Triadica sebifera (L.) Small Family - Euphorbiaceae. Common Name(s) - Chinese Tallow. Synonym(s) - Sapium sebiferum (L.) Roxb.

Answer

Score

1.01

Is the species highly domesticated? (If answer is 'no' then go to question 2.01)

n

0

1.02

Has the species become naturalized where grown?

1.03

Does the species have weedy races?

2.01

Species suited to tropical or subtropical climate(s) (0-low; 1-intermediate; 2-high) – If island is primarily wet habitat, then substitute “wet tropical” for “tropical or subtropical”

2

2.02

Quality of climate match data (0-low; 1-intermediate; 2-high) see appendix 2

2

2.03

Broad climate suitability (environmental versatility)

y

1

2.04

Native or naturalized in regions with tropical or subtropical climates

y

1

2.05

Does the species have a history of repeated introductions outside its natural range? y=-2

y

3.01

Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05

y

2

3.02

Garden/amenity/disturbance weed y = 1*multiplier (see Append 2)

n

0

3.03

Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2)

n

0

3.04

Environmental weed y = 2*multiplier (see Append 2)

y

4

3.05

Congeneric weed y = 1*multiplier (see Append 2)

n

0

4.01

Produces spines, thorns or burrs

n

0

4.02

Allelopathic

n

0

4.03

Parasitic

n

0

4.04

Unpalatable to grazing animals

n

-1

4.05

Toxic to animals

y

1

4.06

Host for recognized pests and pathogens

n

0

4.07

Causes allergies or is otherwise toxic to humans

y

1

4.08

Creates a fire hazard in natural ecosystems

n

0

4.09

Is a shade tolerant plant at some stage of its life cycle

y

1

4.10

Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)

4.11

Climbing or smothering growth habit

n

0

4.12

Forms dense thickets

y

1

5.01

Aquatic

n

0

5.02

Grass

n

0

5.03

Nitrogen fixing woody plant

n

0

5.04

Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers)

n

0

6.01

Evidence of substantial reproductive failure in native habitat

n

0

6.02

Produces viable seed.

y

1

6.03

Hybridizes naturally

n

-1

6.04

Self-compatible or apomictic

y

1

6.05

Requires specialist pollinators

n

0

6.06

Reproduction by vegetative fragmentation

y

1

6.07

Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1

3

0

7.01

Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)

n

-1

7.02

Propagules dispersed intentionally by people

y

1

7.03

Propagules likely to disperse as a produce contaminant

n

-1

7.04

Propagules adapted to wind dispersal

n

-1

7.05

Propagules water dispersed

y

1

7.06

Propagules bird dispersed

y

1

7.07

Propagules dispersed by other animals (externally)

n

-1

7.08

Propagules survive passage through the gut

y

1

8.01

Prolific seed production (>1000/m2)

y

1

8.02

Evidence that a persistent propagule bank is formed (>1 yr)

y

1

8.03

Well controlled by herbicides

y

-1

8.04

Tolerates, or benefits from, mutilation, cultivation, or fire

y

1

8.05

Effective natural enemies present locally (e.g. introduced biocontrol agents)

y

-1

Total score:

14

Notes

Reference

1.01

Although cultivated extensively, there is no evidence that the species has been selected for less invasive traits. (1)The plant was purposely introduced into the southeastern US as early as the 1700s. It comes from China where it has been cultivated for about 1,500 years as a seed-oil crop. (2)Of the many cvs cultivated, more than 100 are found in Taiwan. Two main types are 'Eagle-Claw' and 'Grape', varying according to form of fruit-spikes, fruit-sprigs, fruit stalks and maturing period. (2n = 36) (3)Sapium is native to Asia where it is both naturally occurring and cultivated for 14 centuries.

(1)http://plants.ifas.ufl.edu/sapium.html [Accessed 5 Feb 2008] (2)http://www.hort.purdue.edu/newcrop/duke_energy/Sapium_sebiferum.html [Accessed 5 Feb 2008] (3)SIEMANN, E. and ROGERS, W. E. 2003. INCREASED COMPETITIVE ABILITY OF AN INVASIVE TREE MAY BE LIMITED BY AN INVASIVE BEETLE. Ecological Applications 13(6): 1503–1507.

