Source: CLEMSON UNIVERSITY submitted to NRP
EVALUATING THE NET CLIMATE BENEFITS OF SWITCHGRASS VERSUS PINE PLANTATIONS IN THE SOUTHEAST: A SEED GRANT TO SUPPORT DATA COLLECTION AND MODEL DEVELOPMENT
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1012705
Grant No.
2017-68002-26612
Cumulative Award Amt.
$147,744.00
Proposal No.
2016-11565
Multistate No.
(N/A)
Project Start Date
Jun 1, 2017
Project End Date
Dec 31, 2020
Grant Year
2017
Program Code
[A3171]- Climate and Land Use
Recipient Organization
CLEMSON UNIVERSITY
(N/A)
CLEMSON,SC 29634
Performing Department
(N/A)
Non Technical Summary
Developing resilient agricultural systems that can supply climate mitigation services is key to improving the sustainability of U.S. agriculture. It is imperative to determine whether land use changes driven by agricultural needs could have counterproductive effects on climate through biogeochemical or biogeophysical mechanisms. Producing biomass for energy, for instance, will only be successful if managed plantations accumulate large amounts of carbon uninterruptedly. Therefore, bioenergy production is sensitive to external forces that reduce the productivity of these crops; the bioenergy-agriculture-climate system is thus highly interdependent. In the southeast, switchgrass and loblolly pine have been identified as potentially attractive biomass feedstocks. Herein we propose to leverage two existing eddy flux towers to directly measure the carbon sequestration and biophysical climate impacts of their production. Measuring important variables that drive productivity will determine the sensitivity of production to short term climate variability. Field measurements, and conversions of albedo radiative forcing to determine carbon fluxes and stocks will be used along with parameters from the full production chain to develop a life cycle greenhouse gas emission assessment. This analysis will evaluate and compare the total CO2e emission mitigation potential of using the two feedstocks to generate electricity by co-firing in a coal power plant. Integrating measured field data with modeling more fully represents the net climate effects of land use and identifies points of climate-vulnerability along the production chain. A larger future proposal can increase the scope of this seed grant by expanding to include a full LCA, and more sites and feedstocks.
Animal Health Component
20%
Research Effort Categories
Basic
80%
Applied
20%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1230120106060%
1230611207020%
1310780202020%
Knowledge Area
123 - Management and Sustainability of Forest Resources; 131 - Alternative Uses of Land;

Subject Of Investigation
0120 - Land; 0780 - Grasslands, other; 0611 - Conifer forests of the South;

