Soil nematode responses to heavy metal stress

Abstract

SummaryThe effect of Cu and Zn on soil nematode communities at the depth of 0 -20 cm was investigated along a pollution gradient with increasing distance from a copper smelter in Northeast China. The results showed that the abundance of total nematodes significantly increased with increasing distance from the smelter, and nematode taxon richness also exhibited an increasing trend. Twenty genera were observed in our study, and Paratylenchus was the dominant genus at all the sampling sites. The numbers of total nematodes, bacterivores, plant parasites, omnivores-predators and the values of NCR (Nematode Channel Ratio) negatively correlated with total Cu (P < 0.01), total and available Zn (P < 0.01). The values of SI (Structure Index) negatively correlated with total Cu (P < 0.05). Among the nematode ecological indices examined, NCR and SI were found to be sensitive indicators for assessing the effect of heavy metals on soil nematode communities in this study.

Nematode community structure in the vicinity of a metallurgical factory

“…But in case of Cu, significant negative correlation (P < 0.05) was proved. Similar phenomenon was also observed by Zhang et al (2007). Number of fungivores showed significant negative correlation with Ni content (P < 0.05) but positive correlation with Cr (P < 0.05), which was followed, from sites A to D by a slight rise in fungivorous nematode proportion in the community.…”

“…One possibility could be increasing concentration of Cr, but its low level was not high enough to cause statically significant correlation itself, so it probably affect the community together with other factors (nitrogen, pH, etc.). The lowest abundance of predators under conditions with a high concentration of heavy metals reported also Zhang et al (2007) and Korthals et al (1996a, b).…”

“…Useful tools, which are widely used for assessing the intensity of deterioration of soil are ecological and diversity indices (Porazinska et al 1999;Valocká and Sabová 1997;Urzelai et al 2000;Zhang et al 2007) as indicators of ecosystem quality (e.g. diversity, stability and resilience) and important processes (decomposition, energy flow and nutrient cycles) in ecosystem.…”

“…Other studies describe nematode community changes after fertilizing (Verschoor et al 2001) or using sewage sludge contaminated with heavy metals (Weiss and Larink 1991;Georgieva et al 2002). Šály (1983), Korthals et al (1996b), Nagy et al (2004), Zhang et al (2007) and Pen-Mouratov et al (2008) studied alterations in nematode community structure resulted from heavy metal pollution in natural and laboratory conditions. All these studies confirmed significant differences in the structure of soil nematode communities under stress conditions.…”

Soil nematode community characteristics around the Gangue hill of Fushun West Open-pit mine

“…Total nematode abundance and divesity indices (WI, TD, λ, Hg, SR) and ecological indices (MI, PPI, ∑MI) were significantly lower in polluted than in non polluted soils. Zhang et al (2007b) have studied in northeast China the effect on nematode community of Cu and Zn pollution in corn field near a copper smelter. Cu and Zn soil contents showed significant decreases with increasing distance from the smelter.…”