The Biology of Invasive Alien Plants in Canada. 7. Cabomba caroliniana A. Gray

Abstract

A. Gray. Can. J. Plant Sci. 87: 615-638. The freshwater aquatic plant Cabomba caroliniana, or fanwort, was recently reported in a lake northeast of Peterborough, Ontario, where it has successfully established and survived winter conditions since at least 1991. This is the first documented occurrence of fanwort becoming naturalized in Canada. Fanwort is a popular aquarium plant that is native to South America and possibly the southeastern United States and has been introduced in several Asian, Pacific and European countries through the discarding or deliberate planting of aquarium plants in natural waterways. It is particularly invasive in China, Japan and Australia, and in parts of the United States, where its range is spreading. Fanwort grows rapidly and forms dense stands that clog waterways, impeding flow, obstructing navigation, altering fish habitat and excluding other vegetation. It does not produce mature seed in the northern parts of its North American range, but can multiply clonally and spread quickly by stem fragmentation. It produces turion-like stems at the end of the growing season, which assist in over-wintering under adverse conditions. Fanwort is difficult to control with herbicides and is resistant to mechanical management techniques as populations can quickly re-establish from plant fragments. Populations near the Trent-Severn Waterway in Canada are extensively established and management tools are not available to attempt eradication. An integrated management plan that focuses on early detection and rapid response in surrounding water bodies may succeed in mitigating the economic and environmental impacts and limiting the spread of fanwort. s'avère particulièrement envahissante en Chine, au Japon et en Australie ainsi que dans les parties des États-Unis qui prolongent son aire naturelle. Le cabomba de Caroline pousse rapidement pour former des peuplements denses qui obstruent les cours d'eau, réduisent le débit, nuisent à la navigation, modifient l'habitat des poissons et supplantent d'autres espèces végétales. Ses semences ne parviennent pas à maturité dans les parties septentrionales de son aire nord-américaine, mais la plante se multiplie par clonage et se propage rapidement par fragmentation de la tige. À la fin de la période végétative, ses tiges ressemblent à des turions, ce qui l'aide à traverser l'hiver quand les conditions sont difficiles. Le désherbage chimique du cabomba de Caroline manque d'efficacité et la plante résiste aux techniques de désherbage mécanique, les peuplements se rétablissant rapidement à partir des fragments végétaux. Les populations près de la voie navigable de Trent-Severn, au Canada, sont très bien établis et on ne possède pas les outils de gestion qui permettraient de les éradiquer. Un programme de lutte intégrée misant sur un dépistage précoce et une intervention rapide dans les plans d'eau voisins pourrait concourir à atténuer les conséquences économiques et environnementales du cabomba de Caroline tout en freinant sa propagation.

Effect of water quality and season on the population dynamics of Cabomba caroliniana in subtropical Queensland, Australia

“…In spring, C. caroliniana grows rapidly toward the water surface and can fill the entire water column (Wilson et al, 2007). Peak biomass of 110-240 g dry mass m −2 is reached in the northern hemisphere in late summer to early autumn (August-October) (Noel, 2005;Wilson et al, 2007). Toward the end of the growing season C. caroliniana plants fragment, and in spring new shoots emerge from fragments and turion-like structures (Riemer and Ilnicki, 1968;Wilson et al, 2007).…”

“…In temperate climates of the continental USA (New Jersey) and Canada there is a seasonal cycle of C. caroliniana populations. In spring, C. caroliniana grows rapidly toward the water surface and can fill the entire water column (Wilson et al, 2007). Peak biomass of 110-240 g dry mass m −2 is reached in the northern hemisphere in late summer to early autumn (August-October) (Noel, 2005;Wilson et al, 2007).…”

“…Cabomba caroliniana thrives in freshwater systems with a wide range of nutrient concentrations, from oligotrophic to eutrophic systems (Oki, 1992;Wilson et al, 2007;van Valkenburg et al, 2011). Elevated nutrient concentrations in the substrate can increase its growth performance (Bickel, 2012).…”

“…Peak biomass of 110-240 g dry mass m −2 is reached in the northern hemisphere in late summer to early autumn (August-October) (Noel, 2005;Wilson et al, 2007). Toward the end of the growing season C. caroliniana plants fragment, and in spring new shoots emerge from fragments and turion-like structures (Riemer and Ilnicki, 1968;Wilson et al, 2007). While there is currently no information on C. caroliniana growth in subtropical climates, it is reasonable to expect that C. caroliniana would exhibit seasonal variation in population size similar to those found in temperate climates.…”

“…C. caroliniana is a popular aquarium species and was introduced to aquatic ecosystems worldwide through disposal of aquarium material and escape from culture. Currently C. caroliniana is naturalized in the United States, Canada, Greece, Japan, Malaysia, the Netherlands, Australia, and China (Ørgaard, 1991;Oki, 1992;Les and Mehrhoff, 1999;Zhang et al, 2003;Wilson et al, 2007;Matthews et al, 2013). Once introduced, C. caroliniana causes a range of ecological (Mackey and Swarbrick, 1997;Hogsden et al, 2007;Wilson et al, 2007) and socio-economic impacts (Mackey and Swarbrick, 1997;Dugdale et al, 2013).…”