Field Of Science
2070 - Meteorology and climatology; 2020 - Engineering; 1060 - Biology (whole systems);
Goals / Objectives
The overarching objective of this proposal is to define the net climate benefits, in terms of greenhouse gas emissions and biophysical feedbacks, as well as the climate sensitivity, of switchgrass and loblolly pine plantations, to inform decision makers on the climate mitigation potential of these land use types.Specific objectives are:• Quantify the net CO2 fluxes and aboveground and belowground carbon stocks of switchgrass and loblolly pine plantations using eddy covariance towers and biometry• Define the sensitivity of switchgrass and loblolly productivity to environmental drivers and short-term climate variability• Quantify the biophysical feedback from albedo to climate from these two land use types• Perform life cycle greenhouse gas emission assessment (GHG-LCA) of the full production chain for switchgrass and pine in the southeast to evaluate emission mitigation potential of 1 kWh of electricity generated by co-firing biomass in a coal power plant vs. a conventional coal power plant.
Project Methods
We will follow a task-based approach to achieve the research objectives of our project. The proposed research will collect the greenhouse gas emissions and yield from two biomass feedstocks (Task 1). Measured field data will be integrated with a life cycle assessment model (Task 2) with the aim of more fully representing the net climate effects of intensive land use and identify particular points of climate-vulnerability along the biomass feedstock production chain.Task 1. Field measurements of carbon and energy fluxesTask 1a. Eddy flux and biometric measures of carbon fluxes and environmental drivers. To generate the data needed to assess the carbon footprint and climate sensitivity of the production of switchgrass and pine biomass feedstocks, including biophysical effects, we propose to leverage significant existing resources at the Sweet Briar College Land-Atmosphere Research Station (SBC-LARS). SBC-LARS features two co-located, functioning eddy flux towers, one 36m tall tower in a 28-year-old loblolly pine plantation, and 1.5 km to the south a 5m tripod tower in a 3-year-old switchgrass plantation.Our preliminary results show that while the switchgrass field is approximately carbon neutral over the growing season as defined by cumulative net ecosystem production (NEP), the system is likely to be a net carbon source to the atmosphere when integrated over the whole year (which will include more fallow time). To verify and better understand this result, and to define the climate sensitivity of the production of pine and switchgrass, we propose to make the following measurements: A. one-minute averages of weather/climate variables (sunlight, rainfall, soil moisture, soil temperature, air temperature, humidity); half-hourly eddy flux measurements of B. net ecosystem exchange (-NEE), which in the absence of horizontal advection is equivalent to net ecosystem production, C. ecosystem respiration (Re), which is measured at night when gross primary production (GPP) goes to zero and extrapolated for daytime using air or soil temperature empirical fits D. Daytime GPP is then calculated as NEP minus Re. Since Re is very large at the switchgrass field and will be the primary control of the net carbon balance of the system, we also propose new measurements to partition Re into its autotrophic (Ra) and heterotrophic (Rh) components (Re = Ra+Rh). These new measurements will be: E. Monthly measures of soil respiration (Rs) via LI-8100a soil gas flux system (Li-cor Inc, Lincoln, NE) and a root exclusion technique that isolates the contribution of Ra from roots on Rs using a combination of shallow and deep soil collars; F. Monthly aboveground net primary production (ANPP) via 0.25 m2 clip plots (for grass) and annual ANPP from biometric measurement from collaborators at Virginia Tech and G. Belowground NPP (BNPP) from sequential coring and weighing of fine, medium and coarse root growth.Task 1b. Convert albedo into CO2e. To account for the biophysical impacts of land use change and their potential to generate positive climate feedbacks, we will incorporate our field measurements of albedo into LCA using methods similar to Bright et al., 2012, which equates and weighs albedo against other sources of greenhouse gasses in our target agricultural systems. The TOA albedo radiative forcing will be calculated using the radiative kernel technique, which is an offline calculation of the radiative transfer code inside a global climate model and has been used extensively in land use change literature. The albedo radiative forcing can then be equated to a change in atmospheric CO2 mixing ratio (∂CO2) for inclusion in LCA by a commonly-used CO2 radiative forcing parameterization (Myhre et al. 1998).Task 2. Life Cycle Assessment modelingWe will apply GHG-LCA in this task to identify hotspots along the supply chain of forest (pine) and herbaceous (switchgrass) biomass production and delivery to a co-firing power plant with the aim of reducing greenhouse gas emissions, and improving carbon sequestration. Specifically, we will examine the interplay between land use change and contributors to climate variability through the specific tasks of this project.We will use the TRACI (tool for the reduction and assessment of chemical and other environmental impacts) method because it is the only available LCIA tool developed specifically for the U.S. by the EPA. In a GHG-LCA only the impact category of global warming potential (GWP) is evaluated- it aggregates all greenhouse gasses (namely CO2, CH4 and N2O) and conveys them in the form of carbon dioxide equivalents (CO2e)(4) Interpreting results is the final step where uncertainties are characterized through the application of methods such as Monte Carlo, sensitivity and scenario analysis.We will use one kWh of electricity generated from co-firing biomass with coal as the functional unit and compile the LCI for the entire supply chain based on this unit.1. On-farm/forest activitiesa. Biomass feedstock cultivation, maintenance and harvest: We will work with a company managing switchgrass in the Sweet Briar region (FDC Enterprises) to obtain data specific to the on-farm production of switchgrass. We will use specific data on yields, fertilizer and chemical use, farm equipment, etc. from this company to build the lifecycle inventory (LCI) of this stage. We will use literature review to supplement any data gaps in the switchgrass inventory. For loblolly pine, we will use measurements of standing carbon stocks provided by collaborators at Virginia Tech and supplement with existing literature and US government reports to build the LCI for its planting, maintenance and harvest operations and inputs.b. Factoring the interplay of land use change and climate variability: Additionally, we will factor in the effects of biogeochemical and biophysical processes related to land use change effects of producing these two sources of biomass. We will include in the LCI phase of the analysis data from the eddy covariance towers for CO2e fluxes from soils (biogeochemical) and CO2e fluxes resulting from each specific land use-albedo radiative forcing (RF) effects of both switchgrass and pine. Conversion from RF values to CO2e will be performed according to the methods described in Task 1b2. Intermediate storage: Degradation and losses in biomass quality and quantity occurs in the period between harvest and transport to processing. The analysis will factor in biomass degradation and losses by including factors to compensate for the yield of lost biomass and losses in carbon from the biomass. This will assist in accurately portraying loss and storage issues, assessing how such supply chain issues propagate further downstream, and identifying solutions to these challenges.3. Transport: We will use existing data for logistics from FDC Enterprises using their transport modes and distances, such as to a direct fired boiler fuel located at the Commonwealth of Virginia's Piedmont Geriatric Hospital in Burkeville, VA.4. Biomass co-firing: We will use existing literature and reports from sources such as the DOE, EIA and NREL on biomass co-firing, and use the ecoinvent database to build a comprehensive MS Excel-based model for this stage. This model will include all pre-and-post-processing steps that take place on-site to account for the energy or fuel use in such processes.Finally, we will combine and compile the GHG emissions from all the aforementioned stages in order to calculate the global warming potential of the aggregate system. We will compare the kgCO2e emission values from the aggregate pine and switchgrass systems, while also identifying the stages of the supply chain with largest contributions to the overall emissions. We will use this analysis to benchmark against emissions from existing conventional coal-fired power plants to assess whether any benefits exist to using biomass co-fired with coal.

