July 29, 2014

Brown-MBL Student Will Daniels Receives Brown University ISES Fellowship

Will Daniels Lake Ice Core

Will Daniels holds an archive of 10,000 years of Alaskan climate and environment data from one deep lake sediment core in northern Alaska. Photo by Will Longo.

Will Daniels will be entering his fourth year in the Brown-MBL Program in the fall of 2014. He is a PhD candidate in the Brown University Department of Geological Sciences recently renamed in July 2014 to the Department of Earth, Environmental and Planetary Sciences (DEEPS). He is co-advised by Anne Giblin at the Ecosystem Center at MBL and James Russell at Brown. In May, Will received a one-year graduate student fellowship with the Institute for the Study of Environment and Society (ISES) at Brown University. The fellowship will continue to support his paleoclimate research in remote Arctic lakes in northern Alaska.

In May, Will and fellow researchers from Brown University traveled to remote regions of the Alaskan Arctic to collect sediment cores from Arctic lakes including Upper Capsule Lake. The expedition was sponsored by the National Geographic Society. The goal of the project and field work is to retrieve deep lake bottom sediment cores and use novel and traditional paleolimnologic proxies to study the past climate of the region. Coupling this study with modern studies of sediment deposition, lake ecosystems, and meteorology will help provide a robust interpretation of the paleoclimate records. He will spend the summer and fall analyzing and interpreting the mud samples. To see more photos and read more about Will’s Arctic travels and research follow his blog.







MBL Ecosystems PhD Student Xi Yang Defends Dissertation and Receives A Postdoc at Brown University

Jack Mustard (Brown), Joe Berry (Stanford/Carnegie Institute for science), Xi Yang (Brown-MBL), Jung-Eun Lee (Brown), Meredith Hastings (Brown), and Jim Tang (Brown-MBL).

Jack Mustard (Brown), Joe Berry (Stanford/Carnegie Institute for Science), Xi Yang (Brown-MBL), Jung-Eun Lee (Brown), Meredith Hastings (Brown), and Jim Tang (Brown-MBL).

Brown MBL PhD candidate Xi Yang defended his dissertation “The Times They Are A-Changin’: Scaling Seasonality of Plant Physiology from Leaf to Satellite and Implications for Terrestrial Carbon Cycle” on April 28th at Brown University. Xi, a former geography and geosciences student from Beijing began his PhD in the Department of Geological Sciences at Brown University in 2009. He is co-advised by Professor Jack Mustard from Brown University and Jim Tang, Assistant Scientist, at MBL.

Xi combined a detailed study of leaf optical properties with remote sensing and modeling techniques to understand the seasonality of plant physiology and its environmental drivers. First Xi used digital repeat photography to estimate the budburst date of trees in New England. Then he up-scaled a species-level phenology model to the New England area that reconstructed and predicted the changes of budburst dates. By collecting weekly sampled leaf traits such as chlorophyll concentration to interpret the data from digital repeat photography, he found a temporal mismatch between greenness index and chlorophyll concentration in the spring. In the fall, the redness index was a good indicator of vegetation senescence.  Xi used vegetation spectroscopy to successfully capture the seasonal variability of leaf traits and developed a system to continuously measure solar-induced fluorescence (SIF) over a temperate deciduous forest for the first time. His research found a strong correlation between SIF and vegetation photosynthesis, and absorbed photosynthetically active radiation.

Remote sensing studies such as Xi’s research can provide spatially explicit estimates of properties which are related to key ecological processes, while the mechanistic understanding of how environmental factors control these processes can help to understand how terrestrial ecosystem will respond to climate change.

Xi’s work was financially supported by the Brown-MBL Graduate Program in Biological and Environmental Sciences and the lab of Dr. Jim Tang, a Stanley Watson Fellowship from MBL and a Hartnett Fellowship from Brown University, the Brown–ECI phenology working group, and a Brown University Office of International Affairs seed grant.

In June, Xi will start work as a Post-doc with Dr. Jung-Eun Lee at Brown University in Providence, RI, and Dr. Joe Berry at the Carnegie Institute for Science using fluorescence to understand the response of tropical ecosystems to water stress.

