Participation of small mammals in the biogenic transit of trace elements under chemical pollution of the environment

Abstract

The participation of small mammals (SM) in the migration of essential (Cu, Zn) and toxic (Cd, Pb) trace elements (TEs) in forest ecosystems under conditions of severe industrial pollution of the environment (1990–2000) by a large copper smelter (Middle Urals, Russia) and after a significant reduction in its emissions (2010–2019) was considered. The peculiarity of transit food flows (TFF) in the pollution gradient was determined by the composition and abundance of animals of different trophic groups (phytophages, mixophages, zoophages), as well as the specifics of their diet. The reduction in emissions was accompanied by positive changes in the SM communities, expressed in an increase in the number and structural rearrangements of trophic groups (TG), which led to partial changes in the composition and amount of food consumed, as well as the content of TEs in them. By the end of the observation period in the background zone, the animal-controlled TFF remained stable for most TEs (Cu, Zn, Cd), for Pb it decreased by a factor of 2, but not as a result of reduced emissions. In contaminated areas, the value of TFF Zn has not changed, Cd has increased, Cu and Pb - decreased. It was concluded that in the taiga zone the main contribution to the dynamics of biogenic TEs flows over time and space was made by a group of mixophages that dominated the pollution gradient.