Heavy metals are extremely persistent in the environment; they are not biodegradable and not degradable by heat and thus readily accumulate to toxic levels, mainly due to long-term anthropogenic activities (Sharma
As reported by Kašpárek (1984), the Litavka River frequently floods. Large floods (water flows >55 m3 · s−1) occurred here 27 times between 1931 and 2007 (unpublished data from the Czech Hydrometeorological Institute). Ponds that hold and sediment mine waste are close to the Litavka River, so their walls have been breached several times by these floods, and the contents of the ponds, containing very high amounts of heavy metals and other risk elements, have been released into the river water and to the alluvia. Therefore, the soils in the alluvia are extremely polluted (Borůvka
Several studies have assessed the accumulation and/or contents of heavy metals in the floodplain soils around the Litavka River (Borůvka
Relationships between heavy-metal contamination and communities of soil nematodes have attracted increasing attention in recent years (Li
This study was performed in five alluvial meadows along the stream of the Litavka River as linear sources of pollution from a waste-sedimentation pond near the river. Selected sites were: (A) a control meadow 3.6 km upstream of the source of pollution (49°40¢N, 13°58¢E), (B) a meadow near the waste-sedimentation pond (49°42¢N, 13°59¢E), (C) a meadow near a mining Terril 680 m downstream from site B (49°42¢N, 13°59¢E), (D) a meadow near an old bakery mill 3.7 km downstream from (B) (49°43¢N, 14°07¢E), and (E) a meadow close to the village of Jince 13.3 km downstream from the source of pollution (49°47¢N, 13°59¢E) (Fig. 1). The river has a gradient of approximately 5 m/km and a single active channel, with no artificial source of pollution upstream before the control site. The river valley has a typical width of 100 m to 200 m and is relatively flat with abundant ditches (Faměra
Before the analysis, soil samples were air-dried, pounded, and sifted through a 0.2 mm sieve. Soil acidity (pH KCl) was determined using a HI2031B pH electrode meter (Hanna Instruments, Voehringen, Baden-Wuerttemberg, Germany) in the suspension of soil (10 g) and soil sample preparation solution HI7051L (25 ml) at room temperature. Soil moisture of the replicates was measured gravimetrically as the loss of weight after drying the 100 g of soil to a constant weight at 105°C for 12 hr. The contents of organic carbon (C) and total nitrogen (N) were determined from 0.25 g of soil using a Vario MACRO Elemental Analyzer (CNS Version; Elementar Analysensysteme, Langenselbold, Germany). Organic C content was determined based on the difference between total C and C bound in carbonates. The pseudo-total contents of elements in the 0.25 g of soil were determined by decomposing the samples using pressurized wet ashing (Ethos 1 microwave-assisted wet-digestion system, Milestone, Leutkirch im Allgau, Germany) as described by Fröhlichová
A combination of Cobb sieving and decanting (Cobb, 1918) and a modified Baermann technique (van Bezooijen, 2006) were used for extracting nematodes from 100 g of fresh soil in aqueous soil suspensions using a set of two cotton-propylene filters. One or two filter trays were used for each sample to prevent material from exceeding 0.5 cm in depth above the filter. Aqueous suspensions were removed after 48 hr of extraction at room temperature, and nematodes were counted under a stereomicroscope (40× magnification). Excessive water was removed, and the nematodes were fixed with a hot solution of 4% formaldehyde and 1% glycerol (Seinhorst, 1962). At least 100 nematodes were identified at the species level based on the original species descriptions and accessible taxonomic keys of nematode genera and groups using an Eclipse 90i light microscope (Nikon, Tokyo, Japan) at standard magnifications.
