Lab News

Group Members Wanted: See Open Positions

Upcoming Meetings We Will Attend

The ACT-America Annual Science Meeting will be attended by PhD Student Yu Zhou and Dr. Williams in July 2017, Fort Collins, CO (Colorado State University).

10th International Carbon Dioxide Conference will be attended by Dr. Williams in August 2017, Interlaken, Switzerland.

FIA Science Meeting will be attended by Dr. Williams in October 2017, Park City, UT, where he will present an invited talk.

CMS Science PI Meeting will be attended by Dr. Williams in November 2017, Norman, OK.


July 2017

Dr. Williams Joins the NACP Science Leadership Group, nominated by members of the Carbon Cycle Science Interagency Working Group. Williams has also been appointed to serve as a co-Chair of the NACP Science Implementation Plan. For more information see the Clark News Announcement.

May 2017

Tong Jiao has just been Awarded a NASA Earth Science Fellowship to fund her Ph.D. research documenting impacts of the Millennium Drought in Australia with a widespread suite of remote sensing observations, Congratulations!

Prof. Williams joined the March for Science – Boston: See his personal statement about why.

April 2017

Congratulations to Savannah Cooley for being awarded an Edna Bailey Sussman Fellowship to support her summer research at NASA JPL in Pasadena, CA! Ms. Cooley will continue her work exploring applications of ECOSTRESS data to support decisions about water use and management in landscapes with irrigated agriculture with a focus on the Guanacaste Province of Costa Rica along with partners from Earth University.

Congratulations to Yu Zhou for being awarded an Edna Bailey Sussman Fellowship to support her summer research at the Harvard Forest LTER! Ms. Zhou will (1) participate in field measurement programs recording biomass in recently harvested landscapes, and (2) use time series of plot-measured biomass to constrain a biogeochemical model for estimating rates of carbon uptake and release.

November 2016

Dr. Williams Co-Authors Paper in Nature Communications. The research paper, published with open access here and highlighted by Clark here, and BBCNews, documents how terrestrial ecosystem uptake of atmospheric CO2 has risen in recent decades, largely due to enhanced productivity likely caused by elevated CO2 concentrations, and also how the past decade or so has seen a pause in the growth rate of atmospheric CO2 partly because of a relatively modest rate of warming over land and a corresponding slow down in the rate of ecosystem respiration.

September 2016

The Data-Driven and Simulation Science Summer School in Jena hosted by Friedrich Schiller University and the Max Planck Institute for Biogeochemistry will be attended by doctoral student Yu Zhou in September 2016.

Dr. Williams Co-Authors Paper in Nature Climate Change. The research, highlighted by Clark here, documents how dry air can stress plants just as much as dry soils, and how this source of stress is becoming increasingly severe as the planet warms.

Congratulations to Dr. Williams on receiving a new award from the NASA CMS Program. The project, led by Dr. Robert Kennedy of Oregon State University, funds research to develop and apply new tools to quantify and characterize the carbon impacts of forest disturbances with remote sensing analyses combined with modeling frameworks.

Congratulations to Yu Zhou for a Travel Award to attend the Data-Driven and Simulation Science Summer School in Jena being hosted by Friedrich Schiller University and the Max Planck Institute for Biogeochemistry.

June 2016

Dr. Williams’s Sabbatical Research is Featured by Clark University. The highlight, available here, features a conversational introduction to Prof. Williams’s work on vegetation stress and dieback in response to droughts and heat contrasted with enhanced plant growth stimulated by rising concentrations of carbon dioxide.

May 2016

Congratulations to Dr. Williams on receiving a new award to join the NASA ACT-America project. NASA ACT-America is an Earth Ventures Suborbital 2 activity being led by Science PI Ken Davis of Penn State University. Dr. Williams’s team will assist with estimating spatially-explicit, time-varying fluxes of carbon dioxide between the surface and atmosphere.

