My work spans questions that address uncertainties in Earth system feedbacks to quantifying soil health outcomes and forest processes. I am primarily interested in how organisms and their interactions affect decomposition and soil carbon stocks. Increasingly my work is focused on quantifying the effects of agircultural and forest management, to build evidence that supports actions to improve environmental stewardship.
Mail: Yale School of the Environment, 195 Prospect St., New Haven, CT 06511, USA
Office: Kroon Hall 202
Lab: Greeley 106
Steve is a soil scientist in the Global Lands team of The Nature Conservancy and has a joint appointment as an Associate Research Scientist at Yale F&ES. He is working to develop cutting-edge science to support soil activities across The Nature Conservancy. He has an interdisciplinary background, with degrees in ecology, economics, and philosophy. Steve’s topical expertise is in soil and ecosystem ecology, sustainable agriculture, sustainability science, and statistical modeling.
I am a forest ecologist who likes to ask questions about the link between above-ground and below-ground processes. I’m interested in the feedbacks that exist between plants and their associated soil microbial communities, as well as the relationship between plant traits and carbon cycling.
My research focuses on plant-soil interactions and their effects on carbon and nitrogen cycling and storage in forests. Specifically, my work investigates feedbacks between invasive plants, soil nutrient availability, and disturbance as well as the influence of mycorrhizal functional types on soil biogeochemical processes. Many of the systems that I work in are strongly influenced by human use, such as urbanization and forest management, and I am particularly interested in applications of my research for conservation and restoration.
I am interested in the ecosystem services provided by large mammals as well as the impacts of local or regional extinction. Working between the Bradford Lab and the Schmitz Lab, I explore the impact of migratory mammals on soil dynamics, nutrient cycles, and carbon storage through both field experiments and models.
How are micro-organisms interacting with plants, macro-organisms, nutrients, and each other? I look at how bacterial and fungal activity influences the micro-environment and, in-turn, the broader ecosystem!
Doctoral Student, 1st year
I am a new doctoral student, focused on connecting applied science on forest management to positive economic and environmental outcomes. My current work focuses on forest farming (understory herbs) and agroforestry.
The list of those that have come through the group, strongly shaping our current work for the better and who, in many cases, remain valuable collaborators.
Given are the names of folks, their destination on departing the lab and/or their current position, and a brief description of what they did while with the group.
Angela Oliverio, Postdoctoral Fellow 2021-2022: Assistant Professor, Syracuse University
Angela was a National Science Foundation Postdoctoral Fellow in Biology working on microbial -omic relationships with ecosystem functioning, in particular litter decomposition at macrosystem scales. We continue to collaborate with her on this and other work, since she started her faculty career in fall 2022 at the Biology Dept. at Syracuse. Check out her lab group.
Daniel Kane, Ph.D. 2021: Senior Manager, Agricultural Land Management, TerraCarbon LLC
Dan’s dissertation work had two themes. The first focused on quantifying how soil organic carbon in agrciultural soils affects water availability, and specifically quantified the extent to which it can protect yields under drought. The second focused on developing hardware and software tools and approaches to rapidly estimate soil carbon stocks.
Meghan Taylor, Postdoctoral Associate 2019-2021: Postdoctoral Associate, University of Vermont
At Yale, Meghan focused on understanding methane fluxes from peatland and forest ecosystems, to identify the controls on emissions and the potential for management interventions as a component of natural climate solutions.
Annise Dobson, Postdoctoral Associate 2018-2021: Postdoctoral Associate and Lecturer, Yale University
Annise’s research is motivated by forest conservation for all, particularly in urban and managed forests. She is interested in the role of soil fauna in plant community and nutrient dynamics within these ecosystems and at Yale was performing still ongoing research into jumping worms as a new threat to urban and rural forests alike.
Sally Donovan, M.E.Sc. 2021: Doctoral student, University of Minnesota
At Yale , Sally studied how land-use legacies (of agriculture) affect the carbon and nitrogen cycling in soils of forested natural areas in New York City, and linked the consequences to management of problem invasive species that threaten the health of these forests.
At Yale, Emily quantifed how soil organic matter (SOM) contributes to soil function. Specifically, her research focused on SOM’s contribution to the productivity and resilience of agricultural landscapes.
Clara Pregitzer, Ph.D. 2020: Deputy Director of Conservation Science, Natural Areas Conservancy, New York City
At Yale, Clara looked to understand how the urban context can influence forest structure and function and how to best manage complex and dynamic landscapes for the future.
Javier Rivero, 2019-2020: At Yale, Javi completed a Masters of Environmental Management and then spent 6 months with the lab working as a research technician launching an NSF Macrosystems Biology project to gain further expertise in field and lab ecosystem science, before entering the professional environmental world.
Nicholas Fields, 2019-2020: At Yale, Nick completed a Masters of Environmental Management and then spent 6 months with the lab working as a research technician launching an NSF Macrosystems Biology project to gain further expertise in field and lab ecosystem science, before returning home to Barbados and entering the professional environmental world.
Noah Sokol, Ph.D. 2018: Postdoctoral Associate, Lawrence Livermore National Laboratory
At Yale, Noah focused on plant-soil linkages in the terrestrial carbon cycle. He studied how plant inputs go on to form stable soil organic mater (SOM), and how these SOM stocks are altered through deforestation and thespread of invasive species.
