Species list of vascular plants observed on Peberholm 1999–2020

Peberholm is a constructed Danish island in the Øresund strait. It was
primarily constructed by calcareous clay from the seafloor and is
traversed by a highway and a railway. Being constructed from material
without a seed bank, Peberholm constituted a good opportunity to study
primary succession in an anthropogenic context. In this study, data from a
survey of the vascular plant community of Peberholm was studied. The data
span a 22-year period, between 1999 and 2020. The development of the flora
was analysed with regards to indicators for environmental factors and
vegetation types, as well as occurrence of alien species or species of
conservation concern. Peberholm experienced a rapid succession during its
first 5 years. The effects of the initial ground disturbance quickly wore
off, resulting in a relative decline in plant communities associated with
ruderal land. These highly anthropogenic habitats were replaced with
grasslands. The shrubification also began early on. The rapid initial
changes were then replaced with a much slower but also more continuous
change, resulting in the development of both more natural grasslands and
an increased shrubification. Although several rare or threatened species
colonized Peberholm from the beginning, the conservation value of the
flora on a whole increased during the succession process of forming more
natural vegetation types. The succession process demonstrated at Peberholm
has more in common with the succession at urban soils than with naturally
occurring primary succession.