September 2015

Welcome to incoming PhD student Yu Zhou and congratulations on being awarded Clark’s Libbey Fellowship in Earth System Science. Yu joins us from the Chinese Academy of Sciences M.S. program in Remote Sensing and Digital Earth in Beijing. She brings expertise with remote sensing of ecosystem water and carbon cycles and their linkages to climate with a recent thesis titled “Analysis of spatial and temporal patterns of water use efficiency (WUE) in Central Asia”.

Sabbatical begins for Prof. Williams at the Hawkesbury Institute for the Environment of UWS in Australia where he will be examining detailed mechanisms of ecosystem functional and structural responses to drought and seeking to incorporate these dynamics in ecosystem process models along with his sabbatical hosts, Dr. Belinda Medlyn (lab group) and Dr. Remko Duursma.

Congratulations to Prof. Williams for being awarded Clark University’s Oliver and Dorothy Hayden Junior Faculty Fellowship for excellence in teaching, excellence in scholarship, and deep and sustained engagement with the Clark community.

May 2015

Clark Convenes a Climate Change Teach-In — Dr. Williams Delivers Plenary Lecture: Video is available on the teach-in website, with Williams’s fourth from the top titled “The Truth About Climate Change and a Pathway to a Safer Future“.

February 2015

Welcome to Dr. Huan Gu who recently joined the group to work on our NASA Carbon Monitoring System project.

Dr. Williams presented in the Yale School of Forestry Lunch Forum of the Global Institute of Sustainable Forestry.

December 2014

MacLean and Williams are off to the American Geophysical Union Fall Meeting in San Francisco to present their work.  Come see us if you have a chance!

November 2014

Congratulations to Alex Kappel for successfully defending his M.S. thesis titled “Mapping of the Asian Longhorned Beetle’s Time to Maturity and Risk to Invasion across the Contiguous United States“, and earning his M.S. in Geographic Information Science.  We thank Dr. Robert (Talbot) Trotter III, Research Ecologist at the USDA Forest Service, for serving as a committee member bringing us expert advice and for providing excellent mentorship.  Alex is currently employed AidData based at William & Mary.

October 2014

A Recent Perspective by Dr. Williams Explores How Heatwaves and Drought Are Likely to Stress Ecosystems Even More in a Warmer, CO2 Rich Future, solicited by Environmental Research Letters as a response to a recent paper by Ian Williams and colleagues at the Lawrence Berkeley National Lab. web copy

September 2014

Welcome to incoming PhD student Tong Jiao and congratulations on being awarded Clark’s Libbey Fellowship in Earth System Science. Tong joins us from Beijing Forestry University with expertise in remote sensing of forests and biogeosciences of terrestrial ecosystems, one of 11 new members of the Geography PhD program in Fall 2014.

New Grant Funding from NASA’s Carbon Monitoring System: Congratulations to Dr. Williams for securing funding from NASA’s Carbon Monitoring System for a proposal entitled “Translating Forest Change to Carbon Emissions/Removals Linking Disturbance Products, Biomass Maps, and Carbon Cycle Modeling in a Comprehensive Carbon Monitoring Framework“. The project involves close collaboration with Co-Is Dr. G. James Collatz and Dr. Jeff Masek of NASA GSFC and Dr. Gretchen Moisen of the US Forest Service Forest Inventory and Analysis Program. See an associated Clark News Hub announcement.

July 2014

Congratulations to Dr. Melanie Vanderhoof for successfully defending her dissertation and earning her doctoral degree in July.  Many thanks to her committee, including Dr.’s Rogan and Kulakowski from Clark University and Dr. Jeffrey Masek of NASA GSFC.

Tenure for Prof. Williams: Congratulations to Dr. Williams for earning tenure and being promoted to the level of Associate Professor effective September 2014.

May 2014

Reviewing Excellence Award for Prof. Williams: Congratulations to Dr. Williams for receiving the “Excellence in Reviewing” award for 2013 from Journal of Geophysical Research – Biogeosciences.

