Negative impacts of Prunus laurocerasus in deciduous forests in Switzerland
Prunus laurocerasus (Rosaceae) is a shrub species native to Southeastern Europe and Southwestern Asia. In the USA, the species is reported as having invasive behaviour in California, Oregon and Washington. P. laurocerasus was introduced into central Europe approximately 400 years ago and has since colonised forests and has become invasive, especially in the understory of deciduous forests in Switzerland. To evaluate the impact of the species on native plants, four plots were established in patches of P. laurocerasus and in adjacent uninvaded areas in twelve forest areas in Switzerland. Native species richness, diversity and species composition of the ground vegetation and shrub layer were assessed in each plot. Furthermore, in each plot physical and chemical characteristics of the soil were measured. The maximum age of P. laurocerasus in each plot was determined using tree ring analysis, indicating the time of establishment. Species richness of native plants was lower in both ground vegetation and the shrub layer compared to plots invaded by P. laurocerasus. Species composition of the ground vegetation was also affected by the presence of P. laurocerasus. However, the diversity of native plants was largely unaffected by the presence of P. laurocerasus. Plots invaded by P. laurocerasus had a lower soil moisture content than uninvaded plots. The study showed that the effects of P. laurocerasus became more pronounced with the age of establishment suggesting that early intervention and removal of the species was critical in mitigating the negative impacts of the species.
Sources
Rusterholz HP, Schneuwly J, Baur B (2018) Invasion of the alien shrub Prunus laurocerasus in suburban deciduous forests: Effects on native vegetation and soil properties. Acta Oecologica 92, 44-51.