Peatland microbial community structure and function along a metal contamination gradient in Sudbury, Ontario
Year: 2016
Type: dissertation
Abstract: The Sudbury, Ontario region has had over a century of metal mining/smelter activity that has led \nto significant sulphur and metal deposition and this has negatively affected both freshwater and \nterrestrial ecosystems, including peatlands. Peatlands store organic materials, regulate nutrient \nturnover and act as a carbon sink for global climate change, yet relatively little is known in \nregards to the impact of the mining legacy of this region and the potential microbial communities \naffected. Eleven peatland sites (poor to intermediate fens) around Sudbury were chosen in order \nto study the microbial diversity and function that control decomposition and nutrient cycling. The \nanalysis of microbial communities was accomplished via high-throughput sequencing of 16S \nrRNA genes in bacteria and archaea on the Illumina MiSeq platform, while the analysis of \nmicrobial function was conducted through the Sinsabaugh enzyme protocol and gas \nchromatography of in situ greenhouse gases. There was a difference across the site gradient with \nmicrobial diversity, community structure, and microbially mediated gas efflux differing between areas closest to current and historical smelters to areas 55-km away. There was also a difference \nwithin each peatland where vertical profiles in microbial enzyme function varied over four \ndepths, with the surface depth having the highest enzyme activity. Metal impact and pH are major \ndrivers of microbial diversity and community with pH driving metal availability. This is seen \nwhere the sites with the lowest pH having the lowest microbial diversity and unique communities, \nand sites with the highest pH having the highest microbial diversity and distinct communities. We \ncan also deduce that microbial function differs over depth because of the difference between the \naerobic and the anaerobic communities, where the aerobic communities appear to be more active. \nWe can reason that methane efflux was higher in impacted sites because of the increased \nconcentrations of Nickel, Copper, pH and possibly Sulphur creating restrains on microbially \nmediated gas effluxes through the inhibition of methane production.
Author: Shanay Williams-Johnson
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDG: Life on land
Open Access status: green
OpenAlex ID: W2586493924