Progress 06/01/17 to 12/31/20

Outputs
Target Audience:Target audience: scientists, engineers and other professionals working in the bioenergy, forestry and climate sectors. Changes/Problems:Co-PDs Pragnya Eranki and Sarah Cadieux both left their positions and have not been involved in the project since their original subwards expired at the end of year 2 of the project. What opportunities for training and professional development has the project provided?Undergraduates - This project partially supported four undergraduate summer research interns from Sweet Briar College, a small, undergraduate woman's college. One of those students presented her findings at a national meeting (Natalie Jones, Geological Society of America). It also partially supported one Clemson undergraduate research intern who received training in using drones (UAVs) to map ecosystem carbon stocks. Graduate students - Virginia Tech Ph.D. student Ben Ahlswede also worked extensively on the project and has received training in eddy covariance methods, but he is was not directly funded by the project and receives support elsewhere. He is currently writing his dissertation and has one manuscript submitted to a journal with two forthcoming. Technicians - Environmental Sensor technician Mike Kline (Clemson) worked on the project and was trained on eddy covariance methods and sensor deployment on tall towers. How have the results been disseminated to communities of interest?We have given several conference presentation and seminars on this project and attended the USDA Project Directors meeting twice. We have submitted one journal paper for review and have two more in draft that will be submitted in 2021. What do you plan to do during the next reporting period to accomplish the goals?We tried three times, unsuccessfully, to convert this seed grant into a funded NIFA project. Part of the problem may have been that the project was originally funded in a Climate Change Challenge Area that was discontinued. A Quantitative Framework to Incorporate Biophysics as an Ecosystem Service: Field Measurements and Model Development in Forestry and Bioenergy Crops (2nd resubmission). T.L. O'Halloran (PI), R.Q. Thomas (VT), D. Coyle (CU), R. Bright (NIBIO), B. Brinkman (Sweet Briar College), $500,000 Submitted 4/16/2020. In review.

Impacts
What was accomplished under these goals? The overall goal of this seed grant project was to determine, from a landowner's perspective, does loblolly pine or switchgrass have more benefits to climate in terms of carbon sequestration and solar energy absorbed into the local energy balance (i.e., the effect of albedo or surface reflectance). To accomplish this goal, this project directly supported field measurements (while leveraging other projects and available equipment) to measure the net ecosystem water, carbon and energy fluxes by eddy covariance in mature and clearcut/replanted loblolly pine plantations and an adjacent switchgrass bioenergy plantation in central Virginia. At the time of writing this final report, several conference papers have been given, one manuscript has been submitted to a journal, and two more manuscripts are in draft stages and are expected to be submitted in 2021. The main findings of this project, including annual sums of net ecosystem production (NEP) are: Over four years, mature (~30 year old starting age) loblolly pine was a strong and stable sink of carbon from the atmosphere (890 +/- 140 gC m^2 year^-1). This is consistent with previous findings from North Carolina. These results are significant because they are the only known measurements of net ecosystem production in loblolly pine in Virginia, which is at the northern range of loblolly pine. Over three years, a new (~3 year old starting age) switchgrass plantation was carbon neutral to a weak carbon source to the atmosphere (-80 +/- 110 gC m^2 year^-1). Our result is not consistent with previous finding which have found that switchgrass usually provides a carbon sink, which is a fundamental assumption of biomass feedstocks. Using literature review of other studies, we deduce that our result may be unique because our site is one of the few (if only) very lightly managed switchgrass plantations that did not use fertilizer. The site produces modest to small yields of harvested biomass. The albedo of a pine plantation starts high (after a clearcut) but decays exponentially to a very low value compared to switchgrass and other ecosystems. This low albedo value translates to more absorbed solar energy and relative local heating in a pine plantation compared to switchgrass. When this radiative forcing is converted to CO2 equivalents, the albedo effect largely negates the enhanced carbon sink of the pine forest. However, when integrated over a 30 year pine rotation, the combined biophysical albedo and carbon effects lead to more net carbon sequestration and climate benefits in the pine plantation relative to the switchgrass plantation. In terms of outcomes, taken together, our results suggest that in central Virginia, loblolly pine plantations provide more climate benefits than unfertilized switchgrass plantations, when accounting for carbon and albedo effects together. These results should inform landowner decisions who are interested in maximizing climate benefits with their land. It could also inform bioenergy policy in terms of incentives for particular land cover types.

