also been bred and/or selected, some named. It is commonly known as the princess tree, royal paulownia or empress tree, reflecting its beauty as an ornamental.

Description

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P. tomentosa is a large deciduous tree with an umbrella-shaped crown and grows to 10-18 m tall with a diameter at breast height of at least 1 m. Its bark is smooth and pale yellow to brown with numerous large lenticels when young, becoming rough and grey-brown with age, often with interlaced smooth areas that are often shiny. Olive brown to dark brown twigs are stout and brittle, mostly glabrous except at the tip, around buds and along upper edges of leaf scars, lenticels pale, prominent, and elongated longitudinally. Deciduous leaves are opposite, acuminate, cordate or broadly ovate, 20-30(-40) cm long, (10-)15-30 cm wide when mature, though leaves of stump sprouts may be twice as large, acute or obtuse, base cordate, margins entire or shallowly 3-5 lobed, sometimes toothed on small plants, pubescent and dull, light-green above, undersurfaces pale-green and tomentose. Terminal bud absent, axillary buds sunken in bark, winter buds with several outer scales, superposed. Cymes penduncled, the penduncles as long or longer than the pedicels, growing on the main axis and branches of paniculate inflorescences 40-60 cm long, though SE-EPPC (2003) observed the blossoms in much smaller upright clusters only 15-30 cm long and borne at the ends of stout, hairy twigs. Calyx deeply lobed, the lobes as long or longer than the tube. Flowers perfect, fragrant, showy, corolla 8-10 cm long, purple, tubular (or bell-shaped, SE-EPPC, 2003), pale violet with yellow stripes inside, with 5 shallow, rounded, unequal lobes. Brown fruit, ovoid, pointed, woody capsules 2.5-4 cm long borne in terminal clusters, with 2 carpels and numerous (up to 2000) tiny winged seeds attached to the 2 very large placentas. Seeds, tiny, winged, flat, 1.5 mm long.

Plant Type

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Broadleaved
Perennial
Seed propagated
Tree
Vegetatively propagated
Woody

Distribution

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P. tomentosa is native to China, and is widely distributed in central and northern regions, especially Shaanxi, Shanxi, Gansu, Henan, Hebei, Shandong, Anhui, Hubei, Jiangsu, and the Liaoning peninsula. It occurs in Japan and South Korea, but some Japanese taxonomists believe that these are naturalized populations resulting from past introduction and cultivation of this species in these countries, though Japan is accepted here as part of the native range (USDA-ARS, 2008). Within P. tomentosa, the three varieties have distinct distributions. P. tomentosa var. lucida occurs mainly in northern China, var. lanata in the northern Yangtse River region and var. tsinlingensis in central and southwestern China (Jiang, 1988).

