Author
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Whittemore, Alan |
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Submitted to: Sida
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/26/2002 Publication Date: 7/6/2004 Citation: Whittemore, A.T. 2004. Sawtooth Oak (Quercus Acutissima, Fagaceae) in North America. Sida, Contributions to Botany. v:21, pp:447-454. Interpretive Summary: The sawtooth oak, Quercus acutissima, is now widely planted in eastern North America, both for wildlife food and as a street and park tree. It has been reported to escape from cultivation at some sites and there has been concern that it could be invasive enough to become troublesome. However, little is known about the situations in which it escapes and the rate at which it can spread. There is almost no published data on the ecology of sawtooth oak in North America and no detailed descriptions or other identification aids in the North American floristic literature. Field and herbarium work, and inquiry among active fieldworkers in the area, indicate that Quercus acutissima escapes much more widely in the eastern United States than has been realized. The current range and habitat preferences of Q. acutissima in North America are summarized, and identification aids (a full taxonomic description, illustration and keys) are supplied. Feral populations of sawtooth oak are mostly confined to open, often disturbed areas, and it spreads very slowly, apparently due to limited dispersal of the acorns. Planting large stands of Quercus acutissima in wilderness or revegetating areas for wildlife food is likely to result in the naturalization of this exotic species and its spread into adjacent habitats, but the use of sawtooth oak as a landscape tree in developed areas usually poses much less danger of escape. The data supplied here on the habitats in which Q. acutissima escapes from cultivation in the United States, and the limited dispersal it displays, helps to identify sites where sawtooth oak should not be used, and the identification aids provided will allow accurate identification of the species so that its status can be monitored in the future. Technical Abstract: Sawtooth oak (Quercus acutissima Carruth.), native to eastern Asia, is widely planted in the eastern United States as a source of food for wildlife (especially turkeys) and as a landscape tree in developed areas. It has been reported to escape from cultivation at some sites, and there has been concern that it could be invasive enough to significantly impact North American vegetation. However, little is known about the habitats in which it escapes and its dispersal rate in the wild. The species is very poorly treated in North American floristic literature, and there is almost no published data on the ecology of Quercus acutissima in North America. Field and herbarium work, and inquiry among 0active fieldworkers in the area, revealed feral populations of Quercus acutissima in seven states and the District of Columbia; it is here reported new to the District of Columbia, Maryland, and North Carolina. The current range and habitat preferences of Q. acutissima in North America are summarized, and a full taxonomic description, illustration and keys are provided. Feral populations of sawtooth oak are mostly confined to open, often disturbed areas, and dispersal is very slow, apparently due to limited dispersal of the acorns. Planting large stands of Quercus acutissima in wilderness or revegetating areas for wildlife food is likely to result in the naturalization of this exotic species and its spread into adjacent habitats, but the use of sawtooth oak as a landscape tree in developed areas poses much less danger of escape. |
