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MILJØ2015-Norsk miljøforskning mot 2015

FORURENS: Trace metals (Cd, Zn and Hg) in multiple stressed environments: effects on microbial communities and functions in soils

Awarded: NOK 3.8 mill.

Water quality and atmospheric concentrations of greenhouse gases are profoundly affected by soil microbial functions. Surface soils are increasingly utilized for human purposes, which imply various stressors on the microbial communities. Sustaining vital soil functions is a crucial environmental issue; strict guidelines and limits as to the contamination of the soil environment are needed. Many experiments have demonstrated extreme tolerance, and in particular resiliency, of most microbial functions when exposed to single stress factors, such as trace metal contamination. Less is known, however, about the tolerance when exposed to several different stressors, concomitantly or in sequence, and in particular how such stresses affect the diversity within eac h functional group. Soils are naturally variable as to their contents of stressors such as trace metals. Little is known about possible long-term selection in naturally trace metal rich soils versus recently contaminated soils, and how this affects the t olerance to other stress factors. In the present project, we address this question by studying the combined effect of soil pollution by Cd, Zn Hg, since they presently cause great concern, with naturally occuring environmental stressors (starvation and o xygen concentration). Two microbial functions with key roles in global change biogeochemistry will be studied; CH4 oxidation and the reduction of N2O as a part of the denitrification process. We will assess if critical limits for trace metals on soil micr obes and their biochemical functions can be determined and how multiple stresses affects these limits in anthropogenically and naturally contaminated environments. Community DNA analyses (functional genes; MMO, nirK and nosZ) will be used to investigate c omposition of the functional groups.These studies will be carried out using sound and updated techniques in collaboration with some of the most outstanding scientists and laboratories in their scientific field.

Funding scheme:

MILJØ2015-Norsk miljøforskning mot 2015