Sara Kuebbing, Postdoctoral Associate 2014-2018: Research Scientist, Director of the Yale Applied Science Synthesis Program, Yale University
At Yale, Sara studied studying biological invasions and their impacts on native plant communities and ecosystems. She researched the impacts and interactions among co-occurring invasive plant species and how these impacts might differ from invasions by single invasive plants. Specifically, she studied whether trait differences among co-occurring native and nonnative species can predict the magnitude and direction of ecosystem impacts of nonnative plants. Personal site: https://www.sarakuebbing.com
Dan Maynard, Ph.D. 2017: Research Scientist, ETH Zurich.
At Yale, Dan focused on the intersection of ecosystem ecology and community ecology. His broad focus was on how climate change will affect ecosystem processes by altering species distribution and function, and how this will in turn affect the community composition of forests. His specific research showed how interference competition (combat!) in fungal communities strongly shaped their diversity and function; highlighting the need to revisit this long ignored process as central to structuring microbial dynamics. Dan first went to a postdoctoral position at the University of Chicago, before moving to ETH in April 2019.
Kris Covey, Ph.D. 2016: Assistant Professor, Skidmore College.
At Yale, Kris focused on quantifying the flux of methane from living trees through a novel stem-based source. His major advisor was Prof. Chad Oliver but he collaborated closely with our group and brought a novel perspective given his focus on integration of his science into practical silvicultural solutions for the management of mixed-species forests.
Thomas Crowther, Postdoc 2012-2015: Assistant Professor, ETH Zurich.
At Yale, Tom explored how biotic and abiotic factors governed the biogeography and functioning of microbial communities at different spatial scales. And, oh yeah, he counted the number of trees in the world (as a side project).
At Yale Madeleine studied how the activities of fungal decomposers responded to past and current temperature conditions, and showed that past exposure to warmer temperatures selected communities more active at higher temperatures. She is writing her work up for publication.
Ashley Keiser, Ph.D. 2014: Assistant Professor, Univ. of Massachusetts, Amherst
At Yale Ashley studied how forest dynamics and how global change affected nutrient feedback loops between microbial and plant communities. She then went to Iowa before taking a prestigious NatureNet Fellowship. She will soon start a faculty position - check back soon to reveal where!
At Yale Avishesh studied how temperate forest termites influenced the decomposition of wood both above- and belowground, to begin filling in the knowledge gap about how these organisms affect ecosystem processes, especially in light of the fact their abundance may dramatically increase with warming.
Anna Wade, BSc Environmental Studies 2013: Ph.D. student, Duke University
Tara Ursell, MESc 2013: Ph.D. student, UC Davis
At Yale Tara studied the consequences of invasive grasses for nitrate (both a water pollutant and essential nutrient) dynamics in soils across a broad regional landscape, forming the water source for much of the southeastern U.S. In addition, she investigated how scientific synthesis could be better conducted to inform recommendations for meeting environmental policy demands.
Robert Warren II, Postdoc 2010-2012: Associate Professor, Buffalo State College (SUNY)
Robert’s research at Yale focused on 1) the abiotic and biotic drivers behind current and predicted species distributions and 2) the correspondence between species distributions and suitable habitat as determined by species- and stage-specific niche requirements. Website
Michael Strickland Postdoc 2010-2012: Associate Professor, University of Idaho
Mike’s research at Yale investigated how community structure affects ecosystem function within the context of environmental change. I tackle this interest by specifically assessing how changes in the structure of soil microbial communities, either due to historical and/or contemporary environmental change, impact ecosystem biogeochemical cycles.
Bhavya Sridhar, MESc 2012: Ph.D. student, Cornell University
Wile at Yale, Bhavya studied the consequences of nitrogen fertilization and soil warming for soil carbon storage and cycling.
Taylor Gregoire-Wright, BSc Environmental Studies 2012: TERI, India
At Yale, Taylor studied the effects of different resource histories on the functioning of microbial communities.
Steve’s research at Yale involved understanding how land use and environmental change affect human well-being and ecosystem functioning, with a particular focus on West Africa.
Emily Stevenson (Oldfield), MESc 2011: see above
Tim Kramer, MESc 2010: Environmental Emergency Response Technician, ENTRIX, Inc.
Tim’s research at Yale was based out of the Coweeta Long Term Ecological Research (LTER) program, where he studied how Microstegium vimineum, an invasive grass, may be affecting soil fertility and carbon storage potential within different soil carbon pools in Southern Appalachian forests.
While at Yale F&ES Caitlin researched potential soil carbon storage after rangeland restoration in eastern Oregon. She was awarded a Wyss Scholarship to pursue innovative western land conservation and studied watershed management and ecosystem services. Caitlin currently lives in Portland, Oregon
While at Yale, Yaya’s research examined how the invasive Japanese stilt grass is being incorporated into above and below ground food webs in the Southeastern Appalachian forests. She is also interested in urban ecosystem patterns and how ecological processes can be incorporated into the urban landscape.
Brian Watts, BSc 2011: Teaching English and Environmental Volunteering, South Korea
Calley Mersmann, BSc 2011: Indiana University, Masters in Public Administration
Ken Leonard, Ph.D. 2010: Instructor, School of Science and Technology, Georgia Gwinnett College
Mike Strickland, Ph.D. 2009: See above
Dr Christian Davies, postdoc to 2009: Environmental Biotechnologist, UK Project Leader – Biodomain Technology Group, Shell Research Ltd, England
Tara Gancos, BSc 2008: PhD program in Environmental Life Sciences, Arizona State Univ.
Becky Ball, Ph.D 2007: Associate Professor, New College Division of Mathematical and Natural Sciences, Arizona State University