Last week Erin attended the American Geophysical Union (AGU) annual fall meeting in Washington, DC. Erin gave an invited presentation, “Scaling Pattern and Process in Fluvial Networks”, in a special session: "River Corridor Biogeochemical and Hydrologic Dynamics across Scales”. Erin also co-convened a special session with Diego Riveros-Iregui titled “Beyond Ecosystem Boundaries: Integrating Terrestrial and Aquatic Processes to Advance Catchment Biogeoscience”.

Students from the Hotchkiss, Barrett, Carey, McLaughlin, and Brown labs assisted graduate student Stephen Plont with fieldwork sampling for a multi-day experiment on Stroubles Creek and Walls Branch near Prices Fork last weekend. Stephen is using whole-stream pulse additions of dissolved organic matter and nutrients to measure the role of microbial metabolism, above and below stream confluences, in controlling downstream water quality. Exciting science and a great example of a supportive and collaborative student network thanks to Virginia Tech's Stream Team and Cross-Boundary Biogeosciences groups!

Erin and Brynn posted their "day of science" on twitter to share their experience as scientists, educators, mentors, and science communicators as part of the 2018 Earth Science Women's Network (ESWN) Science-A-Thon. Click on the following links to: see recent posts by Brynn, read Erin's #dayofscience thread, and learn more about science-a-thon and ESWN.

Master's student Stephen Plont co-authored a paper now online in Limnology & Oceanography: Methods: Lee-Cullin et al. "Toward measuring biogeochemistry within the stream‐groundwater interface at the network scale: An initial assessment of two spatial sampling strategies". Congratulations, Stephen and co-authors!

Erin Hotchkiss attended an international workshop on “Heterotrophic Regimes” in Ovronnaz, Switzerland. The workshop was supported by the U.S. National Science Foundation (NSF) and Swiss National Foundation (SNF) and brought together selected scientists from the US, Europe, and Australia who study carbon cycling and ecosystem metabolism in streams and rivers. Working groups that emerged from this workshop are collaborating on papers exploring topics related to: modeling terrestrial controls on ecosystem respiration regimes, understanding basal metabolism in streams, quantifying hypoxia in running waters, and linking the physiology of freshwater ecosystems and consumers. Thanks to Tom Battin and Amber Ulseth of SBER EPFL and Jim Heffernan / StreamPULSE for coordinating a great week of science in the mountains!

Erin Hotchkiss and Stephen Plont recently returned from conducting fieldwork in Montana for a newly funded collaborative NSF project (“Rivers and the carbon cycle: A mechanistic basis for dissolved organic carbon removal” - PIs Baker, Hall, & Hotchkiss). We successfully tested new methods to trace organic carbon transformations in streams. Additionally, Erin gave an invited seminar to students and researchers at Flathead Lake Biological Station (“Aquatic ecology, water quality, and food webs”) and Stephen completed a summer intensive course on “Environmental Sensors: Designing, Building and Deploying” at Flathead Lake Biological Station’s SensorSpace.

What processes drive organic carbon removal in streams? How does dissolved organic carbon removal regulate the degree to which running waters are biological reactors versus exporters of carbon? This newly funded project will address these unresolved questions by (1) integrating carbon spiraling metrics with more common stream carbon cycling measurements and (2) developing a proof-of-concept approach to test the degree to which non-additive effects of mixed organic matter sources (i.e., priming) control organic carbon removal in streams. PIs: MA Baker (Utah State), RO Hall (Montana), ER Hotchkiss (Virginia Tech). "Collaborative Research - Rivers and the carbon cycle: a mechanistic basis for dissolved organic carbon removal" - funded by the National Science Foundation Division of Environmental Biology.

MSc Student Brynn O'Donnell spoke about her fascination with / research on "Ghost Streams" during this month's New River Valley Science on Tap. Did you know that the ancient romans honored a goddess (Cloacina) of their largest buried waterway? That the Stroubles Creek network is buried throughout much of Blacksburg and the Virginia Tech campus? Or that Brynn and others on campus are conducting research to try to better understand the loss of function and resilience that occurs when we bury and alter streams in other ways? Lots of great food for thought (while enjoying local beer at Rising Silo and painting water with Robin Scully). Well done, Brynn!

Our proposed special session for AGU 2018 in Washington, D.C. was recently accepted for abstract submissions: "Beyond Ecosystem Boundaries: Integrating Terrestrial and Aquatic Processes to Advance Catchment Biogeoscience." We hope to include diverse perspectives from research crossing traditional aquatic-terrestrial, terrestrial-terrestrial, and aquatic-aquatic ecosystem boundaries. Abstracts are due by 01 August 2018. More information about the proposed session and how to submit an abstract can be found here.

UPDATE from 2018-06-25: We have two confirmed invited speakers! We are thrilled to have invited contributions from Dr. Nandita Basu & Dr. Irena Creed for this special session.