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Last updated: 25 Feb 2021

Continent/Country/Region	Distribution	Origin	Invasive	Planted	Reference	Notes
Asia
China	Present	Native			Flora of China Editorial Committee (2007) USA, USDA-ARS (2008)	Exact native range in China unclear due to extensive cultivation
-Anhui	Present	Native			Flora of China Editorial Committee (2007) USA, USDA-ARS (2008)
-Fujian	Present				CABI (2005)
-Gansu	Present	Native			Flora of China Editorial Committee (2007) USA, USDA-ARS (2008)
-Guangdong	Present				CABI (2005)
-Guangxi	Present				CABI (2005)
-Guizhou	Present				Chen LongQing et al. (1995)
-Hebei	Present	Native			Flora of China Editorial Committee (2007) USA, USDA-ARS (2008)
-Henan	Present	Native			Flora of China Editorial Committee (2007) USA, USDA-ARS (2008)
-Hubei	Present	Native			Flora of China Editorial Committee (2007) USA, USDA-ARS (2008)
-Hunan	Present	Native			Flora of China Editorial Committee (2007) USA, USDA-ARS (2008)
-Jiangsu	Present	Native			Flora of China Editorial Committee (2007) USA, USDA-ARS (2008)
-Jiangxi	Present	Native			Flora of China Editorial Committee (2007) USA, USDA-ARS (2008)
-Liaoning	Present	Native			Flora of China Editorial Committee (2007) USA, USDA-ARS (2008)
-Shaanxi	Present	Native			Flora of China Editorial Committee (2007) USA, USDA-ARS (2008)
-Shandong	Present	Native			Flora of China Editorial Committee (2007) USA, USDA-ARS (2008)
-Shanxi	Present	Native			Flora of China Editorial Committee (2007) USA, USDA-ARS (2008)
-Sichuan	Present	Native			Flora of China Editorial Committee (2007) USA, USDA-ARS (2008)
-Yunnan	Present				Chen LongQing et al. (1995)
-Zhejiang	Present				CABI (2005)
India	Present	Introduced			Verma et al. (2005)
-Himachal Pradesh	Present	Introduced			Verma et al. (2005)
Japan	Present	Native			USA, USDA-ARS (2008)
-Hokkaido	Present				CABI (2005)
-Honshu	Present				CABI (2005)
-Kyushu	Present				CABI (2005)
-Ryukyu Islands	Present				CABI (2005)
-Shikoku	Present				CABI (2005)
North Korea	Present				Yoo TaeKyung and Jung HeeSuk (1997)
Pakistan	Present	Introduced		Planted	Siddiqui and Khan (1989) Bajwa and Gul (2000)
South Korea	Present				Yoo TaeKyung and Jung HeeSuk (1997)
Taiwan	Present	Introduced			Hu (1959)
Turkey	Present	Introduced			Boydak (2000) Mohammed et al. (2016) Keçe and Ulusoy (2017)
Europe
Austria	Present			Planted	CABI (2005)
Belgium	Present			Planted	CABI (2005)
Croatia	Present	Introduced			Idžojtić and Zebec (2006) Šimala et al. (2009)	"Potentially dangerous"
France	Present	Introduced		Planted	Jeanmonod and Schlüssel (2006)	Corsica, subspontaneous
-Corsica	Present	Introduced			Jeanmonod and Schlüssel (2006)	Subspontaneus
Germany	Present			Planted	CABI (2005)
Italy	Present	Introduced		Planted	Gridelli et al. (2002) Mezzalira and Colonna (2002)	Plantations in northern Italy
Romania	Present				Ion and Raluca (2019)
Switzerland	Present, Few occurrences	Introduced			Horisberger (1997)	Single tree
United Kingdom	Present			Planted	CABI (2005)
North America
United States	Present, Localized	Introduced	Invasive		PIER (2008) USA, USDA-NRCS (2008)
-Alabama	Present	Introduced		Planted	USA, USDA-NRCS (2008)
-Alaska	Present			Planted	CABI (2005)
-Arizona	Present			Planted	CABI (2005)
-Arkansas	Present	Introduced			USA, USDA-NRCS (2008)
-Connecticut	Present	Introduced			USA, USDA-NRCS (2008)
-Delaware	Present	Introduced			USA, USDA-NRCS (2008)
-Florida	Present	Introduced			USA, USDA-NRCS (2008)
-Georgia	Present	Introduced	Invasive	Planted	USA, USDA-NRCS (2008) Haysom and Murphy (2003)
-Illinois	Present	Introduced			USA, USDA-NRCS (2008)
-Indiana	Present	Introduced			USA, USDA-NRCS (2008)
-Kansas	Present			Planted	CABI (2005)
-Kentucky	Present	Introduced	Invasive		Haysom and Murphy (2003) USA, USDA-NRCS (2008)
-Louisiana	Present	Introduced			USA, USDA-NRCS (2008)
-Maryland	Present	Introduced			USA, USDA-NRCS (2008)
-Massachusetts	Present	Introduced			USA, USDA-NRCS (2008)
-Minnesota	Present			Planted	CABI (2005)
-Mississippi	Present	Introduced			USA, USDA-NRCS (2008)
-Missouri	Present	Introduced			USA, USDA-NRCS (2008)
-New Jersey	Present	Introduced			USA, USDA-NRCS (2008)
-New York	Present	Introduced			USA, USDA-NRCS (2008)
-North Carolina	Present	Introduced		Planted	USA, USDA-NRCS (2008)
-North Dakota	Present			Planted	CABI (2005)
-Ohio	Present	Introduced			USA, USDA-NRCS (2008)
-Oklahoma	Present	Introduced			USA, USDA-NRCS (2008)
-Oregon	Present	Introduced	Invasive		Haysom and Murphy (2003)
-Pennsylvania	Present	Introduced			USA, USDA-NRCS (2008)
-Rhode Island	Present	Introduced			USA, USDA-NRCS (2008)
-South Carolina	Present	Introduced		Planted	USA, USDA-NRCS (2008)
-South Dakota	Present			Planted	CABI (2005)
-Tennessee	Present	Introduced	Invasive	Planted	USA, USDA-NRCS (2008) Haysom and Murphy (2003)
-Texas	Present	Introduced		Planted	USA, USDA-NRCS (2008)
-Virginia	Present	Introduced		Planted	USA, USDA-NRCS (2008)
-West Virginia	Present	Introduced			USA, USDA-NRCS (2008)
Oceania
Australia	Present, Localized	Introduced			Jiang (1988) PIER (2008)	First reported: 1950s
-New South Wales	Present, Few occurrences	Introduced		Planted	Royal Botanic Gardens Sydney (2008)
-Queensland	Present	Introduced		Planted	Royal Botanic Gardens Sydney (2008) Batianoff and Butler (2002) PIER (2008)
-South Australia	Present			Planted	CABI (2005)
-Tasmania	Present			Planted	CABI (2005)
-Victoria	Present, Few occurrences	Introduced		Planted	Royal Botanic Gardens Sydney (2008)
New Zealand	Present	Introduced	Invasive	Planted	PIER (2008)
South America
Argentina	Present	Introduced		Planted	Missouri Botanical Garden (2008) Jiang (1988)	First reported: 1950s
Brazil	Present	Introduced		Planted	Jiang (1988)	First reported: 1950s
Guyana	Present			Planted	CABI (2005)
Paraguay	Present	Introduced		Planted	Jiang (1988)	First reported: 1950s

