Our faculty are drawn from several departments on the main campus—Biology, Mathematics, and STIA (Science, Technology, and International Affairs)—and conduct research on a range of topics. They have extensive experience catalyzing student interest in research and guiding students to becoming independent scientists.
Ali Arab: Professor Arab’s research focuses on the statistical modeling of complex data including spatial data, time series data, Spatio-temporal data, remote sensing data and satellite imagery, and complex count data (e.g., data with excessive zero counts). The application areas of Professor Arab’s research include environmental studies, ecology, epidemiology, and human rights. Current research topics include: 1) modeling long-term spatial patterns and temporal trends in the spring arrival of migratory birds in North America; 2) modeling spatial and temporal abundance patterns of fish species in large rivers (with application to data from a monitoring program in the Missouri River); and 3) modeling satellite imagery data with applications to environmental studies (e.g., detecting deforestation, receding water levels in lakes and rivers, and land use change) and human rights studies (detecting mass graves, forced evictions and relocations, and assessing damage to civilian infrastructures during conflicts).
Peter Armbruster: The Armbruster lab combines studies of ecology, quantitative genetics, genomics, and molecular physiology to elucidate processes of phenotypic evolution in natural populations and the molecular bases of adaptation. Container-breeding mosquitoes are used as a model system, with a focus on the invasive and medically important mosquito Aedes albopictus. In addition to addressing fundamental hypotheses in ecology and evolution, much of the work is directly relevant to public policy. For example, the Armbruster lab recently participated in collaborative ecological studies examining the causes of variation in vector abundance among socio-economically diverse neighborhoods in Washington, DC. These studies have applications in vector control and increase our understanding of the potential for disease outbreaks. Another major area of research in the Armbruster lab has been the molecular physiology of climatic adaptation in Ae. albopictus, with a specific emphasis on photoperiodic diapause. These studies have important implications for understanding invasion and range expansion and for anticipating biological responses to climate change.
Shweta Bansal: The Bansal lab focuses on the mathematical modeling of host contact patterns and pathogen dynamics to answer fundamental questions in infectious disease ecology. Current research topics include: 1) disease transmission dynamics under disruptions to the host population contact structure (e.g., translocations in desert tortoises); and 2) the tension in complex societies, such as bottlenose dolphins and carpenter ants, between the benefit of cooperation versus the cost of disease transmission.
Edd Barrows: The work of the Barrows lab is primarily a long-term study identifying the arthropod species of Dyke Marsh Wildlife Preserve (DMWP) in Virginia. This preserve is part of the George Washington Memorial Parkway (GWMP) administered by the U.S. National Park Service. The main goals of this research are to document the arthropod diversity in DMWP, including habitat usage, abundances, and aspects of phenology and life history. This study provides baseline information to the U.S. National Park Service for use in documenting and tracking the preserve’s biological diversity in view of its environmental challenges, including invasive species, erosion, pollution, and climate change. Work to date has contributed to the passing of a 2009 U.S. Congressional bill (House Resolution 701), which recognizes DMWP as “a unique and precious ecosystem.”
Hans Engler: Prof. Engler’s research is in applied mathematics and computational statistics, with scientific questions coming from climate science, transportation modeling, and remote sensing, among other areas. He employs methodologies from applied mathematics to study conceptual models for parts of the climate system and uses computational approaches for the analysis of large datasets that arise through observation or large-scale simulations. Current projects focus on spatio-temporal patterns in transportation networks (bikeshare systems) and in planetary climate models with latitudinal or longitudinal structure, and also conceptual models for glaciation cycles in paleoclimatology.
Mark Giordano: The Giordano lab pursues research examining the interaction between environmental science and policy, primarily in Asia and Africa. Current projects measure the impact of water saving technologies on actual water use in India and Pakistan, examine how internationally funded environmental impact assessments are used in dam construction decisions in the Mekong region, and explore if unilateral changes in groundwater management and use can reduce tensions over shared water in the Aral Sea Basin. (Prof. Giordano will be unavailable for mentoring students in the summer of 2016.)