1.02

1.03

2.01

(1)Favorable climatic conditions are mean air temperatures of 12.5 to 30.1°C, and an annual precipitation from 13 to 37 dm. It is a subtropical to warm temperate plant. It is hardy and able to withstand a few degrees of frost, but unripened twigs are susceptible to frost injury. It will grow at elevation of 100 to 800 m.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Sapium_sebiferum.html [Accessed 5 Feb 2008]

2.02

2.03

(1)Favorable climatic conditions are mean air temperatures of 12.5 to 30.1°C, and an annual precipitation from 13 to 37 dm. It is a subtropical to warm temperate plant. It is hardy and able to withstand a few degrees of frost, but unripened twigs are susceptible to frost injury. It will grow at elevation of 100 to 800 m.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Sapium_sebiferum.html [Accessed 5 Feb 2008]

2.04

(1)Native to many provinces of central China, especially north of the Yangtze Valley, and Japan, Chinese tallow tree is also cultivated there and on Hainan Island, Hong Kong, Taiwan and Korea. It has been introduced and naturalized into Sri Lanka, and introduced to Indochina, Bengal, India, Sudan, Martinique, southern United States (S. California, S. Arizona, and Texas to Florida, north to South Carolina), southern France and Algeria.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Sapium_sebiferum.html [Accessed 5 Feb 2008]

2.05

(1)Native to many provinces of central China, especially north of the Yangtze Valley, and Japan, Chinese tallow tree is also cultivated there and on Hainan Island, Hong Kong, Taiwan and Korea. It has been introduced and naturalized into Sri Lanka, and introduced to Indochina, Bengal, India, Sudan, Martinique, southern United States (S. California, S. Arizona, and Texas to Florida, north to South Carolina), southern France and Algeria.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Sapium_sebiferum.html [Accessed 5 Feb 2008]

3.01

(1)Chinese tallow has become naturalized in the southern coastal plain from South Carolina south to Florida and west to Texas. (2)Native to many provinces of central China, especially north of the Yangtze Valley, and Japan, Chinese tallow tree is also cultivated there and on Hainan Island, Hong Kong, Taiwan and Korea. It has been introduced and naturalized into Sri Lanka, and introduced to Indochina, Bengal, India, Sudan, Martinique, southern United States (S. California, S. Arizona, and Texas to Florida, north to South Carolina), southern France and Algeria.

(1)http://plants.ifas.ufl.edu/sapium.html [Accessed 5 Feb 2008] (2)http://www.hort.purdue.edu/newcrop/duke_energy/Sapium_sebiferum.html [Accessed 5 Feb 2008]

3.02

Environmental weed

3.03

No evidence of lost productivity in agricultural or forestry settings. (1)The species can readily become the dominant plant in disturbed vacant lots and abandoned agricultural land.

(1)http://plants.usda.gov/plantguide/pdf/pg_trse6.pdf [06 Feb 2008]