History of Introduction and Spread

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In the past, P. tomentosa has been introduced as an ornamental in many European countries and in the USA. It was brought to Europe in the 1830s by the Dutch East India Company, and taken to North America a few years later, and has been naturalized in the eastern USA and is also grown on the west coast (SE-EPPC, 2003). P. tomentosa is regarded by many as an invasive species in parts of eastern USA, but Williams (1993) noted that “Unlike many exotic woody plants naturalized in forests of the eastern United States, P. tomentosa is non-invasive and functions much as it does in the mesophytic forests of eastern Asia, producing small, scattered populations that arise chiefly as a result of large-scale disturbance”, observing that in a streamside forest in Virginia, USA, P. tomentosa trees were 6-30 years old (mean 17) with strong peaks in the 18 and 20 year age classes demonstrating episodic establishment in the early 1970s following Hurricane Camille.

The tree was introduced to the parks of central and southern Europe in 1830 as an ornamental, with widespread plantation establishment for timber in Italy after 1989, and as windbreaks in the Mediterranean (Mezzalira and Colonna, 2002). Since the 1950s it has been gradually introduced to Brazil, Paraguay, Argentina and Australia, and is used mainly for timber production (Jiang, 1988).

Risk of Introduction

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P. tomentosa is on invasive species lists for the states of Connecticut and Tennessee, USA (USDA-NRCS, 2008) and is showing invasive characteristics elsewhere. It has also failed risk assessments for Australia and the Pacific (PIER, 2008). It may become invasive where already introduced in Europe and South America, but noting its value as a fast-growing plantation timber and ornamental species, it is highly likely that it will be further introduced elsewhere, where it could also become invasive.

Habitat

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P. tomentosa naturally occurs in deciduous and mixed forests, and to a lesser extent in secondary forest. Where introduced, it is becoming common on roadsides, clearings, forest margins, cliffs, steep rocky slopes, riverbanks and disturbed habitats including fire sites and forests defoliated by pests such as gypsy moths, and landslides (Remaley, 1998; SE-EPPC, 2003; PIER, 2008). It may also be occasionally near gardens or in pavement cracks or similar places. It can invade rapidly after disturbances such as fire, construction or floods, and its ability to resprout prolifically allows it to survive fire, cutting, and even bulldozing on building sites. It tolerates high soil acidity, drought, and low soil fertility, but prefers full sunlight, ample soil moisture and fertile soil.

