Abstract
Abstract
Introduction
Road verges provide refuge habitats for semi‐natural grassland species but can also facilitate the spread of invasive alien plant species such as
Lupinus polyphyllus
Lindl., which negatively impacts biodiversity.
Objectives
We studied how different mowing regimes affect
L. polyphyllus
performance, species richness, and plant community composition.
Methods
A factorial combination of mowing heights (10 or 30 cm) and mowing frequencies (two or three times per year) was applied to permanent plots along six road verges in Sweden over 3 years.
Results
Mowing height had a larger effect than mowing frequency on
L. polyphyllus
. Plots mown at 10 cm showed significantly lower lupine biomass (treatment years 2 and 3) and re‐flowering (only tested in treatment year 3) than plots mown at 30 cm. In treatment year 1, mowing had no effect at all. No further reduction of lupine biomass was found from treatment year 2 to 3. Effects of treatments on species diversity were small. While community composition differed between plots with and without lupine at the onset of the study, the mowing treatments did not affect community composition.
Conclusions
Mowing at a height of 10 cm may potentially enhance biodiversity by significantly reducing
L. polyphyllus
biomass. However, considerable variation in treatment efficiency among sites indicates that local abiotic conditions need to be considered when planning mowing regimes.