List of Citations:

Yang X, Tang J, Mustard J (2014). Beyond leaf color: comparing camera-based phenological metrics with leaf biochemical, biophysical and spectral properties throughout the growing season of a temperate deciduous forest. Journal of Geophysical Research-Biogeosciences, DOI:10.1002/2013JG002460.

Yang, X., J. Mustard, J. Tang, and H. Xu (2012), Regional-scale phenology modeling based on meteorological records and remote sensing observations, Journal of Geophysical Research-Biogeosciences, 117(G3), G03029.

Brown-MBL Alumni Gillian Galford Attends White House NCA release

Former Brown-MBL PhD graduate student Dr. Gillian Galford attended the release of the National Climate Assessment at the White House on May 8th. Gillian was a Brown-MBL student in the Geological Sciences Department at Brown University working with Professor Jack Mustard at Brown and Dr. Jerry Melillo at MBL. Gillian graduated in 2009 and is currently a fellow at the GUND Institute for Ecological Economics at the University of Vermont.

Read her story on the release on the National Climate Assessment and a related story on how the climate predictions will affect Vermont.

Brown-MBL Neuroscience Student Justine J. Allen Defends Dissertation

Justine Allen with her adviser Dr. Roger Hanlon

Justine Allen with her adviser Dr. Roger Hanlon

Justine J. Allen, a Brown-MBL graduate student in the Department of Neuroscience at Brown University and the Program in Sensory Physiology and Behavior at the MBL successfully defended her PhD dissertation entitled ‘Adaptive edge design for visual camouflage: Biomechanics of morphing 3D skin papillae in cephalopods and changeable cryptic body patterning in the slender filefish’ on Monday March 24th, 2014 at Brown University. She is advised by Dr. Roger T. Hanlon, Senior Scientist, at MBL.

Justine studied the functional morphology of the changeable, 3-dimensional skin papillae in several species of octopus and cuttlefish and found that most types of papilla are muscular hydrostats where movement and structural support are provided by muscles. One type of papilla was found to function by a buckling mechanism. Justine also performed a comparative study on the fixed, 3-dimensional dermal flaps of the slender filefish. This work contributes to our understanding of soft tissue actuation and the use of complicated skin projections for camouflage.

Justine’s research was supported by grants from the National Defense Science and Engineering Graduate Fellowship, National Science Foundation Graduate Research Fellowship and the Brown University – MBL Graduate Program.

Several publications have already been published on Justine’s research. For more information on her work see the following three citations:

Allen JJ, Bell GRR, Kuzirian AM, Hanlon RT. (2013) Cuttlefish skin papilla morphology suggests a muscular hydrostatic function for rapid changeability. Journal of Morphology. 274: 645-656.

Allen JJ, Bell GRR, Kuzirian AM, Velankar SS, Hanlon RT. (2014) Comparative morphology of changeable skin papillae in octopus and cuttlefish. Journal of Morphology. 275: 371-390.

Allen JJ, Akkaynak D, Hanlon RT. (In Review) Adaptive camouflage body patterning and dermal flap morphology in the cryptic slender filefish, Monacanthus tuckeri, on a coral reef. Biological Journal of the Linnean Society.

Brown MBL Alumni Lindsay Brin Publishes Research in L&O

Brown-MBL alumni Dr. Lindsay Brin recently published her PhD research on denitrification and anammox potential rates in estuarine and continental shelf coastal sediments in the Association for the Sciences of Limnology and Oceanography (ASLO) Journal of Limnology and Oceanography.  The paper entitled  ‘Environmental controls of anammox and denitrification in southern New England estuarine and shelf sediments’ was co-authored by her advisors Anne Giblin of MBL’s Ecosystems Center and Assistant Professor Jeremy Rich, Brown University, and conducted in research labs at MBL and Brown.  Lindsay was a student in the Department of Ecology and Evolutionary Biology at Brown University and graduated in September 2013. Her publication can be found on the ASLO website.