Publications

  • Type: Journal Articles Status: Submitted Year Published: 2020 Citation: Ahlswede, Benjamin*; O'Halloran, Thomas; Thomas, R. Quinn. A minimally managed switchgrass ecosystem in a humid subtropical climate is a source of carbon to the atmosphere. Global Change Biology  Bioenergy. Submitted December 11, 2020


Progress 06/01/19 to 05/31/20

Outputs
Target Audience:Target audience: scientists, engineers and other professionals working in the bioenergy, forestry and climate sectors. Efforts to reach them: During the reporting period we gave one conference paper at a national meeting (American Geophysical Union) to disseminate results to an interdisciplinary audience of environmental scientists. Changes/Problems:The end of this reporting period includes the beginning of COVID-19 disruptions. We were not able to travel to the field sites to perform equipment maintenance and repairs from March until August 2020. The full impacts of this are not fully known yet, since we have not yet analyzed the data. However, our remote access has indicated that the flux towers sites have been running with little interruption and data quality appears to be fine. We have recently visited and conducted maintainence in August of 2020 and all appears well. What opportunities for training and professional development has the project provided? Undergraduates - Under the no cost extension, we have no funds remaining for student support, so summer undergraduates from Sweet Briar College (a woman's college) are no longer working on the project. However, we hope to employ students again if our next proposal (in review) is funded. Graduate students - Virginia Tech Ph.D. student Ben Ahlswede also works extensively on the project and has received training in eddy covariance methods, but he is not directly funded by the project and receives support elsewhere. He is currently writing his dissertation and has one manuscript complete that is very close to submission to a journal. We expect he will have two more papers finished in the coming year. Ben is currently interviewing for postdoctoral positions, so this project has had a positive outcome training a Ph.D. student who will likely enter a professional position in the area of ecosystem/climate interactions. Technicians - Environmental Sensor technician Mike Kline (Clemson) works on the project and was trained on eddy covariance methods and sensor deployment on tall towers. How have the results been disseminated to communities of interest?During the reporting period we gave one conference paper at a national meeting (American Geophysical Union) to disseminate results to an interdisciplinary audience of environmental scientists. We contributed data to a large NSF-funded PhenoCam dataset that was published with many national and international collaborators. This is a high profile dataset that increases the exposure of this project. We are also very close to submitting a journal publication out of Ben Ahlswede's (Virginia Tech) Ph.D. dissertation. Ben's progress has been somewhat slow due to family circumstances. What do you plan to do during the next reporting period to accomplish the goals?We have worked very hard to write, submit and revise (twice) a proposal to AFRI BNRE to expand and continue this work (see reference below). The proposal is currently in review and we are extremely hopefully it is funded, as it will allow us to get much more value (through impacts and products) from our seed grant. Our seed grant project primarily focuses on data collection. Having the full follow-on project funded will allow us to fully analyze that dataset, expand our modeling activities with international partners, and significantly enhance our outreach and extension activities by bringing on new collaborators at Sweet Briar College and with Clemson extension faculty. Otherwise, in this next, no cost extension year, we will finish collecting data in 2021 and then shut the experiment down. Publications will continue to come out as part of Ben Ahlswede's dissertation, and as future funding allows. A Quantitative Framework to Incorporate Biophysics as an Ecosystem Service: Field Measurements and Model Development in Forestry and Bioenergy Crops (2nd resubmission). T.L. O'Halloran (PI), R.Q. Thomas (VT), D. Coyle (CU), R. Bright (NIBIO), B. Brinkman, L. Powell (Sweet Briar College), $500,000 Submitted 4/16/2020. In review.

Impacts
What was accomplished under these goals? We continue to generate a "world class" dataset by operating three eddy covariance towers to measure the carbon, water and energy cycling in mature and young loblolly pine and compare it against a co-located switchgrass plantation. Our results to date show that the mature pine site is a strong and steady carbon sink. However, the switchgrass plantation is near carbon neutral, or a small source of carbon to the atmosphere. The switchgrass carbon sink is also extremely sensitive to weather variability and the timing of harvest and bailing. The clearcut and replanted young pine plantation started as a carbon source, but the dataset is still short (approaching three years) and has not been fully analyzed. We are hopeful a follow-on project will be funded so we can extend that dataset to five years and perform a full analysis. This project will determine how switchgrass compares to commercial pine plantations in terms of water, carbon and energy cycling for the benefit of climate. For now, this seed grant project continues in "low power mode" under a no cost extension, which allows us to continue collecting data from three flux towers, as well as perform annual biomass surveys in the switchgrass plantation. Specific accomplishments from this reporting period include: Continued operation of three eddy covariance towers in a mature and clearcut/replanted loblolly pine plantations and a switchgrass plantation to measure CO2, water vapor, heat and radiometric fluxes continuously every half hour. Ancillary meteorology and phenology variables are also measured. Measurement of peak biomass in the switchgrass at the end of the growing season in 2019. Determination of the baled switchgrass biomass in 2019 via data shared from our collaborator, FDCE, who manage the switchgrass plantation. The sensitivity of production to short term climate drivers (weather) will be determined at the end of the project when the data record is longer. An analysis of the biophysical feedbacks to climate will also be performed at that time (see future work outlined below).

