Currently funded projects (2022):

LEAD - Do changing terrestrial-aquatic interfaces in Arctic-boreal landscapes control the form, processing, and fluxes of carbon? NASA ABOVE (2022-2025)

Co. I Larry Smith Brown University, Providence RI Co. I. Rob Spencer, Florida State University, Tallahassee, FL

US-Collaborators: Dr. Jonathan Wang, University of California-Irvine Dr. Fenix Garcia-Tigreros, University of RI, Narragansett, RI Dr. Kimberly Wickland, U.S. Geological Survey, Boulder, CO Student – Martin Kurek, Florida State University, Tallahasse, FL Student – Ethan Kyzivat, Brown University, Providence RI Canadian-Collaborators: Dr. Sherry Schiff, University of Waterloo, Waterloo, Ontario, Canada Dr. Paul DelGiorgio, University of Quebec, Montreal, Quebec, Canada Dr. Suzanne Tank, University of Alberta, Edmonton, Alberta, Canada Dr. Kevin Turner, Brock University, St. Catharines, Ontario, Canada Dr. Matt Bogard, University of Lethbridge, Lethbridge, Alberta, Canada

Inland waters represent >3% of the total continental surface of the pan-arctic, with surface waters covering >10% of the landscape in low slope, deltaic environments dominated by lakes.  The input of carbon to lakes requires hydrologic connectivity, whether across the surface or through the subsurface, and significant uncertainty exists regarding the delivery of water in low slope/low precipitation environments. In fact, the pan-arctic region is dominated by very flat landscapes, with very low annual precipitation. These characteristics make defining where uplands and wetlands end and lakes begin difficult and highlight an often overlooked component of ecosystem carbon flows, the terrestrial-aquatic interface. Aquatic boundaries are not static in space or time. Arctic-boreal lake areas and perimeters can change on decadal, annual, seasonal, and spatial timeframes as well as spatially, and may be influenced by the underlying distribution of permafrost soils as well as adjacent changes in land cover. To date, there has not been a systematic approach to link empirical observations of aquatic carbon and water chemistry to the expanding record of satellite observations.

Here we propose to initiate and formalize the first harmonized Arctic-boreal database for inland water carbon chemistry and flux for the northern latitudes of North America, called the Harmonized Arctic-Boreal Lake database (HABL). . We will design this to be a living database moving forward. We will utilize existing time series of ALOS/PALSAR and optical imagery to quantify littoral vegetation and inundation extent, and quantify the temporal trends in optical characteristics associated with open water. We will utilize advanced regression modeling to address three main hypotheses. (H1) Changing precipitation patterns and temperature influence observed concentrations of inorganic and organic carbon across boreal lake ecosystems. (H2) Temporal heterogeneity of inundation extent drive variation in the concentrations and form of organic carbon and GHG emissions in lake ecosystems. (H3) Trends in lake reflectance (proxies for productivity and carbon source) are driven by both climate and water surface area and the temporal dynamics of land surface change.

LEAD - NASA ABoVE: CROSSING THE DIVIDE 2018-2023

COLLABORATORS: ROB SPENCER (FLORIDA STATE UNIVERSITY), ROB STRIEGL (USGS-NRP, BOULDER), KIMBERLY WICKLAND (USGS-NRP, BOULDER), TAMLIN PAVELSKY (UNIVERSITY OF NORTH CAROLINA, CHAPEL HILL), LARRY SMITH (UNIVERSITY OF CALIFORNIA, LOS ANGELES)

Carbon emissions from high latitude lakes can exceed 340 Tg C yr-1, and release upwards of 16.5 Tg C CH4 yr-1. This represents one of the largest natural sources of atmospheric methane from the Arctic-boreal region. Surface water significantly impacts landscape-scale estimates of carbon emissions. Field studies show that the input of carbon to lakes requires hydrologic connectivity, both across the surface or within the subsurface. Significant uncertainty exists regarding the exchange of water in low slope/low precipitation environments. These characteristics make defining where uplands and wetlands end and lakes begin difficult, and highlight an often overlooked component of ecosystem carbon flows, the terrestrial-aquatic interface. Currently the magnitude and extent of Arctic-Boreal seasonally inundated land remains unknown, and we hypothesize that the region of regularly inundated soils are hotspots for the cycling of carbon and are highly vulnerable to change.

Here we will quantify inundation extent across four important classes of hydrologic connectivity: open water, permanent inundation, transient inundation, and dry uplands. Using NASA airborne remote sensing data we will map these classes across a hydrological gradient of landscapes: fluvial-connected lowland (the Peace-Athabasca Delta, Canada); fluvial-disconnected lowland (Yukon Flats, Alaska), and bedrock controlled (Yellowknife-Daring Lake, Canada). We will produce validated map products of vegetation classification and inundation extent, as well as direct estimates of carbon concentrations, flux, and carbon source.

