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 Will Cook
Associate in Research
cwcook duke.edu
The Duke Free Air CO2 Enrichment (FACE) experiment studies how elevated carbon dioxide and nitrogen affect a Loblolly Pine (Pinus taeda) plantation with a naturally succeeding understory. My research at FACE focuses belowground, on the effects of elevated CO2 and N on root biomass and soil respiration. Surprisingly, even after 12 years, the stimulation of root growth and respiration under elevated CO2 is still increasing. N fertilizer decreases both fine root biomass and soil respiration, but increases coarse root biomass. In the lab, I maintain a handful of websites, run various analytical instruments, and serve as lab manager. I also enjoy the role of resident naturalist, specializing in birds, lepidopterans, and woody plants.
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| Measuring soil respiration at the FACE site |
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 Adrian Down
PhD student
ad159duke.edu
Natural gas could be an important energy source in the future. Through my research, I seek to better understand the environmental tradeoffs involved in the extraction, transportation, and combustion of natural gas. When combusted, natural gas emits less carbon dioxide per unit of energy gained than other forms of fossil fuel. However, methane itself is a powerful greenhouse gas. Leak rates from natural gas distribution systems, both rural and urban, remain uncertain, which makes it difficult to tell how the greenhouse warming footprint of natural gas compares to other fuels. Extraction of natural gas through hydraulic fracturing is poised to become a major fuel extraction technology worldwide in the near future, but questions remain about what environmental consequences, if any, this practice entails. My field research focuses on groundwater testing in the Marcellus Shale of Pennsylvania and New York, background water sampling in the Sanford Basin of central North Carolina, and urban air measurements in Boston, Massachusetts. |
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| Adrian admiring a shelf fungus |
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 Chris Ellis
Postdoctoral Research Associate
jce9duke.edu
How do the microflora that live in our body contribute to health and disease states? This is the fundamental question that drives my research. To address it, we need good model systems. Because all humans are born microbe free, infants offer a glimpse into how microbes colonize us and the health implications associated with these colonization events. One segment of this population is extremely low birth weight infants. These infants weigh less than 1000 g at birth (2 lbs 3 oz) and are usually born before 27 weeks of gestation and require prolonged hospitalization. Since these infants are under the specialized care of highly trained medical staff in a controlled environment most of their environmental inputs are captured in their medical charts. This unique setting offers a rare opportunity to examine the succession of intestinal microbial population and its response to environmental stimuli. To examine the intestinal microbial community structure I employ Titanium 454 pyrosequencing and concurrently develop novel bioinformatic tools to analyze the data. This research will help researchers and clinicians better understand how the microbiome shifts in response to environmental factors such as feedings and antibiotics. Furthermore, this research will also aid us in determining if the intestinal tract is a reservoir for nosocomial (hospital acquired) infections of these special infants.
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 Dan Johnson
Research Scientist
dj74duke.edu
My research can be broadly classified as physiology and ecology of tree and shrub species, population dynamics of those species and plant functional morphology (i.e. adaptive traits). Currently, my primary focus is on water transport (hydraulic architecture and function) in tree and shrub species Ongoing projects in this area include impacts of leaf hydraulic architecture and function on gas exchange and growth, mechanisms of drought-induced tree mortality, embolism repair mechanisms and efficiency and the coordination of root, stem and leaf water transport. My other interests include physiological ecology and population biology of young seedling establishment, which is critical for forest regeneration and migration with climate change.
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| Measuring leaf hydraulic conductivity |
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 Esteban Jobbágy
International Collaborator/Visiting Scholar
jobbagyunsl.edu.ar
I study the influence of plants on the cycle of materials (water, nutrients, salts, carbon) in terrestrial ecosystems; the impact of vegetation changes (afforestation of grasslands, deforestation and cropping in forests, overgrazing degradation) on ecosystem functioning, its interaction with the hydrological system; biological carbon uptake and sequestration; biogeography of terrestrial ecosystems; and productive systems design. Approaches and methodology include: hydrological observations, physical and chemical determinations on soils and sediments, ecophysiological measurements on plants, biophysical characterization of the terrestrial surface with remote sensing, simulation models, and stable isotope natural abundance.
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| Eucalyptus plantation and adjacent grassland in Uruguay |
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 Marcelo Nosetto
Postdoctoral Research Associate
marcelo.nosettogmail.com
Interests: water and salts dynamics in arid to humid ecosystems, groundwater-vegetation interactions, biogeochemistry.
I am interested in the reciprocal influences between water/salts dynamics and vegetation. I am currently focused on the interactions between shallow groundwater and crops in the flat humid landscapes of the Pampas. I also study the effects of land-use on the water cycle and energy balance components and the potential climatic impacts of land-use changes. The approaches and methodologies I used involve: remote sensing and GIS, hydrological observations, physical and chemical analysis in soil, water and sediments, natural and artificial water tracers and modeling, among others.