Nematode abundance in each sample was expressed as the number of individuals per 100 g of dry soil. Nematode genera were assigned to trophic groups as described by Yeates
Statistical analyses were done using STATISTICA version 14.0 (TIBCO, 2020) and CANOCO 5 for Windows version 5 (Ter Braak and Šmilauer, 2012). All response variables were subjected to a one-way ANOVA to determine the overall effect of heavy-metal content on the nematode communities, after checking the homogeneity of variance using Levene’s test. When necessary, data were log(x + 1) transformed. Tukey’s honestly significant difference (HSD) was applied to identify significant differences in the variables between sites at
A redundancy analysis (RDA) was used on the main nematode genera associated with the alluvial meadows, with the heavy-metal contents as explanatory variables, to identify the relationships between the nematodes and trace elements. All data were log-transformed before use. The effects of the explanatory variables were quantified by automatic forward selection.
The soils at sites A and E had neutral pH of 6.89 and 6.75, respectively. The soils at sites B, C, and D were moderately acidic, with pH ranging from 5.20 to 5.50, which differed significantly from the control site (A) to site E, the meadow farthest from the source of pollution (
Soil physico- chemical properties (mean ± SD) associated with alluvial meadows in the vicinity of the Příbram mine along the Litavka River.
Parameter | Sites |
||||
---|---|---|---|---|---|
A | B | C | D | E | |
pH/KCl | 6.89 ± 0.25a | 5.42 ± 0.21a | 5.20 ± −0.11b | 5.56 ± 0.16b | 6.75 ± 0.18a |
Soil moisture (%) | 35.2 ± 5.6a | 31.5 ± 2.9a | 29.5 ± 3.1a | 30.5 ± 3.3a | 31.5 ± 2.8a |
Ntot (%) | 0.87 ± 0.15a | 0.61 ± 0.10b | 0.74 ± 0.32b | 0.66 ± 0.15b | 0.83 ± 0.22a |
Cox (%) | 14.25 ± 1.69a | 8.25 ± 2.19b | 10.67 ± 3.61b | 12.29 ± 2.69a | 12.87 ± 3.16a |
Means followed by the same letters on the same rows are not statistically different by Tukey's honestly significant difference (HSD) at
All heavy-metal contents in the soil samples were significantly higher (
Total concentrations of heavy metals (mg/kg) (mean ± SD) associated with alluvial meadows in the vicinity of the Příbram mine along the Litavka River.
Element | Sites |
Max | ||||
---|---|---|---|---|---|---|
A | B | C | D | E | ||
As | 38.2 ± 3.3a | 688.8 ± 91.8c | 677.4 ± 181.1c | 176.2 ± 47.7b | 31.8 ± 17.8a | 20 |
Cd | 1.9 ± 0.2a | 19.5 ± 1.9b | 51.5 ± 23.1c | 28.4 ± 12.9bc | 2.1 ± 1.0a | 0.5 |
Cr | 37.9 ± 5.1a | 58.2 ± 1.3b | 68.8 ± 59.9a | 40.4 ± 5.7a | 28.7 ± 1.7a | 90 |
Cu | 35.7 ± 5.3a | 97.6 ± 8.7b | 139.6 ± 24.6c | 61.9 ± 30.7ab | 23.1 ± 11.9a | 60 |
Ni | 19.1 ± 1.3a | 38.1 ± 2.4b | 33.2 ± 8.2ab | 22.9 ± 8.3a | 15.4 ± 1.8a | 50 |
Pb | 553.3 ± 237.6a | 3734.1 ± 1915.6b | 4030.9 ± 165.1bc | 2682.2 ± 460.3b | 689.8 ± 474.3a | 60 |
Zn | 346.2 ± 34.6a | 2949.5 ± 435.9b | 6867.8 ± 1374.9c | 3866.4 ± 1146.2b | 566.4 ± 490.1a | 120 |
Means followed by the same letters on the same rows are not statistically different by Tukey's honestly significant difference (HSD) at
Max – limits posted by The Decree of the Ministry of Land Management of the Czech Republic No. 437/2016 on the admissible values of harmful substances in uncontaminated soil.