Matthew Hamilton: The Hamilton lab focuses on evolutionary and conservation genetics and pursues both empirical and computational research. Current research topics include comparison of nucleotide substitution rate variation in annual and perennial plants, estimation of genetic effective population size (Ne) in age-structured and spatially structured populations, genetic diversity in foundation plant species and their consumer insect species communities, and the action of genetic drift and natural selection in response to ecological heterogeneity. Most projects in the lab are testing fundamental conceptual hypotheses that can be applied to biological habitat or species conservation and management.
Sarah Johnson: The Johnson lab pursues research at the nexus of planetary science and geo-biology, striving to understand how Mars, a planet once very similar to Earth, could have evolved in such a dramatically different way and searching for evidence of habitable or once-habitable environments there. Current projects use systems modeling, with particular emphasis on the role of sulfur in the evolution of planetary environments, as well as the power of novel techniques for genetic and bio-signature analysis.
Janet Mann: Professor Mann’s long-term study of wild bottlenose dolphins (field site in Shark Bay, Australia, a UNESCO World Heritage site; see monkeymiadolphins.org) affords students access to one of the richest empirical datasets in existence for any mammal. The Shark Bay Dolphin Research Project (SBDRP) began in 1984, and Mann has curated the long-term project data since the early 1990s, including development and design of a web-based database in collaboration with Dr. Lisa Singh (Associate Professor, Computer Science). The Mann lab studies a range of questions concerning bottlenose dolphin development, life history, behavior, communication, social relationships, habitat, reproduction, diet, genetics, mortality, predators, prey, human impacts, and conservation. In addition to the SBDRP, Professor Mann has teamed up with Dr. Eric Patterson and Professor Bansal in studying bottlenose dolphins in the Potomac River and Chesapeake. This new study focuses on behavior patterns associated with disease transmission. We conduct transect surveys of the population in the lower Potomac and Chesapeake. Students will have an opportunity to learn field research techniques and work with our burgeoning dataset.
Leslie Ries: The Ries lab focuses on large-scale drivers of species distributions and community change, with a particular focus on how climate and land-use changes impact butterflies in North America. The majority of research draws on large-scale data sets collected by citizen scientists to examine range shifts, population trends, and interactions between resources, consumers, and predators. The main focus of research is the monarch butterfly, the most intensively monitored species for which we have large-scale data sets not only on adult abundance but also on larval development, natural enemy pressure, and movement. Another major focus is on community composition shifts, using species-level traits to understand differential responses to the same driver. Much of this research uses physiological responses to temperature to understand observed shifts in abundance or distribution. Laboratory measurements of physiological responses in a number of butterfly species can be used to make predictions about distributional shifts, which can then be tested using continent-wide monitoring data on butterflies.
Mahlet Tadesse: Professor Tadesse’s research focuses on the development of statistical methods for the analysis of high-dimensional data with an emphasis on “-omics” applications (genomics, proteomics, metabolomics). Over the past few years, she has also been building collaborative efforts focused on climate change and ecology. In particular, she is working on methods for modeling species distributions in highly biodiverse ecosystems, taking species interactions into account. The ability to predict the evolving structure of such ecosystems in the face of climate change (e.g., increased temperatures, alteration of rainfall patterns) and anthropogenic pressure (e.g., mining, timber logging, fuel-wood exploitation, land conversion) is crucial for designing effective conservation and sustainable management policies and programs. (Prof. Tadesse will be unavailable for mentoring students in the summer of 2016.)
Martha Weiss: Research in the Weiss lab addresses questions of evolutionary ecology, with a focus on the role of behavior, by both plants and insects, in mediating interactions amongst the two groups of organisms. Current projects include investigations of determinants of diet breadth in herbivorous insects, the role of learning in larval and adult Lepidoptera, the ecological context of defecation behaviors, and chemical and visual components of ant-mimicry.
Gina Wimp: The Wimp lab seeks to understand the forces, both natural and anthropogenic, that shape ecological interactions in salt marsh communities. Specifically, the research examines the impact of predators, nutrient runoff, and habitat fragmentation on salt marsh population, community, and ecosystem dynamics. For example, habitat fragmentation is one of the primary factors leading to species extinctions worldwide, and predators may be especially susceptible to fragmentation relative to lower trophic levels. Previous research in the Wimp Lab has demonstrated that different predator functional groups—and even different species within a functional group—are differentially susceptible to habitat edges and fragmentation. It therefore becomes important to examine the way in which the loss of different predators and predator functional groups may influence important ecosystem processes, such as prey suppression.