3.04

(1)Chinese tallow (Sapium sebiferum) might be called the "north Florida melaleuca": like melaleuca, it's a tree that grows and spreads rapidly, is difficult to kill, and tends to take over large areas by out-competing native plants. Chinese tallow is spreading rampantly in large natural areas, including Paynes Prairie State Preserve near Gainesville, state-owned protected lands along the St. Johns River, and a park in Volusia County. It can thrive in well-drained uplands as well as in bottomlands, shores of waterbodies, and even on floating islands. It also is referred to as "Florida aspen" and "popcorn-tree", and continues to be sold in plant nurseries. (2)Chinese tallow tree Sapium sebiferum (L.) Roxb. (Euphorbiaceae) is a serious invader in the south-eastern USA that aggressively displaces native plants and forms monotypic woodlands (Jubinsky & Anderson 1996; Bruce et al. 1997; Grace 1998). (3)Chinese tallow, Sapium sebiferum (L.) Roxb., is a subtropical deciduous tree native to China, where its seeds are used for a variety of products including soap, candles, and oil. This species was introduced to the United States in the late 1700s. The Bureau of Plant Industry (U.S. Department of Agriculture) established plantations of tallow along the Gulf Coast in the early 1900s to study its feasibility as an agricultural crop. At this time it became a popular ornamental. Because of tolerance to different types of soils, rapid growth, precocity, high fecundity, and the presence of few pests or pathogens in the United States, Chinese tallow spread to a variety of natural habitats in the southeastern United States. Native prairies invaded by Chinese tallow suffered altered ecosystem structure as a result of the monospecific stands of tallow trees that persisted. Currently, tallow is controlled by mechanical means, but some herbicides are effective. (4)Chinese tallow is the most successful exotic invader of the chenier woodlands in southwestern Louisiana. It has had a major impact on plant community structure and species composition by becoming the most abundant woody species. It has the potential to invade surrounding marshes, changing them from herbaceous to woody plant communities

(1)http://plants.ifas.ufl.edu/sapium.html [Accessed 5 Feb 2008] (2)WILLIAM E. ROGERS and EVAN SIEMANN. 2005. Invasive ecotypes tolerate herbivory more effectively than native ecotypes of the Chinese tallow tree Sapium sebiferum. Journal of Applied Ecology 41: 561–570. (3)Bruce, KA; Cameron, GN*; Harcombe, PA; Jubinsky, G. 1997. Introduction, impact on native habitats, and management of a woody invader, the Chinese tallow tree, Sapium sebiferum (L.) Roxb. Natural Areas Journal. Vol. 17, no. 3, pp. 255-260. (4)Neyland, R. & H. A. Meyer 1997. Species diversity of Louisiana chenier woody vegetation remnants. Journal of the Torrey Botanical Society 124:254-261.

3.05

(1)Monospecific genus.

(1)http://www.itis.gov/servlet/SingleRpt/SingleRpt [06 Feb 2008]

4.01

(1)No spines, thorns or burrs.

(1)Huang, Tseng-Chieng Ed. 1993. Flora of Taiwan Vol 3. Department of Botany, National Taiwan University Ta'an, Taipei, Taiwan 106, the Republic of China.

4.02

(1)The rapid transition from grassland to Chinese tallow tree (Sapium sebiferum) woodland may be partly due to allelopathic effects on native plants. A bioassay was performed using aqueous extracts of Sapium or little bluestem (Schizachyrium scoparium) and Schizachyrium seeds. Schizachyrium germination rates and germination timing were unaffected by watering treatments. Growth of Schizachyrium seedlings was significantly facilitated by watering with Sapium extracts versus watering with water. These results suggest that allelopathic effects are not responsible for the competitive success of Sapium in coastal prairies. (2) Our experiment questions the validity of allelopathic interference as a mechanism enhancing tallow invasion or maintaining woodlands once established. Because of its enhanced germination and seedling growth when exposed to its own experimental treatments, tallow may in fact be perpetuating its own woodland(s) by self facilitation, rather than inhibiting other plant survival by allelopathic interference.

(1)KEAY J. ; ROGERS W. E. ; LANKAU R. ; SIEMANN E. 2000. The role of allelopathy in the invasion of the Chinese tallow tree (Sapium sebiferum). The Texas journal of science . 52(4): 57-64. (2)CONWAY WC, SMITH LM, BERGAN JF. 2002. Potential Allelopathic Interference by the Exotic Chinese Tallow Tree (Sapium sebiferum). The American Midland Naturalist 148(1): 43–53

4.03

Not parasitic.

4.04

(1)Grazing: Sheep and goats will eat the leaves of S. sebiferum, but toxicity to cattle limits their effectiveness as a control agent. Cattle will eat seedlings less than 6 cm tall.

(1)Bruce, K.A., G.N. Cameron, P.A. Harcombe, G. Jubinsky. 1997. Introduction, impact on native habitats and management of a woody invader, the Chinese tallow tree, Sapium sebiferum (L.) Roxb. Natural Areas Journal, 17(3): 255-260.