The average nematode abundance ranged from 513 to 2,193 individuals per 100 g of dry soil. Abundance was highest at site A and lowest at site C (Table 3). The most polluted sites (B, C, and D) had significantly fewer nematodes compared with site A (
Total nematode abundance, number of genera, nematode community indices associated with alluvial meadows in the vicinity of the Příbram mine along the Litavka River (mean ± SD).
Indices | A | B | C | D | E |
---|---|---|---|---|---|
Nematode abundance | 2193.2 ± 358.9a | 595.8 ± 130.9b | 513.8 ± 122.3b | 974.9 ± 340.4b | 1674.1 ± 263.5a |
Genera number | 31.8 ± 1.7a | 25.8 ± 1.5b | 27.5 ± 5.1a | 21.5 ± 3.1b | 30.5 ± 4.2a |
Maturity Index | 2.68 ± 0.12a | 2.12 ± 0.09b | 2.20 ± 0.10b | 2.22 ± 0.21b | 2.63 ± 0.15a |
Maturity Index (2-5) | 2.89 ± 0.07a | 2.33 ± 0.16b | 2.37 ± 0.15b | 2.33 ± 0.19b | 2.85 ± 0.22a |
Plant Parasitic Index | 2.69 ± 0.11a | 2.80 ± 0.18a | 2.88 ± 0.04a | 2.77 ± 0.14a | 2.73 ± 0.16a |
Diversity Index (H´gen) | 3.49 ± 0.15a | 2.13 ± 0.25b | 2.47 ± 0.26b | 2.22 ± 0.18b | 3.09 ± 0.10a |
Channel Index | 8.8 ± 4.0a | 23.0 ± 11.8b | 36.4 ± 12.9b | 30.9 ± 6.6b | 22.9 ± 19.6ab |
Basal Index | 16.6 ± 2.3a | 32.9 ± 8.3b | 33.9 ± 10.7b | 33.7 ± 4.6b | 19.9 ± 9.3a |
Enrichment Index | 71.5 ± 4.4a | 53.2 ± 10.9b | 50.3 ± 11.5b | 37.9 ± 16.2b | 66.7 ± 10.1b |
Structure Index | 72.0 ± 3.2a | 44.5 ± 18.7b | 49.8 ± 13.1b | 47.9 ± 16.2b | 73.8 ± 12.3a |
Total biomass, mg | 7.5 ± 1.2a | 2.1 ± 1.2b | 1.9 ± 1.3b | 4.9 ± 2.9b | 8.6 ± 2.5a |
Means followed by the same letters on the same rows are not statistically different by Tukey's honestly significant difference at
A total of 78 nematode genera were recorded in the alluvial meadows downstream along the Litavka River. Of these genera, 25 were bacterivores (Ba), 8 were fungivores (Fu), 11 were omnivores (Om), 7 were predators (P), 26 were plant parasites (Pp), and 1 was an insect parasite (In) (Table 4). The genera
A abundance of nematode genera (mean ± SD) associated with alluvial meadows in the vicinity of the Příbram mine along the Litavka River.