April 2014

Congratulations to  Rich MacLean, who received an award from the Edna Bailey Sussman Foundation to support summer research on the climate impacts of forest management with study at Harvard Forest.

NASA Carbon Cycle Science awarded Co-I Williams support for a project titled “Quantification of the regional impact of terrestrial processes on the carbon cycle using atmospheric inversions” being led by PI Ken Davis of Penn State University.

Prof. Williams accepted an invitation to join as Editor of Biogeosciences.

Reviewing Excellence Award for Prof. Williams: Congratulations to Dr. Williams for receiving the “Excellence in Reviewing” award for 2013 from Biogeochemistry.

December 2013

Melanie Vanderhoof (Ph.D. candidate) recently published two research papers on albedo impacts of bark beetle outbreaks recently published in JGR-Biogeosciences (pdf copy) and Biogeosciences (web copy), both of which were also presented at the recent AGU Fall Meeting.  (See updated pdf copies on the publications page)

Congratulations to undergraduate student Rebecca Walker (Harvard Forest REU ’13, UVA BA ’14) for her excellent poster presentation delivered at the recent Fall Meeting of the American Geophysical Union.

Albedo and Land Change Meeting Hosted: Dr. Williams hosted a group of leading remote sensing scientists for a team meeting to conclude a three-year, NASA-funded study on “Albedo Trends Related to Land Cover Change and Disturbance: A Multi-sensor Approach”. (see the write-up at Clark’s News Hub)

October 2013

Post-Clearcut Research Paper published: see highlights and photos plus press resources covering our recent publication documenting carbon, water, and energy exchanges following forest clearing at Harvard Forest, authored by Prof. Williams’s Lab, (web copy). Also see the Clark University News Release.

August 2013

Congratulations to Prof. Williams for receiving the 2013 Hodgkins Junior Faculty Award from Clark University. This award is given to an un-tenured junior faculty member to promote and recognize outstanding research and teaching successes.

Congratulations to Dr. Prajjwal Panday on his paper “Application and evaluation of a snowmelt runoff model in the Tamor River basin, eastern Himalaya using a Markov Chain Monte Carlo (MCMC) data assimilation approach” recently accepted in Hydrological Processes. After earning his doctorate from the Graduate School of Geography at Clark University in May of 2013, Dr. Panday joined the Woods Hole Research Center to advance ecological modeling of vegetation dynamics in the Amazon.

Thanks to Rebecca Walker (Univ. of Virginia ’14) and Lowell Chamberlain (SUNY ESF ’14) for their excellent work during the 2013 REU program at the Harvard Forest LTER. In addition to collecting data supporting our core research at the clearcut site, Rebecca analyzed vegetation transect data to study early successional species interactions and Lowell examined possible determinants of relative abundance for various species following recent clearing. You can read more about their experience in a 2013 Undergraduate Research Blog. Congratulations to both!

May 2013

Congratulations to Alex Kappel for earning High Honors on his thesis entitled “Post Disturbance Soil Respiration Dynamics in a Clear Cut Temperate Forest”. Congratulations also on earning your Bachelor’s in Environmental Science with the Earth System Science Track.

Congratulations to Thor Akerley for his excellent research presentation entitled “Quantifying Species-Specific Differences in Leaf Area—Leaf Mass Relations in a Regenerating Temperate Forest”, and for earning his Bachelor’s in Environmental Science with the Earth System Science Track.

Prof. Christopher A. Williams was involved in a live radio broadcast of Locus Focus (KBOO-FM out of Portland, OR) where he discussed the current severe drought conditions being experienced throughout many parts of North America in the context of historic droughts, and the role that climate change is playing in the intensification of extreme weather events.

