Maintaining flat bug (Aradus spp.) species in boreal forest landscapes; an experiment mimicking natural disturbances.
Industrial forest harvest and fire suppression have led to reduced structural heterogeneity with subsequent declines of biodiversity in Swedish boreal forests. In order to achieve environmental certification many forest companies implement some environmental consideration such as tree retention and leaving buffer zones against waters. In order to improve prerequisites for biodiversity it would also be desirable to practice more active restoration. In our expriment we have set up a replicated such as prescribed forest fires and creating artificial gaps, which mimic natural disturbance and recreate a more diverse forest landscape. By using replicated prescribed burns, artificial gap cuts and forest set asides as experimental controls, we tested the efficiency of restoration efforts for maintaining biodiversity. Fungivorous flat bugs, within the poorly known Aradus genus were positively affected by forest fire. Significantly more Aradus specimens were found in burned stands than in gap cuttings and controls. Aradus corticalis, A. betulaeand A. brevicollis which previously were not considered pyrophilous, were exclusively found in burned sites. We suggest that more species of Aradusare strongly favored by forest fire than previously known. In contrast to the fire favored species, Aradus depressuswas primarily found in stands with artificially created gaps. Only one single specimen of Aradus (A .depressus) was found in the control sites. In order to maintain multiple Aradusspecies in the landscape our recommendation to forest managers is the use of a diverse restoration toolbox, including prescribed forest fire and artificial gap creation, as part of their management practices.