what we do

The environmental-change group studies contemporary surface processes, past environments, and the future of the Earth system. This group has two interrelated focuses; we operate in the critical zone, where physical, chemical, hydrologic, geological, and biological processes interact, to better understand the functioning of the Earth system. We also use our understanding of modern processes and patterns to uncover the impacts of global change. We work closely with one another and encourage students to develop projects that take advantage of our complementary interests.

critical zone:  hydrology, geomorphology, geochemistry, and biogeochemistry

Our research in the critical zone seeks to understand how the Earth system “works.” Our modern-process studies use instrumental and sampling data that measure ecological, biogeochemical and climatic parameters at field sites. We integrate these data using computational models and laboratory experiments to develop a more complete understanding of the structure and function of the critical zone. Ongoing projects include snowmelt hydrology, stream restoration, fate and transport of metals, mineral weathering, soil formation, ancient and modern Mars surface environments, microclimate weather stations in Antarctica, carbon cycling in temperate forests and global peatlands.  We emphasize course work in the disciplines of ecology, hydrology, glaciology, geochemistry, meteorology, and stable isotopes. Our research takes place in field locations across the globe, including Alaska, the Yukon, the Rocky Mountains, the Appalachians, Crete, South America, and the western Antarctic Peninsula.

global change: ecology, climatology, and paleoclimatology

The Global Change group is interested in understanding the patterns and processes of natural and human-induced environmental changes at annual to millennial timescales. We employ multidisciplinary approaches to examine recent and ongoing changes in ecosystems, derive biological, geochemical, and geological proxy records from natural archives preserved in lakes, peatlands, glaciers, corals, and caves, and use computational modeling to understand recent historical processes and formulate predictions about the future. Our current research interests seek to understand global change through documenting the temporal and spatial patterns of hydroclimate variability, biological community and ecosystem responses to climate variability, peat carbon storage, geochemical and magnetic records, and through Earth system modeling, and understanding internal feedbacks. Faculty work with students on research projects in many locations, including the Great Lakes region, northeastern North America, Alaska, the Yukon, the Tibetan Plateau and northwest China, Patagonia, the western Antarctic Peninsula, and the Peruvian Andes.

research facilities

We have excellent field, laboratory and computational facilities to conduct research in hydrology, ecology, paleoecology, geochemistry, environmental magnetism, climate modeling, ecosystem modeling, GIS and remote sensing. Field equipment includes peat and sediment corers, field deployed datasondes, and automatic water sampling systems. General lab facilities are used for carbon and sediment analysis, sample processing, and optical and SEM/EDS analysis. Mass spectrometers and cavity ring-down instruments are available for stable isotope determination of C, O, H, and N, with ICP-MS for general aqueous chemistry. Magnetic analysis facilities include a cryogenic magnetometer in a field free room and a selection of demagnetization systems.  Computational facilities include high-performance parallel clusters for climate models, and individual workstations for processing satellite remote sensing and GIS data.

If you're interested in graduate work at Lehigh, start here for links to the research we do, and then learn more about our graduate curriculum and our admissions procedures. More than anything, we encourage you to contact the person or persons you're interested in working with.

Recent publications by group members

• 2016

Jiang, M., Felzer, B.S., and Sahagian, D., 2016. Characterizing predictability of precipitation means and extremes over the conterminous United States, 1949-2010. J. Climate, http://dx.doi.org/10.1175/JCLI-D-15-0560.1.

Jiang, M., Felzer, B.S., and Sahagian, D., 2016. Predictability of precipitation over the conterminous U.S. based on the CMIP5 multi-model ensemble. J. Climate, doi:10.1038/srep29962. http://www.nature.com/articles/srep29962.

Zhang, J. Felzer, B.S., and Troy, T.J., 2016. Extreme precipitation drives groundwater recharge: the Northern High Plains Aquifer, Central United States, 1950-2010. Hydrological Processes, doi:10/1002/hyp.10809.

• 2015

Andrews, T.A., and Felzer, B.S. 2015. Very-heavy precipitation in the greater New York City region and widespread drought alleviation tied to western US agriculture. PLOS ONE10(12): doi10.1371/journal.pone.0144416.

Burrows, J.E., Peters, S.C., Cravotta, C.A., 2015. Temporal and geochemical variations in above- and below-drainage coal mine discharge, Applied Geochemistry Special Issue Dedicated to Kirk Nordstrom. doi:10.1016/j.apgeochem.2015.02.010

Clifford, M.J. and R.K. Booth. 2015. Late-Holocene drought and fire drove a widespread change in forest community composition in eastern North America. The Holocene 25: 1102-1110.

Gallen, S. F., Pazzaglia, F. J., Wegmann, K. W., Pederson, J. L., and Gardner, T. W., 2015, The dynamic reference frame of rivers and apparent transience in incision rates: Geology, doi: 10.1130/G36692.1.