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: B.J. Ahlswede, T.L. OHalloran, R.Q. Thomas. Controls on Land Surface Temperature along a Gradient of Managed Land-Cover Types in Central Virginia. American Geophysical Union Fall Meeting, San Francisco, CA., December 9-13, 2019.
  • Type: Other Status: Published Year Published: 2019 Citation: Seyednasrollah, B., A.M. Young, K. Hufkens, T. Milliman, M.A. Friedl, S. Frolking, A.D. Richardson, M. Abraha, D.W. Allen, M. Apple, M.A. Arain, J. Baker, J.M. Baker, C.J. Bernacchi, J. Bhattacharjee, P. Blanken, D.D. Bosch, R. Boughton, E.H. Boughton, R.F. Brown, D.M. Browning, N. Brunsell, S.P. Burns, M. Cavagna, H. Chu, P.E. Clark, B.J. Conrad, E. Cremonese, D. Debinski, A.R. Desai, R. Diaz-Delgado, L. Duchesne, A.L. Dunn, D.M. Eissenstat, T. El-Madany, D.S.S. Ellum, S.M. Ernest, A. Esposito, L. Fenstermaker, L.B. Flanagan, B. Forsythe, J. Gallagher, D. Gianelle, T. Griffis, P. Groffman, L. Gu, J. Guillemot, M. Halpin, P.J. Hanson, D. Hemming, A.A. Hove, E.R. Humphreys, A. Jaimes-Hernandez, A.A. Jaradat, J. Johnson, E. Keel, V.R. Kelly, J.W. Kirchner, P.B. Kirchner, M. Knapp, M. Krassovski, O. Langvall, G. Lanthier, G.l. Maire, E. Magliulo, T.A. Martin, B. McNeil, G.A. Meyer, M. Migliavacca, B.P. Mohanty, C.E. Moore, R. Mudd, J.W. Munger, Z.E. Murrell, Z. Nesic, H.S. Neufeld, T.L. O'Halloran, W. Oechel, A.C. Oishi, W.W. Oswald, T.D. Perkins, M.L. Reba, B. Rundquist, B.R. Runkle, E.S. Russell, E.J. Sadler, A. Saha, N.Z. Saliendra, L. Schmalbeck, M.D. Schwartz, R.L. Scott, E.M. Smith, O. Sonnentag, P. Stoy, S. Strachan, K. Suvocarev, J.E. Thom, R.Q. Thomas, A.K. Van den berg, R. Vargas, C.S. Vogel, J.J. Walker, N. Webb, P. Wetzel, S. Weyers, A.V. Whipple, T.G. Whitham, G. Wohlfahrt, J.D. Wood, S. Wolf, J. Yang, X. Yang, G. Yenni, Y. Zhang, Q. Zhang, and D. Zona. 2019. PhenoCam Dataset v2.0: Vegetation Phenology from Digital Camera Imagery, 2000-2018. ORNL DAAC, Oak Ridge, Tennessee, USA. https://doi.org/10.3334/ORNLDAAC/1674
  • Type: Journal Articles Status: Other Year Published: 2020 Citation: Ahlswede, B.S., R.Q. Thomas and T.L. OHalloran. An established biofuel switchgrass (Panicum virgatum) ecosystem is a source of carbon to the atmosphere in Central Virginia. Global Change Biology Bioenergy (anticipated submission winter 2020).