Genus/trophic group | c-p | A | B | C | D | E |
---|---|---|---|---|---|---|
1 | 251.6 ± 103.4 | 24.3 ± 13.0 | 22.6 ± 14.2 | 5.3 ± 8.3 | 24.8 ± 14.5 | |
2 | 241.3 ± 44.1 | 23.9 ± 20.7 | 10.5 ± 2.9 | 0.9 ± 0.5 | 15.4 ± 2.8 | |
1 | 187.0 ± 63.9 | 21.8 ± 17.7 | 5.9 ± 1.2 | 9.5 ± 11.6 | 26.3 ± 10.8 | |
2 | 143.3 ± 75.1 | 72.1 ± 8.4 | 15.4 ± 7.9 | 51.1 ± 26.6 | 40.5 ± 35.6 | |
2 | 123.5 ± 61.0 | 12.1 ± 8.9 | 5.9 ± 3.9 | 9.6 ± 10.2 | 23.2 ± 18.7 | |
2 | 53.3 ± 27.8 | 12.2 ± 9.3 | 20.5 ± 10.8 | 22.5 ± 15.9 | 11.6 ± 10.1 | |
3 | 51.1 ± 60.8 | 12.1 ± 7.9 | 7.0 ± 3.3 | 11.9 ± 17.5 | 17.6 ± 5.3 | |
1 | 27.4 ± 14.9 | - | - | - | 2.2 ± 4.4 | |
2 | 26.2 ± 24.1 | 4.6 ± 5.9 | 5.0 ± 2.4 | - | 4.4 ± 8.7 | |
2 | 18.3 ± 5.6 | 4.5 ± 3.4 | - | 8.6 ± 3.9 | - | |
4 | 9.1 ± 18.1 | 0.6 ± 1.1 | 4.3 ± 7.3 | - | 12.2 ± 9.8 | |
3 | 8.7 ± 5.9 | 2.1 ± 4.2 | 2.6 ± 1.9 | 1.9 ± 3.8 | 4.6 ± 9.3 | |
2 | 8.0 ± 5.4 | 1.9 ± 1.4 | - | - | - | |
2 | 7.9 ± 15.8 | - | - | 8.1 ± 6.6 | 47.0 ± 12.8 | |
3 | 2.3 ± 4.6 | 1.4 ± 2.9 | 9.5 ± 2.6 | 1.9 ± 3.8 | 10.3 ± 5.9 | |
2 | 1.5 ± 3.0 | 0.5 ± 1.0 | - | 1.9 ± 3.8 | 2.3 ± 4.6 | |
2 | - | - | - | 1.9 ± 3.8 | 16.8 ± 11.5 | |
4 | - | - | 1.9 ± 3.8 | - | - | |
2 | - | 1.1 ± 2.3 | 2.2 ± 2.5 | - | - | |
1 | - | 1.4 ± 1.7 | - | - | 2.2 ± 4.4 | |
2 | - | 4.0 ± 3.8 | 3.0 ± 2.0 | - | - | |
2 | - | - | - | 2.9 ± 3.7 | 8.6 ± 10.6 | |
1 | - | 1.0 ± 2.1 | - | - | 2.2 ± 4.4 | |
3 | - | 1.5 ± 2.0 | - | - | - | |
2 | - | 15.4 ± 14.8 | - | 1.9 ± 2.1 | 12.4 ± 8.3 | |
4 | 104.9 ± 59.4 | - | - | - | - | |
2 | 113.6 ± 54.2 | 7.9 ± 5.9 | 8.2 ± 6.6 | 9.5 ± 11.5 | 39.6 ± 7.8 | |
2 | 24.4 ± 37.3 | 20.9 ± 12.3 | 2.1 ± 3.0 | 11.9 ± 6.2 | 2.2 ± 4.4 | |
2 | 12.5 ± 15.4 | 9.3 ± 7.6 | 6.5 ± 3.0 | 2.9 ± 5.9 | 3.2 ± 6.5 | |
3 | 10.9 ± 14.9 | 5.0 ± 5.0 | 8.5 ± 4.5 | 6.2 ± 2.8 | 6.0 ± 4.2 | |
4 | 5.4 ± 6.3 | 4.2 ± 8.3 | - | - | 7.6 ± 10.2 | |
4 | 4.5 ± 9.1 | 0.5 ± 1.0 | - | - | - | |
2 | - | 1.2 ± 2.5 | - | - | 1.6 ± 3.2 | |
4 | 91.1 ± 61.5 | 3.0 ± 3.9 | 0.9 ± 0.9 | 2.9 ± 3.7 | 53.1 ± 38.5 | |
4 | 76.2 ± 26.6 | - | - | - | 4.4 ± 8.7 | |