Citation:  L. D. Brin, A. E. Giblin, J. J. Rich (2014). Environmental controls of anammox and denitrification in southern New England estuarine and shelf sediments’ Limnol. Oceanogr., 59(3), 2014, 851–860.

New Research by Brown MBL Graduate Student Published in JGR

Xi Yang, Brown MBL graduate student, collects leaf data on seasonality on Martha's Vineyard, MA

Xi Yang, Brown MBL graduate student, collects leaf data on seasonality on Martha’s Vineyard, MA

Xi Yang, a fourth year graduate student advised by Jim Tang at the Ecosystems Center at MBL and Jack Mustard in the Geological Sciences Department at Brown University, recently published his work on plant phenology in the Journal of Geophysical Research: Biogeosciences.  Xi and the scientists from MBL and Brown University set up a digital camera in a deciduous white oak dominated state forest on Martha’s Vineyard in the spring of 2011 to discover more about the relationship between canopy level camera phenological metrics and leaf properties and the relationship between remote sensing data and camera phenological metrics.

Digital repeat photography has become a popular tool to track the seasonality of tree canopy color. Yet how this technique can be used for the studies of ecosystem functioning is unclear. Yang et al. (2014) found that there is a mismatch between the canopy greenness and the leaf biochemical content such as chlorophyll concentration. While in the fall, the canopy redness can be used as an indicator of fall senescence.

For more information on his research and findings go to the MBL Blog or read about his work in the Vineyard Gazette and in his recent publication in the Journal of Geophysical Research: Biogeosciences.

Citation: Yang X, Tang J, Mustard J (2014) Beyond leaf color: comparing camera-based phenological metrics with leaf biochemical, biophysical and spectral properties throughout the growing season of a temperate deciduous forest. J. Geophys. Res. DOI:10.1002/2013JG002460

Brown MBL Student Lindsay Brin Defends PhD Dissertatation and Receives a NSF Postdoc Fellowship in Canada

Brown-MBL student Lindsay Brin successfully defended her PhD dissertation on September 6th, 2013 at Brown University. Lindsay, a student in the Department of Ecology and Evolutionary Biology at Brown University, conducted her doctoral research in the labs of Brown University Assistant Professor Jeremy Rich and MBL Ecosystems Center Senior Scientist Anne Giblin.

Brin’s research focused on the relationship between environmental factors and microbially-mediated nitrate reduction processes in coastal sediments, particularly denitrification, anammox and dissimilatory nitrate reduction to ammonium (DNRA). The rates and relative importance of these processes affect how much nitrogen (N) is available in coastal ecosystems for primary productivity and eutrophication, and are linked to climate through global marine N cycling. Understanding the controls on these processes is essential for predicting the effects of climate change and other environmental alterations on coastal ecosystems.

Brin illustrated the role of temperature, organic matter and nitrate in determining rates of nitrate reduction in New England coastal sediments, providing some of the first seasonal data on these processes and the first measurements of anammox and DNRA in these sediments. She demonstrated that warming and changes in organic matter availability could affect positive feedbacks on primary productivity by altering fluxes of N between the sediments and the water column, and further showed that DNRA may be an important unappreciated process in temperate continental shelf sediments.

During her graduate studies, Brin’s research was supported by a National Defense Science and Engineering Graduate Fellowship, a Stanley Watson Graduate Fellowship in Environmental Studies, and a Sounds Conservancy Grant.

In October, Lindsay will begin a National Science Foundation Postdoctoral Research Fellowship in Biology at the Potato Research Centre in Fredericton, NB, Canada, to study the effects of climate change, particularly altered snow cover, on N cycling in agricultural soils. Through a two year field study she will address the question of how does altered snow cover affect soil N cycling and microbial communities in the winter and through the following growing season.