4.05

(1)Grazing: Sheep and goats will eat the leaves of S. sebiferum, but toxicity to cattle limits their effectiveness as a control agent. Cattle will eat seedlings less than 6 cm tall.

(1)Bruce, K.A., G.N. Cameron, P.A. Harcombe, G. Jubinsky. 1997. Introduction, impact on native habitats and management of a woody invader, the Chinese tallow tree, Sapium sebiferum (L.) Roxb. Natural Areas Journal, 17(3): 255-260.

4.06

(1)Tree is remarkably free of insect pests. The root-knot nematode, Meloidogyne javanica has been reported (Golden, p.c. 1984). Fungi known to attack this tree include: Cercospora stillingiae, Clitocybe tabescens, Dendrophthoe falcata, Phyllactina corylea, Phyllosticta stillingiae, and Phymatotrichum omnivorum.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Sapium_sebiferum.html [Accessed 5 Feb 2008]

4.07

(1)The milky, white sap of S. sebiferum may also be a skin irritant or diarrhetic in humans. (2)Ingestion of plant material causes gastrointestinal upset with nausea and vomiting. Contact with the plants can cause dermatitis

(1)Bogler, D. J. 2000. ELEMENT STEWARDSHIP ABSTRACT for Sapium sebiferum Chinese tallow-tree, Florida aspen, popcorn tree. The Nature Conservancy, Arlington, Virginia. http://tncweeds.ucdavis.edu/esadocs/documnts/sapiseb.pdf [Accessed 06 Feb 2008]. (2)http://plants.usda.gov/plantguide/pdf/pg_trse6.pdf [Accessed 06 Feb 2008]

4.08

(1)Sapium sebiferum exhibits the ability to reduce fuel loads and prevent the spread of fires that suppress woody vegetation and sustain prairie ecosystems through shading and the rapid decay of its leaves

(1)Cameron, G. N., and S. R. Spencer. 1989 Rapid leaf decay and nutrient release in a Chinese tallow forest. Oecologia 80: 222–228.

4.09

(1)S. sebiferum can grow rapidly in full sunlight as well as establish under closed canopies. (2)Chinese tallow trees are remarkably free of insect pests and serious pathogenic organisms. This precludes the use of biological controls or integrated pest management programs. A few organisms known to associate with tallow trees include the bagworm, Eumeta, which feeds on the leaves. The root-knot nematode, Meloidogyne javanica, has been reported. Fungi known to attack this tree include Cercospora stillingiae, Clitocybe tabescens, Dendrophthoe falcata, Phyllactina corylea, Phyllosticta stillingiae, and Phymatotrichum omnivorum.

(1)Bogler, D. J. 2000. ELEMENT STEWARDSHIP ABSTRACT for Sapium sebiferum Chinese tallow-tree, Florida aspen, popcorn tree. The Nature Conservancy, Arlington, Virginia. http://tncweeds.ucdavis.edu/esadocs/documnts/sapiseb.pdf [Accessed 06 Feb 2008]. (2)http://plants.usda.gov/plantguide/pdf/pg_trse6.pdf [06 Feb 2008}

4.10

(1)Adapted for growing on canal banks, on steep mountain slopes, granite hills or sandy beaches, it grows in alkaline, saline or acid soils. Said to thrive in alluvial forests, on low alluvial plains, and on rich leaf-molds, growing best in well-drained clayey-peat soils.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Sapium_sebiferum.html [Accessed 5 Feb 2008]

4.11

(1)Chinese tallow is a fast-growing, medium-sized tree that may reach heights of 50 feet

(1)http://plants.usda.gov/plantguide/pdf/pg_trse6.pdf [Accessed 06 Feb 2008]

4.12

(1)Chinese tallow spread to a variety of natural habitats in the southeastern United States. Native prairies invaded by Chinese tallow suffered altered ecosystem structure as a result of the monospecific stands of tallow trees that persisted. (2)These new, anthropogenic woodlands are virtually monospecific stands of tallow, although they contain some native tree species.

