Progress 07/01/21 to 12/31/23

Outputs
Target Audience: For this reporting period, the target audience of this work has been other scientists, researchers, and students investigating global change, pollination biology, plant physiology, or pollinator health. Primary efforts include science communication via social media networking on Twitter, in-person networking at department events, such as seminars, and conferences, as well as a conference presentation at the North Central Branch Meeting of the Entomological Society of America in Aprilof 2023, Departmental seminars at the University of Wisconsin-Madison in March 2023, Wayne State University in April 2023, and Texas A&M in October 2023, and at the Wisconsin Pollinator Meeting in April 2023. Changes/Problems:As reported in the previous progress report, the plant species studied in objective 1 of this project did not respond to elevated CO2 growing conditions as we expected them to with most species not responding at all. Therefore, we revised objective 2 to focus on bumble bee foraging under temperature change and expanded objective 1 to conduct an experiment on plant growth and pollen chemistry under eCO2 with and without the addition of N fertilizer, objective 3 was not addressed and efforts instead focused on revised objectives 1 and 2. What opportunities for training and professional development has the project provided?PD Bernauer participated in a workshop to learn machine learning techniques to improve their understanding of how this tool can be used and applied to big data sets: 2023Introduction to Machine Learning, Data Science Hub, University of Wisconsin-Madison, USA. Further, PD Bernauer had several opportunities to polish public speaking skills at several invited talks, as listed in the other products of this report. PD Bernauer has also continued to hone scientific writing skills through writing up the findings of this work as scientific manuscripts. PD Bernauer has also improved mentoring skills working with undergraduate mentees throughout this project. How have the results been disseminated to communities of interest?To disseminate the results of this work, PD Bernauer has given several presentations to colleagues around North America as detailed in the other products section of this report. Additionally, PD Bernauer has shared progress and updates about this work on their Twitter account, which has an audience of other scientists. PD Bernauer in collaboration with co-authors is in the process of publishing scientific manuscripts on the outputs of Obj 1 and Obj 2 as detailed in the Publications section of this work as well as above in the accomplishments of this project. Currently, there are two manuscripts that exist as full drafts with plans to get these submitted in the next month and a third on its way that PD Bernauer intends to submit to a scientific journal before mid-year. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective 1: How does the projected increase in atmospheric CO2 affect the nutritional value of floral resources? For objective 1, we evaluated the effects of eCO2 on fourteen flowering plant species and found that for most plant species, the nutritional value of floral resources was unaffected by eCO2 and when plants responded to eCO2, they had differential responses (some increasing and others decreasing in pollen protein (%N)). This objective is complete and a corresponding manuscript is prepared, has had feedback from all co-authors and will be submitted to a scientific journal before the end of the month. In addition to the proposed work on eCO2 and plant growth and pollen nutrition, we also added a project investigating if there is an interaction between eCO2 and N fertilizer levels. This project was led by an undergraduate mentee of PD Bernauer for the student's senior thesis. This project is complete and a manuscript has been fully drafted for submission to a scientific journal. The manuscript is currently being reviewed by co-authors and should be submitted within the next month. Objective 2: Does bumble bee foraging behavior or floral preferences change when floral resources are grown under elevated CO2? Given that the plant species studied for objective 1 did not respond strongly to elevated CO2, we decided to revise this objective to focus on another important aspect of global change: warming temperatures. PD Bernauer and an undergraduate mentee investigated whether bumble bee learning was influenced by temperatures, with specific attention to warming temperatures. Together, PD Bernauer and the undergraduate mentee used video cameras and custom computer vision code to track bumble bees within an arena to document their foraging behavior in different temperatures. All data for this objective have been collected, final video processing will occur shortly, and then PD Bernauer will analyze and write up this work for publication in a scientific journal. Objective 3: What are the impacts of elevated CO2 pollen resources on bumble bee queen overwintering, survival, and colony growth? Given that the plant species studied for objective 1 did not respond strongly to elevated CO2, we focused our efforts on expanding Obj. 1 and the modified Obj. 2 instead of focusing on this objective.

Publications

• Type: Journal Articles Status: Other Year Published: 2024 Citation: in prep. Bernauer, OM, Jain, A, de Bivort, B, Holbrook, NM, Myers, SS, Ziska, LH, Crall, JD. Elevated atmospheric CO2 has inconsistent effects on pollen chemistry and plant growth across flowering plant species. For submission to Scientific Reports.
• Type: Journal Articles Status: Other Year Published: 2024 Citation: in prep. VanDerhei, GC, Ziska LH, Crall, JD, Bernauer, OM. The dynamics of eCO2 and N fertilizer on borage (Boraginaceae: Borago officinalis) growth, flowering, and pollen nutrition. For submission to J Plant Research.