Teal Carbon –Stakeholder-driven Monitoring of Forested Wetland Carbon NASA-CMS 2020-2023

PI: Dr. L. Monika Moskal, Co-I: Dr. Meghan Halabisky, Co-I: Dr. David Butman, Co-I: Dr. Brian Harvey, Collaborator: Dr. Chad Babcock

Terrestrial or inland wetlands are the largest reservoir of carbon in North America, with roughly half of the wetland area occurring in forested systems. Wetlands are defined here as areas saturated at a frequency and duration sufficient to support a prevalence of vegetation typically adapted for life in saturated conditions, and typically contain more carbon in their soils than upland areas due to prolonged periods of soil saturation. Knowledge of carbon stored in terrestrial wetlands, referred to as teal carbon by Nahlik and Fennessy (2016), is often overlooked or limited. Part of these terrestrial teal carbon stocks is comprised of forested wetlands, which are considered to be important long-term carbon sinks and significant in global carbon monitoring systems (CMS) and accounting but have received little attention and lack baselines and inventories.

 We propose to develop new data-driven methods to produce high-resolution maps of forested wetlands, employing both NASA-generated and complimentary aerial remote sensing while leveraging existing forest inventory data to understand the distribution, area, and variability of wetland features across forested ecosystems.  Furthermore, we will develop a robust estimate of both AGC and BGC using field samples and modeling to assess the carbon budget of forested wetlands in WA State along a precipitation gradient. The results of this study will be one of the first large-scale studies to quantify forest wetland carbon budgets - including BGC storage in wetland soils. As such it will help to close key gaps in our understanding of the contribution of forested wetlands to carbon storage and provide a path forward for operational monitoring. In partnership with key stakeholders in the PNW, the project will also inform on-the-ground forest practices, inform adaptive management regulations of forest practices, and as well as the impacts of forestry practices on carbon sources and sinks that will improve global CMS and accounting.

NSF NRT-INFEWS: Future Rivers: Innovative Graduate Science Education at the Food-Energy-Water Nexus for Sustainable Management of Transboundary Watersheds 2020-2025 (LINK)

Lead - G. Holtgrieve (SAFS), D. Butman (SEFS & CEE) F. Houssain (CEE), M. Balazinska (CSE), C. Wood (SAFS)

The objective of the University of Washington (UW) Future Rivers NRT program is to develop an innovative, culturally-aware STEM workforce fluent in state-of-the-art quantitative approaches for sustaining food-energy-water (FEW) services in large river ecosystems, who are prepared to effectively safeguard ecosystem services for a growing world population. Program activities are centered around five primary educational objectives that will produce increasingly diverse cohorts of interdisciplinary freshwater scientists and professionals who have the necessary skills for research-related careers within and outside academia. These are: 1) develop new technical and data science skills; 2) foster innovative interdisciplinary and international science integration; 3) improve trainee communication skills; 4) increase cultural awareness and inclusivity among faculty, trainees, and participants; and 5) create networks and opportunities for student career development. Specific activities include: 1) data science coursework and annual ‘waterhack’ weeks; 2) interdisciplinary river FEW graduate courses, biennial seminar series, and annual week-long Summer Institutes, two of which will be held internationally; 3) communications and outreach workshops and biennial ‘film-making to communicate science’ contests; 4) equity and inclusivity workshops with the UW Center for STEM Equity and Inclusivity, and 5) data science career fairs and research summits. The Future Rivers training program will support 60 trainees, with 18 of those receiving stipends and tuition support. All told the Future Rivers program will provide at least 36 student years of funding. Funded trainees will include both Master’s and Ph.D. tracks, matching workforce needs and the needs of our non-academic partners. Broad graduate student interest and participation by the UW Freshwater Initiative suggest that an estimated 20–30 additional students are likely to participate in parts of the program.

NSF-Macrosystems: MRA: Linking land-to-water transport and stream carbon cycling to inform macrosystem carbon balance (2020-2024)

COLLABORATORS: LEAD - Erin Hotchkiss - Virginia Tech, Co-I David Butman - University of Washington, CO-I Jay Jones, UAF, Wil Wolheim UNH, Kaelin Kawley NSF-NEON.