(1)Bruce, KA; Cameron, GN*; Harcombe, PA; Jubinsky, G. 1997. Introduction, impact on native habitats, and management of a woody invader, the Chinese tallow tree, Sapium sebiferum (L.) Roxb. Natural Areas Journal. Vol. 17, no. 3, pp. 255-260. (2)Katherine A. Bruce, Guy N. Cameron, Paul A. Harcombe. 1995. Initiation of a New Woodland Type on the Texas Coastal Prairie by the Chinese Tallow Tree (Sapium sebiferum (L.) Roxb.). Bulletin of the Torrey Botanical Club, Vol. 122, No. 3: 215-225.

5.01

Terrestrial tree

5.02

Euphorbiaceae

5.03

Euphorbiaceae

5.04

Woody tree

6.01

No evidence.

6.02

(1)Propagated by seed, cuttings, layering or top-grafting on seedling stock. Seed usually sown in late autumn or early spring.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Sapium_sebiferum.html [Accessed 5 Feb 2008]

6.03

(1)Monospecific genus.

(1)http://www.itis.gov/servlet/SingleRpt/SingleRpt [06 Feb 2008]

6.04

(1)Freely self-seeds, and can be somewhat weedy and invasive in optimum growing conditions. (2)It is also capable of self-pollination and subsequent reproduction, and at times will sucker freely from the roots.

(1)http://www.mobot.org/gardeninghelp/plantfinder/Plant.asp?code=A908 [06 Feb 2008] (2)http://www.hsu.edu/default.aspx?id=6415 [06 Feb 2008]

6.05

(1)The inflorescences are very attractive to bees and other insects (2)The flowers of Chinese tallow are favored by honeybees, which produce a desirable, light-colored honey from it.

(1)http://plants.ifas.ufl.edu/sapium.html [Accessed 5 Feb 2008] (2)http://plants.usda.gov/plantguide/pdf/pg_trse6.pdf [Accessed 06 Feb 2008]

6.06

(1)S. sebiferum is characteristic of a woody invader, in that it grows rapidly, begins reproduction when young (after only 3 years), produces abundant viable seed, and can reproduce from cuttings. It produces seeds soon after establishment, leading to a rapid increase in stem and cover density. S. sebiferum was documented in a Florida wetland as becoming a co-dominant species twenty years after its introduction (based on tree age), and was found to reproduce from seedlings and vegetative sprouts much more prolifically than the local native species (Jubinsky and Anderson 1996).

(1)Jubinsky, G. and L.C. Anderson. 1996. The invasive potential of Chinese tallow-tree (Sapium sebiferum Roxb.) in the Southeast. Castanea. 61(3): 226-231.

6.07

(1)Plants require from 3–8 years to bear, but then continue to bear for years, averaging 70–100 years. Trees attain full size in 10–12 years.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Sapium_sebiferum.html [Accessed 5 Feb 2008]

7.01

(1)No. Seeds have no means of attachment.

7.02

Ornamental and agricultural uses. (1)Chinese tallow tree is cultivated for its seeds as a source of vegetable tallow, a drying oil and protein food, and as an ornamental. Fruits yield two types of fats: outer covering of seeds contain a solid fat with low iodine value, known as Chinese Vegetable Tallow; kernels produce a drying oil with high iodine value, called Stillingia Oil. Tallow is used for manufacturing candles, a layer of wax being placed over the tallow body to prevent too rapid burning; has excellent burning quality, and gives an inodorous clear bright flame; also used for making soap, cloth dressing and fuel. Pure tallow fat is known in commerce as Pi-yu. Oil is used in making varnishes and native paints because of its quick-drying properties, in machine oils and as a crude lamp oil. Pure oil expressed from the inner part of the seeds is known in commerce as Ting-yu. Oil cakes made from crushed seeds with tallow and oil together is known as Mou-yu. Residual cake, after oil is expressed, is used as manure, particularly for tobacco fields. Wood is white and close-grained, suitable for carving and used for making blocks in Chinese printing; also used for furniture making and incense. Chinese prepare a black dye by boiling leaves in alum water. Tree grows rapidly, developes an attractive crown, and, as leaves turn red in fall, is cultivated as a shade or lawn tree about houses. It is used as a soil binder along roads and canals. Chinese place an insect on the tree to feed; it lays eggs in the seed, making some of the "jumping beans," because of movements of larvae inside.

