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).