New Frontiers

Blue and orange microbes Soil is a complex ecosystem with diverse microenvironments ranging from bulk soil with low quality substrates and no or very limited microbial growth, to high quality C-rich environments near decomposing litter and rhizosphere where microbial growth and death rates are high. Soil contains different microbial communities, supports varying microbial activities and carbon (C) and nitrogen (N) availabilities. This research, a collaboration among NAU and two DOE National Labs (PNNL & LLNL) addresses whether the microbial taxa exhibit differences in growth and death rates and underlying biochemistry in these environments, and to what degree these responses are genetically determined or environmentally induced. In this work, we have gathered data to test the overarching hypothesis that microbes in these environments exhibit diverse metabolic capabilities and activities, from gluconeogenesis in bulk soil where mainly small organic acids are present...

Microscopic microbes When new carbon enters soil, especially carbon that is easily assimilated and decomposed by soil microorganisms, a chain reaction occurs leading to the breakdown of older soil carbon, carbon that would otherwise have remained stable. Current theory does not explain this chain reaction, sometimes called the “priming effect.” But understanding this is important, because soil carbon is a major reservoir in the global carbon cycle, storing about three times the amount of carbon contained in the atmosphere as carbon dioxide. Some soil processes promote carbon storage, locking it away in stable forms, resistant to decay. The priming effect has the opposite effect, converting carbon that was thought to be stable to carbon dioxide, and contributing to the atmospheric pool, amplifying rising carbon dioxide due to human burning of coal, oil, and gasoline. Carbon stability is a major uncertainty...

We’ve got your number: Tracing the source of invasive Japanese beetles March 9, 2016 Sonya Daw news.nau.edu Japanese beetle (Popilia japonica) copyright enterlinedesign/Adobe Stock Like a Southern drawl popping up on the West Coast, our accents mark us as newcomers. With time they fade, leaving only traces of our past in the occasional slip of a word. Northern Arizona University researchers led by Bruce Hungate, director of the Center for Ecosystem Science and Society, have found the microscopic equivalent of an accent in an invasive pest: the Japanese beetle. This microscopic “accent” is the amount of a rare but stable hydrogen isotope in the beetles’ body tissues. The results, published in PLOS ONE, can help invasive pest managers answer the question of whether a beetle detected in new territory is new or part of an established population in the area....