(1)http://www.hort.purdue.edu/newcrop/duke_energy/Sapium_sebiferum.html [Accessed 5 Feb 2008]

7.03

Not grown with produce

7.04

(1)Its primary vectors are birds (pileated woodpeckers have been observed eating the seed) and moving waters (tests show viability even after several weeks of floating in water).

(1)http://plants.ifas.ufl.edu/sapium.html [Accessed 5 Feb 2008]

7.05

(1)Its primary vectors are birds (pileated woodpeckers have been observed eating the seed) and moving waters (tests show viability even after several weeks of floating in water).

(1)http://plants.ifas.ufl.edu/sapium.html [Accessed 5 Feb 2008]

7.06

(1)Its primary vectors are birds (pileated woodpeckers have been observed eating the seed) and moving waters (tests show viability even after several weeks of floating in water). (2)Heavy use and effective seed dispersal by different birds have contributed to the invasion success of the Chinese tallow tree in coastal South Carolina.

(1)http://plants.ifas.ufl.edu/sapium.html [Accessed 5 Feb 2008] (2)RENNE IJ, GAUTHREAUX SA, GRESHAM CA. 2000. Seed Dispersal of the Chinese Tallow Tree (Sapium sebiferum (L.) Roxb.) by Birds in Coastal South Carolina. The American Midland Naturalist 144(1): 202–215

7.07

No means of external attachment.

(1)http://plants.ifas.ufl.edu/sapium.html [Accessed 5 Feb 2008]

7.08

(1)Its primary vectors are birds (pileated woodpeckers have been observed eating the seed) and moving waters (tests show viability even after several weeks of floating in water).

8.01

(1)The fast-growing habit, massive seed production, and great seed germinability allow this species to invade areas occupied by natives. (2)A mature tree may annually produce an average of 100,000 seeds that are spread mainly by birds and water

(1)http://el.erdc.usace.army.mil/pmis/plants/html/triadica.html (2)http://plants.usda.gov/plantguide/pdf/pg_trse6.pdf [Accessed 06 Feb 2008]

8.02

(1)The viability of seeds averages 95% and germination is 26%-65% in the laboratory. Germination is highest in January and February and lowest in late fall and early spring. Ten to 50% of seeds were viable after one year in Louisiana soil. Seeds in sealed metal cans remained viable 7 years, with maximum germination rates continuing even after 1-2 years of storage (Bruce et al. 1997).

(1)Bruce, K.A., G.N. Cameron, P.A. Harcombe, G. Jubinsky. 1997. Introduction, impact on native habitats and management of a woody invader, the Chinese tallow tree, Sapium sebiferum (L.) Roxb. Natural Areas Journal, 17(3): 255-260.

8.03

(1)Currently, herbicide control is being achieved with GARLON 4 and a spray adjuvant formulated to mix with oil-soluble herbicides. JLE OIL PLUS is one such adjuvant. A spray solution of approximately 15% has proven to be effective. (2)The most effective method for the control of S. sebiferum is the basal bark application of herbicide. Several organizations, including the Florida Department of Environmental Protection, the Florida Exotic Pest Plant Council, Florida Native Plant Society, the Florida Nature Conservancy, the Louisiana Nature Conservancy, and the Texas Nature Conservancy, have adopted this method of treatment (Jubinsky and Anderson, 1996; Randall and Meyers-Rice, unpublished). Effective treatment consists of spraying a band at least 15 cm wide around the lowest 30-60 cm of the trunks with triclopyr (brand names Garlon 3A, Garlon4, Pathfinder II and others) at a concentration of approximately 15%. Concentrations up to 20% might be required for larger trees. Vegetable oil and other similar products are effective surfactants. Basal bark applications may be ineffective on large trees with thick bark; for such trees a cut-stump method may be necessary. For a cutstump treatment, excellent results are reported with a 50% solution of the triclopyr formulation Garlon 3A or with a 10% solution of the herbicide imazapyr (brand names Arsenal, Chopper and others). Imazapyr is a soil-active herbicide that requires careful use when applied near desirable plants or trees to prevent it from killing them. Other herbicides that have successfully controlled S. sebiferum include the combined 2,4-D and picloram formulations (Grazon P+D and Grazon) applied to foliage, or hexazinone (Velpar L) applied to soil near plants (Bruce et al. 1997; Jubinsky and Anderson 1996). Frilling using glyphosate (Rodeo) is also an effective control method. Bergen (1998, pers. comm.) reports from Texas that the most effective time to apply herbicide to minimize seed spread is in late summer to early fall.

