Can mollusks or insects serve as bioindicators of the risk element polluted area? Gastropods (Gastropoda) versus leaf beetles (Coleoptera: Chrysomelidae)

Two groups of invertebrates, terrestrial mollusks (Gastropoda) and Chrysomela populi leaf beetles (Coleoptera: Chrysomelidae), were sampled to estimate the suitability of these organisms as bioindicators of risk element pollution (predominantly Cd, Pb, and Zn) alongside the risk element concentration gradient in the contaminated area (former mining/smelting areas in the vicinity of Příbram city, Central Bohemia, Czech Republic). The individuals representing ten species of terrestrial snails and imagoes of C. populi were collected manually at five sampling sites, differing in the level of soil contamination with risk elements. The findings showed high variability of the results regardless of the element determined, animal species, and sampling location. Among the elements, higher accumulation ability was observed for Cd and Zn, given the higher bioaccessibility of these elements in soils compared to Pb, Cr, and Cu. Higher Cd and Zn accumulation in the soft tissues of gastropods (without any statistically significant differences among the species) compared to C. populi was also recorded. Medians of the bioaccumulation factors (BAFs) reached up to 33.2 for Cd and 5.8 for Zn, in gastropods while reaching up to 3.4 for Cd, and 2.3 for Zn, for C. populi. For both groups of organisms, paradoxically, a higher rate of accumulation of risk elements was observed in all analyzed organisms in sites with lower soil contamination compared to heavily contaminated sites. This indicated the ability of the organisms living in extreme conditions to avoid the uptake of these elements or to move among areas of different contamination levels. Thus, terrestrial gastropods and C. populi proved to be unsuitable bioindicators for assessing soil pollution.

Diversity and abundance of soil macroinvertebrates along a contamination gradient in the Central Urals, Russia

Background

Since the late 1980s, long-term monitoring of terrestrial ecosystems in metal-contaminated areas near the Middle Ural Copper Smelter has been carried out in the Central Urals. As a part of these monitoring programmes, the data on species diversity, community composition and abundance of soil macroinvertebrates continue to be gathered.

New information

The dataset (available from the GBIF network at https://www.gbif.org/dataset/61e92984-382b-4158-be6b-e391c7ed5a64) includes a 2004 census for soil macroinvertebrates of spruce-fir forests along a pollution gradient in the Central Urals. The dataset describes soil macrofauna’s abundance (the number of individuals per sample, i.e. the density) and community structure (list of supraspecific taxa, list of species for most abundant taxa and supraspecific taxa or species abundance). Seventeen sampling plots differed in the levels of toxic metal (Cu, Zn, Pb, Cd and Fe) soil contamination from air emissions of the Middle Ural Copper Smelter (heavily polluted, moderately polluted and unpolluted areas). The dataset consists of 340 sampling events (= samples corresponding to upper and lower layers of the 170 soil monoliths) and 64658 rows (2907 and 61751 for non-zero and zero density of taxa, respectively). Arachnida (Araneae and Opiliones), Carabidae (imagoes), Elateridae (larvae), Chilopoda, Diplopoda, Gastropoda, Staphylinidae (imagoes) and Lumbricidae were identified to species level. In contrast, Mermithida, Enchytraeidae, Lepidoptera larvae, Diptera larvae, Hemiptera, Hymenoptera and some other insects were identified to family or order levels. In total, 8430 individuals of soil macroinvertebrates were collected in two soil layers (organic and organic-mineral horizons), including 1046 Arachnida (spiders and harvestmen), 45 Carabidae, 300 Elateridae, 529 Myriapoda, 741 Gastropoda, 437 Staphylinidae, 623 Lumbricidae and 4709 other invertebrates. The presence-absence data on each taxon are provided for each sampling event. An overwhelming majority of such absences can be interpreted as “pseudo-absences” at the scale of sampling plots or study sites. The dataset contains information helpful for long-term ecotoxicological monitoring of forest ecosystems and contributes to studying soil macrofauna diversity in the Urals.