Beech forest management does not affect the infestation rate of the beech scale Cryptococcus fagisuga across three regions in Germany

The effects of management on insect communities have been studied in several forest ecosystems, although the consequences for single potential pests are only known for a few species. The present study investigated whether forest management affects the infestation of European beech trees by the beech scale Cryptococcus fagisuga. We assessed the densities of C. fagisuga on a total of 520 trees (Fagus sylvatica) at 104 forest sites, representing three main types of beech forest management intensity across three regions in Germany. The infestation rates on beech trees were 16% in the South-West, 20% in the Centre and 35% in the North-East of Germany, although the rates per plot did not differ significantly among regions. No significant differences between unmanaged beech, managed even-aged beech and managed uneven-aged beech forests were found because of high variability in beech scale infestation observed among forest sites and within forest management types. Highest infestation rates occurred on widely dispersed mature trees within thickets with shelterwood stage and lowest infestation rates occurred on young beech trees in the thicket stage. The results of the present study suggest that the infestation rates of C. fagisuga on beech depend on tree age and canopy openness rather than on management intensity.