Habitat List

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Category	Sub-Category	Habitat	Presence	Status
Terrestrial	Managed	Disturbed areas	Present, no further details	Harmful (pest or invasive)
Terrestrial	Managed	Rail / roadsides	Present, no further details	Harmful (pest or invasive)
Terrestrial	Managed	Urban / peri-urban areas	Present, no further details	Harmful (pest or invasive)
Terrestrial	Natural / Semi-natural	Natural forests	Present, no further details	Natural
Terrestrial	Natural / Semi-natural	Riverbanks	Present, no further details	Harmful (pest or invasive)
Terrestrial	Natural / Semi-natural	Rocky areas / lava flows	Present, no further details	Harmful (pest or invasive)
Terrestrial	Natural / Semi-natural	Scrub / shrublands	Present, no further details	Harmful (pest or invasive)
Littoral		Coastal areas	Present, no further details	Harmful (pest or invasive)

Biology and Ecology

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Genetics

Many provenance trials have been conducted in the main growing areas of P. tomentosa in China, with superior provenances identified and plus trees propagated and planted in large-scale plantations. Further provenance trials are being conducted to identify Paulownia witches' broom (PWB) resistance or frost tolerance, and three research institutes are involved, Beijing Research Institute, National Paulownia Research Institute, and Henan Agricultural University, with several germplasm banks established (Jiang et al., 1981; Xiong et al., 1994). It is known to hybridise with P. fortunei in Beijing, China (Kumar et al., 1999), and a hybrid has been selected for improved growth and wind resistance (Ni and Shi, 1998).

Reproductive Biology

P. tomentosa can reproduce from seed or from root sprouts; the latter can grow to over 5m (15 ft) in a single season. The root branches are shallow and horizontal without a strong taproot. Seed-forming pollen is fully developed before the onset of winter, and in spring the flowers are pollinated by insects, seeds germinating within a few days on suitable substrate; seedlings grow quickly and flowering in 8-10 years (Remaley, 1998; SE-EPPC, 2003). The perfect flowers are borne in terminal panicles up to 25 cm long in April and May before leaves emerge, woody capsules 3-5 cm long turning brown as they mature in September or October and persist on the tree through the winter. Trees start bearing fruit after 8-10 years and are very prolific, each capsule containing up to 2000 seeds and a large tree may produce as many as 20 million seeds a year. The tiny, flat, winged seeds weigh about 0.17 mg and as the capsules break open on the trees throughout the winter and into spring, wind dissemination occurs easily (Bonner, 1990). Substantial long-term seed banks do form within temperate forest gaps and patterns of above-ground vegetation can have substantial effects on their dynamics (Hyatt and Casper, 2000).

Physiology and Phenology

P. tomentosa is a strongly light-demanding species which readily colonizes exposed fertile soil, and tolerates drought, wind and weeds, and has an ability to sucker; regenerate rapidly, and self-prune. In central China, plantations of P. tomentosa are intensively managed, with trees reaching a mean height of 15 m and a mean diameter of 30 cm in 10 years (Li and Wang, 1987).

Seeds are not dormant but light is required for germination, which is epigeal and can occur quickly and they grow rapidly when conditions are favourable. Like most pioneer species, P. tomentosa needs bare soil, sufficient moisture, and direct sunlight for good seedling establishment, and seedlings are very intolerant of shade. On good sites P. tomentosa grows rapidly, plantations at 3000-7000 trees/ha can yield saw logs in 15 years, and heights of 13 m in 11 years have been reported in Russia, but on poor sites such as surface mine spoils, growth is considerably slower, though its ability to survive and reproduce on harsh sites has made it a favourite for revegetation (Bonner, 1990). Although resprouting ability is dependent upon belowground biomass, P. tomentosa seedlings can resprout at an early age, even in low light. This ability may allow the species to become established even in areas of high herbivore density (Longbrake and McCarthy, 2001). Roots sprout easily.

