Progress 03/01/19 to 02/28/22
Outputs
Target Audience:The target audience of this project includes academics and regional meadow restoration practitioners. We have communicated with academics through presentations at meetings and conferences and through peer-reviewed publications. To date, the work has led to one publication that was influenced by this project, published in Ecological Applications. We are preparing additional publications. Our presentations have included the 2019 American Geophysical Union Fall meeting and the 2021 NSF-funded CZCN meeting at the Sagehen Creek Research Station. At both meetings, graduate students and postdocs presented meadow carbon-nitrogen cycling research. We have communicated with restoration practitioners primarily through direct conversation, though we presented at the 2019 Sierra Meadows Partnership annual meeting. At that time, our discussion of this project was anticipatory, for the project had only recently been funded. The COVID-19 pandemic resulted in the cancellation of other Sierra Meadows Partnership annual meetings. Numerous regional restoration organizations are aware of and interested in this research, including: USFS, South Yuba River Citizens League, Plumas Corporation, Truckee River Watershed Council, and the California Tahoe Conservancy. In addition, we have developed a collaboration with the Working Lands Initiative, based in Logan Utah, to advance soil carbon sequestration. This collaboration has led to the USDA funding research through that organization. Changes/Problems:The COVID-19 pandemic caused numerous changes and problems to the project. The timing of this two-year seed grant was such that we used the first growing season to restart the fertilization plots and get the project team oriented within the Sagehen meadow with plans for a full sampling campaign in 2020. With the support of a no-cost extension, we were able to extend the grant to include the 2021 field season, though 2021 was still complicated by COVID results. The problems caused by the pandemic were logistical (we were unable to obtain some supplies in 2020; Sagehen Field Station temporarily shut down), bureaucratic (the project required administrative permission from two University systems - Nevada System of Higher Education for the Soil Ecology Lab, the University of California System for the Sagehen Creek Field Station reserve; training personnel in lab work was impossible because only one person was allowed in the lab at a time, only one person was allowed in a vehicle), personnel-based (lab employees on other projects quit/abandoned work; lab personnel were severely constrained by episodic losses of childcare during the pandemic), financial (paying project employees for three years with two budgeted years of funding resulted in less money available for planned isotope analysis - we collected the samples and PI Sullivan hopes to analyze them in the future), and scientific (being unable to sample twice in 2020 changed our experiment by sampling once in 2020 and once in 2021 which alters our research questions). In 2021, the pandemic continued to impact our ability to do lab work and the northern Sierra was subsantially impacted by numerous large forest fires that caused forest closures and dangerously smoky air that prevented field work. PI Sullivan was awarded a sabbatical in Fall 2021, but was unable to make some of the progress expected on this project during that period due to personal and administrative problems associated with issues described above. Despite all these challenges, it's important to acknowledge how hard the project team worked to overcome these limitations to the best of our ability and I am proud of the work we have accomplished. We have made valuable findings that will spur future research directions. What opportunities for training and professional development has the project provided?This project has supported the training of a postdoc, Cody Reed, a PhD student, Brian Morra, a MS student, Jacob Anderson, and a field technician, Julia Stiltz. The postdoc and MS student were directly financially supported by this work and participated in most field and lab activities. The PhD student took advantage of the lableing work in Sagehen meadows to link this project with a Hatch funded research project in which he was labeling C in Nevada meadows located in a drier ecosystem. The technician contributed and gained botanical and plant identification skills and assisted in lab work and sample processing. The MS student discovered a passion for data analysis and coding during his MS degree progress. Consequently, while he contributed field and lab work to the project and performed enzyme analyses associated with the research, he wrote his thesis on a data analysis package associated with an instrument in our lab. He has recently taken a position as a data analyst for a cancer research position. The PhD student continues work on his dissertation, which was recently described in a final report for his Hatch project. The postdoc continues her position within the lab. The COVID-19 impacted our ability to link trainings associated with our project partners in the Sierra Meadows Partnership and with the citizen science orgnaization Earthwatch. How have the results been disseminated to communities of interest?In June 2022, we shared preliminary results at the NSF-funded CZCN meeting held in Sagehen Creek Field Station. We have shared results with project partner organizations (described in Target Audience). In addition to the thesis and publications already noted in this report and others, we anticipate producing two more manuscripts: one related to the dual isotope C-N labeling study and another related to the fertilizer plots. We will continue to share these results at academic meetings. The Soil Ecology Lab has not attended academic conferences as frequently as we used to given the pandemic substantially overlapped with this project. