Spatial avoidance of patches of polluted chernozem soils by soil invertebrates

Abstract

Soil invertebrates and heavy metal concentrations are heterogeneously distributed in the soil of steppe plots surrounding an iron mining enterprise in southern Russia. This study assesses whether patches of high soil invertebrate abundance coincide with patches of low concentrations of pollutants. For this aim, spatial analysis by distance indices (SADIE) was applied. Three valleys in Belogorye Nature Reserve were chosen. One valley faced the tailing pond to the north and the other two faced south-east or south-west. Two sampling plots were chosen in each valley, 60 m apart from each other. On every plot 16 soil cores were collected from a grid of 4 × 4 units with a 5-m distance between each sample unit. Each soil core had an area of 76 cm 2 and was 12-15 cm deep. All macroinvertebrates were hand-sorted and identified to family. Abundance of soil invertebrates was not controlled by patches of metal concentration in the soil. Epigaeic groups, like insects and other invertebrates inhabiting the litter layer, were not directly associated with local parameters of the soil. On the contrary, belowground invertebrate abundance (elaterid larvae and earthworms) showed significant dissociation with some heavy metal (Fe, Pb, Zn) concentrations in the soil. The patchiness of soil pollution may act as a leading factor of belowground soil invertebrate distribution. The spatial structure of animal populations in industrially transformed soils needs further research.

The impacts of metals and metalloids on insect behavior

“…Other studies examining mixtures of metals in contaminated soils revealed that F. candida consistently avoided heavily contaminated soils, though there was high variability in individual response (Natal da Luz et al, 2004). Reporting an overall response of a conglomerate soil insect fauna, Gongalsky et al (2009) found consistent avoidance of heavily contaminated soils. Collectively, the broadly contradictory results from the available research suggest there are many environmental factors that may influence movement.…”

Extent of Heavy Metal Accumulation in Sewage Irrigated Soils and Their Impact on Distribution of Earthworm Communities: Linking Chromium and Zinc Toxicity on Growth and Reproduction in Selected Earthworm Species.

“…Cocoon formation and its development time vary from species to species and are dependent on species age, population density and climatic factors like temperature, moisture and energy content of the food. Anthropogenic activities leads to increase metal concentrations of toxic metals in surface soils resulting in decreased earthworm density 43 , and its extinction caused by metal overload is directly related to soil compaction and inconsistent litter build up which is critical in evaluating soil quality 44 .…”

Evidence for avoidance of Ag nanoparticles by earthworms (Eisenia fetida)

“…That study found evidence that soil organic matter content and pH contributed to worm avoidance behavior and could explain the avoidance in certain exposures. In a field study, Gongalsky et al (2009) found some relationship between earthworm density and metal (e.g. Mn and Zn) concentrations but no relationship between earthworm density and soil quality measurements (e.g.…”

“…Anthropogenic activities that increase concentrations of toxic metals (Cd, Cu, Pb, Zn, etc. ) in surface soils have been implicated in the decrease in density (Gongalsky et al 2009;Klok et al 2007;Van Zwieten et al 2004) and local extinction (Bengtsson et al 1983;Eijsackers et al 2005;Vorobeichik 1998) of earthworms in various impacted environments. In turn, earthworm extinction caused by metal contamination has been linked to soil compaction and excessive litter buildup in (Eijsackers et al 2005;Rombke et al 2005;Van Zwieten et al 2004) both of which are detrimental to soil quality.…”