Progress 06/01/18 to 05/31/19

Outputs
Target Audience:Target audience: scientists, engineers and other professionals working in the bioenergy, forestry and climate sectors. Efforts to reach them: in year 2 we gave several conference and symposium presentations and invited seminars in university environments to reach professionals working in these fields Target audience: underrepresented STEM groups (undergraduate females) Efforts to reach them: this project is hosted by Sweet Briar College, a liberal arts college for women, and the project has employed three summer interns who have received specialized training in field methods in environmental science. We believe the impact has gone beyond just these three students, since those students have interacted with their peers, and the college has promoted the USDA project on their website: https://sbc.edu/news/sweet-briars-campus-is-excellent-ecosystem-for-grant-funded-sustainability-internships/ Changes/Problems:We have had some issues with turnover in personnel that have slowed progress towards publishing results. CO-PD Eranki left her position at the Colorado School of Mines and the graduate student working with her on publishing the LCA results accepted a postdoctoral position before he could finish writing up and publishing the results. We still hope to publish that paper but have included a new LCA co-PD in our follow up proposal in hopes a new LCA team will have more success with publishing. Also, Dr. Sarah Cadieux, the original co-PD from Sweet Briar College, left the college soon after the project was funded and was replaced with Dr. Linda Fink, although this had no negative impact on the project. Dr. Cadieux helped mentor an undergraduate researcher on the project who presented her results at a national meeting (GSA). What opportunities for training and professional development has the project provided?Undergraduates - in summer of 2018 this project supported one undergraduate at Sweet Briar College, an undergraduate women's college, who worked as an intern on the project. She (Natalie Jones) was trained to use the Licor LI-8100 to measure soil CO2 efflux from the loblolly clearcut. Graduate students - While in his last year of his PhD work, Tyler Harris has worked with this project's PD and researchers on completing a traditional GHG-LCA that integrates albedo changes and soil carbon sequestration with the global warming potential (GWP) impact characterization method used for LCA. Over this reporting period, weekly project meetings were completed to monitor and guide progress on the project's goals and deliverables. Tyler Harris also had the opportunity to present findings at CSMGRADS conference and being first author on submission to the ACLCA 2018 LCA XVIII international conference accepted for oral presentation. Virginia Tech Ph.D. student Ben Ahlswede also works extensively on the project and has received training in eddy covariance methods, but he is not directly funded by the project and receives support elsewhere. Technicians - Environmental Sensor technician Mike Kline worked on the project (as a new employee of PD O'Halloran) and was trained on eddy covariance methods and sensor deployment on tall towers. How have the results been disseminated to communities of interest?Our efforts to disseminate results increased significantly in year 2 of the project. We had one paper published that developed a new model that was also published separately as a dataset/model with its own DOI. The team also gave 6 conference presentations at national meetings or university symposia, and three invited seminars, for a total of 11 products in year 2, all with attribution given to the USDA NIFA project. The meetings included geological sciences, AmeriFlux, and LCA engineering practitioners, so results were disseminated to a diverse disciplinary range of research professionals and students. Wider audiences were reached via a series of invited university seminars and lectures. What do you plan to do during the next reporting period to accomplish the goals?Our project is currently operating in "low power" mode as a no cost extension, effectively extending the two year seed grant into a third project year. The remaining funds should allow us to continue operating the three eddy covariance sites and to collect biomass data from the switchgrass field, however we will not have a reserve of funds to make major repairs, if needed. Also, there are no funds remaining to support further modeling work, so it is unclear whether the LCA team will be able to finish the publication. Also, because the seed grant budget was small, we depend largely on leveraging another NIFA project at Virginia Tech (PD Dr. Quinn Thomas) that supports a Ph.D. student (Ben Ahlswede). Ben helps run the field sites and is the lead in analyzing and synthesizing results. Ben is developing three manuscripts for his dissertation based on this project, and we anticipate those will start to come out in 2020 and will acknowledge this project. The dataset reached appropriate length to finish his analyses in 2019, so we have been limited in reaching our data analysis objectives by data completeness up until now. Progress should accelerate in the third year. Furthermore, we have revised and re-submitted a follow up proposal to the 2019 BNRE RFA to keep this project running.

Impacts
What was accomplished under these goals? Year 2 of the seed grant has been successful, as we met all of our stated goals, including running three eddy covariance towers continuously during the project period. We also revised and resubmitted a follow up full proposal to the 2019 RFA for BNRE to expand and continue this project. This seed grant project is currently continuing after project year 2 as a no cost extension. Specific accomplishments from project year 2 include: Continued operation of three eddy covariance towers in a mature and clearcut/replanted loblolly pine plantations and a switchgrass plantation to measure CO2, water vapor, heat and radiometric fluxes continuously every half hour. Ancillary meteorology and phenology variables are also measured. Measurement of peak biomass in the switchgrass at the end of the growing season in 2018. Determination of the baled switchgrass biomass in 2018 via data shared from our collaborator, FDCE, who manage the switchgrass plantation. A field campaign during the growing season of 2018 to measure soil respiration in the clearcut site, as conducted by an undergraduate female researcher, who developed her results into a poster and presented at a national meeting (Geological Society of America). The sensitivity of production to short term climate drivers (weather) will be determined at the end of the project when the data record is longer. An analysis of the biophysical feedbacks to climate will also be performed at that time (see future work outlined below). On the modeling side, a full first-order GHG-LCA model of switchgrass and pine biomass production in the southeast US that included biophysical and biogeochemical feedbacks was completed and initial results were presented at the ACLCA 2018 LCA XVIII meeting.

