Current: Christopher Williams  | Huan Gu | Natalia Hasler | Rich MacLean | Tong Jiao | Yu Zhou | Savannah Cooley

Former: Christopher Schwalm | Myroslava Khomik | Melanie Vanderhoof | Bardan Ghimire |

Alex KappelMarcus Pasay | Angela Marshall | Krittika Govil | Graham Twibell | Thor Akerley

Chris Williams

CWilliams [at]

B.A., Biology/Environmental Studies, Bucknell University (1996)
M.S., Watershed Science, Colorado State University (2000)
Ph.D., Environmental Science, Duke University (2004)

Professor Christopher A. Williams joined the faculty in the Graduate School of Geography in Fall 2008. Prior to coming to Clark University he was a Research Scientist at Colorado State University’s Natural Resource Ecology Laboratory, followed by faculty appointment as Assistant Research Scientist with the Goddard Earth Sciences and Technology Center of the University of Maryland Baltimore County and based in the Biospheric Sciences Branch of NASA’s Goddard Space Flight Center.

More about Chris here

Detailed CV

Google Scholar Page

ResearchGate Website

Huan Gu

HuGu [at]

B.Eng. Geographic Information System, China University of Geosciences (2007)
M.Eng. Photogrammetry and Remote Sensing, Wuhan University (2009)
Ph.D. Forestry, University of Wisconsin-Madison (2014)

Dr. Gu was born and raised in the city of Yancheng, Jiangsu Province, China and moved to Wuhan, Hubei Province for her undergraduate and graduate studies in 2003. She received her Bachelors degree in Geographic Information System (GIS) from China University of Geosciences in 2007, and earned her Masters degree in Photogrammetry and Remote Sensing from LIESMARS at Wuhan University in 2009. In August of 2009, she arrived in the U.S. to perform her Ph.D. studies with Dr. Phil Townsend at University of Wisconsin-Madison. With spare time, she enjoys traveling, swimming and outdoor activities.

Dr. Gu’s Ph.D. research focused on quantification and mapping of forest structure (including aboveground biomass), tree species gradient and forest growth in the city of Madison and neighboring municipalities using airborne discrete lidar and AVIRIS hyperspectral imagery. The overall objective was to understand urban ecosystem services and function by linking field measurements to different types of remote sensing data using statistical modeling approaches. At Clark, Dr. Gu is continuing this line of research by expanding to study broadscale carbon dynamics across forests of the conterminous United States by merging field inventory and satellite remote sensing data with a carbon cycle modeling framework.

Detailed CV

Natalia Hasler

hasler.natalia [at]

B. Eng, M.S., Environmental Engineering, École Polytechnique Fédérale de Lausanne (1995)
Ph.D., Atmospheric Sciences, École Polytechnique Fédérale de Lausanne (2002)

Dr. Hasler’s research is broadly centered on land-atmosphere interactions, with detailed focus on a) precipitation response to land cover changes such as deforestation and conversion to agriculture, and b) determining controls on terrestrial water and carbon dioxide exchanges with the atmosphere. She employs a variety of methods including synthesis of flux-tower observations, regional climate simulation (RAMS), and general circulation modeling. Presently, she is assisting our group with mapping and monitoring forest carbon stocks across forests of the conterminous US and modeling seasonal and interannual variability of surface-atmosphere exchange of carbon dioxide.

Detailed CV

Richard MacLean

RMacLean [at]

B.A. Biology, Western Washington University (2004)
M.S. Natural Resources, University of New Hampshire (2010)
Ph.D. Geography, Clark University (expected 2016)

Rich MacLean earned a B.Sc. in Biology from Western Washington University in Bellingham, WA in 2004. After his undergraduate studies he moved east to the University of New Hampshire (UNH) for an M.S. in Natural Resources and the Environment in 2010. His master’s dissertation was an exploration of nitrogen cycling in New England forest soils using isotopic tracers. At UNH he also worked as a research associate investigating questions in forest carbon storage. His research interests in Clark build on that previous biogeochemistry background with a greater focus on the human management effects on biogeochemical cycles.

Detailed CV

Tong Jiao

TJiao [at]

B.S. Geographic Information System, Beijing Forestry University (2011)
M.S. Quantitative Remote Sensing, Institute of Geographic Sciences sand Natural Resources Research (2014)
Ph.D. Geography, Clark University (expected 2019)

Tong Jiao earned a B.Sc. in GISci from Beijing Forestry University in 2011 and a follow-on M.S. in Quantitative Remote Sensing in 2014. Her master’s study examined the mapping of global seasonal forest background reflectivity with MISR data. Her research interests focus on the investigation of forest ecosystem carbon, water, and energy dynamics by using field measurements, remote sensing, and modeling.

Detailed CV

Yu Zhou

YuZhou2 [at]

B.S. Remote Sensing Science & Technology, Shandong University of Science and Technology (2012)
M.S. Cartography & GIS, Institute of Remote Sensing and Digital Earth, CAS (2014)
Ph.D. Geography, Clark University (expected 2020)

Yu Zhou earned a B.S. in Remote Sensing Science & Technology from Remote Sensing Science & Technology in 2012 and a follow-on M.S. in Cartography & GIS from Institute of Remote Sensing and Digital Earth (Chinese Academy of Sciences) in 2015. Her Master’s study examined the carbon cycling on grassland in Central Asia. Her research interests focus on the ecological modeling, ecosystem carbon and water cycling, global change, human-environment interactions, remote sensing.