5 | 60.5 ± 40.2 | 0.8 ± 1.6 | - | - | 1.6 ± 3.2 | |
4 | 24.3 ± 40.7 | 0.5 ± 1.0 | 2.4 ± 1.8 | - | 1.6 ± 3.2 | |
5 | 13.9 ± 16.4 | 1.0 ± 2.1 | 2.0 ± 1.4 | 3.8 ± 4.1 | 21.1 ± 6.9 | |
4 | 10.7 ± 12.6 | 0.4 ± 0.8 | 0.5 ± 1.0 | - | 4.9 ± 5.7 | |
3 | 3.1 ± 6.1 | - | - | - | - | |
4 | 1.5 ± 3.0 | 6.7 ± 6.3 | 1.5 ± 1.9 | 1.9 ± 1.2 | - | |
5 | - | 2.8 ± 5.7 | - | - | - | |
4 | - | 2.1 ± 4.2 | - | - | - | |
4 | - | - | 0.5 ± 1.1 | 9.5 ± 11.4 | - | |
5 | - | 0.4 ± 0.8 | - | - | - | |
3 | 7.7 ± 9.1 | 2.9 ± 5.9 | - | 1.9 ± 3.8 | - | |
4 | 7.3 ± 9.0 | 0.5 ± 1.0 | 3.4 ± 2.1 | - | - | |
4 | 6.2 ± 8.7 | - | - | - | 1.6 ± 2.1 | |
4 | 3.1 ± 6.1 | 0.9 ± 1.0 | 8.0 ± 4.6 | 8.1 ± 5.0 | 14.4 ± 9.8 | |
4 | 3.1 ± 6.2 | 3.7 ± 5.9 | 1.1 ± 2.1 | - | 17.3 ± 14.6 | |
5 | - | - | - | - | 2.2 ± 4.4 | |
3 | 163.8 ± 82.9 | 38.7 ± 31.1 | 60.9 ± 21.6 | 85.7 ± 64.8 | 118.0 ± 57.6 | |
3 | 57.9 ± 47.4 | 31.8 ± 2.4 | 27.8 ± 17.3 | 78.6 ± 21.8 | 52.3 ± 134.8 | |
3 | 36.9 ± 30.1 | 5.0 ± 1.2 | - | - | - | |
2 | 50.9 ± 52.7 | 9.2 ± 2.5 | 5.8 ± 2.4 | 95.5 ± 21.9 | 2.2 ± 4.4 | |
3 | 29.3 ± 31.7 | - | 0.5 ± 1.1 | 0.9 ± 1.9 | - | |
3 | 27.0 ± 20.3 | 67.7 ± 47.0 | 62.5 ± 16.3 | 53.8 ± 4.4 | 22.4 ± 16.6 | |
2 | 26.6 ± 12.9 | 39.8 ± 33.0 | - | - | 7.0 ± 13.9 | |
2 | 15.3 ± 12.0 | 5.1 ± 4.7 | 0.9 ± 1.9 | 4.3 ± 3.3 | 9.2 ± 10.6 | |
3 | 14.7 ± 12.0 | 23.9 ± 27.1 | 3.9 ± 5.1 | - | 4.9 ± 5.7 | |
3 | 7.5 ± 8.2 | 10.7 ± 26.2 | - | 20.5 ± 14.5 | 99.6 ± 33.9 | |
2 | 6.8 ± 9.9 | 0.8 ± 1.6 | 0.5 ± 1.1 | 1.9 ± 3.8 | - | |
2 | 6.1 ± 12.2 | 2.8 ± 3.7 | - | - | 2.3 ± 4.6 | |
3 | 3.0 ± 6.1 | 1.3 ± 2.0 | - | - | - | |
2 | 2.6 ± 5.3 | - | - | 3.8 ± 7.6 | - | |
3 | - | - | - | - | 9.7 ± 7.0 | |
3 | - | - | 105.7 ± 49.2 | 303.1 ± 63.3 | 195.3 ± 110.3 | |
5 | - | 3.4 ± 4.3 | - | - | 23.8 ± 8.2 | |
3 | - | - | 1.6 ± 2.1 | - | 15.6 ± 12.1 | |
4 | - | 4.1 ± 1.5 | - | - | 24.9 ± 30.2 | |
2 | - | 27.0 ± 16.2 | 33.3 ± 10.8 | 23.4 ± 9.7 | 177.1 ± 159.5 | |
3 | - | 31.6 ± 8.4 | 45.1 ± 14.1 | 107.1 ± 28.9 | 122.8 ± 40.2 | |
4 | - | 4.3 ± 5.9 | - | - | 20.5 ± 18.4 | |
3 | - | 4.3 ± 7.2 | - | - | - | |
