Erin Hotchkiss standing in Stony Creek, Virginia

Dr. Erin R. Hotchkiss

Assistant Professor, Department of Biological Sciences | Faculty Affiliate, Global Change Center | Virginia Tech

Office: Derring Hall 2006B | Phone: +1 540-231-7005 | email: ehotchkiss[at]

@FluvialBenthos | Google Scholar | ResearchGate | ORCID | Curriculum Vitae

I am an ecologist who uses empirical data and statistical models to understand how environmental change, land-water interactions, and ecosystem processes shape the transport, transformation, and fate of carbon and nutrients in freshwaters. Questions of interest include: How, when, and where do biological processes regulate carbon and nutrient export and emission fluxes at the ecosystem and meta-ecosystem scale? In what ways do climate and landscape changes alter freshwater biogeochemistry, metabolism, and food webs? What is the function and fate of algal and terrestrial organic matter in river networks? I use a combination of monitoring (chemistry, hydrology, biology), experimental (manipulating carbon and nutrients, stable isotope tracers), and quantitative (Bayesian, inverse modeling) approaches to study freshwater ecosystems.


Carla López Lloreda

M.Sc. Student | National Science Foundation Graduate Research Fellow | Department of Biological Sciences | Virginia Tech

@carlalopezpr | LinkedIn | carlalopez[at]

I am interested in how freshwater ecosystems process and transport nutrients and solutes across the landscape and how these processes can be different or possibly fundamentally altered after extreme climatic events such as hurricanes and droughts. I have a particular interest in understanding these processes in places that might be more vulnerable to climate change, like tropical islands or coastal ecosystems, with the ultimate goal of understanding the future of our water resources.

Katherine X. Pérez Rivera

Ph.D. Student | Fulbright Research Fellow | Department of Biological Sciences | Virginia Tech

ResearchGate | kperezrivera[at]

I am interested in understanding dissolved organic matter and nutrient cycling, transport, processing and exchange in freshwater ecosystems, and how this is influenced by inputs from the surrounding landscape. I am also interested in how water quality changes along river networks as a result of landscape disturbances and determining the drivers that influence the response of aquatic ecosystems to in-stream processing of terrestrial inputs and microbial activity.

Kristen Bretz hiking on snowy trail

Kristen Bretz

Ph.D. Student | Department of Biological Sciences | Interfaces of Global Change Program | Virginia Tech

@ka_bretz | ResearchGate | kabretz[at]

I am interested in how changes in the timing of carbon and nutrient inputs influence biogeochemical processes in streams and how these changes will affect different parts of a watershed. I'm also curious about how aquatic ecosystems respond to the impacts of climate change at different spatial scales and what we can do to better quantify and understand how factors like warming temperatures, flow extremes, and terrestrial ecosystem changes feed back on each other in ways that may fundamentally after stream systems.

Stephen Plont standing in front of lake and mountains

Stephen Plont

Ph.D. Student | National Science Foundation Graduate Research Fellow | Department of Biological Sciences | Interfaces of Global Change Program | Virginia Tech

@stephenplont | ResearchGate | plontste[at]

I am interested in understanding the spatial and temporal variability of ecosystem processes, their influence on the transport and transformation of carbon and other nutrients throughout stream networks, and ultimately how water quality is influenced by environmental and hydrologic change at the ecosystem-scale.

Mohammed Hamdan coring through ice on experimental ponds in Sweden

Mohammed Hamdan

Ph.D. Student | Umeå University, Sweden

Co-supervised by Jan Karlsson, Pär Byström, & Erin Hotchkiss

ResearchGate | website | mohammed.hamdan[at]

Dissertation topic: Top-down and bottom-up control of ecosystem production in northern lakes.


Natalie Murphy

Biochemistry | Virginia Tech


Undergraduate Research:

Ecohydrology of intermittent streams (2019-present)

Cameron Braswell hiking in the woods

Cameron Braswell

Biological Sciences | Virginia Tech


Undergraduate Research:

Carbon metabolism in streams and rivers: Confluence- to global-scale assessments (2019-present)

Lauren Morris

Biological Sciences & Green Engineering | Virginia Tech


Undergraduate Research:

Ecological applications of high-frequency data and ecosystem metabolism estimates (2020-present)


Graduate Students

Brynn O'Donnell with nutrient uptake sampling equipment

Brynn O'Donnell

M.Sc., Biological Sciences | Virginia Tech | 2019

Thesis: The flow regime of function: Influence of flow changes on biogeochemical processes in streams

@_brynnodonnell | website | LinkedIn | Submerge Podcast

Currently: Project Manager, Seafood Alliance for Legality and Traceability Initiative, FishWise

Marie Gérardin sampling the Romaine River complex in Québec, Canada

Marie Gérardin

M.Sc., Biology | Université du Québec à Montréal, Canada | 2019

Thesis: Sources et facteurs menant à la sursaturation en CO2 et CH4 des rivieres boreales