Detailed CV

Personal Website

Savannah Cooley

SaCooley [at]

B.A. Economics & Minors in Math and Geography, Concentration in Computation Science, Clark University (2016)
M.S. Geographic Information Science & Clark University (expected 2017/18)

Savannah Cooley was recruited to Clark University as a Traina Scholar in the sciences. Along with completing an impressive combination of major, minors, and a concentration, Ms. Cooley secured a competitive NASA DEVELOP Research Internship for Summer 2016. While there she worked on Simulated ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) land surface temperature Level 2 data and delivered data to project partner EARTH University in Costa Rica. This work is continuing during her M.S. studies in our GISci program with continued support by NASA JPL as well as an Edna Bailey Sussman Fellowship for summer research.

Detailed Resume

Personal Website


*********** FORMER MEMBERS *************

Alex Kappel

AKappel [at]

B.A., Environmental Science, Clark University (2013)
M.S., Geographic Information Science, Clark University (2014)

Alex Kappel has been active in the Williams Lab since 2011, studying ecosystem ecology with a specific focus on factors that control soil respiration in a recent clearcut environment of central MA. He participated in the National Science Foundation REU program during the summer of 2012, collecting field data during an intensive 11-week residential program based at the Harvard Forest Long-Term Ecological Research station. He continued this work during the successive year and earned High Honors for his thesis titled “Post Disturbance Soil Respiration Dynamics in a Clear Cut Temperate Forest”. The work was presented at the 2013 Annual Meeting of the American Association of Geographers held in Los Angeles, CA. Mr. Kappel is now pursuing his MS degree in GISci with a thesis examining environmental controls affecting time to maturity for Asian Long-horned Beetle to map relative risk of invasions of host species across forests of the conterminous US.

Myroslava Khomik

** Now at McMaster University **

Ph.D. School of Geography and Earth Sciences, McMaster University in Ontario, Canada (2009)
M.S. School of Geography and Earth Sciences, McMaster University in Ontario, Canada (2004)
Hon.BSc Chemistry, minor Environmental Science, also at McMaster U (2003)

Postdoctoral Researcher Dr. Myroslava Khomik has expertise in nutrient, water and carbon flows in forests, centering on the measurement and modeling of plant physiology and soil organic matter decomposition in mature and afforested environments. She has been brought on board to assist with the study of how of disturbances and regrowth affect carbon, water, and energy fluxes of temperate forests.

More about Myroslava here

Detailed CV (outdated)

Melanie Vanderhoof

MeVanderhoof [at]

** Now at USGS Research Center **
** Formerly at US EPA **

B.S., Biology and Society, Cornell University (2004)
M.A., Geography, San Francisco State University (2007)
Ph.D., Geography, Clark University (2014)

Melanie Vanderhoof began her PhD in the Graduate School of Geography in Fall 2010. Prior to Clark, Melanie was employed as a biologist for environmental consulting firms in Oakland, California, as well as Pittsburgh, Pennsylvania.

Detailed CV

Research Page

Bardan Ghimire

BGhimire [at]

**Now at Lawrence Berkeley National Laboratory**

B.Tech., Civil Engineering, Indian Institute of Technology Roorkee (2003)
M.S., Environmental Science, Kathmandu University (2005)
Ph.D., Geography, Clark University (2012)

Research Interests:
Biogeochemical and Biophysical Modeling, Ecosystems Ecology, Geographic Information Science and Remote Sensing

Detailed CV

Thor Akerley

TAkerley [at]

B.A., Environmental Science, Clark University (2013)
M.S., Environmental Science and Policy, Clark University (2014)

Thor has been active in the Williams Lab since 2012. He has assisted with field data collection at the Harvard Forest Long-Term Ecological Research station and in the lab weighing leaf samples. He continued this work with a directed research project entitled “Quantifying Species-Specific Leaf Area – Leaf Mass Relations in a Regenerating Temperate Forest”. The work was presented at the 2013 Academic Spree Day at Clark University.


Marcus Pasay

MPasay [at]

B.A. Environmental Science, Clark University (2012)
M.S. Environmental Science & Policy, Clark University (2013)

Research Interests: Factors controlling wood decomposition rates including microclimate and wood types

Research Spotlight on undergraduate involvement in the lab.

Christopher Schwalm

schw0516 [at]


**Now at Northern Arizona University**

B.A., German, Cleveland State University (1992)
M.S., Forest Conservation, University of Montana (1997)
Ph.D., Natural Resources Science and Management, University of Minnesota (2003)

Detailed CV (outdated)

Krittika Govil

KGovil [at]

B.A. Environmental Science, Clark University (2011)

Now pursuing M.S. Hydrology at Texas A&M.

Graham Twibell

GTwibell [at]

B.A. Environmental Science, Clark University (2010)
M.A. Environmental Science & Policy, Clark University (2011)

Graham Twibell recieved his undergraduate degree in Environmental Science from Clark in the Spring of 2010, and his Master’s in Environmental Science and Policy within the Department of International Development Community and Environment (IDCE) in 2011. While at Clark he worked with Professor Williams since 2009 and is interested in forest ecology and management, aquatic ecology, natural resources management’s effects on the climate system, and energy policy. Graham is currently working at the Cary Institute for Ecosystem Studies as a Research Assistant.

Current Research / Professional Webpage

Angela Marshall

AMarshall [at]

B.A., Environmental Science, Clark University (2011)
M.A., Environmental Science & Policy, Clark University (expected 2012)

Angela Marshall graduated in Environmental Science in May, 2011 and is currently in the Environmental Science and Policy Masters program and Clark University. During her undergraduate studies she completed a thesis based on data collected on post-disturbance woody debris during an internship at Harvard Forest under the mentorship of Professor Williams and Melanie Vanderhoof. She also recently completed an internship with the Institute for Energy and Sustainability.

Detailed CV
Research Experience video
Research Webpage