Headwater streams are the primary interface between terrestrial and freshwater ecosystems. The flux of terrestrial carbon (C) across this land-water interface controls the C balance o watersheds and is a fundamental driver of ecological processes in recipient ecosystems. Consequently, headwater streams are ideal testbeds to advance understanding of terrestrial-aquatic C transfers and meta-ecosystem ecology (i.e., the study of multiple ecosystems linked by energy and material transfers). This proposed research will quantify multi-scale properties of watershed C cycling by linking ecosystem processes (terrestrial net ecosystem exchange, stream net ecosystem production and emissions) with meta-ecosystem C fluxes in watersheds that have varying terrestrial productivity, soil C stocks, climate, geology, and hydrologic regimes. This research seeks to answer the following overarching questions: (1) What is the magnitude and variability of lateral (land-to-water) C transfers and in-stream C losses in watershed C balances? (2) What are the cross-scale controls that determine the form, flux, and fate of C in meta-ecosystems? (3) How do event-, seasonal-, and annual-scale dynamics influence C cycling among biomes? The factors regulating biological C transformations and fluxes are predicted to operate at distinct spatiotemporal scales. By deploying in-stream CO2 sensors, increasing the spatiotemporal resolution of ongoing NEON  groundwater and stream C sampling, and integrating new and ongoing NEON data to estimate biome-specific and emergent controls on C fluxes and fate at ecosystem, meta-ecosystem, and watershed scales,  this research will be uniquely poised to close the cross-ecosystem C budget across NEON domains. 

NSF Postdoctoral Fellowship LEAD- Dr. Benjamin Miller: Impoundment Enhances Riverine Productivity through Chemoautotrophic Pathways on the Mekong and Snake River

Cambodia’s Lower Mekong River (LMR) harbors one of the largest and most productive freshwater fisheries in the world1. Catches by the LMR fishery account for 80% of the daily protein intake by Cambodians and 5% of the gross domestic product2,3. More broadly, it is estimated that the health and livelihoods of nearly 60 million people in Southeast Asia are affected by the productivity of the LMR4. The LMR fishery is only the most visible part of an aquatic food web that also includes microbes, zooplankton, phytoplankton, and invertebrates. Each of these general components of biodiversity in the LMR provides an essential pathway for carbon (C) as it passes through the food web, the fishery, and the region’s human population. Ultimately, the amount of C entering this food web dictates how many fish and people the LMR fishery can sustain. However, fundamental pathways for the entry of C into this food web are poorly understood and may be impacted by imminent hydropower development.

Project objectives:

1)     Determine whether methanogenic C produced in reservoir sediments and floodplain soils enters riverine food webs on the Mekong River.  a. Consolidating three museum collections, analyze stable C isotopes in fish tissues collected from the Sesan River during the wet and dry seasons prior to Lower Sesan II’s construction. b. Purchase fish from markets near the Lower Sesan II Reservoir and analyze them for stable C isotopes during the wet and dry seasons.

2)     Quantify rates of CH4 production, oxidation, and emissions in the Lower Sesan II Reservoir at different points of the hydrograph, during the wet and dry seasons.

3)     Quantify rates of photoautotrophic production during the wet and dry seasons for comparison.

NSF-RCN: Coastal Rainforest Margins Research Network - understanding materials flux in linked terrestrial and marine systems in the face of climate change 2018-2023. (LINK)

The Coastal Rainforest Margins Research (CRMR) Network is designed to facilitate collaborative research initiatives to quantify materials flux from coastal watersheds to coastal marine ecosystems, within the context of regional geographic variation and long-term environmental change. The Network will focus on PCTR ecosystems as a model for understanding processes in other globally-important CTRs and coastal margins.  Because the delivery of freshwater, carbon, and nutrients from coastal watersheds is a key driver of the ecology and biogeochemistry of nearshore marine ecosystems along the PCTR margin, changes in materials flux may impact downstream ecosystems and economies in both predicted and unanticipated ways. The wide range in latitude, elevation, and associated climate gradients in the PCTR, and well-established research capacity at the University of Alaska, the University of Washington, the US Forest Service Pacific Northwest Research Station, and partner institutions in Canada and elsewhere, provide a unique opportunity to improve our current understanding of ecosystem processes as the climate changes. The Network will address critical information gaps, develop regional collaborations, and synthesize knowledge regarding water, carbon, and nutrient fluxes in a landscape where intense transformations and rapid transfers between terrestrial and freshwater environments control the delivery of these materials to the coastal ocean. We will achieve these goals through two main activities: 1) annual synthesis workshops structured around disciplinary working groups to produce high-level, theory-driven publications, standardized methodology papers, coordinated assessments of research needs, and common proposal ideas; and 2) organized information sharing among and between working groups such as regular web-hosted meetings, research webinars, field site visits, and student exchanges.  A primary goal of the PCTR-RCN will be to establish a core community of scientists and stakeholders to function as an information and guidance resource for ecosystem management and community adaptation in the future.  An improved understanding of ecosystem function across the PCTR will be integral to building resilience in local communities and ecosystems in a warming and increasingly variable climate. 

