Abstract.: Güsewell S., Zuberbühler N. and Clerc C. 2005. Distribution and functional traits of Solidago gigantea in a Swiss lakeshore wetland. Bot. Helv. 115: 63-75. Alien plant species are of particular ecological concern when they invade native vegetation of high conservation value and alter its functioning.We mapped the area and cover of stands of invasive alien species in the lakeshore wetland "Grande Cariçaie” (CH) and examined whether the main invader, Solidago gigantea Ait., differs functionally from the resident vegetation. Seven alien species considered to be invasive in Switzerland occurred with a total area of 22.2ha. The most frequent invaders were S. gigantea (60 stands) and Robinia pseudoacacia (42 stands, mostly in forest). Less than 1 area was colonised by alien species, mostly S. gigantea. Dense stands of S. gigantea (> 50 vegetation, suggesting that its spread is limited by high water level rather than by low nutrient availability. S. gigantea appeared functionally similar to the invaded wetland vegetation: its shoot size, specific leaf area, and biomass N and P concentrations were similar to or lower than those of co-occurring native species. Total soil N and P concentrations under S. gigantea stands did not differ from those under non-invaded vegetation. Thus, the impact of invasive alien species on the non-forested wetlands of the Grande Cariçaie currently seems rather low but possible changes in soil processes as well as effects on other biota remain to be investigate