2 | - | - | - | 3.9 ± 2.5 | - | |
2 | - | - | 2.8 ± 3.5 | - | - | |
2 | - | - | 1.1 ± 1.2 | - | - | |
1 | - | - | 2.8 ± 5.7 | 3.8 ± 4.4 |
The nematode communities at site A (control) were characterized by the prevalence of bacterivores (Ba1,2), followed by plant parasites (Pp2,3), fungivores (Fu2,4), omnivores (Om4), and predators (P5) (Table 5). All bacterial functional guilds had significantly fewer individuals at sites B, C, and D than site A (
Mean (±SD) abundance of nematode trophic groups and functional guilds associated with alluvial meadows in the vicinity of the Příbram mine along the Litavka River.
A | B | C | D | E | |
---|---|---|---|---|---|
Ba1 | 466.1 ± 142.5a | 48.5 ± 31.2b | 28.4 ± 18.3b | 14.8 ± 10.2b | 57.6 ± 30.0b |
Ba2 | 623.3 ± 149.5a | 152.3 ± 41.3b | 61.9 ± 8.3b | 109.3 ± 54.1b | 182.3 ± 78.9b |
Ba3 | 62.1 ± 60.6a | 17.1 ± 13.8b | 19.1 ± 15.3b | 15.7 ± 25.1b | 32.3 ± 27.2ab |
Ba4 | 9.1 ± 18.1a | 0.6 ± 1.1b | 0.6 ± 1.1b | - | 10.0 ± 11.7a |
P3 | 7.7 ± 9.2a | 2.9 ± 5.8a | 2.9 ± 5.8a | 1.9 ± 3.8a | - |
P4 | 19.5 ± 12.1a | 5.1 ± 5.0b | 12.4 ± 9.8a | 8.1 ± 5.0a | 33.3 ± 10.8a |
P5 | 60.4 ± 40.2a | 0.8 ± 1.6b | - | - | 3.8 ± 4.5b |
Fu2 | 150.3 ± 39.8a | 39.4 ± 15.1b | 16.8 ± 7.9b | 24.3 ± 7.1b | 46.6 ± 31.4b |
Fu3 | 10.9 ± 14.9a | 5.0 ± 5.0a | 8.5 ± 7.9a | 6.2 ± 6.5a | 6.0 ± 8.2a |
Fu4 | 114.8 ± 46.3a | 4.6 ± 8.0b | 4.6 ± 8.0b | - | 7.6 ± 10.2b |
Om3 | 3.0 ± 6.1 | - | - | - | - |
Om4 | 203.6 ± 90.0a | 12.7 ± 10.1b | 5.9 ± 3.7b | 14.3 ± 14.7b | 63.9 ± 40.6b |
Om5 | 14.0 ± 6.4a | 4.3 ± 5.0b | 2.0 ± 2.4b | 3.8 ± 4.4b | 21.1 ± 5.6a |
Pp2 | 108.3 ± 52.5a | 84.6 ± 40.5a | 44.4 ± 25.7b | 187.3 ± 121.4a | 397.7 ± 262.4a |
Pp3 | 340.1 ± 15.7a | 206.1 ± 67.4a | 308.0 ± 84.9a | 589.2 ± 206.3a | 540.5 ± 111.2a |
Pp4 | - | 8.4 ± 6.7 | - | - | 45.5 ± 35.8 |
Pp5 | - | 3.4 ± 4.3 | - | - | 23.8 ± 28.9 |
Means followed by the same letters on the same rows are not statistically different by Tukey’s HSD at
Ba1,2,3,4 bacterivores; Fu2,3,4 fungivores; P3,4,5 predators; Om3,4,5 omnivores; Pp2,3,4,5 plant parasites.