December 2012

Prof. Williams participated in a NASA Press Briefing reporting recent trends in wildland fires, their link to climate change now and into the future, and the associated carbon emissions feedback to climate change (Clark Coverage). Dr. Bardan Ghimire is the lead author of the corresponding publication (see Publications, 2012 JGR-B). This news ran in a numerous outlets including ScienceNewsline, Science Codex,, Bloggera Science News, Science Daily, TheStreet, and many local newspapers and online blogs (full press briefing). You can also see Prof. Williams’s related invited talk.

Congratulations to Dr. Bardan Ghimire for being selected as one of the early career scientists sponsored to attend the upcoming RCN FORECAST meeting focused on model-data fusion techniques in biogeosciences.

Congratulations to Bardan Ghimire, Ph.D. for earning his doctorate from the Graduate School of Geography at Clark University with a dissertation entitled, “Biogeochemical and Biophysical Consequences of Disturbances in Forests of the Western United States”.

August 2012

Prof. Williams’ research on droughts in the American West received significant press, including an Opinion piece in the NYTimes, an interview with Tom Ashbrook on NPR’s On-Point, and a blog posting in the NYTime’s Dot Earth Blog maintained by Andrew Revkin. This work also initiated a local TV news spotlight with New England Cable News.

Dr.’s Christopher Schwalm (NAU, formerly Clark), Prof. Williams (Clark), Dr. Kevin Schaefer (NSIDC) and others just published in Nature-Geoscience a paper documenting the carbon, water, and crop impacts of the severe 5-year drought striking western North America at the turn of the century (2000-2004). Carbon uptake declined by around 50% during the drought. The study also showed how projected changes in rainfall and drought severity foretell a coming megadrought-like condition in the late 21st century, likely causing the present-day carbon sink in western North America to disappear by the end of the century as well as bringing a host of additional water resource challenges to a region already accustomed to frequent water stress. Clark University press release.

Congratulations to Melanie Vanderhoof (Clark PhD student) and Marcus Pasay (Clark ’12, pursuing MS ’13) on a successful field season in Colorado exploring biophysical impacts of bark beetle outbreaks.

Welcome to incoming PhD student Rich MacLean and congratulations on being awarded Clark’s Libbey Fellowship in Earth System Science. Rich joins us from the University of New Hampshire and arives with expertise in forestry and ecosystem biogeochemistry, one of 8 new members of the Geography PhD program starting in Fall 2012.

June 2012

A recent publication by Prof. Williams, featured in Water Resources Research and the AGU weekly newspaper Eos, documents how vegetation and climate types influence water resource availability by regulating the amount of water that runs into rivers compared to how much is lost to the atmosphere through evaporation.

See the Undergraduate Research Profile featuring Alex Kappel (Clark ’13) and Paul Quackenbush (Middlebury ’14) immersed in field research at Harvard Forest as part of the LTER Research Experience for Undergraduates (REU) program.

Congratulations to Melanie Vanderhoof for winning a student presentation competition at the recent AMS 30th Agricultural and Forest Meteorology/First Atmospheric Biogeosciences Conference.

May 2012

Welcome to Dr. Myroslava Khomik, the group’s new postdoctoral researcher arriving from the Max-Planck Institute for Biogeochemistry in Jena, Germany. She will officially start at Clark in September 2012, but is visiting in May and July-August to assist with field research activities. Dr. Khomik examines nutrient, water and carbon flows in forests with expertise centering on the measurement and modeling of plant physiology and soil organic matter decomposition in mature and afforested environments.

Undergraduates Alexander Kappel (Clark ’13) and Paul Quackenbush (Middlebury ’14) have been selected to participate in our 2012 field research at Harvard Forest as part of the LTER Research Experience for Undergraduates (REU) program with the mentorship of Melanie Vanderhoof (Clark PhD student), former REU Marcus Pasay (Clark ’12, pursuing MS ’13), and Prof. Williams.

December 2011

Congratulations to Christopher Schwalm (former Postdoc) for securing a Research Assistant Professor position at Northern Arizona University.

