The Soil Microbiome and Its Response to Permafrost Thaw in Arctic Tundra ...

• Main Author: Romanowicz, Karl
• Format: Article in Journal/Newspaper
• Language: English
• Published: My University 2022
• Subjects: microbial ecology; Arctic climate change; permafrost thaw; Ecology and Evolutionary Biology; Science; Arctic; Climate change; permafrost; Tundra
• Online Access: https://dx.doi.org/10.7302/5919; http://deepblue.lib.umich.edu/handle/2027.42/174188

A majority (~60%) of the global belowground organic carbon (OC) pool is trapped in a perennially frozen state in permafrost soils underlying the Arctic tundra. Climate warming has initiated thaw in large regions of permafrost. Such thaw will likely trigger increased microbial activity leading to faster degradation of previously frozen OC and its release as carbon dioxide (CO2) and methane (CH4) to the atmosphere. Yet it remains uncertain how the soil microbiome (community of microorganisms) will respond to permafrost thaw or modulate the relative proportions of CO2 and CH4 produced by the decomposition of OC in thawing permafrost soils. This dissertation advances our understanding of the dynamics and functions of the tundra soil microbiome in response to permafrost thaw using field-based and laboratory experiments. Permafrost soils remain water-saturated during thaw, leading to oxygen (O2) limitations that promote anaerobic and fermentative microbial processes responsible for OC degradation. Rainfall ...