Ground beetle (Coleoptera, Carabidae) communities as natural indicators of ecosystem restoration on the terminated fly ash dump of the thermoelectric power station (Novosibirsk, Russia)

Abstract

The aim of the study. The aim of the study was to reveal regularities in the development of ground beetles (Coleoptera, Carabidae)’ communities, to determine their species peculiarities as dependent on soil formation rate and soil ecology in the ecosystems developed on the terminated fly ash dump of the thermoelectric power station over nine years of restoration. Location and time of the study. The main object of the study was a terminated fly ash dump No.1 of the thermoelectric power station No.5 in Novosibirsk, Russia. (54°59' NL, , 83°03' EL). Soil samples were collected in 2019, whereas the ground beetles were collected in 2017 and 2019. Methodology. Six study sites, corresponding to the fly ash dump sedimentation zones, were chosen. The undisturbed white birch forest and clover-brome meadow were chosen as controls representing mature climax ecosystems. Soil cover, developing on the fly ash dump after its termination, was described according to the soil classification of technogenic landscapes, and was shown to consist of various types of embryozems (Technosols). Soil water content on each study site was measured in 0–5cm layer by gravimetric method. Soil samples were collected in May 2019. To collect ground beetles five traps were placed on each study site, each trap filled up to 1/3 of its volume with 4% acetic acid for fixing the trapped beetles. The beetles were collected in May–June 1017 and in June–July 2019. The data obtained were used to calculate α-biodiversity indices and perform cluster analysis using PAST v.3.09 software. Main results. Altogether 74 species of the ground beetle we found: 60 species of ground beetles were identified in the revegetating fly ash dump areas, with 48 species found at the sites amended with potentially fertile substrate (PFS), and 35 species found at the sites without PFS addition. The control sites under birch forest and meadow had 14 and 10 species, respectively. Thus the ground beetles’ abundance in the reclaimed area was almost 3 times greater than in the non-reclaimed area (973 specimens vs. 347). Cluster analysis discriminated three groups in the studied fly ash dump sites, namely dry non-reclaimed sites, dry PFS sites and moist sites. Soil cover of the studied fly ash dump was represented by initial, organic matter accumulating, humus-accumulating and sod embryozems (Technosols). Conclusion. Over nine years of spontaneous restoration at the terminated fly ash dump of the thermoelectric power station species rich and abundant communities of ground beetles were formed. These communities differed significantly from those at the adjacent undisturbed climax ecosystems used for comparison. Species richness and dynamic density of ground beetles was shown to increase from the control sites to non-reclaimed sites and PFS-reclaimed sites. The autonomous position in the catena was found to be occupied by the less evolutionary developed embryozem type, whereas downwards along the catena, i.e. with increasing soil moisture content, identified soil types belonged to higher evolutionary order. Therefore technical recultivation with fly ash dump overlaying with potentially fertile substrate or fertile soil allow accelerating soil cover development, as well as the development of an entire biogeocenosis.