HSD, honestly significant difference.
Indices MI, MI2–5, SI, EI, and BI were significantly lower in the heavily polluted sites B, C, and D than in site A (
The graphic representation of the “weighted faunal analysis” for the enrichment and structure indicators indicated that only the soil samples from sites A and E were mapped to quadrant B, which is characterized as a maturing soil food web, weakly to moderately disturbed, with the decomposition of organic matter controlled by both bacteria and fungi (Fig. 3). In contrast, the samples collected in the heavily polluted meadows were mapped to quadrats A and D, which represent soil food webs within a degraded and highly disturbed ecosystem. Similarly, the characteristics of the metabolic footprint of the nematode communities differed among the meadows (Fig. 4). The shape of the total functional footprint (total area) was similar to a square, and the footprint was largest at sites A and E, suggesting that the system was more metabolically balanced and stable than at the sites heavily polluted by heavy metals, which had rhomboid-shaped footprints.
The soil contents of hazardous elements in the area of our study were naturally higher than in other areas of the Czech Republic due to the specific composition of the parental rocks. The bedrocks consisted mainly of schists, sandstones, graywackes, and quartzes. These rocks were mostly covered in the alluvia by non-calcareous alluvial sediments. Minerals rich in potential risk elements include galenite (PbS), sphalerite (ZnS), boulangerite (Pb5Sb4S11), and antimonite (Sb2S3) (Borůvka and Vacha, 2006). These minerals are consistent with the data obtained from two of the alluvial meadows in our study. As, Pb, and Zn contents were relatively high (exceeding the admissible limits of harmful substances in soils) at control site A 3.6 km upstream from the main source of pollution and at site E 13.3 km downstream from the source.
Surveys conducted in the last two decades (Vaněk
Our assumption that the differences in the nematode communities between our surveyed meadows could be attributed to the effects of Zn, Pb, and As contamination and higher soil acidity was thus reasonable. Nisa
Spearman’s rank correlation coefficients between soil physico-chemical properties, heavy metals, and nematode parameters in the alluvial meadows in the vicinity of the Příbram mine along the Litavka River.
As | Cd | Cr | Cu | Ni | Pb | Zn | pH/KCl | Ntot | Cox | SM | |
---|---|---|---|---|---|---|---|---|---|---|---|
Abundance | Ns | ns | ns | ns | ns | −0.862** | −0.748** | −0.659** | ns | ns | ns |
No. genera | ns | ns | ns | ns | ns | ns | −0.451* | ns | ns | ns | ns |
Ba1 | −0.524* | ns | ns | ns | ns | −0.599* | −0.482* | ns | ns | ns | ns |
Ba2 | −0.633** | ns | ns | ns | ns | −0.826** | −0.859** | 0.467* | 0.561* | ns | ns |
Ba3 | −0.489* | ns | ns | ns | 0.442* | −0.631** | −0.745** | ns | ns | ns | 0.412* |
Ba4 | ns | ns | ns | ns | ns | −0.455* | ns | ns | ns | ns | ns |
P3 | −0.583* | ns | −0.409* | −0.460* | ns | −0.741** | −0.692** | ns | ns | ns | ns |
P4 | ns | ns | ns | ns | ns | ns | −0.423* | ns | ns | ns | ns |
P5 | ns | ns | ns | −0.559* | ns | −0.699** | −0.711** | ns | ns | ns | 0.431* |
Fu2 | −0.507* | ns | ns | ns | ns | −0.853** | −0.626** | −0.492* | ns | ns | ns |
Fu3 | ns | ns | ns | ns | 0.455* | ns | ns | −0.522* | ns | ns | ns |