Progress 07/01/22 to 06/30/23

Outputs
Target Audience: The target audience of this work has been other scientists, researchers, and students investigating global change, pollination biology, plant physiology, or pollinator health. Primary efforts include science communication via social media networking on Twitter, in-person networking at department events, such as seminars, and conferences, as well as a conference presentations. Changes/Problems:Objective 1 was expanded to include a study on the interaction between elevated CO2 x N fertilizer levels. Objective 2: Since our results of Objective 1 did not show a strong effect of elevated CO2 on pollen nutrition, though we were still interested in studying bee foraging, we changed the study for Objective 2. Instead of studying how plants grown under elevated CO2 affect bumble bee foraging, we shifted to studying how changes in temperature impact bumble bee learning and foraging behavior, another important facet of climate change. Objective 3: Because the results of Objective 1 did not show a strong effect of elevated CO2 on pollen protein, we did not carry out objective three as we would expect no changes to pollen nutrition or queen development when fed a diet of plants grown under elevated CO2. What opportunities for training and professional development has the project provided?During August of 2022, PD Bernauer attended the Bee Course in Portal, AZ for ten days where she improved her bee taxonomy skills and networked with other peers similarly studying bees, including several investigating climate change and pollinators. PD Bernauer has learned to use low-cost electronics in her research, both through trial and error, but also through auditing a course titled "Digital Ecology" taught by co-PI Crall in the Spring of 2023. How have the results been disseminated to communities of interest?In the last year, PD Bernauer and colleagues have presented upon this work nine times during seminars or conferences to scientific peers. As the project has progressed, PD Bernauer has shared progress on twitter with her growing network of peers. What do you plan to do during the next reporting period to accomplish the goals?For Objective 1, we plan to have two manuscripts submitted to scientific journals in coming months to share our findings with scientific peers. This will accomplish all goals for Objective 1. For Objective 2, the bumble bee foraging data will be analyzed, then summarized and published in a scientific journal. As Objective 3 was shifted to a broader focus on Objective 1, see plans described in Obj 1 above.

Impacts
What was accomplished under these goals? Objective 1: In this reporting period, efforts on Obj. 1 have focused on writing and communicating the scientific findings generated in this study. The manuscript summarizing these results is in preparation with plans to submit to a scientific journal within weeks. Objective 1 was expanded to include a study on the interaction between CO2 and N fertilizer on a single plant species to see if additional N fertilizer can effectively fertilize away the negative impacts of elevated CO2 on bumble bee nutrition. This work on CO2 and N fertilizer was undertaken by an undergraduate student for their senior thesis in exchange for research credits. The results from this work have been summarized in her thesis and we are planning to publish these in a scientific journal in late summer or early fall. Objective 2: Objective 2 was revised to focus on bumble bee foraging and learning in response to temperature change instead of CO2 as response to elevated CO2 was not as strong as we initially predicted. For objective 2, a data set on bumble bee foraging under different learning and testing temperatures has been carried out using a foraging arena created by PD Bernauer. This data set will be analyzed shortly. Objective 3: Given that elevated CO2 did not strongly impact pollen nutrition for most of our studied plant species, we decided to forego objective three, and instead focus more efforts on Obj. 1 and carrying out the CO2 x N fertilizer experiment.

Publications

• Type: Theses/Dissertations Status: Submitted Year Published: 2023 Citation: VanDerhei (2023) INFLUENCE OF NITROGEN FERTILIZATION ON BORAGO OFFICINALIS GROWTH AND POLLEN NUTRITION UNDER ELEVATED CARBON DIOXIDE CONDITIONS