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Beginning in 2019, we restored and restarted the existing fertilization plots in the Sagehen meadows. This included rebuilding fencing and remarking plots. The meadow fertilization plots have been maintained every year since 2019 and were sampled intensively prior to fertilization in 2019. We connected with and obtained data from the NutNet fertilization plot network that oversaw the fertilization plots prior to 2012. We planned to do our dual-isotope labeling work in the spring and summer of 2020. Of course, this was altered by the COVID-19 pandemic (see Changes/Problems). By the time we were permitted to access the field in 2020, the oppoortunity to sample in the early growing season had lapsed. Therefore, we sampled in a wet and dry site at or after peak productivity in Sagehen meadows. When we returned in 2021 (thanks to a no-cost extension) to sample the earlier growing season, we found, to our surprise, that the "wet" and "dry" meadow areas had switched. This switch was likely due to complex subsurface hydrology associated with snowpack melt within the Sagehen Creek watershed. We sampled in near our 2021 locations nonetheless, but this resulted in a change from measuring C/N fluxes in both the early and late growing seasons in wet and dry locations to four sampling locations that span a range of soil water contents. Aboveground vegetation biomass varied significantly by whether a site was "wet" or "dry" condition (p < 0.01) but not by season (p = 0.29). Soil moisture levels were significantly different by season (p < 0.01, F = 24.2) as well as site condition (p < 0.01, F = 7.04). Rates of gross primary productivity (GPP), calculated as the total amount of C (12C and 13C) assimilated by plants during the labeling period, ranged from 10.7 to 28.4 umol m-2 s-1. Gross primary productivity varied significantly different by site condition (p < 0.01, F = 9.92) but not by season (p = 0.82, F = 0.055). Gross primary productivity varied significantly with soil moisture across all sites and seasons (p < 0.01, r2 = 0.35) and within each season (early growing: p < 0.01, r2 = 0.64; peak productivity: p < 0.01, r2 = 0.64). However, the slope of the relationship varied between seasons and greater increases in GPP were measured for every percent increase in soil moisture during peak productivity than the early growing season. Carbon was immediately allocated belowground with the greatest rate of belowground allocation of the added 13C occurring within two hours of the labeling. During the early growing season, the initial rate of uptake of both 15NH4 and 15NO3 by roots was positively correlated with the average rate of belowground C allocation over the course of the study period (calculated as per Reed et al. 2021; 15NH4: p < 0.01, r2 = 0.82; 15NO3: p=0.04, r2 = 0.63). Total soil nitrogen (N) stocks ranged from 173 - 658 g N m-2 and were not significantly different between sites in 2021 (p=0.15, F=2.18). Inorganic N pools were small relative to total N stocks and comprised <0.0001% of total N pools. Nitrogen (N) demand at the time of labeling, calculated as: N demand = GPP * (1-fraction of GPP to autotrophic respiration) / C:N, ranged from 5.5 to 15.3 mg N m-2 h-1. Rates of uptake of the labeled 15N (NH4 or NO3) were equivalent to 0.6-15.9% of calculated plant N demand (5.2-31.9% combined NO3 and NH4) in the early growing season. Total potential N release by extracellular enzymes at the beginning of the growing season in 2021 was 18.1-60.6 times greater than plant N demand. Rates of potential enzyme activity were lower later in the growing season but stil 9 - 28.9 times higher than early season vegetation N demand. Potential N release from enzyme activity increased significantly with soil moisture content (p < 0.01, r2 = 0.81) across all sites and sampling dates. Total potential C and N release by extracellular enzymes were also correlated (p<0.01, r = 0.94) across all sites and sampling dates. Across all sites and sampling dates, potential enzyme activity for acquiring carbon, nitrogen, and phosphorus was positively correlated with soil moisture (p < 0.01) but not rates of GPP. Total potential release of C, N and P by extracellular enzymes was approximately three times higher at the wet site during the early growing season than any other site or sampling date. Enzyme activity for acquiring C, N and P were also positively correlated with rate of 15NH4 uptake by roots (p < 0.01) and rates of belowground C allocation (p < 0.1) in the early growing season. At peak productivity, rates of total enzyme activity for C, N and P release were negatively correlated with soil NH4 concentration (p < 0.01) but not with soil NO3 concentration. Rates of enzyme activity for all three nutrients at peak productivity were also negatively correlated with belowground CO2 fluxes (p < 0.01)
Publications
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2022
Citation:
Reed, Cody C., Asmeret A Berhe, Kimber C. Moreland, Jim Wilcox, Benjamin W. Sullivan. 2021. Restoring function: Positive responses of carbon and nitrogen to 20 years of hydrologic restoration in montane meadows. Ecological Applications, accepted and available online: https://doi.org/10.1002/eap.2677
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2021
Citation:
Anderson, Jacob F. 2021. peak.gas: An R package for data wrangling and plotting trace gas concentrations from
instantaneous output produced by benchtop instruments. MS Thesis, University of Nevada, Reno.
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Progress 03/01/20 to 02/28/21
Outputs
Target Audience:The target audience of this research includes scientists and land managers. Scientists will be interested in understanding what we learn about nutrient acquisition by productive plants. Managers will have an opportunity to use this information to justify meadow management actions. Changes/Problems:Covid threw a pretty big wrench in our fieldwork, as we were hoping to get started during the period when my University shut down all research activities and the Unviersity of California locked down the Sagehen field station where our sites are. While we were ultimately able to get to the field by late June, it prevented us from doing important early season work. While field work could be accomplished last summer, we were very limited in our ability to do lab work due to covid protocols. It's hard to teach students in the lab when i can't be in the same space as them. Fortunately, we were able to get an extension to this project for an extra year (thank you!) and that has been a saving grace. What opportunities for training and professional development has the project provided?Two graduate students were trained; one, Cody Reed, defended her dissertation and started a postdoc position on the project. The other, Jacob Anderson, continues to make progress. How have the results been disseminated to communities of interest?One manuscript has been published in Ecosystems by members of the project team. The manuscript builds towards the ideas being tested here and we considered what we're learning in this project as we wrote it. Another manuscript is in draft form for submission and more strongly incorporates C-N linkages. What do you plan to do during the next reporting period to accomplish the goals?We will isotopically label the sites earlier in the growing season this year. Last summer we labeled at peak biomass, but we want to sample early in the growing season while plants are still building biomass. There will be a lot of labwork processing samples.
