IMG_1735 2Steven Hall

Steven is an Assistant Professor in the Department of Ecology, Evolution, and Organismal Biology at Iowa State University. He received a BS in Botany and an MS in Environment and Resources from the University of Wisconsin, and a PhD in Ecosystem Science from the University of California-Berkeley. Before coming to ISU, he was a post-doc at the University of Utah Global Change and Sustainability Center. Aside from science, he enjoys biking on and off road, construction projects, and making music.




Postdocs and staff scientists


wenjuan jj reduced

Wenjuan  Huang

Wenjuan (wjhuang [at]  is a postdoctoral researcher in the lab. She earned her B.S. degree in Ecology from the China Agricultural University in 2007 and her Ph.D. in Ecosystem Ecology from the South China Botanical Garden, Chinese Academy of Sciences in 2013. She is interested in the interactions of carbon, nitrogen (N), phosphorus (P), and iron (Fe) in plant and soil systems and their responses to global change. Her past research has focused on taking biogeochemical approaches to study how N and P cycles control ecological functions in (sub)-tropical forests. At ISU, her work explores linkages between iron redox cycling and decomposition and nutrient dynamics using stable isotopes. She is broadly interested in understanding how climate change could alter soil carbon turnover by regulating microbial and geochemical processes.




Robert Johnson

Robert is a postdoctoral researcher working with the lab. He earned a BS in Zoology from the University of Wisconsin-Madison and a PhD in Zoology from the University of Florida. Broadly, he is interested in how food web interactions drive ecosystem functions. Within this context his research has largely focused on understanding how grazing affects benthic carbon dynamics in aquatic ecosystems. At Iowa State University he is interested in understanding how food web dynamics drive greenhouse gas fluxes from aquatic ecosystems within a nutrient-rich landscape.



carlos lab photo_redCarlos Tenesaca

Carlos (Charlie4 {at} is a research associate in the lab leading the EPA study on  environmental impacts of farmed and restored pothole wetlands. He earned a masters degree in soil science from ISU in 2013, where his research focused in soil health and greenhouse gas emissions in areas used for corncob residue storage (cellulosic ethanol production). Before coming to the lab, he was a research associate at the Soil and Plant Analysis Laboratory (ISU); where he analyzed soil and plant samples for farmers and researchers. He is excited to learn more about the environmental impacts of potholes in Iowa.



Graduate students


holly bog red


Holly Curtinrich

Holly (hrich [at] is a PhD student in the Environmental Science program. Her current work focuses on iron oxidation-reduction cycling in bogs and fens and how this may affect organic carbon stabilization and loss. Holly enjoys sampling peat cores and extracting iron in the lab with her colleagues. She graduated from the University of Virginia in 2013 with a BS in Environmental Science. When she’s not working, Holly enjoys running, hiking, and eating non-dairy ice cream.





nate pit cropped Nate Lawrence

Nate (natelaw [at] is a PhD student in the lab who completed his undergraduate degree from the University of Illinois (while conducting research with friend of the lab Wendy Yang).  His past research focused on carbon and nitrogen cycles in Panama, Maine, and California.  Nate is primarily interested in how soils mediate ecosystem response to global change and managing these systems to reduce greenhouse gas emission.  At ISU, his research explores controls on nitrogen cycling in grassland and managed ecosystems in the prairie pothole region. He has been instrumental in building and developing autochambers to measure N2O and CO2 fluxes at high resolution in hydric agricultural soils.




Holly Loper

Holly (hjloper [at] is a PhD student in the interdepartmental Microbiology program. She joined the lab in the Fall of 2019 and is interested in ways microbes can greatly change the world around us.  Her current research focuses on how nitrogen from bacteria used to improve fertilizer efficiency may be making its way into the air, water, and maize crops.  She received a Bachelors of Science with a double major in Bioinformatics and General Biology from Michigan Technological University. When not at school, Holly enjoys going camping, hiking and spending quality time with her cat at home.






wjyu_croppedWenjuan Yu

Wenjuan Yu (wjyu [at]  is a PhD student in the Environmental Science program who arrived in 2019. She received a BS in Chemistry from Fudan University of China and a MS in Food Microbiology from Shanghai Jiao Tong University of China. Before coming to ISU, she has been working in the Instrumental Analysis Center of Shanghai Jiao Tong University. Her dissertation work will focus on linkages between microbial communities and organic matter decomposition using soils from across the National Ecological Observatory Network (NEON). She is also interested in soil organic matter (SOM) chemistry.



