Insect community structure and insect biodiversity conservation in an Alpine wetland subjected to an intermediate diversified management regime

The paper deals with the structure of insect communities and insect biodiversity conservation in the Alpine wetland of Pian Gembro (Italy). For over a century, the wetland was subjected to diversified peat harvesting procedures, to agricultural exploitation and recently, to a superimposed diversified intermediate management regime (DIMR) aiming at plant species and plant diversity conservation. The purpose of this paper is to evaluate whether the DIMR is likewise effective for insect biodiversity conservation. Pitfall traps, sweep and collections of visually observed insects yielded 997 individuals representing 141 species from 11 insect families. The rank-frequency curve for bog insects was relatively steep indicating a low evenness due to the high abundance of low ranking species. The curve for insects collected in the surroundings was less steep pointing to a relatively high evenness due to a lower abundance of low ranking species. In both the bog and the surroundings the Shannon diversity index was generally highest at intermediate levels of disturbance. These results indicate that the DIMR strategies implemented for plant biodiversity conservation is also appropriate to conserve insect species biodiversity.