Erin Hotchkiss gave an invited tutorial talk (30 minutes on “the state of the science and future research opportunities”) for a special session at the 2018 summer meeting of the Association for the Sciences of Limnology and Oceanography (ASLO) in Victoria, BC, Canada. The title of her talk was “Pipes, chimneys, and processors: Synthesizing perspectives on organic matter transport, reactivity, and fate in aquatic ecosystems.” Two graduate students at different universities but co-advised by Erin presented their research: Marie Gérardin (MSc student, Université du Québec à Montréal, Canada) “Identifying the factors controlling the pCO₂ decline along a riverine continuum" and Mohammed Hamdan (PhD student, Umeå University, Sweden) “Carbon dioxide limits benthic primary production in boreal lakes”. The Carey Lab was also well-represented at ASLO: Dr. Cayelan Carey gave her award talk for the 2018 Yentsch-Schindler Early Career Award (congrats, Cayelan!!); PhD students Ryan McClure and Mary Lofton presented new results from their dissertation research.

The Hotchkiss Lab and other Biological Sciences Stream Team members recently attended the annual Society for Freshwater Science conference in Detroit, MI. As always, the meeting provided a great opportunity to catch up with friends and collaborators from around the globe (it's our "freshwater family reunion"), learn about exciting new research, and meet new scientists. Below are a few photos from the meeting and presentations from Hotchkiss Lab members and collaborators. See you at #2019SFS in Salt Lake City, UT!

• Gallagher, M.T.^U & E.R. Hotchkiss. 2018. Dynamic heterogeneity of greenhouse gases in streams. Poster.

• O’Donnell, B.M.^G & E.R. Hotchkiss. 2018. Moving from concentration-discharge to process-discharge relationships. Poster.

• Plont, S.^G, B.M. O’Donnell^G, M.T. Gallagher^U, & E.R. Hotchkiss. 2018. Linking energy flow and nutrient cycling in streams. Poster.

• Sponseller, R.A., A. Lupon, L. Gomez Gener, H. Laudon, & E.R. Hotchkiss. 2018. Connecting stream metabolism to riparian hydrology through dissolved organic matter supply.

• Hotchkiss, E.R., R.O. Hall, M.A. Baker, & S. Plont^G. 2018. Simulating interactive effects of primary production and terrestrial organic matter subsidies on stream organic carbon spiraling. Invited.

G = graduate student

U = undergraduate student

Erin took a couple of much-needed mental health break / bonus hiking days and worked on her southeastern US wildflower IDs while in TN & NC. Great timing for flowers! Locations: Great Smoky Mountain National Park, TN & Coweeta Hydrologic Lab, NC. Next up: VA!

Congrats to Virginia Tech Biological Sciences undergraduate students Sumaiya Rahman & Quentin Pitts (& grad mentors Brynn and Stephen) on rocking their own research projects this semester! What is the influence of storm magnitude on dissolved oxygen in streams? How does stream salinization alter dissolved organic matter dynamics? Cool results + many more questions! Quentin is graduating and has been accepted into the Physical Therapy Program at Carilion Roanoke Community Hospital / Radford University. Sumaiya will continue her undergraduate studies and research in our lab. (And yes, the Stream Team Blue Room is very blue.)

How can we develop a more integrative understanding of inland water carbon cycling? To address this question, my coauthors and I applied a general metabolism model to compare carbon fluxes/fates among ecosystems and discuss opportunities for linked ecosystem research: https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.1002/lol2.10081

Hotchkiss and colleagues (Jacob Barney, Bryan Brown, David Haak, Scott Salom, and Todd Schenk) recently organized a workshop to bring together a multidisciplinary group of stakeholders interested in invasive species issues. We were thrilled to host keynote speakers on science and policy, Dr. Heather Reynolds and Dr. Jamie Reaser, and look forward to working with others on campus and across the state to ensure Virginia Tech is well-positioned to tackle the "wicked problem" of invasives.

Creed et al. (2018) emerged from discussions during a working group in Abisko, Sweden in 2014. From the abstract: "we explore the potential consequences of these global change‐driven effects for lake food webs at northern latitudes. Notably, we provide evidence that increased allochthonous DOM supply to lakes is overwhelming increased autochthonous DOM supply that potentially results from earlier ice‐out and a longer growing season. Furthermore, we assess the potential implications of this shift for the nutritional quality of autotrophs in terms of their stoichiometry, fatty acid composition, toxin production, and methylmercury concentration, and therefore, contaminant transfer through the food web. We conclude that global change in northern regions leads not only to reduced primary productivity but also to nutritionally poorer lake food webs, with discernible consequences for the trophic web to fish and humans." We're excited to share this final product!

Students in the CU-Boulder Hydrologic Sciences Graduate Program invited Erin to give a keynote address at the 13th annual Hydrologic Sciences Research Symposium. Erin gave an overview of recent and ongoing research in the Hotchkiss Lab, “Pipes, Chimneys, and Processors: Examining Thresholds of Carbon Transport, Reactivity, and Fate in Inland Waters”, and served on a career panel for students with other water science professionals. Thanks to the students, faculty, and staff for a fun and engaging visit! Lots of great science happening on the front range. Views are OK too.

Erin and Stephen recently joined collaborators from University of Alabama, University of Georgia, Coastal Carolina, and University of Connecticut for our first all-scientists meeting for a recently-funded whole-stream warming project at Coweeta Hydrologic Lab in North Carolina. In addition to having great science discussions, we enjoyed our time hiking along streams, testing new research methods, tracking groundwater inflows, and learning about needle ice.