Impacts
What was accomplished under these goals?
We maintained the fertilization sites in Sagehen this past year and also isotopically labeled soil with C and N. We collected soil for enzyme analysis in multiple seasons.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Reed, C.C., A.G. Merrill, W.M. Drew, B. Christman, R. Hutchinson, L. Keszey, M. Odell, S. Swanson, P.S.J. Verburg, J. Wilcox, S.C. Hart, B.W. Sullivan. 2020. Montane Meadows: A Soil Carbon Sink or Source? Ecosystems DOI 10.1007/s10021-020-00572-x
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Progress 03/01/19 to 02/29/20
Outputs
Target Audience:We presented a talk at the American Geophysical Union in San Francisco, CA in December 2019 (presented by lead author and graduate student [soon to be postdoc] Cody Reed). This reached both scientists and managers; it led to a request by a USFS employee (non research position) to give a brown-bag webinar to the Pacific Southwest region soil scientists in February 2020 (again by C. Reed). The AGU meeting was also attended by Jacob Anderson, a MS student helping with the project. It was his first time attending a professional meeting and as it was his first year, he did not present. Changes/Problems:This project has experienced two major problems. The first was the record-setting snowfall and late spring moisture in the Sierra Nevada in 2019, leading to a lack of site access until mid June. This limited our ability to work in the site prior to peak vegetation production. Consequently, we were unable to begin a full sampling season in 2019. We reduced our scope for 2019 to: improving existing resources (such as the old NutNet fertilization plots being "rekindled" by this project), establishing connections with the ETH-Zurich team running eddy covariance towers near by, getting the sites ready for a full campaign in 2020. In 2020 we have been severely curtailed by the COVID-19 outbreak. The University of Nevada has ceased nearly all activities. Sullivan obtained permission from the President of the University to visit Sagehen once this year, alone, in order to check on the old NutNet sites and fertilize them. Sullivan also obtained permission from the University of California Chancellor's office to access Sagehen because Sagehen is a UC system field station. However, we will not be able to perform stable isotope experiments or enzyme analyses until such a time as multiple people are able to access the field and when laboratory operations are fully opertaional. Presently, our colleagues in stable isotope analytical labs (e.g., NV Stable Isotope Lab, UC Davis SIF) are shut down, so no samples could be processed even if collected. Enzyme analyses will not be possible until personnel are allowed back in UNR buildings. We hope that we will still be able to get some sampling done this summer, but it is likely that PI Sullivan will need to contact the program officer to discuss an extension to the project timeline because of these two unique conditions - particularly COVID-19. In addition, Sullivan is now providing in-home care for his toddler (while maintaining his status as professor) because his spouse is a healthcare worker in a hospital and daycare is closed. This has severely curtailed working opportunities; please accept sincere apologies for any delay in the submission of this Report. Between being unable to work much and trying to understand/quantify the impacts of the COVID crisis on research, Sullivan has been delayed in reporting on the status of the project. What opportunities for training and professional development has the project provided?The project has resulted in the training and professional development of a graduate student who is enthusiastic about beginning his field work whenever he can (see COVID issues in Changes/Problems section). The postdoc named in the grant is due to finish her PhD this summer and will start as a postdoc in the summer, but she has been involved in project implementation and research design. Several other graduate students have assisted in the maintenance of plots. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?Our plans are contingent upon COVID-related restrictions. At a minimum, the sites will be accessed and plots maintained - fertilization will be applied. Coming into this field season, we were hoping to accomplish the full objectives of the project this summer. However, that appears unlikely given the challenge of doing field and lab work. Instead, we may need to adjust our timeline, which could require a request for an extension (I will expand upon this in the "Changes/Problems" section).
Impacts
What was accomplished under these goals?
In the past (first) project year, we established plots for C/N isotope measurements and found, sampled, and resumed fertilization of the old NutNet fertilziation sites in Sagehen. Re-establishing the fertilzation sites took a substantial amount of work re-finding the sites and fixing fencing to exclude large and small herbivores. The project strengthened two collaborations - one with the NutNet community, and another with Jim Kirchner and his lab from ETH-Zurich that runs eddy covariance towers near our C/N isotope plots in Sagehen. We were developing the foundation for a full season of research this summer (that has been impacted by COVID-19 problems; see comments about problems).
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Reed, Cody C., Benjamin W. Sullivan. 2019. Restoring function? The impacts of hydrologic restoration on carbon cycling in Sierra Nevada montane meadows. American Geophysical Union, invited oral presentation.
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