Influence of lead on the activity of soil microorganisms in two Beskidy landscape parks

The aim of the study was to assess the potential impact of lead on soil metabolism in two landscape parks localized in the Beskid Śląski and Beskid Żywiecki mountains which were affected, among others, by air pollution from the Upper Silesian Industrial Region, the largest industrial zone in Poland. The study was carried out in six locations with different lead levels in the soil environment. Each plot was equipped with four pairs of vacuum ceramic lysimeters to assess the mobility of Pb in the soil. The metabolic activity was assessed by measuring: soil enzyme activity, soil respiration and by studying community-level physiological profiling (CLPP) using Biolog EcoPlates technique. The soil to the examination was collected near the stands with the lysimeters from two soil horizons (A and B layer). The analyses carried out showed that the factors that had the greatest influence on lead mobility were the organic carbon content and the soil pH. The elevated lead level in the topsoil (layer A) could affect the functional biodiversity of soil microorganisms, but low soil pH was a more likely limiting factor. In the subsoil (layer B), lower lead content was found and its probable effect on soil microbial activity was small. In summary, it can be concluded that the assessment of the influence of heavy metals on soil metabolism is not easy, and the Biolog system has proven to be a sensitive tool for assessing the potential impact of heavy metals on the soil environment.

Assessment of heavy metals contamination in soils in the Beskidy mountain forests and their potential impact on soil enzyme activities and microbial community

The research was carried out in the Beskid Śląski and Beskid Żywiecki mountains which were affected, among others, by air pollution from the Upper Silesian Industrial Region, the largest industrial zone in Poland. The aim of the study was to assess the heavy metal load in the soils of the studied area and to determine their potential impact on soil metabolism. The research was carried out on 6 permanent sites. For each site, the total content of zinc (Zn), lead (Pb) and cadmium (Cd) was determined for three soil levels (A, B and C). Moreover, the following were determined: total nitrogen, organic carbon, pH and soil moisture and the amount of heavy metals in soil solutions. The metabolic activity of the soil was assessed by measuring: soil enzymes activity, soil respiration and by studying community-level physiological profiling (CLPP) using Biolog ECO-plates. In the case of Pb and Cd their increased content in the topsoil was found, which indicates their anthropogenic origin. Statistical analysis showed that in the case of very acidic forest soil even slightly elevated lead level probably can affect the functional biodiversity of soil microorganisms. The study showed that it is not easy to assess the impact of heavy metals on soil metabolism. Some indicators such as the activity of soil enzymes used individually may not be sufficient to illustrate the changes occurring in the soil environment.