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| Groundwater observations in a maize field |
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 Stephen Osborn
Postdoctoral Research Associate
so56duke.edu
My research interests broadly consist of utilizing elemental and isotopic analyses of multiple substrates (gas, rock, and formation water) to address fundamental questions of fluid and solute transport, biogeochemistry of solutes and radionuclides, microbial processes, and diagenetically induced water-rock reactions in subsurface environments. Currently, I am working on a project that tries to understand interactions between shallow dilute groundwater systems and deep seated fluids (formation water and gas), that may be highly saline, contain toxic levels of trace elements, and have elevated concentrations of natural gas and/or carbon dioxide. This research may be important for understanding the potential for environmental impacts on drinking water resources from oil/gas well drilling and hydro-fracturing operations as well as carbon sequestration in deep saline aquifers.
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| Sampling brine and gas from an oil well in Pennsylvania
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 Gervasio Piñeiro
Postdoctoral Research Associate
pineiroagro.uba.ar
Interests - biogeochemistry, afforestation impacts, atmospheric deposition
I am analyzing biogeochemical impacts of afforestations in Uruguay and Argentina, performing mass balances of C, N, Na, Ca, Mg, K, Cl, P, and S, and evaluating the relative impact of alternative plantation species (Eucalyptus and Pines). I am also evaluating atmospheric depositions over souther South America with a network of collection sites, with special interest in tracking spatial redistribution of nutrients and water in the region. Finally I am also analyzing the C cycle in agricultural systems with a special emphasis in developing C sequestration strategies in both food and biofuel crop systems.
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| Eucalyptus plantation and adjacent grassland in Uruguay |
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 Andrew Procter
PhD candidate
andrew.procterduke.edu
Interests - biogeochemistry, C sequestration, microbial ecology
Rising levels of atmospheric CO2 are a primary cause of climate change, but what about their direct effects on ecosystems? I work on a collaborative project in Texas aimed at this question. We expose prairie to a continuous gradient of CO2 concentrations spanning from preindustrial levels to levels expected mid-century. We are investigating numerous aspects of the system, including changes in plant physiology, ecosystem water balance, and nutrient cycling. I am curious how the capacity of this ecosystem to store carbon changes along the gradient, and how microbial processes (decomposition, N cycling) affect this capacity. My current work involves analyzing soil respiration and soil microbial community composition along the gradient.
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| The "tunnel" CO2 gradient experiment in Temple, Texas |
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 Danielle Way
Postdoctoral Research Associate
danielle.wayduke.edu
Interests - plant physiological ecology and global change ecology
I study the mechanisms underlying plant responses to global change factors such as rising temperatures, CO2 concentrations and drought stress. Much of my work involves investigating how plants respond to stressful conditions, what limits their ability to acclimate to global change and how these responses scale up to the community level. Some of my current projects include: 1) examining whether drought is more stressful at low CO2 concentrations; 2) studying how the emission of isoprene from leaves is affected by growth CO2 and the repercussions of this for photosynthetic thermotolerance; and 3) determining how growth temperature alters tree growth.
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| Measuring gas exchange at the "tunnel" site in Temple, TX. |
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 Chi-Jen Yang
Research Scientist
cy42duke.edu
I conduct research on policy analysis for a low-carbon energy system. I have published policy reports on wind power, energy storage, electrical transmission, and peer-reviewed articles in technology innovation policy, solar energy, electric vehicle, pumped hydroelectric energy storage, nuclear power, and methanol fuel. My recent focus is on the development in China’s energy policy, including the efficiency improvement in the coal-fired power sector, the disturbances in coal market, and the global implications of China’s unique institutional context and policy approaches.
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 Kaiguang Zhao
Postdoctoral Research Associate
kz22duke.edu
My academic interest has been partly driven by a thrust to raise the level of rigor and precision in environmental research, with my major area of expertise in use of various geospatial approaches and computational methods to address practical and scientific environment issues. A key tool for my research is remote sensing for which I work on both physically-based modeling of imaging processes and data-driven applications of remotely-sensed information, particularly in the areas of lidar, hyperspectral and microwave remote sensing. My dissertation research is focused on exploring novel remote sensing techniques for mapping forest ecosystems, with a primary scientific goal being to better understand the terrestrial carbon dynamics in the face of global change. Currently, my postdoc project is to examine the impacts of forests and land cover on climate, aiming to link carbon uptake in terrestrial ecosystems with other climate forcing factors including albedo, latent and sensible heat, and surface roughness, through the combined use of remote sensing, eddy-covariance, and land-surface models.
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| Forest survey at a deciduous tree plot in Eastern Texas |
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