Former Brown MBL Student, Pedro Flombaum, Publishes Article in Oecologia

Former Brown-MBL student Dr. Pedro Flombaum recently published a new journal article entitled Interactions among resource partitioning, sampling effect, and facilitation on the biodiversity effect: a modeling approach.  Pedro was a 2008 graduate student in the Brown University EEB Program and a former student of Dr. Ed Rastetter at MBL.  He now works at the Centro de Investigaciones del Mar y de la Atmósfera (CIMA) in Buenos Aires, Argentina.  His journal article can be found here.

Brown MBL student Cassandra Bilogan successfully defends her dissertation

Cassandra Bilogan defends her dissertation at Brown University

Cassandra Bilogan defends her dissertation at Brown University

Cassandra Bilogan successfully defended her dissertation on August 5th, 2013 at Brown University in Providence, RI.  Cassandra described her doctoral research that was completed in Dr. Marko Horb’s lab at the MBL’s Bell Center for Regenerative Biology and Tissue Engineering. Cassandra’s research focused on elucidating the molecular mechanisms involved in endoderm development and pancreatic organogenesis in Xenopus laevis. Specifically, she identified a novel role for a well-conserved RNA-binding protein during endoderm development. This research provided new insights into a previously unappreciated role of the spatial-temporal regulation of germ layer patterning during gastrulation. During her graduate studies Cassandra published two first author papers and a second author review paper.

Cassandra is also the first Ph.D. student to graduate from the Bell Center. Her research was supported by grants to Dr. Horb from the National Institutes of Health and a Canadian Institute of Health Research fellowship to Bilogan.

In October, Cassandra will start a postdoctoral fellowship at the Cleveland Clinic in the lab of Dr. Takuya Sakaguchi.

For more information on Cassandra click here

New Harvests for Research on Agricultural Intensification

CN Mbola 17-01-12091 compress

Photo by Chris Neill

Agricultural activities are changing globally in response to increased demand for foods and other goods, but how are these changes occurring and affecting people and ecosystems differently across the planet?

From 14-16 January 2013, postdoc Rebecca Ryals of the Marine Biological Lab (MBL) and the Brown Environmental Change Initiative (ECI) convened a workshop at MBL for faculty, researchers and graduate students working in Brazil, Africa, China and North America to share recent findings from research on agricultural change, spanning natural and social science fields.  Participants hailed from numerous ECI-affiliated departments at Brown, including Ecology and Evolutionary Biology, Geological Sciences, and Sociology, the Marine Biological Laboratory (MBL), the Woods Hole Research Center (WHRC) and institutions across the country, including The Earth Institute at Columbia University and the Cary Institute of Ecosystem Studies in New York, and the University of Virginia.

Researchers presented projects on facets of agricultural intensification from Brazil, East Africa, North America and China.  For Brazil, presented research showed surprising dynamics of the fate and transport of fertilizer-added nitrogen and phosphorus through soils, differing seasonal variations in soil moisture across land use areas, impacts of riparian forest buffers on stream water quality, innovative satellite remote sensing techniques for studying extents and patterns of double-cropping, and relationships between national currency valuation, markets, social dynamics and agricultural production.  For East Africa, preliminary results demonstrated relationships between seasonal patterns in nitrogen transport dynamics through soils , new multi-satellite-based approaches for mapping land cover in complex, small land-holder dominated landscapes, and impacts of fertilizer use on soil microbial diversity.  Research in North America focused on range and livestock management impacts for watershed biogeochemistry, and web tools for increasing public awareness of how personal food choices connect to ecosystem nitrogen losses.  Research in North America and China highlighted relationships between fertilizer rates, and CO2 and N2O losses from soils to the atmosphere.

Together, presentations highlighted that agricultural intensification, the increased use of technology (e.g. fertilizers, mechanization, new cultivars) to improve crop yields per unit area, has progressed in starkly contrasting patterns between places such as Brazil and East Africa.  Environmental and social consequences such as fertilizer-applied nitrogen losses and local food security were shown to matter differently across continents. Discussions stressed that factors from a region’s economic development status before intensification occurs, to soil texture, must be considered integrally for scientists across disciplines to pursue appropriate future research.  The workshop produced outlines for interdisciplinary research papers, watershed-scale research projects, conference proposals, and new senses of camaraderie among participants.