Tuesday, April 12, 2011

Invasive Tree Species Reunited with Its Natural Enemy

An article by Marie Lapointe and Jacques Brisson in Ecoscience on the effect on Norway maple in North America when reunited with an adventive fungus, Rhytisma acerinum, to which it is susceptible. The invasion of Norway maple (Acer platanoides) into North American forests is considered to reduce native flora richness. Lack of predators is one reason Norway maple is more successful than the native, sugar maple (Acer saccharum). The fungus causes tar spot disease.The researchers found a strong link between the outbreak of the disease and a very sharp decline in sapling and tree growth, together with high mortality of Norway maple saplings.  While Norway maple usually out grows sugar maple, the reverse situation was observed after the epidemics. The researchers results suggest that the invasion potential of Norway maple could be reduced by the fungus, Rhytisma acerinum. You can find the article 'Tar Spot Disease on Norway Maple in North America: Quantifying the Impacts of a Reunion between an Invasive Tree Species and Its Adventive Natural Enemy in an Urban Forest' Marie Lapointe and Jacques Brisson. Ecoscience Mar 2011 : Vol. 18, Issue 1, pg(s) 63-69 doi: 10.2980/18-1-3378.
Sugar maple, photo by Paul Wray, Iowa State University, Bugwood.org

Norway maple, photo by Paul Wray, Iowa State University, Bugwood.org