Biology subjects

Seitz, T. J.

Publications and source records attributed to Seitz, T. J..

2 recordsLinked to original sources

bioRxiv2021

Unearthing Shifts in Microbial Communities Across a Soil Disturbance Gradient

Permafrost, an important source of soil disturbance, is particularly vulnerable to climate change in Alaska where 85% of the land is underlain with discontinuous permafrost. Boreal forests, home to plants integral to subsistence diets of many Alaska Native communities, are not immune to the effects of climate change. Soil disturbance events such as permafrost thaw, wildfires, and land use change can influence abiotic conditions which can then affect active layer soil microbial communities. Previously, we found negative effects on boreal plants inoculated with microbes impacted by soil disturbance compared to plants inoculated with microbes from undisturbed soils. Here, we identify the key shifts in microbial inoculant communities altered by soil disturbance using 16S rRNA amplicon sequencing as well as changes in potential functional mechanisms that influence plant growth using long read metagenomics. Across our soil disturbance gradient, microbial communities differ significantly based on the level of soil disturbance. Consistent with previous results, the family Acidobacteriaceae, which consists of known plant promoters, was abundant in undisturbed soil, but practically absent in most disturbed soil. In contrast, Comamonadaceae, a family with known agricultural pathogens, was overrepresented in most disturbed soil communities compared to undisturbed. Within our metagenomic data, we found that soil disturbance level drives differences in microbial community function. These results indicate that a decrease in plant growth can be linked to changes in the community and functional composition driven by soil disturbance and climate change. Together these results build a genomic understanding of how shifting soil microbiomes may affect plant productivity and ecosystem health as the Arctic warms.

microbiology↗

bioRxiv2020

Soil disturbance affects plant growth via soil microbial community shifts

Recent advances in climate research have discovered that permafrost is particularly vulnerable to the changes occurring in the atmosphere and climate, especially in Alaska where 85% of the land is underlain by mostly discontinuous permafrost. As permafrost thaws, research has shown that natural and anthropogenic soil disturbance causes microbial communities to undergo shifts in membership composition and biomass, as well as in functional diversity. Boreal forests are home to many plants that are integral to the subsistence diets of many Alaska Native communities. Yet, it is unclear how the observed shifts in soil microbes can affect above ground plant communities that are relied on as a major source of food. In this study, we tested the hypothesis that microbial communities associated with permafrost thaw affect plant growth by growing five plant species found in Boreal forests and Tundra ecosystems, including low-bush cranberry and bog blueberry, with microbial communities from the active layer soils of a permafrost thaw gradient. We found that plant growth was significantly affected by the microbial soil inoculants. Plants inoculated with communities from above thawing permafrost showed decreased growth compared to plants inoculated with microbes from undisturbed soils. We used metagenomic sequencing to determine that microbial communities from disturbed soils above thawing permafrost have differences in taxonomy from microbial communities in undisturbed soils above intact permafrost. The combination of these results indicates that a decrease in plant growth can be linked to soil disturbance driven changes in microbial community membership and abundance. These data contribute to an understanding of how microbial communities can be affected by soil disturbance and climate change, and how those community shifts can further influence plant growth in Boreal forests and more broadly, ecosystem health.

microbiology↗