Status worldwide |
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| Sycamore index page | ||
| Invasive Woody Plants | In pace with the European colonization of the world, sycamore has been introduced outside its native range throughout the temperate zones, including Europe (e.g. Jones 1944, Weeda 1987), North America (Little 1953), South America (e.g. Reide 1907) and New Zealand (Webb et al. 1988). It has been introduced to India, where it is an economically important species in Tamil Nadu (Nair & Henry 1983) and was a favourite with the European residents of Kodaikanal in the Palni Hills (Matthew 1969). The Germans even tried to acclimatize maples (probably including among others sycamore) in the Amani Botanic Gardens in the East Usambara Mountains (Tanzania), however without success. The reasons for its increased distribution are varied and include silviculture in continental Europe (Schrötter 1975), wind resistance and general uses in Britain, firebreaks in New Zealand (Anon 1958), but in most areas the main reason for its introduction was amenity planting (e.g. in Chile, Reide 1907; in western France, Jovet 1953; in Russia, Bulygin et al. 1986 and North America, Little 1953). The ease of seed transportation, seed germination and seedling establishment is probably the main reason why it has been so widely introduced. Throughout its introduced range sycamore has been reported as producing frequent and abundant regeneration. The first report of natural regeneration was made in Britain (see Status in Great Britain), and early this century in New Zealand (see Status in New Zealand). In Chile, Reide (1907, p 327) reported that sycamore occurred north of Lake Llanquihue with the following comment: "Ehemalige Kulturpflanzen, heute verwildert oder zu tatsachlichen Umkrautern geworden." ("Formerly cultivated, nowadays has become wild or strongly weedy."). This region of Chile has mild winters with an average annual temperature of 12°C and an annual rainfall of 120cm and has been described as the Chilean Switzerland (Heim 1953). In Nothofagus dombeyi forest of Patagonia sycamore has been found to be invasive in disturbed areas (Bicon et al. 1989). Elsewhere, sycamore has been reported as self-seeding in Leningrad (Bulygin et al. 1986), as spontaneous in the Valois country, north-east of Paris (Jovet 1953), as naturally regenerating in Northern Germany (Schrötter 1975), as a weed in Christmas tree plantations in Denmark (Christensen 1988), as gaining importance in Swedish managed beech forests (Falkengren-Grerup & Tyler 1991) and in Argentina where it gives rise to dense and extensive populations (Neher & Roic 1972). In the eastern United States, according to Little (1953), sycamore is escaping and becoming locally established and in time it may become naturalized. On Danish farmland abandoned in 1929, sycamore quickly became dominant in the vicinity of the wood where it had been planted (Halberg 1984, pers. comm.). Recently, sycamore has been found to be invading the unique Madeiran laurel forest (Hamilton 1990). The laurel forest is dense, evergreen and degraded, and young sycamores are locally common in gaps, probably disseminated from plantations. Locals were unaware of the potential danger which sycamore could create if it were allowed to spread freely and its early eradication has been suggested (Hamilton 1990). Despite these reports of sycamore establishment in several parts of the world, besides the British Isles, only in New Zealand has a substantial amount of evidence been published. It is not clear whether this is due to the importance of the problem there or to the lack of interest in invasive woody species and autecology elsewhere. |
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| Copyright © 1999 Pierre Binggeli. All rights reserved. |