Category: Research
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Rate-yield tradeoffs and soil respiration in a high elevation forest
While studying seasonal changes in microbial growth kinetics in soils of a subalpine forest in the Colorado Rocky Mountains, I noticed a negative relationship between maximum growth rate and growth efficiency, or yield (the fraction of carbon consumed that is converted into biomass, as opposed to being respired as CO2). Turns out this is a…
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Differential responses of native and exotic coastal sage scrub plant species to N additions and the soil microbial community
JDPE student, Francis Bozzolo, published part of his dissertation in Plant and Soil. Part of the motivation for this study was that the dominant shrubs of Coastal Sage Scrub ecosystems are generally clumped in patches, as in the photo above. Do they partition N by depth or chemical form? What happens to N partitioning when…
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Changes in microbial communities along redox gradients…
In collaboration with Janet Jansson (now with PNNL), we published this study in Environmental Microbiology Reports, showing that redox gradients are a dominant force in structuring microbial communities in wet Arctic tundra soils.
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Methane suppression by iron and humic acids in soils of the Arctic Coastal Plain
Recently graduated Ph.D. Student, Kimberly Miller, published part of her dissertation in Soil Biology and Biochemistry, showing that the addition of alternative electron acceptors, ferric iron and humic acid, reduced methane fluxes in the tundra near Barrow, Alaska. This work resulted from our NSF grant to study the significance of iron and humic substances in…