Environmental Requirements

P. tomentosa is found in a wide range of temperate semi-humid or semi-arid sites, with an altitude range up to 3000 m. It is the hardiest species of the genus and is fairly frost resistant with some provenances tolerating a minimum temperature of -18°C, however seedlings and young trees are more susceptible to frost damage (Zhu et al., 1986). In China, the natural range extends south of the 0°C January isotherm in areas which receive an annual rainfall of at least 1020 mm. P. tomentosa tolerates a maximum temperature of 40°C, but generally prefers milder areas in subtropical and temperate climates with an optimum annual temperature of 24-29°C and an annual rainfall of approximately 1000 mm though tolerating mean annual rainfall of 500-2500 mm. Such subtropical and temperate climates are found in the Yellow River and Yangtse River ranges in China, and in central and northern China growth of P. tomentosa is particularly favoured by the long dry season. A modified description of climatic requirements (see climatic data table of this data sheet) was prepared by CSIRO (see Booth and Jovanovic, 2000).

P. tomentosa is grown on a diversity of soil types with a pH range 5-8.5 (Zhu et al., 1986), preferring moist, freely drained sands, loams or clays on steep slopes or open valleys, and only rarely on saline and alkaline soils. However, fertile farmland is necessary for high-production plantations.

Climate

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Climate	Status	Description
A - Tropical/Megathermal climate	Tolerated	Average temp. of coolest month > 18°C, > 1500mm precipitation annually
As - Tropical savanna climate with dry summer	Tolerated	< 60mm precipitation driest month (in summer) and < (100 - [total annual precipitation{mm}/25])
Aw - Tropical wet and dry savanna climate	Tolerated	< 60mm precipitation driest month (in winter) and < (100 - [total annual precipitation{mm}/25])
B - Dry (arid and semi-arid)	Tolerated	< 860mm precipitation annually
BS - Steppe climate	Tolerated	> 430mm and < 860mm annual precipitation
BW - Desert climate	Tolerated	< 430mm annual precipitation
C - Temperate/Mesothermal climate	Preferred	Average temp. of coldest month > 0°C and < 18°C, mean warmest month > 10°C
Cf - Warm temperate climate, wet all year	Preferred	Warm average temp. > 10°C, Cold average temp. > 0°C, wet all year
Cs - Warm temperate climate with dry summer	Preferred	Warm average temp. > 10°C, Cold average temp. > 0°C, dry summers
Cw - Warm temperate climate with dry winter	Preferred	Warm temperate climate with dry winter (Warm average temp. > 10°C, Cold average temp. > 0°C, dry winters)

Latitude/Altitude Ranges

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Latitude North (°N)	Latitude South (°S)	Altitude Lower (m)	Altitude Upper (m)
40	28	3	3000

Air Temperature

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Parameter	Lower limit	Upper limit
Absolute minimum temperature (ºC)	>-18
Mean annual temperature (ºC)	14	20
Mean maximum temperature of hottest month (ºC)	26	33
Mean minimum temperature of coldest month (ºC)	-10	10

Rainfall

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Parameter	Lower limit	Upper limit	Description
Dry season duration	3	9	number of consecutive months with <40 mm rainfall
Mean annual rainfall	500	2500	mm; lower/upper limits

Rainfall Regime

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Summer
Uniform

Soil Tolerances

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Soil drainage

free

Soil reaction

acid
neutral

Soil texture

light
medium

Special soil tolerances

infertile
shallow

Notes on Natural Enemies

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The main pest found on P. tomentosa in China is the defoliator Eumeta variegata (syn. Clania variegate) which develops one generation in northern China and two generations in the south, with seedling stock the major source of spread (Yang and Li, 1982; Yang et al., 1975). Paulownia witches' broom (PWB) is the main disease found in P. tomentosa plantations, caused by a phytoplasma identified by distinctive yellow broom-like shoots which die back in the autumn. In its native range it is spread by Halymorpha picus and infected nursery stock, though seeds from infected trees grow disease-free. It is commonly found in seedlings and young trees (3-6 years old) which can greatly reduce growth; and it may also occur in adult trees but has little effect. Anthracnose disease is a another major disease in saplings, which injures leaves, petolies and shoots and causes early leaf drop. P. tomentosa also suffers damping-off disease caused by Rhizoctinia solani and Fusarium spp. (Zhu et al., 1986). Other diseases include the nematode Meloidogyne marioni which infects seedling roots leading to mortality, and the fungus Sphaceloma tsugii which commonly damages seedling shoots and causes dieback. Zheng et al. (2006) report that at least 10 species of fungi infect Paulownia spp., of which eight can live on P. tomentosa, and four of these, Ascochyta paulowniae, Gloeosporium kawakamii, Mycosphaerella corylea and Phyllactinia paulowniae appear to be host specific, and 113 insects in 39 families within 7 orders associated with Paulownia, of which all are listed along with their host-specificity.