Publications

  • Type: Journal Articles Status: Accepted Year Published: 2019 Citation: Bright, R. M. and OHalloran, T. L.: Developing a monthly albedo change radiative forcing kernel from satellite climatologies of Earths shortwave radiation budget: CACK v1.0, Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2019-15, in review, 2019. Submitted 1/16/2019. Accepted. In final typesetting.
  • Type: Other Status: Other Year Published: 2019 Citation: O⿿Halloran, T.L., Forests or fields? Choosing the ideal land cover for cooling the climate. Bromery Lecture. Morton K. Blaustein Department of Earth & Planetary Sciences. Johns Hopkins University. April 11, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: O⿿Halloran, TL., P. Eranki, T. Harris, R.Q. Thomas, B. Ahlswede, and L. Fink. Climate-regulating services of pine and switchgrass biomass plantations. USDA-NIFA Climate and Agroecology Project Directors⿿ Meeting. USDA NIFA, Washington D.C., December 6-7, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: B.J. Ahlswede, T.L. O⿿Halloran, R.Q. Thomas, Dynamics of Carbon and Temperature of Managed Ecosystems from Land-Use Land-Cover Change in the Virginia Piedmont, Ameriflux PI Meeting, Bloomington, Indiana, October 25th, 2018.
  • Type: Other Status: Other Year Published: 2019 Citation: B.J. Ahlswede, T.L. O⿿Halloran, R.Q. Thomas, Carbon and temperature dynamics of loblolly pine and switchgrass, Virginia Tech FREC Department Seminar, Blacksburg, VA, February 8th, 2019.
  • Type: Other Status: Other Year Published: 2019 Citation: B.J. Ahlswede, Examining the interaction of managed ecosystems and the atmosphere, perspectives from the globe to the field, Shippensburg University Biology Seminar, Shippensburg PA, April 18th, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: O⿿Halloran, T.L. Measuring landscape-scale fluxes of water, energy and greenhouse gases in managed and natural ecosystems. Clemson University Research Symposium. Clemson, SC. May 8, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: N. Jones**, T.L. O⿿Halloran, P. Eranki, S. Cadieux and R.Q. Thomas. Temporal and spatial variability o fsoil CO2 fluxes in a recent clearcut of loblolly pine in central Virginia. Geological Society of America Annual meeting, Indianapolis, Indiana. November 4-7, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: B.J. Ahlswede, T.L. O⿿Halloran, R.Q. Thomas, Switchgrass as a climate change mitigation tool in central Virginia, Interfaces of Global Change Symposium, Blacksburg VA, April 25th, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: T. Harris, P. Eranki and T.L. O⿿Halloran. 2018. A GHG-LCA integrating biophysical feedback from loblolly pine and switchgrass feedstocks cultivated for co-firing in the southeast U.S. ACLCA meeting LCA XVIII Fort Collins, Colorado, September 25-27, 2018.


Progress 06/01/17 to 05/31/18

Outputs
Target Audience:Year 1 of the seed grant is focused on data colleaction and model development, and not on dissemination of results. However, we have formally presented one conference presentation, reaching a scientific audience of students and faculty, mostly in the broad areas of sustainability and engineering. We have also informally reached audiences of undergraduatte students in Environmental Science through presentations and training of summer interns. We have also worked with stakeholders and land managers over the course of the project, as we interact and coordiante with the forest manager and the company (FDCE) that manages the switchgrass bioenergy plantation that hosts our reserach towers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Undergraduates - in summer of 2017 this project supported two undergraduates at Sweet Briar College, an undergraduate women's college, who worked as interns on the project. These students were trained to use the Licor LI-8100 to measure soil CO2 efflux from switchgrass and loblolly pine plantations. They also received training and participated in soil coring for soil carbon sampling as well as in methods for aboveground biomass sampling. Training was largely provided by Clemson technician James LeMoine Graduate students - While in his last year of his PhD work, Tyler Harris has worked with this project's PD and researchers on completing a traditional GHG-LCA that integrates albedo changes and soil carbon sequestration with the global warming potential (GWP) impact characterization method used for LCA. Over this reporting period, weekly project meetings were completed to monitor and guide progress on the project's goals and deliverables. Tyler Harris also had the opportunity to present findings at CSMGRADS conference described below, as well as being first author on submission to the ACLCA 2018 LCA XVIII international conference accepted for oral presentation. Technicians - Technician James LeMoine from Clemson received training from a collaborator at UNC Chapel Hill to operate a Picarro® Isotopic Cavity Ring-down Spectrometer to measure isotopes of carbon for distinguishing the C3 vs C4 signature of soil respiration in the switchgrass plantation Senior personnel - PI O'Halloran received the same training with the Picarro®, as described above. He has developed professionally by gaining experience leading weekly team conference calls and attending and presenting at the Project Director's meeting in Tampa, FL in October of 2017. Co-PD Eranki gained professional development by mentoring a graduate student (and now post-doc) Tyler Harris, thereby providing her with experience in her early career as faculty. How have the results been disseminated to communities of interest?As this was year 1 of a seed grant, we were focused on data collection not dissemination of results. Even so, results from this USDA seed grant have been disseminated to communities of interest through a conference presentation and discussions. An oral presentation titled "GHG-LCA of Loblolly Pine and Switchgrass Bioenergy Feedstocks Cultivated in the Southeast US" was given on April 5, 2018 at the Colorado School of Mines Graduate Research and Discovery Symposium (CSMGRADS). An oral presentation has also been accepted at the ACLCA LCA XVIII international conference in September 2018. More information will be disseminated to communities of interest in the second project year. What do you plan to do during the next reporting period to accomplish the goals?Our project is divided into two main components: measurements and model development. Our plan in those two areas, and to synthesize results is as follows: Measurements Continued operation of three eddy covariance towers in a mature pine, pine clearcut and switchgrass plantation. Continued operation of a soil greenhouse gas flux measurement system. The system runs continuously in the clearcut and is taken offline to perform spatial surveys each month in the clearcut and switchgrass sites. Collection of peak switchgrass biomass via destructive harvesting Collection of baled switchgrass biomass from data shared through the switchgrass management company (FDCE). Modeling A final Excel-based LCA model, verification and improvement of the GHG-LCA and biophysical feedback model will be completed. The findings will be presented in manuscript(s) submitted to prestigious, peer-reviewed academic journals. The ACLCA LCA XVIII oral presentation and conference proceeding will be completed over the next reporting period. Weekly project meetings will continue to ensure completion of these goals and deliverables within the next reporting period. Synthesis and Products The seed grant primarily supports data collection and initial development of a modeling framework that synthesizes measurements to determine the net climate benefits of switchgrass and loblolly pine production for biomass energy. In year 1, we have made good progress towards developing that modeling framework. We expect to submit a manuscript on developing the LCA and incorporating biophysics (albedo) into the LCA by the end of the seed grant project period (May 2019). This will be the primary product of the modeling component of the project, but also the main synthesizing product. We are developing other manuscripts as output for this project, but they depend on the data to be collected during year 2 of the seed grant, and as such are not likely to be submitted during the project period. However, we briefly introduce them with preliminary titles here: "Environmental controls on loblolly pine productivity: untangling sensitivities to diffuse light and vapor pressure deficit" "Importance of management and phenology in determining the biophysical cooling properties of switchgrass and loblolly pine" "Contribution of legacy carbon to soil CO2 efflux after conversion of a pasture to switchgrass production for bioenergy"