(1)Jubinsky, G. and Anderson, L.C. 1996. The Invasive Potential of Chinese Tallow-Tree (Sapium sebiferum Roxb.) in the Southeast. Castanea 61(3): 226-231. (2)Bogler, D. J. 2000. ELEMENT STEWARDSHIP ABSTRACT for Sapium sebiferum Chinese tallow-tree, Florida aspen, popcorn tree. The Nature Conservancy, Arlington, Virginia. http://tncweeds.ucdavis.edu/esadocs/documnts/sapiseb.pdf [Accessed 06 Feb 2008].

8.04

Invasive ecotype from North America tolerant of mutilation. (1)Our results are consistent with the predictions of the EICA hypothesis. Sapium height growth, shoot mass, root mass and competitive ability of native Chinese ecotypes were all significantly reduced by mechanically severed roots, whereas invasive Texas ecotypes better compensated for damage. Simulated herbivory studies have been criticized because artificial damage often removes more tissue than herbivores in natural conditions and exaggerates damage severity (Hendrix 1988; Baldwin 1990). However, this concern strengthens support for the EICA hypothesis in our study because Texas ecotypes compensated for these high damage levels over a relatively short time period. Long-lived perennial plants often replace tissues lost to herbivory damage over several growing seasons (Hendrix 1988; Sacchi & Conner 1999; Haukioja & Koricheva 2000) suggesting that Chinese ecotypes may compensate for damage with time. Regardless, it is the differential responses of the native vs. invasive ecotypes to tolerate and compensate for root damage in the short term that most strongly emphasizes their evolutionary divergence. The most notable result of this study is that Texas ecotypes were not significantly affected by mechanical root damage relative to undamaged plants, whereas all aspects of growth for Chinese ecotypes were negatively impacted by root damage, compared with undamaged plants. These results are consistent with our other studies revealing that invasive North American ecotypes of Sapium are capable of considerable herbivory tolerance and rapid compensatory regrowth (Rogers et al. 2000; Rogers & Siemann 2002, 2003), whereas native Asian ecotypes of Sapium allocate significantly greater resources to costly defences (Siemann & Rogers 2001, 2003b,c) and leaf damage results in significantly reduced growth (Rogers & Siemann 2004).

(1)WILLIAM E. ROGERS and EVAN SIEMANN. 2005. Invasive ecotypes tolerate herbivory more effectively than native ecotypes of the Chinese tallow tree Sapium sebiferum. Journal of Applied Ecology 41: 561–570.

8.05

(1)In Hawaii, in contrast, an Asian herbivore, Adoretus sinicus (Chinese rose beetle) is abundant, and S. sebiferum is not invasive. In Hawaiian common garden plots, A. sinicus caused greater damage to North American genotypes, and Asian genotypes were competitively superior. Our results suggest that exotic plants freed from herbivory can evolve greater competitive ability, allowing them to become much more abundant than in their native ranges. This did not seem to occur, though, if herbivores from the native range were abundant.

(1)SIEMANN, E. and ROGERS, W. E. 2003. INCREASED COMPETITIVE ABILITY OF AN INVASIVE TREE MAY BE LIMITED BY AN INVASIVE BEETLE. Ecological Applications 13(6): 1503–1507.