User:Gscrib1/Tallow
3 Possible Illustrations: 1) Many Chinese Tallow Trees surrounding one Cyprus Tree. 2) Herbivores, grasshoppers, feeding on a native tree species leaves which is adjacent to the Chinese Tallow owing to the acidity in the Chinese Tallow's leaves. 3) Many Chinese Tallow Trees living in high salt walter area as other native trees die out.
The Chinese Tallow tree, Triadica sebifera, is a tree native to eastern Asia and is becoming an invasive species in the southeastern United States due to it naturally occurring in similar latitudes of southeastern United States which provides a similar habitat and climate for the Chinese tallow to be a successful invader (1). Triadica sebifera has become a successful invader due to it's evolution of increased competitive ability in that it has evolved reduced efforts in defense and increased efforts in growth and reproduction owing to the lower herbivore activity in its introduced range (2,3) . Triadica sebifera underwent beneficial changes when it moved from its natural habitat to its introduced range in southeastern United States (2). The Chinese tallow tree is providing problems for the gulf coast region because of its invasive abilities (4). According to Nature Conservancy, in 1996 the chinese tallow tree was named one of the worst plant invaders in the United States (3).
In it's native habitat, Triadica sebifera has costly herbivore defenses that require large amounts of energy and resources when there is damage to leaves owing to increased herbivore activity (2). Whereas in southeastern United States, Triadica sebifera produces much less costly tissue or herbivore defense which is capable of rapid regeneration (2). This may be due to that fact that the Chinese tallow tree has leaves which contain highly toxic chemicals known as phenolic compounds, Beta-glucogallin, chlorogenic acid, tercatain, chebulagic acid, and geranin, which causes low herbivory to the Chinese tallow tree and gives it a higher competitive edge (3). For example, In Texas, The Chinese tallow tree has changed the flora from native coastal grasslands to woodlands filled with mainly Chinese Tallow trees (3). Generalist herbivores avoid the Chinese tallow in its introduced range (3). Another reason why the tallow is extremely invasive plant species is because of it's ability to adapt to a wide range of soils including alkaline, acidic, and saline soils (1). Triadica sebifera is able to tolerate periods of flooding, freezing, drought, and high sun and shade exposure (1).
E. Glumac performed a case study on the Chinese tallow tree (7). During the study, seedlings from the tallow tree were gathered from Taiwan, part of the tallow's native range in asia, and from its introduced range in Louisiana, Georgia, and Texas (7). These seedlings were grown in a greenhouse and after the 14th growth year some alarming results were gathered (7). In the tallow's introduced range the girth or basal area was much larger than that of it's native range in Taiwan (7). The percentage of trees producing seeds was also much higher in the introduced range compared with the native range (7). The foliar carbon to nitrogen ratio, or the tree's nutritional value to herbivores, was much higher in the introduced range compared with the native range (7). The amount of tannin, chemical defense, was much higher in seedlings from the native range compared with the seedlings of the introduced range (7). Overall these results support the hypothesis that the chinese tallow is extremely invasive due to it's evolution of an increased competitive ability (2,3). The tallow allocates more of it's resources for growth and reproduction in its introduced range due to the lack of competitors and predators which it tolerated in it's native range (2,3)
Warren C. Conway, Loren M. Smith, and James F. Bergan conducted an experiment to test if the Chinese tallow has any alleopathic effects on neighboring trees, the black willow and the bald cypress (5). In order to test this, extracts from the tallow litter, soil under the tallow, and fresh tallow leaves were collected from the tallow in October, January, April, and July to determine if there were any seasonal differences in it's alleopathic effects(5). The test attempted to observe if the germination, root length, shoot length, and seedling mass differed with any combination of tallow litter, tallow soil, and tallow leaves (5). Overall, there was no correlation between altered germination, root and shoot length, and seedling mass when the baldcypress and black willow were exposed with the various tallow treatments (5). Although, when the tallow was exposed with it's own soil, leaves, and plant litter, the researchers observed increased germination and seedling growth (5). This fact may support the theory that the tallow has little to no alleopathic effects on neighboring trees, but that the tallow is increasing it's own growth, reproduction, and dispersal through self facilitation, when exposed to it's own plant litter, leaves, and soil (5).
In the southeastern United States, coastal wetlands are being threatened by the increase in sea levels, increase in hurricane activity, and increase in invasive species, Triadica sebifera 4. Louisiana's wetland are disappearing at a rate up to 90 square kilometers a year, among the highest land loss rates in the world (5). As sea levels rise and hurricane activity increases, flooding and salinity are killing off native trees, cyprus trees, which are crucial part of the gulf coast storm surge protection (4). In studies, seedlings of the Triadica sebifera exhibit higher tolerance of flooding and salinity than to the native cyprus tree (4).
Sources: 1. The Invasive Potential of Chinese Tallow-Tree (Sapium sebiferum Roxb.) in The Southeast. G. Jubinsky and Loran C. Anderson Castanea Vol. 6, No.3(Sep., 1996), pp226-231 ((http://www.jstor.org/pss/4033675))
2. ROGERS, W. E. and SIEMANN, E. (2004), Invasive ecotypes tolerate herbivory more effectively than native ecotypes of the Chinese tallow tree Sapium sebiferum. Journal of Applied Ecology, 41: 561–570. ((http://onlinelibrary.wiley.com/doi/10.1111/j.0021-8901.2004.00914.x/full))
3. An investigation of the allelopathic potential of Chinese tallow tree (Sapium sebiferumRoxb). Amy L. Johnson Rice University (May., 2006) UMI Number: 1435734 ((http://scholarship.rice.edu/bitstream/handle/1911/17886/1435734.PDF?sequence=1))
4.The Effect of Salinity and Waterlogging on Growth and Survival of Baldcypress and Chinese Tallow Seedlings. William H. Conner Journal of Coastal Research Vol. 10, No. 4 (Autumn, 1994), pp. 1045-1049 ((http://www.jstor.org/pss/4298295)) 5.Science 15 September 2000: Vol. 289 no. 5486 pp. 1860-1863 DOI: 10.1126/science.289.5486.1860
6. http://www.issg.org/database/species/ecology.asp?fr=1&si=712&sts
7. Lee, C. E. Evolutionary genetics of invasive species. Trends in Ecology and Evolution (Aug 2002) 17: 386-391