Undergraduates and post-bac researchers

 Hannah lab_red

Hannah Craven

Hannah Craven is an undergraduate technician in the lab in her sophomore year at ISU double majoring in Chemistry and Environmental Science. She joined the lab in the spring of 2019, and she is now helping with the NEON studies. Her favorite thing to do in the lab is run the TGA, but outside of lab you can find her playing the trombone in the ISU marching band!  







Matthew Ford

Matthew is from Corona, California and went to school in Flagstaff, AZ. His hobbies include backpacking, birding, climbing and fly fishing. His degree is a BS in environmental science and a minor in chemistry. His interests are focused in environmental chemistry and the foundation it sets for unique and healthy ecosystems. He hopes to study and rehabilitate abused soil and water systems in wetland areas.








Laura James

Laura is majoring in biology and environmental studies at ISU and hopes to continue her research in plant-environment interactions. I love working at the lab and it was actually the catalyst for me deciding that I want to go to graduate school! Outside of the lab, I enjoy hiking, running, and being a part of ISU’s Students for Open Discussion club where we casually discuss all things controversial.






Jessie Ribera

Jessie is a technician working in the lab, she received her undergraduate degree in Organismal Biology while minoring in Media Studies. She has her hands in helping many of the researchers projects including fertilization efficiency, nitrogen cycling in agricultural fields, and microbial soil emissions. When not at the lab she enjoys crafting, cooking, and playing rugby!

Lab Alumni

Graduate students

Chenglong coring

Chenglong Ye

Chenglong (chenglongye [at] was a visiting PhD student (funded by the China Scholarship Council)  from Nanjing Agricultural University. His research focuses on physiochemical mechanisms of organic C persistence. At ISU, his research explored the impacts of different cropping systems on soil organic C dynamics using high-frequency C isotope measurements of CO2. He is also exploring continental-scale patterns in soil organic matter chemical composition as part of our  NSF Macrosystems grant.





Technicians and undergraduates

Charles Garrett



Stephanie Tsui

Stephanie  is a technician in the lab helping with the EPA and NEON studies. She graduated from the University of California, Davis in 2018 with a BS in Environmental Science and Management and a minor in Soil Science. Her favorite part of the lab is running the GC.


Mariana and lab_red



Mariana Gonzalez

Mariana is a student at Marshalltown Community College and joined the lab as an LSAMP-IINSPIRE summer research fellow during 2019. She led a study examining patterns in soil nitrogen availability across sites from the NEON network to determine sampling intensity needed to detect differences among sites.





Lindsay Mack

Lindsay is an ISU undergrad majoring in Environmental Science and Environmental Studies, originally from the Quad Cities, IL. She was a stellar technician in the lab, and has moved on to pursue environmental policy work.


Kristopher Mueller

Kris worked in the lab in 2018-19 during his senior year as an ISU forestry major and was instrumental in building and deploying resin lysimeters to measure nitrate leaching across topographic gradients of hydric and better-drained agricultural soils, among other things. He is now working as a forest ranger somewhere out west…


Anthony Mirabito

Anthony hails from Iowa City, Iowa and double majored in biology and environmental science at ISU. He has cool hands working at the TGA, and we were very happy to have him around! He led projects focusing on cryptic iron cycling in agricultural soils, and the potential for carbonates to provide proxies for ponding duration in hydric soils. He has now escaped Iowa and moved on to a lab position in Florida.





Lucio sampling

Lucio Reyes

Lucio graduated from ISU in Biology and Anthropology, and hails from El Paso, TX. He is an all-star lab technician and problem-solver, and enjoys getting out in the field (even in the winter). He is headed to grad school at the University of South Florida in fall 2017… we will be sad to see him leave!






Collin Stratton

Collin is an ISU undergraduate student from Genoa, IL, majoring in Animal Ecology and Minoring in Statistics. He started in the lab working as a first-years honors student with Wenjuan, and we didn’t want to let him leave because he brings such great enthusiasm and dedication to the lab! Nevertheless, next summer we hope he has a chance to work at Steven’s old stomping grounds at the El Verde Puerto Rico field station.




jerry poster session

Jerry Young Bear

Jerry worked in the lab during summer 2016 as a research fellow with the HHMI program, and kept everyone well entertained with his witty stories! We wish Jerry all the best with his future endeavors. This is a photo from the HHMI poster session, where he aced his presentation!