Prof. Williams enjoyed a refreshing Fall 2011 sabbatical as a Visiting Professor at the Swiss Federal Institute of Technology, Lausanne (EPFL) within the ecohydrology and environmental fluid mechanics group of Prof. Marc Parlange (

June 2011

Congratulations to Melanie Vanderhoof (PhD student, Geog.) for receiving a NASA Earth and Space Science Fellowship to support her doctoral research (PI Williams).  Her proposal is titled “Albedo and Evapotranspiration Consequences of Bark Beetle Outbreaks as Detected by Remote Sensing in Coniferous Forests, Rocky Mountains, USA”.

Undergraduates Marcus Pasay (Clark ’12) and Katharine Chute (Harvard ’11) have begun their summer of field research at Harvard Forest as part of the LTER Research Experience for Undergraduates (REU) program with the mentorship of Melanie Vanderhoof (Clark PhD student), former REU Angie Marshall (Clark ’11), and Prof. Williams.

May 2011

Congrats and good luck to Graham Twibell (Clark ’10 BA, ’11 MA) as he begins work with the Cary Institute of Ecosystem Studies, Millbrook, NY.

Good luck to Krittika Govil (Clark ’11) as she continues her studies to work toward a Masters in hydrology at Texas A&M.

Congratulations to Angela Marshall (Clark ’11) for receiving the NCGE Excellence in Scholarship Award at graduation.

February 2011

Prof. Christopher Williams has been funded by NASA The Science of Terra and Aqua as a Co-PI on a three-year, $866,082 project examining remotely sensed albedo trends related to land cover change and disturbances.

Melanie Vanderhoof (PhD Geog. student) has received a Geller Endowment Research Award, administered by Clark’s George Perkins Marsh Institute, for her proposal “Woody debris decomposition dynamics in a post-harvest chronosequence”.

Angie Marshall (Clark ’11 Honors) presented a poster at the Massachusetts Climate Action Network hosted at Clark University. The presentation was titled, “Harvest-induced elevation of coarse and fine woody debris imposes a legacy of carbon emissions: Comparison to pre-harvest and undisturbed forest”.

October 2010

Prof. Christopher Williams has been funded by the NASA Terrestrial Ecology Program for a three-year, $655,000 project on carbon consequences of forest disturbances.

Prof. Christopher Williams is the co-author of a recent report in Nature, “the leading weekly international science journal” 13 October 2010, Recent decline in the global land evapotranspiration trend due to limited moisture supply.

July 2010

Prof. Christopher Williams co-authored a report in Science, the journal of the American Association for the Advancement of Science and the “world’s leading journal of original scientific research, global news, and commentary.” 7/5/2010 Terrestrial Gross Carbon Dioxide Uptake: Global Distribution and Covariation with Climate.

Undergraduates Angie Marshall (Clark ’11) and Crystal Garcia (Baylor Univ ’11) completed a successful summer of field research at Harvard Forest as part of the LTER Research Experience for Undergraduates (REU) program.

Bardan Ghimire (PhD Geog. candidate) was funded by a NASA Summer Fellowship to explore “Biogeochemical and Biogeophysical Consequences of Forest Disturbances across the Conterminous U.S.”

Melanie Vanderhoof (PhD Geog. candidate) was awarded Clark’s Libbey Fellowship in Earth System Science. She joined the Geography PhD program in Fall 2010.

January 2010

Prof. Christopher Williams has been invited to serve as an Associate Editor of Biogeochemistry, a highly-ranked international journal publishing original papers on ecosystem carbon and nutrient cycles. With his new position, Prof. Williams has been asked to help raise the journal’s profile with regards to plant and ecosystem carbon cycle science.

August 2009

Clark Undergraduates Graham Twibell (Clark ’10) and Michelle Smith (Clark ’11) completed a successful summer of field research having been selected for NSF REU supplement award supporting Prof. Williams’ NSF grant.