Impacts
What was accomplished under these goals? Year 1 of the seed grant has been a great success. We have made significant progress towards all of our stated goals and also used the grant as leverage to expand to include two activities that are not directly supported by the project. We have also used the data collected and progress with model development from year 1 to develop and submit a proposal for a full project to the 2018 RFA for BNRE. Specific accomplishments form project year 1 include: Continued operation of two eddy covariance towers in a mature loblolly pine plantation and a switchgrass plantation to measure CO2, water vapor, heat and radiometric fluxes continuously every half hour. Ancillary meteorology and phenology variables are also measured. A field campaign in summer 2017 to measure soil carbon stocks at both sites. Measurement of peak biomass in the switchgrass at the end of the growing season in 2017. Determination of the baled switchgrass biomass in 2017 via data shared from our collaborator, FDCE, who manage the switchgrass plantation. Measurement of the aboveground biomass and carbon stocks in the pine plantation by survey and allometry. Establishment of a new soil greenhouse gas flux measurement system (Licor® LI-8100). The system ran in the switchgrass field in continuous mode except when it was periodically taken offline to perform spatial surveys. In 2017 these surveys were performed approximately monthly between July and December in the switchgrass and pine plantations by undergraduate interns supported by the project. The sensitivity of production to short term climate drivers (weather) will be determined at the end of the project when the data record is longer. An analysis of the biophysical feedbacks to climate will also be performed at that time (see future work outlined below). We leveraged the seed grant to attract a collaborator, Diego Riveros-Iregui from UNC Chapel Hill, to bring a Picarro® isotopic analyzer to measure the C isotopes of respiring CO2 from the switchgrass field. This will determine the fraction of CO2 that originates from old C3 carbon from the prior land use (pasture) versus new C4 carbon from the switchgrass. This will help quantify the 'legacy effects' of the land cover conversion on determining the present day carbon budget. This is critical since our initial measurements revealed the switchgrass field is a net source of carbon to the atmosphere three years after establishment (in terms of net ecosystem production, NEP). The second major leveraged activity was purchase and establishment of a third eddy covariance tower in a recent clearcut of loblolly pine that is co-located with the other towers. This was done through our unfunded collaborator, Dr. Quinn Thomas at Virginia Tech, with funding from the Global Change Center at Virginia Tech, and institutional funds from Clemson University and Sweet Briar College. That tower was established and operational in March 2018 and we believe will provide critical and complimentary information on the carbon, water and energy fluxes during pine harvest activities. This provides important datasets on the impacts of pine harvesting on carbon, water and energy fluxes, and provides parallel datasets to those at switchgrass, which capture a full harvest cycle each year. Despite its wide coverage and economic importance in the southeast, there are very few datasets on carbon and energy fluxes immediately after clearcutting loblolly pine plantations. On the modeling side, a full first-order GHG-LCA model of switchgrass and pine biomass production in the southeast US that included biophysical and biogeochemical feedbacks has been nearly completed at the end of the first project year. Extensive literature review was performed to develop the model for the full lifecycle and bioenergy conversion of pine and switchgrass. Data from switchgrass and pine growers was incorporated into the model. Through extensive discussions in weekly project calls, data was exchanged between Clemson University and Colorado School of Mines to populate crucial model parameters such as net ecosystem productivity and albedo conversions to CO2e essential to the development of this model. The model is entering the verification stage, and the findings are being developed into a manuscript for publication in an academic journal.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Tyler Harris, Pragnya Eranki, Tom OHalloran, GHG-LCA of Loblolly Pine and Switchgrass Bioenergy Feedstocks Cultivated in the Southeast US, Oral presentation at the Colorado School of Mines Graduate Research and Discovery Symposium (CSMGRADS), April 2018