Using mowing as a management tool for Solidago gigantea
Solidago gigantea (Asteraceae: EPPO List of Invasive Alien Plants) is a rhizomatous perennial herb native to North America and widely distributed in the EPPO region. The species can have negative impacts on biological diversity and ecosystem services. In the current study, competition between the native Tanacetum vulgare and S. gigantea was assessed under different management regimes. Seeds of both species were collected from Hungarian populations and planted in fifty 50 x 50 cm plots within a mesic meadow in May 2010. Half of the plots contained S. gigantea alone and half of the plots contained both T. vulgare and S. gigantea. Following planting, the plots were allowed to grow and interact with the native vegetation for two years without any intervention. Competition between the two species, mowing frequency and the duration of management was assessed in a full factorial design experiment. Mowing was simulated with a hand clipper in June 2012 and 2013 by cutting individual plants 5-10 cm above the soil surface and removing the biomass. T. vulgare was shown to supress S. gigantea by 79 % in the absence of management. Mowing reduced the density of S. gigantea by 80-98 % in the absence of T. vulgare. When T. vulgare was present, moving did not reduce the density of S. gigantea, in fact the density of the non-native species was increased. It is not clear why the effect of T. vulgare changes from competition, in the absence of disturbance, to facilitation with management associated disturbance. Studies have shown that T. vulgare can create plant soil feedback that benefits S. gigantea. Therefore, mowing may reduce aboveground competition, but positive effects belowground remain unchanged. The results indicate that consideration should be given to the plant community when management is undertaken to control invasive alien plants.
Sources
Nagy DU, Rauschert ESJ, Callaway RM, Henn T, Filep R, Pal RW (2021) Intense mowing management suppresses invader, but shifts competitive resistance by a native to facilitation. Restoration Ecology. https://doi.org/10.1111/rec.13483