Progress 07/01/21 to 06/30/22

Outputs
Target Audience:For this reporting period, the target audience of this work has been other scientists, researchers, and students investigating global change, pollination biology, plant physiology, or pollinator health. Primary efforts include science communication via social media networking on Twitter, in-person networking at department events, such as seminars, and conferences, as well as a conference presentation at the North Central Branch Meeting of the Entomological Society of America in March of 2022. Changes/Problems:As the work in objective 1 is a continuation of previous work by mentors Crall and Ziska, some preliminary data sets have recently become available. The original study (Ziska et al., 2016, Proc. R. Soc. B.: Biol. Sci.) which this work was based upon, found a clear decrease in pollen protein in goldenrod as atmospheric CO2 increased (eCO2). Data from a follow-up study conducted by mentors Crall and Ziska and collaborator AnuprekshaJainat Harvard University during the summer of 2021suggest that responses to increasing atmospheric CO2 are species-specific and that not all plant species exhibit a decrease in pollen protein following eCO2 growing conditions. The data collected in the experiment in objective 1 of this study will provide data on additional plant species. We initially hypothesized that pollen protein would be uniformly decreased, which would have obvious negative consequences for pollinator health, but now that we have more data, the story is less clear. If most plant species exhibit no changes to pollen protein in response to eCO2, there are unlikely to be changes to foraging behavior (objective 2) or queen bumble bee physiology (objective 3). The experiments in objectives 2 and 3 may change in response to more data on pollen nutrition, but the details of this will not be decided until the results from objective 1 on pollen nutrition and metabolomics are available. What opportunities for training and professional development has the project provided?The project has offered PD Bernauer the opportunity to network with new colleagues at UW-Madison (in the department and during weekly seminars of invited speakers), as well as in the Midwest in general, at the North Central Branch meeting of the Entomological Society of America in March of 2022 (Minneapolis, MN). Additionally, PD Bernauer has been learning about chemical ecology,automation techniques, and using neural networks and is preparing to implement these automated techniquesin her upcoming experiment on foraging behavior (objective 2). Alongside PD Bernauer's new technological skills, she has improved her ability to code using Python. The University of Wisconsin-Madison also offers a plethora of workshops and seminars on topics including mentoring, job searching, and promoting healthy work environments;PD Bernauer has attended 6 of theseseminars to date. PD Bernauer has had the opportunity to work with other members of the lab to assist in peer-reviewing their research plans and providing mentoring as needed. Additionally, PD Bernauer has mentored an undergraduate student during the spring semester of 2022 to conduct their own independent research, this student will be returning in the fall to continue to be mentored by PD Bernauer. How have the results been disseminated to communities of interest?PD Bernauer utilizes her network on the social media platform Twitter to share updates about her research. Most of her followers are other scientists and members of the public interested in pollinator health and biology. In March of 2022, PD Bernauer presented a poster at the North Central Branch Meeting of the Entomological Society of American conferences in Minneapolis, MN, on her upcoming experimental plans to study bee foraging behavior when provided with plants grown under elevated CO2 (objective 2). Additionally, as this work (the entire postdoc) is a continuation of an ongoing collaboration started by mentor Crall and collaborative mentor Ziska, a second poster was presented at the meeting in Minneapolis by another student (Anupreksha Jain) who helped with earlier aspects of this study, and which detailed preliminary results from objective 1, on plant responses to elevated CO2. What do you plan to do during the next reporting period to accomplish the goals?To accomplish objective 1, once the results of pollen analyses are back, I plan to finish analyzing the final data set, and prepare the results for publication in a scientific journal. I plan to continue to share the results of this work on social media and present these results at a scientific conference next year. For objective 2, I plan to conduct the foraging behavior experiment to determine if changes to plant physiology or nutrition alter bumble bee foraging behavior. PD Bernauer will need to build the foraging arenas, implement the automated foraging behavior technology (cameras, software, etc.), grow flowering plants, and run the experiments.Once the experiment is complete, I plan to analyze the collected data and summarize the findings in scientific publication.

Impacts
What was accomplished under these goals? To date, efforts have focused primarily on objective 1. During the winter of 2021-2022, PD Bernauer conducted experimental studies in a greenhouse to investigate the impacts of increasing atmospheric carbon dioxide (CO2) on plant growth, physiology, and the protein content of pollen, an important resource for pollinators. Two experimental rounds were completed, the first with 9 species of flowering plants, grown from seed, and the second with 7 species. Each experimental round lasted approximately four months and during this time, plant height, leaf number, and flower number were monitored weekly to document plant growth. Once plants were in flower, pollen samples were collected. Due to time constraints and small flower sizes, nectar was not evaluated. The data on plant growth has been entered and preliminary analyses are underway. A subset of pollen samples from four plant species has been set aside for metabolomic analyses, which we expect to occur this summer in an ongoing collaboration with colleagues at Harvard. The remaining pollen samples have been dried and are currently being analyzed for carbon and nitrogen (as a proxy for pollen) content. Forobjective 2, the experimental design for the foraging arenas has been created, and the plant species included in this study will be determined once we get the results of the pollen analyses back.

Publications