Investigating the Impacts of Heavy Metals and the Environmental on the Soil Biodiversity (Hexapoda: Collembola)

The increasing population, the expansion of industrial and urban wastewater, and the lack of proper treatment have significantly contributed to the existance heavy metals in the soil ecosystem. Preventing the impacts of heavy metals on the quality and health of the soil ecosystem requires selecting appropriate bioindicators. Thus, this study aims to investigate the impacts of heavy metals and the effective environmental parameters of the soil on Collembola, at genus level. For this purpose, in two stages, soil samples were taken from the stations around Charmshahr industrial wastewater treatment plant and Khin Arab and Parkandabad municipal wastewater treatment plants in Mashhad, Iran. Twenty-eight soil samples, each obtained by mixing four sub-samples, were collected from 14 stations. Statistical analysis was performed using R software. In the studied area, a total of 15 genera of Collembola were identified. All these genera were reported for the first time from Mashhad. The results of comparing the concentration of chemical parameters and the genera richness in Collembola showed that there is a significant correlation between them. The results show that the number of genera has a negative correlation with two metals, iron and chromium, and among the measured elements in soil, only total carbon has a positive correlation with the number of genera (p<0.05). The results of the canonical correspondence analysis showed that the response of the abundance of each Collembola genera to the concentrations of heavy metals and the environmental parameters is different. Thus, even if Collembola is advising as a proper bioindicator, we should mention that the response of the biodiversity to the abiotic parameters in soil is various, which must be deliberated in the ecosystem management.