• 2014

A. Bodzin, D. Anastasio, D. Sahagian, T. Peffer, C. Dempsey, and R. Steelman-Couch, 2014. Investigating Climate Change Understandings of Urban Middle School Students, Jour. Environ. Education, 62, 417-430.

Dangal, S. R. S., Felzer, B. S., and Hurteau, M. D., 2014. Effects of agriculture and timber harvest on carbon sequestration in the eastern US forests, Journal of Geophysical Research,-Biogeosciences. doi:10.1002/2013JG002409. 119(1): 35-54.

Felzer, B. and Sahagian, D., 2014. Climate impacts on regional ecosystem services in the United States from CMIP3-based multimodel comparisons, Climate Research.  doi0.3354/cr01249.

Jiang, M., Felzer, B., Hargreaves, B., and Zhang, J., 2014. Parameterization and sensitivity analysis of a biogeochemical model for Pennsylvania dairy pasture carbon flux under climate change scenarios. Crop Science. doi10.2135/cropsci2014.05.0377.

He, Y., Jones, M., Zhuang, Q., Bochicchio, C., Felzer, B.S., Mason, E. and Yu, Z,. 2014. Evaluating the effects of climate seasonality on CO2 and CH4 cycling of Alaskan Ecosystems during the Holocene Thermal Maximum, Quaternary Science Reviews. 86: 63-77.

Ireland, A.W., M.J. Clifford, & R.K. Booth. 2014. Widespread Dust Deposition on North American Peatlands Coincident with European Land-Clearance. Vegetation History and Archaeobotany.

Jiang, M., Felzer, B., Hargreaves, B., and Zhang, J. 2014. Parameterization and sensitivity analysis of a biogeochemical model for Pennsylvania dairy pasture carbon flux under climate change scenarios, Crop Science.  doi10.2135/cropsci2014.05.0377.

Loisel, J.*, Yu, Z.C., and others, 2014. A database and synthesis of northern peatland soil properties and Holocene carbon and nitrogen accumulation. The Holocene, 24,1028-1042.

Gunderson, K. L., Pazzaglia, F. J., Picotti, V., Anastasio, D. J., Kodama, K. P., Rittenour, T., Frankel, K. F., Ponza, A., Berti, C., Negri, A., and Sabbatini, A., 2014, Unraveling tectonic and climatic controls on synorogenic stratigraphy: Geological Society of America Bulletin, 126, 532-552.

• 2013

Clifford, M.J. & R.K. Booth. 2013. Increased probability of fire during late Holocene droughts in northern New England. Climatic Change 119: 693-704.

Hunt, S., Z.C. Yu, and M. Jones. 2013. Lateglacial and Holocene climate, disturbance and permafrost peatland dynamics on the Seward Peninsula, western Alaska. Quaternary Science Reviews 63: 42-58.

Ireland, A.W., R.K. Booth, S.C. Hotchkiss, & J.E. Schmitz. 2013. A comparative study of within-basin and regional peatland development: implications for peatland carbon dynamics. Quaternary Science Reviews 71: 85-95.

Kodama, K.P., Moeller, R.E., Bazylinski, D.A., Kopp, R.E., and A.P. Chen, 2013, The mineral magnetic record of magnetofossils in recent lake sediments of Lake Ely, PA, Global and Planet. Change, 110, 350-363.

Lee, E. and Felzer, B. S., and Kothavala, Z. 2013. Effects of nitrogen limitation on hydrological processes in CLM4-CN, Journal of Advances in Modeling Earth Systems. 5(4): 741-754. doi:10.1002/jame.20046.

Loisel, J. and Z.C. Yu. 2013. Holocene peatland carbon dynamics in Patagonia. Quaternary Science Reviews 69: 125-141.

Pazzaglia F.J., 2013, Fluvial Terraces, in, John F. Shroder (Editor-in-chief), Wohl, E. (Volume Editor), Treatise on Geomorphology, Vol 9, Fluvial Geomorphology, San Diego: Academic Press, p. 379-412.

Spahni, R. F. Joos, B. D. Stocker, M. Steinacher, and Z.C. Yu. 2013. Transient simulations of the carbon and nitrogen dynamics in northern peatlands: from the Last Glacial Maximum to the 21st century. Climate of the Past, 9: 1287-1308, doi:10.5194/cp-9-1287-2013.

• 2012

Booth, R.K., S.T. Jackson, V.A. Sousa, M.E. Sullivan, T.A. Minckley, & M.J. Clifford. 2012. Multidecadal drought and amplified moisture variability drove rapid forest community change in a humid region. Ecology 93:219-226.

Booth, R.K., S. Brewer, M. Blaauw, T.A. Minckley, & S.T. Jackson. 2012. Decomposing the Mid-Holocene Tsuga Decline in Eastern North America. Ecology 93: 1841-1852.