No major insect pests are known for P. tomentosa in the USA, though minor damage from several foliage diseases has been reported including Phyllosticta paulowniae, Phyllactinia guttata and Uncinula clintonii (Bonner, 1990), and polyphagous pests such as Mylabris pustulata and Helicoverpa armigera (Verma et al., 2005).

In Peshawar, Pakistan, five Paulownia spp. including P. tomentosa, were attacked by fourteen insect species: Agrotis ypsilon [Agrotis ipsilon] (Noctuidae) Aleuroplatus pectiniferus (Aleyrodidae), Catopsilia crocale [Catopsilia pomona form crocale] (Pieridae), Cyrtopeltis tenuis (Miridae) Drosicha stebbingii (Margarodidae), Heliothis armigera [Helicoverpa armigera] (Noctuidae), Heliothis peltigera (Noctuidae), Lymantria sp. (Lymantriidae), Myzus persicae (Aphididae), Odontotermes obesus (Termitidae), Plusia orichalcea [Thysanoplusia orichalcea] (Noctuidae), P. nigrisigna [Autographa nigrisigna] (Noctuidae), Phycodes radiata (Glyphipterygidae) and Precis orithya (Nymphalidae), and among these, D. stebbingii appeared in epidemic form on P. tomentosa and P. fortunei (Bajwa and Gul, 2000). Mehrotra (1997) also records many diseases of Paulownia from India and their management.

Means of Movement and Dispersal

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Natural Dispersal (Non-Biotic)

One tree is capable of producing twenty million seeds that are easily transported in water or wind (SE-EPPC, 2003). However, being so small and light and winged, wind appears to be the principal means of dispersal.

Intentional Introduction

The only means for long-distance dispersal has been due to intentional introduction as an ornamental and forestry species.

Pathway Causes

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Cause	Long Distance	Local	References
Forestry	Yes	Yes	SE-EPPC, 2003
Habitat restoration and improvement	Yes	Yes	SE-EPPC, 2003
Ornamental purposes	Yes	Yes	SE-EPPC, 2003

Pathway Vectors

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Vector	Notes	Long Distance	Local	References
Water			Yes	SE-EPPC, 2003
Wind			Yes	SE-EPPC, 2003

Impact Summary

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Category	Impact
Economic/livelihood	Positive
Environment (generally)	Negative

Impact

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Economic Impact

P. tomentosa is one of the most important trees in China, being fast-growing with high-quality wood, with over one billion trees in plantations producing about 3 million cubic metres of timber annually worth over US$55 million, used in furniture, decorative products and musical instruments. P. tomentosa is also suitable for use in agroforestry systems in temperate sub-humid areas, though a disadvantage is that it grows well only on fertile land. More research is needed in order to improve wood properties and stress tolerance, and increase its use in plantations.

Social Impact

P. tomentosa is native to western and central China where historical records describe its medicinal, ornamental and timber uses as early as 300 BC, and it has been cultivated for many centuries in Japan where it is valued in many traditions (SE-EPPC, 2003). On a negative side, trees cause maintenance problems on roadsides, paths and in gardens (PIER, 2008).

Environmental Impact

P. tomentosa can colonize rocky cliffs and scoured riparian zones where it may compete with rare plants in such marginal habitats.

