Seasonal dynamics of common ground beetles (Coleoptera: Carabidae) along an urbanisation gradient near Sorø, Zealand, Denmark

The seasonal activity of six carabid species (Nebria brevicollis, Carabus nemoralis,
C. hortensis, C. coriaceus, Pterostichus melanarius and Abax parallelepipedus)
was studied along an urbanisation gradient (rural forest – suburban forest
– forest fragments in urban park) in Sorø, Denmark, during April–October
2004 and 2005.Two groups were identified: 1) Species with constant seasonality,
in which seasonal activity profiles did not differ along the gradient (C. hortensis,
C. coriaceus, and A. parallelepipedus); 2) Species with flexible seasonality,with
remarkable differences along the gradient and between the years (C. nemoralis,
N. brevicollis and P. melanarius). In four out of six studied species, 2005 was less
favourable than 2004. Spring activity in the urban habitat started earlier than in
the suburban or forested ones. Abetter understanding of urban green infrastructures
in biodiversity assessments may need the study of seasonality in order to
distinguish whether the bioindicator’s responses are to habitat quality or stochastic
seasonal events.