Fu4 | −0.625** | ns | ns | −0.474* | ns | −0.769** | −0.834** | −0.439* | ns | ns | ns |
Om3 | ns | ns | ns | ns | ns | ns | ns | ns | ns | ns | ns |
Om4 | −0.569* | ns | ns | ns | ns | −0.845** | −0.869** | ns | −0.422* | ns | ns |
Om5 | −0.725** | ns | ns | ns | ns | −0.766** | −0.683** | −0.426* | −0.445* | ns | ns |
Pp2 | ns | ns | ns | ns | ns | −0.432* | −0.457* | ns | ns | ns | ns |
Pp3 | ns | ns | ns | 0.466* | 0.529* | ns | 0.513* | ns | ns | ns | 0.436* |
Pp4 | ns | ns | ns | ns | ns | ns | ns | ns | ns | ns | ns |
Pp5 | ns | ns | ns | ns | ns | ns | ns | ns | ns | ns | ns |
H´spp | ns | ns | ns | −0.425* | ns | −0.722** | −0.634** | ns | ns | ns | ns |
MI | ns | ns | ns | ns | ns | −0.584** | −0.605** | 0.433* | ns | ns | ns |
MI (2–5) | ns | ns | ns | ns | ns | ns | −0.552* | ns | ns | ns | ns |
PPI | ns | ns | ns | ns | ns | ns | ns | ns | ns | ns | ns |
CI | ns | ns | ns | ns | ns | ns | ns | ns | ns | ns | ns |
EI | ns | ns | ns | ns | ns | −0.439* | ns | ns | ns | ns | ns |
SI | −0.548* | ns | ns | ns | ns | −0.658** | −0.742** | ns | ns | ns | ns |
*
CI, channel index; EI, enrichment index; MI, maturity index; PPI, plant-parasitic index; ns, not significant; SI, structure index.
In our study, the Ba1,2 genera
Our findings partially agree with those of previous investigations of the impacts of heavy metals on particular nematode taxa but contradict with some data. For example, Korthals
The lower abundances of the majority of the taxa, and the absence of several taxa, at the polluted sites than the control site indicated changes in the community structures and led to changes in the community indices. The abundances of these taxa were significantly lower at the most heavily polluted sites, and reductions of these indices were less pronounced with increasing distance from the sources of pollution. Our results are in accordance with the findings by Sánchez-Moreno and Navas (2007), Shao
Our findings for obligate plant parasitic nematode taxa were consistent with the results reported by Shao
The relatively large number of nematode taxa recorded in the alluvial meadows of the Litavka River demonstrated the capacity of local soils to harbor diverse nematode fauna in this area. Some of these soils, however, have been affected by heavy metals from ponds that sediment mine waste and from waste heaps, spread repeatedly by contaminated flood waters, and our analyses indicated that these pollutants have adversely affected the community of soil nematodes at the target sites. Pb, Zn, As and, to a lesser extent, Cu were the main pollutants responsible for the observed impact. Nematode abundance, number of taxa, and consequently nematode biomass, as well as the trophic complexity of the nematode communities, were significantly reduced at the heavily polluted sites. Interestingly, the abundances of all functional guilds among the bacterivores (Ba1,2,3,4), predators (P3,5), omnivores (Om4,5), plant parasites (Pp2), and fungivores (Fu2,4) were sensitive to heavy metals, and the abundance of Pp3 nematodes did not indicate heavy-metal contamination. H´gen, MI, MI2–5, EI, SI, and BI were the most valuable community indices for assessing the impact of heavy metals. Our results thus support the general view that communities of soil nematodes provide highly responsive metrics and sensitivities as bioindicators of heavy metal pollution in the environment.