Risk and Impact Factors

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Invasiveness

Proved invasive outside its native range
Has a broad native range
Highly adaptable to different environments
Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
Pioneering in disturbed areas
Highly mobile locally
Long lived
Fast growing
Has high reproductive potential
Reproduces asexually
Has high genetic variability

Impact outcomes

Ecosystem change/ habitat alteration
Increases vulnerability to invasions
Modification of successional patterns
Monoculture formation
Reduced native biodiversity
Threat to/ loss of native species

Impact mechanisms

Competition - monopolizing resources
Competition - shading
Interaction with other invasive species
Rapid growth

Likelihood of entry/control

Highly likely to be transported internationally deliberately
Difficult/costly to control

Uses

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P. tomentosa has a sparse crown and a deep, widely-distributed root system and high adaptability, and is such suitable for use in agroforestry and afforestation. In temperate zones, P. tomentosa is suitable for intercropping with wheat, oilseed rape and sweet potato (Jiang, 1988), and in the sub-tropics it may be intercropped with tea and bamboo. It can also be used for windbreaks on farmlands, roadsides or canal-banks. In some European countries, P. tomentosa is cultivated as an ornamental due to its beautiful flowers, and is found in arboreta, botanical gardens and parks. P. tomentosa is also believed to reduce sulphur dioxide pollution and grows in environments where other trees may suffer leaf loss (Zhu et al., 1986).

P. tomentosa wood is light (250-360 kg/cubic metre) with straight grain and low shrinkage, is easy to plane, saw and carve without splitting or warping, though its nail-holding ability and resistance to fire and decay is low. It is used for furniture, particularly smoke-proof cupboards resistant to insect attack, and being relatively light, it is used for model airplanes and gliders, and interior panels on airplanes, vehicles and ships. The soundboards of some Chinese musical instruments are made from P. tomentosa wood due to its good resonance properties as are traditional musical instruments in Korea (Yoo and Jung, 1997). The wood is also used for oil drums, wine and beer barrels, tea boxes, fruit boxes, grain storage containers, traditional handicrafts, ornaments, agricultural tools, and especially beehives which maintain suitable temperatures resulting in increased honey production (Zhu et al., 1986). In recent years, P. tomentosa has been used for plywood and particleboard manufacture, and for kitchen utensils such as wooden bowls, plates and rice steamers (Zhu, 1980).

The flowers and leaves are traditionally used as fodder for pigs, goats and rabbits in Sichuan and Hebei (Zhu et al., 1986), flowers containing 3-4% glucose and 9% soluble sugars; leaves containing over 4% glucose and soluble sugars. Leaves, containing over 3% nitrogen, are also used as a green manure in rural areas. P. tomentosa has been used in traditional Chinese medicine to treat bronchitis, coughs, asthma and high blood pressure, and flowers, leaves and bark are effective in treating chronic tracheitis. Many of the uses are dealt with in papers promoted the multipurpose nature of the tree, such as “Can Paulownia species be miracle trees?” (Boydak, 2000).

Uses List

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Environmental

Agroforestry
Erosion control or dune stabilization
Land reclamation
Ornamental
Revegetation
Shade and shelter
Soil conservation
Windbreak

Fuels

Fuelwood

General

Ornamental

Materials

Fibre
Wood/timber

Medicinal, pharmaceutical

Source of medicine/pharmaceutical

Wood Products

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Containers

Boxes
Cases
Cooperage
Crates
Pallets
Tanks
Vats

Pulp

Short-fibre pulp

Roundwood

Building poles
Piles
Pit props
Posts
Roundwood structures
Stakes
Transmission poles

Sawn or hewn building timbers

Carpentry/joinery (exterior/interior)
Exterior fittings
Fences
Flooring
For light construction
Gates
Wall panelling

Wood-based materials

Fibreboard
Flakeboard
Improved wood
Laminated strand lumber
Laminated veneer lumber
Laminated wood
Medium density fibreboard
Oriented strand lumber
Oriented strandboard
Parallel strand lumber
Particleboard
Plywood
Waferboard
Wood cement

Woodware

Industrial and domestic woodware
Musical instruments
Sports equipment
Tool handles

Similarities to Other Species/Conditions

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P. tomentosa resembles the USA native catalpa tree, Catalpa speciosa in size, leaf and flower structure but can be differentiated easily by having small round capsules in clusters and not long thin pods as in catalpa, having hollowed or chambered pith and not solid as in catalpa, and leaves are not whorled and have a less elongated tip with catalpa leaves whorled and more distinctly pointed at the tip (SE-EPPC, 2003).

References

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