Primary supervisor, Paul del Giorgio | ResearchGate

Currently: Montréal, Canada

Emelie Landström measuring stream benthic pigments in Krycklan, Sweden

Emelie Landström

M.Sc., Ecology | Umeå University, Sweden | 2015

Thesis: Resource use by macro-invertebrates within boreal stream food webs

Primary supervisor, Jan Karlsson | LinkedIn

Currently: Water Officer, Västerbotten County Administrative Board, Sweden (Vattenhandläggare på Länsstyrelsen Västerbotten)

Undergraduate and Postgraduate Researchers, Virginia Tech

AJ Jackson at frozen Cascade Falls in Virginia

Alexis "AJ" Jackson

Biological Sciences | Virginia Tech

@itsAJrenee | LinkedIn

Undergraduate Research:

Carbon emissions from riparian wetlands (2019-2020)

2019 NSF REU Fellow; 2020 Global Change Center Grant Awardee; 2020 SFS Instars Fellow; & 2020 Virginia Tech Undergraduate Research Excellence Awardee

VT 2020

Jake Riney and a stuffed bear

Jake Riney

Computer Science & Biological Sciences | Virginia Tech


Undergraduate Research:

Ecosystem metabolism at stream confluences (2019-2020)

VT 2020

Jack Monroe measuring stream water from Walls Branch in a graduated cylinder

Jonathon "Jack" Monroe

Biological Sciences, Microbiology, & Chemistry | Virginia Tech


Undergraduate Research:

Microbial metabolic fingerprints in intermittent headwater streams (2019-2020)

2019 Global Change Center Grant Awardee & 2019-2020 Robert Jones Undergraduate Research Excellence Awardee

VT 2020

Sumaiya Rahman measuring water quality at a sensor monitoring station in Stroubles Creek, Virginia

Sumaiya Rahman

Biological Sciences | Virginia Tech

Undergraduate Research:

Influence of storm magnitude on dissolved oxygen in streams (2018); Greenhouse gas emissions from terrestrial-aquatic interfaces and temporary waterways (2018-2019)

2018 NSF REU Fellow

VT 2019

Shawn Becker hiking in the woods with students

Shawn Becker

Science Teacher | Gate City High School

NSF RET Fellow:

Rapid assessment of ecosystem respiration in streams and rivers (2019)

Caitlin Miller on the beach holding a horseshoe crab

Caitlin Miller

Wildlife Conservation, Biological Sciences, & Wetland Science | Virginia Tech


Undergraduate Research:

Stream confluence dissolved organic matter dynamics (2018-2019)

VT 2019

Morgan Gallagher on a ridge overlooking mountains in Virginia

Morgan Gallagher

Environmental Science & French | Virginia Tech

@MorganGa11agher | LinkedIn | ResearchGate | website

Undergraduate Research:

Greenhouse Gas Dynamics in Streams - Sources, Patterns, Processes (2017-2019)

2018-2019 Fralin Research Fellow; 2019 Fulbright Fellow; & 2019 GRFP Awardee

VT 2019

Jacob Beckner holding a fish at a hatchery

Jacob Beckner

Fish Conservation | Virginia Tech


Undergraduate Ecology Research & Teaching:

Freshwater ecology, species invasions, and meta-ecosystem food webs (2019)

VT 2020

Melissa Castillo measuring water quality in Stroubles Creek at the Walls Branch confluence

Melissa Castillo

Pre-Health Sciences | Salt Lake Community College


Undergraduate Research:

Organic matter sources and carbon metabolism in streams (2018)

2018 MAOP Research Fellow

Schuyler van Montfrans in the classroom

Schuyler van Montfrans

Teacher | Decatur High School

NSF RET Fellow:

Temporal variability in carbon and nutrient demands in a dynamic urban stream (2018)

Quentin Pitts at Cascades Falls in Virginia

Quentin Pitts

Biological Sciences | Virginia Tech

Undergraduate Research:

How does stream salinization alter dissolved organic matter dynamics? (2018)

VT 2018

Undergraduate Biological Sciences Field Study, Virginia Tech

2020: Lauren Morris & Bryce Onozuka

2019: Cameron Braswell & Natalie Murphy

2018: Emily Byrd, Jack Monroe, Hank Liu, & Caitlin Miller

2017: Sumaiya Rahman, Quentin Pitts, & Jonathan Cordle

Undergraduate and Postgraduate Researchers, University of Wyoming

Paige Hellbaum (2012-2013), Jessica Neuwerth (2012-2013), Amy Saville Rhoad (2011-2013), Noah Berg-Mattson (2011-2012), Clark Johnson (2011-2012), Sarah Gregory (2010-2011), Trista Niekum Coble (2009-2011), Sahale Casebolt (2009), Brenna Hansen (2008-2009), Tamara Lehnertz Bretting (2007-2008), Elias Anoszko (2007), & Joshua Theurer (2007)

Pictures of undergraduate and post-graduate researchers from the University of Wyoming