Field site
Kungsängen Nature Reserve (N59°50’, E17°40’) is a 12.5-hectare reserve in a larger meadow located in the south of Uppsala, Sweden, along the east shore of the Fyris River (Fig. 1). The eastern mesic-dry part of the meadow is managed by annual hay making in late July, while the western part is managed less frequently because of high soil moisture due to its low elevation and proximity to the Fyris River (Zhang, 1983; Zhang & Hytteborn, 1985). To investigate vegetation in the field, 28 permanent plots (2 x 2 m) were laied out across an east–west transect in the meadow in the 1940s (Sernander, 1948). Along this transect 1, plots are located from 1.07 and 2.57 m above sea level. In the 1980s, three additional parallel transects (2–4) were laid out (Zhang, 1983).