C. Dempsey, A. Bodzin, D. Anastasio, D. Sahagian, and L. Cirucci, Reconstructing environmental change using lake varves as a climate proxy, Science Scope, 35, 42-47, 2012.

Felzer, B., 2012. Nitrogen, and water response to climate and land use changes in Pennsylvania during the 20th and 21st centuries, Ecological Modelling, 240: 49-63.

Gonyo, A., Yu, Z., and Bebout, G. E., 2012. Late Holocene change in climate and atmospheric circulation inferred from geochemical records at Kepler Lake, south-central Alaska, Journal of Paleolimnology 48, 55-67, doi: 10.1007/s10933-012-9603-8.

Ireland, A.W. & R.K. Booth. 2012. Upland deforestation triggered an ecosystem state-shift in a kettle peatland. Journal of Ecology 100:586-596.

Ireland, A.W., R.K. Booth, S.C. Hotchkiss, & J.E. Schmitz. 2012. Drought as a trigger for rapid state shifts in kettle ecosystems: implications for ecosystem responses to climate change. Wetlands 32: 989-1000.

Yu, Z.C. 2012. Northern peatland carbon stocks and dynamics: a review. Biogeosciences 9: 4071-4085, doi:10.5194/bg-9-4071-2012.

Recent environmental-change theses

Michael Clifford (Ph.D.). 2016 Late Holocene drought, fire, and vegetation in northeastern North America inferred from peatland archives. (advisor: Booth)

Nathan Hopkins (Ph.D.) 2016 Magnetic till fabric: Applications of anisotropy of magnetic susceptibility (AMS) to subglacial deformation of till and ice. (advisor: Evenson)

Minkai Jiang (Ph.D.) 2016 On the history and evidence of the Colwell index in quantifying environmental predictability, and its applications in characterizing precipitation predictability in the conterminous United States. (advisor: Felzer)

Jien Zhang (Ph.D.) 2016 Detection and Effects of Climate Extremes on Hydrology and Ecosystems: Case Studies in California and the Great Plains, USA. (advisor: Felzer)

Andrews, T. (Ph.D.) 2015. Why precipitation and forest structure are changing in the eastern US: insight from analysis of large empirical and climate model datasets.  (advisors: Booth and Felzer)

Cleary, K. (M.S.) 2015. Carbon sequestration implication of shrub expansion, peat initiation, and sphagnum growth in Arctic Tundra on the north slope of Alaska. (advisor: Yu)

Henry, J.E. (Ph.D.) 2015. Geochemical factors controlling the fate of Fe, Al, and Zn in coal-mine drainage in the Anthracite Coal Region, Pennsylvania, USA. (advisor: Peters)

Navara, C.E. (M.S.) 2015. The Effects of interspecific interactions on reproductive success of Carolina chickadees (Poecile carolinensis). (advisors: Booth and Rice)

Blake, J.M.T. (Ph.D.), 2014. Geologic, tectonic, and geochemical signatures leading to arsenic in groundwater in the Gettysburg Basin. (advisor: Peters)

Leboeuf, K.A. (M.S.) 2014. Holocene Vegetation, Hydrology, and Fire in the North-Central Adirondacks of New York. (advisor: Booth)

Spicer, M.E. (M.S.) 2014. The legacy of planting: A century-long experiment in forest development at Lehigh University. (advisor: Booth)

Klein, E.S. (Ph.D.) 2013. Differential Response of Alaska Peatlands to Climate Changes of the Last Millennium. (advisors: Booth/Yu)

Zhao, M. (M.S.) 2013. Recent glacier surface snowpack melt in Novaya Zemlya and Severnaya Zemlya derived from active and passive microwave remote sensing data. (Advisor: Ramage)

Semmens, K.A. (Ph.D.) 2013. Passive microwave derived snowmelt timing: significance, spatial and temporal variability, and potential applications. (Advisor: Ramage)

Andrews, T.A. (M.S.) 2012. Testate amoebae as hydrological proxies in the Florida Everglades. (advisor: Booth)

Hunt, S. (M.S.) 2012. Postglacial climate, disturbance and permafrost peatland dynamics on the Seward Peninsula, western Alaska. (advisor: Yu)

Ireland, A.W. (Ph.D.) 2012. Assessing the sensitivity of kettle ecosystems to climatic and anthropogenic disturbances. (advisor: Booth)

Kristen Lazzeri (M.S.). 2012. Storage of nitrogen in silicate minerals and glasses. (advisor: Bebout)

Loisel, J. (Ph.D.) 2012. Autogenic and allogenic controls on carbon dynamics in peatlands from Alaska and Patagonia. (advisor: Yu)

Mason, E. E.  (M.S.) 2012. A model comparison of early Holocene orbital insolation and present-day anthropogenic CO2 climate forcings and their influences on Alaskan ecosystems. (advisor: Felzer)