Past Projects

USGS - LandCarbon Program 2011-2014

Collaborators: Rob Striegl (Lead - USGS - NRP), Sarah Stackpoole (USGS - NRP), David Clow (USGS - Colorado Water Science Center), Edward Stets (USGS-NRP), Zhiliang Zhu (USGS - NRP), David D'Amore (USFS - PNW Research Station), David McGuire (USGS/UA Fairbanks) among many others.

With the U.S. Geological Survey, and the national ‘LandCarbon’ program, we are running a first of its kind large-scale field campaign to physically take measurements of organic and inorganic carbon, methane, and nitrous oxide fluxes from streams and rivers across the US.  The LandCarbon program is designed to assess the carbon sequestration potential and greenhouse gas fluxes from natural ecosystems across the US.  Field data from the summer of 2012 suggests that CO2 and CH4 fluxes from aquatic systems are extremely variable and are influenced by short-term events, where streams can release large fluxes of carbon after intense precipitation. Field measurements will critically improve the results of the national assessment of streams and river carbon fluxes that I have previously completed, as well as provide modern data that matches with the current suite of remote sensing data products.  

Currently, we are developing the first integration of aquatic carbon cycling with terrestrial ecosystem modeling for the state of Alaska under the LandCarbon program. We are  working collaboratively with universities and research institutions, to predict the effects of climate change on regional water and carbon cycles in boreal and arctic systems through integrated remote sensing and ecosystem modeling.  This effort may be expanded across other biomes within the US to develop a unified approach to estimate US carbon and greenhouse fluxes from natural systems. 

CO-PI NSF-RAPID: Colorado River Pulse 2014

Collaborators:  Tom Bianchi, (Lead-University of Florida); Peter Raymond (Yale School of Forestry and Environmental Studies), Karl Flessa (University of Arizona)

A new addition to the 1944 U.S.-Mexico Water Treaty between the United States and Mexico (Minute 319) was signed in late 2012. (International Boundary and Water Commission, 2012) that will allow for greater sharing of water from the Colorado River (Flessa et al., 2013). This agreement also calls for a flooding event, planned for from March 2014 to May 2014, whereby 130 m3 of water will be released into the dry Colorado River channel in Mexico. While only small amounts of water have entered the delta since 2000, and some moderate flooding events occurred in the late 1990s, this region has not experienced natural flow rates and spring floods since prior to dam building in the 1930s. While there have been a few pulse release experiments of this type (e.g., Rio Grande and Truckee Rivers) much of the previous post-pulse research to date has focused on sediment transport and the response of riparian zone communities. Here will examine how rapid mobilization of carbon and greenhouse gasses in newly flooded sediments and soils, affect river-carbon composition and fluxes (land/ocean and land/atmosphere), after being isolated from an active floodplain. Here we posit that during a flow restoration pulse, dissolved organic and inorganic carbon (DOC/DIC) and greenhouse gasses (CH4, CO2, N2O), previously stored as inactive pools in the dry floodplain will enter the modern carbon and greenhouse gas cycles. This is particularly important in light of possible increases in the occurrence of natural flooding events associated with climate change. It is also an important study in terms of understanding the unintended consequences of such ecosystem restoration efforts.

Lead - U.S. Geological Survey Greenhouse gas monitoring  - Columbia River, US 2014-2016

Collaborators: Rob Striegl (USGS-NRP, Boulder), Mark Dornblaser (NRP), John Crawford (NRP).

Partners: Chauncey Anderson and Heather Bragg, USGS Oregon Water Science Center, (OR-WSC)

There is a need for systematic field measurements that concentrate on direct measurement of the spatial and temporal distributions of gas transfer velocity (k) and gas concentration gradient (ΔC), for dissolved carbon dioxide (CO2) and methane (CH4) in natural waters.  Previous research as part of the USGS LandCarbon program has identified the Pacific Northwest (PNW) as a critical region within the conterminous US to address this information gap. Current LandCarbon estimates suggest that the PNW has the largest areal fluxes of CO2 from streams and rivers, driven largely by the high CO2 exchange velocities due to the steep terrain.  Additionally, the Western Cascades have been identified as vulnerable to climate change.  Earlier snowmelt is predicted to shift peak river discharge to occur 20-40 days earlier, in additional to significantly more rain on snow events – altering the biogeochemistry of local alpine watersheds with the consequences on both terrestrial and aquatic carbon cycling largely unknown.  This research will lead to the development of a comprehensive assessment of the seasonality of aquatic carbon biogeochemistry within the Columbia River Basin