Oribatid mite communities on former clay quarries under different reclamation strategy

Abstract

In order to establish or regenerate ecosystems in severely disturbed mining sites, reclamation activities are common practice. However, the effectiveness of reclamation strategy might be depended on the specific conditions of the area under question. To evaluate the ef- fect of provided reclamation activities, we investigated structure and composition of oribatid mite communities at an early succession stage in the abandoned Kaspi clay pit. Effectiveness of natural succession and two alternative reclamation activities was evaluated: 1. M1 - do-nothing approach on land under natural secondary succession; 2. M2 - smoothed ground surface with sown seed mixture of herbs and pasture grasses; 3. M3 -three fenced plots with sown grasses and tree seedlings. Neighboring overgrazed natural meadow is chosen as control. Results show that the “do-nothing” approach with leaving post-mining sites without any reclamation is the worse strategy in development of soil oribatid community on lands without “source” area for vegetation (and consequently for soil humus layer) development. Reclaimed fenced areas were relatively poor by oribatid species richness compared to surrounding reclaimed (but not fenced) or natural areas. High abundance of stress tolerant species in fenced sites shows that the time interval between fencing (2012, 2013 and 2014) and sampling (2015-2016) was not enough for soil structure and faunal recovery and longer period is needed to establish sustainable oribatid communities.