The Berger-Parker index as an effective tool for monitoring the biodiversity of disturbed soils:: a case study on Mediterranean oribatid (Acari : Oribatida) assemblages

Recent data on oribatid mites (Acari: Oribatida) indicates that Mediterranean soil communities tend to show uneven patterns of species abundance distribution (SAD) that are well fitted by a simple model such as the geometric series. In the case of linear distributions, the fraction of total sampled individuals that is contributed by the most abundant species, known as the Berger-Parker index, synthetically describes the SAD of disturbed communities. This study assessed the bioindicator potential of the Berger-Parker index by comparing its variations among Mediterranean oribatid assemblages under different types of soil disturbance. The index significantly changes between undisturbed and disturbed soils reaching the highest values in areas with strong physical disturbance due to agricultural management. The Berger-Parker index is therefore a practical and effective tool for monitoring biodiversity impairment linked to human disturbance in soil ecosystems.