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Microbial drivers of N2O emissions in the Biosphere 2 Tropical Rainforest
Post by Juliana Young The Rainforest at Biosphere 2 is a unique study system because it operates under very high temperatures and has adapted to the Arizona heat. In 2002, Dr. Joost van Haren studied nitrous oxide (N2O) flux in the Rainforest at Biosphere 2 and found that there is a high and low pulse zone of emissions of this gas under the condition of post-drought (van Haren et al., 2005). Our study builds from the foundations of this experiment. We are testing what could be responsible for the spatial difference in N2O gas fluxes. While there are many facets of the Rainforest to study, my interests and area of…
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Carbon cycle tracers, an infographic
I’m happy to present an InfoGraphic on Carbon Cycle Tracers created by University of Arizona art students Melissa Yepiz and Luke Williams in Prof Karen Zimmerman’s course on infographics. Creating this infographic on complex scientific concepts was not an easy task, but Melissa and Luke did an incredible job. Through this collaboration they have provided me with an invaluable resource for sharing my research to a range of audiences (and in a much more aesthetically pleasing way than usual). I learned a lot in the process, including how to better explain my science and to get down to the fundamentals of the message I wanted to share. I was blown away by the talent…
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Soil survey: microbial, chemical and physical drivers of carbon cycle tracers
Two trace gases (carbonyl sulfide and the oxygen isotopes of CO2) show promise to help disentangle carbon cycle processes, but their soil fluxes need additional characterization. As in leaves, we anticipate that carbonic anhydrase (CA) enzymes in soil microbes drive uptake of atmospheric COS by soils (COS + H2O -> CO2 + H2S) and exchange of the oxygen isotopic signature between atmospheric CO2 and water (CO2 + H2O <-> HCO3– + H+). We performed a soil survey to test whether soil microbial CA drive the soil fluxes of these two potential carbon cycle tracers. By measuring the microbial, chemical, and physical properties of a diverse set of soils, we set out to determine…
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Soil systems – the challenges of complexity and scale
Soils are complex systems, in which physical, geochemical and biological processes interact in aggregate structures situated in dynamically shifting air- and water-filled spaces. It is difficult to adequately sample soil properties and to model processes related to those soil measurements. These challenges were discussed in a stimulating three-day conference on Complex Soils Systems in Berkeley a few weeks ago. Attendees came from an incredible diversity of backgrounds with a common interest in tackling issues in soil science. The need to better understand soils was motivated by the importance of soil processes in climate and for figuring out “How to feed the soil and the planet?” in the anthropocene – a question posed…
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Undergraduate Researcher Shersingh’s SURGE Experience
Congratulations to visiting undergraduate researcher Shersingh Joseph Tumber-Davila on completing and thriving in the demanding eight-week Summer Undergraduate Research in Geoscience and Engineering (SURGE) program! Shersingh came to the Welander lab with a strong background in environmental research (news article) from his home institution of the University of New Hampshire. SURGE is a competitive earth science research and graduate school preparation program, which is specifically designed to recruit students of diverse backgrounds from other universities across the country. I was amazed at the number of activities the program had for the students including GRE test preparation, faculty seminars, career and grad school panels, and field trips. This was all while performing graduate-level research including…
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BioDesign course – bridging science and art
Biologist/architect team Tobi Lyn Schmidt and Mike Bogan created a course linking artists, designers, architects, and biologists from the California College of the Arts (CCA) and Stanford University. I served as a postdoc mentor to help inspire and guide the process of cross-hybridizing biology and design (some examples) with three really talented undergraduate CCA students: Leslie Greene, Sakurako Gibo, and David Lee. The students were first charged with creating designs to illustrate scientific concepts in my field of research. I challenged them think about the issue of scale with respect to the biogeochemical cycles I study. The processes I investigate occur over a wide range of spatial and temporal scales,…
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Move to Stanford University!
Boston to the Bay Area! This October I began a new academic life at Stanford University where I am a NSF postdoctoral fellow working on questions regarding the microbiology underpinning large trace gas fluxes between the atmosphere and biosphere. I am working under the guidance of Professor Paula Welander who recently joined the Environmental Earth System Science faculty. I am looking forward to learning from her expertise and from the rest of our group. With this new move, I also began a new social life, which (after many years in tech schools) included my first-ever college football game and tailgating. Should be a great couple of years.
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Manuscript linking consumption of atmospheric H2 to the life cycle of soil-dwelling actinobacteria
Microbe-mediated soil uptake is the largest and most uncertain variable in the budget of atmospheric hydrogen (H2). In Meredith et al. (2014) in Environmental Microbiology Reports, we probe the advantage of atmospheric H2 consumption to microbes and relationship between environmental conditions, physiology of soil microbes, and H2. First, we were interested in whether environmental isolates and culture collection strains with the genetic potential for atmospheric H2 uptake (a specific NiFe-hydrogenase gene) actually exhibit atmospheric H2 uptake. To expand the library of atmospheric H2-oxidizing bacteria, we quantify H2 uptake rates by novel Streptomyces soil isolates that contain the hhyL and by three previously isolated and sequenced strains of actinobacteria whose hhyL sequences span the known hhyL diversity. Second, we…
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Thesis Defense!
I defended my thesis entitled “Field Measurement of the Fate of Atmospheric H2 in a Forest Environment: from Canopy to Soil”. I was honored to receive the 2012 Carl-Gustaf Rossby Prize for my thesis (link to .pdf). It was an incredible feeling to defend. I really enjoyed preparing and giving my thesis defense presentation. It’s not often that one gets to present the culmination of six years of hard work and personal development to colleagues, family, and friends. I am grateful for mentorship from my advisor Ron Prinn, my thesis committee (Steve Wofsy – Harvard, Bill Munger – Harvard, Tanja Bosak – MIT, Colleen Hansel – WHOI, Shuhei Ono – MIT), and…
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ISME conference on “the power of the small”
Last week I attended ISME 14 (International Symposium on Microbial Ecology) in Copenhagen, Denmark. It was a delight to see the city – its juxtaposed giant modern, cool, sterile buildings surrounding the historic old city. More of a delight was unexpectedly running into friends from the MBL Microbial Diversity summer school (2010) and realizing they are now my colleagues. The conference itself was quite good. I appreciated the range of content from very big picture and abstract to focused experimental projects. One message I took away from the community was a sort of -omics backlash, or perhaps whiplash, to the idea that generating more and more -omics data is the…