Changes in the vegetation of clear-fells and closed canopy stands in an English oak wood over a 30-year period

Abstract

The vascular plant ground flora of clear-felled and undisturbed oak stands were studied using 10 m × 10 m temporary and permanent plots over a 30-year period in a wood in southern England. Within the undisturbed stands, the mean species richness declined from 10 to 15 species per plot in 1981 to about five in 2012. The decline was correlated with a decrease in openness of the tree and shrub layer over this period. In the clear-fells, the species richness in the first two growing seasons after felling was 1.5 to 3 times higher than in the undisturbed stands. Ruderal species and grasses in particular increased, but some ancient woodland indicators (AWI) were present, even after a decade of openness. Change in the openness of stands appears to be a strong driver of ground flora richness up to about 50% cover; in more open conditions, competition and other processes within the ground flora assemblage may come to play a greater part. Forest management has played a key role in creating canopy gaps in small ancient woods in Britain but, in future, tree deaths from disease and extreme weather events are likely to increase in importance.