Progress 07/01/20 to 06/30/21
Outputs
Target Audience:The results of this work have reached a more targeted audience than in the previous year, specifically academics and the general public. Academic presentation: The results of this research were presented at the Annual Student Seminar Day at the University of California, Riverside, Entomology department. This audience of academics ranges from scientists interested broadly in insects and agriculture, to those specifically interested in pollination in agricultural systems and pollinator health. General Public: The methods, results, and overall background of this research has been presented at a virtual insect fairand virtual outreach events. These events were mainly designed forK-12 students. In general, these events are geared toward getting the general publicexcited about science, however, I have utilized this to teach people of the community about agriculture, pollination, and microbiology. Changes/Problems:Due to the COVID-19 Pandemic, there were substantial changes to the methods in which we went about answering the same questions proposed in the initial proposal. Goal #2 stated: "Elucidate nectar chemistry shifts under temperature treatments-to understand if plants can mediate nectar colonization under climate change conditions. As temperatures change, plants rapidly respond in many ways including adjusting water content of nectar and altering nectar sugar concentrations. Comparing plants with sterile flowers to those with flowers inoculated with a microbial community will tease apart what impact nectar microbes have on plant nectar compared to how the plant alone alters nectar with climate change." Changes: This goal was written with the intention of using shared equipment in the department. We intended to use sterile growth chambers shared by many labs. However, due to the pandemic, it was no longer possible to use this equipment. Therefore, this experiment was slightly changed to consist of a more manipulative lab experiment. Here instead of using sterile plants, we used lab generated sterile nectar. The results of this study are detailed in the previous "Accomplishments" section and have been accepted for publication in Microbial Ecology. Goal #3 stated: "Characterize nectar-inhabiting microbes' volatile emissions and determine their attractiveness to pollinators. As microbes within nectar metabolize nectar resources, they can emit volatiles which can be detected in the floral headspace. I will characterize volatile emissions under climate change predicted conditions by incubating commonly found nectar microbes to different heat treatments and reading volatile emissions, then presenting them to bumble bees in choice assays." Changes: This goal was written with the intention of collaborating with Dr. Kerry Mauck and using her lab's equipment and reagents. Due to the COVID-19 pandemic, labs were limited on the number of people allowed to work at any given time, and this displaced our collaborative work. However, instead we set up a large-scale field study addressing a similar issue as stated in goal #1: "Determine the effects of climate change on nectar-inhabiting microbes, using manipulative field experiments. In this experiment I will use passive heating devices to warm plants while allowing pollinators to visit and naturally occurring microbes to inhabit the nectar. This will allow the real time determination of the nectar-inhabiting microbial community on plants experiencing an increase in temperature." We were able to use a natural elevation gradient to compare nectar properties, nectar-inhabiting microbial communities, and pollinator visitation on plants subjected to different temperatures. We used a natural elevation gradient instead of the passive heating technique used in goal 2, in order to get a more representative temperature gradient. This experiment led to field realistic results that better address the question of how climate change will affect plants, pollinators, and their associated microbes. These results are detailed in the previous "Accomplishments" section. What opportunities for training and professional development has the project provided? This funding has allowed me to work one-on-one with the PM on the project on enhancing my skills in bioinformatics, statistics, and experimental design. All of these skills are necessary for achieving my ultimate career goal, a tenure-track teaching/research position at a university. I have also been able to take courses in GIS and statistical analysis using R. Other intended training activities were cancelled due to the COVID-19 Pandemic. How have the results been disseminated to communities of interest? The results of these projects have, so far, produced two academic papers (one accepted and one in review), with a third in preparation. The methods, results and overall background of this research has been presented at insect fairs and outreach events aimed at the general public. These events are aimed at K-12 students, their parents, and even community college students. In general, these events are geared to getting the general public excited about science, however, I have utilized this to teach people of the community about agriculture and pollination. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Pollinator populations are declining due to pesticide use, habitat loss, pathogen spread, and climate change. For the sake of global crop production and protection of ecosystem functions, high priority has been placed on the study of pollinator health and decline in the context of these four factors. I proposed here to understand the effects of climate change on plants, pollinators, and their associated microbes. Microbes (fungus and bacteria) play an important role in pollination because microbes can persist in nectar. Nectar, a sugar solution produced by flowers, is considered a main attractant for pollinators. Some microbes found in nectar have been associated with a positive response from insect pollinators. For example, bumble bees prefer nectar that has yeast in it (even if the yeast has consumed some of the nectar sugars), to nectar that is sterile and more sugar rich. I conducted a lab-based study and two field experiments to answer the question "How does climate change affect the tripartite interaction between plants, nectar-inhabiting microbes, and pollination success?" Overwhelmingly, I found that temperature does influence nectar-inhabiting microbial communities. Whether by allowing for faster growth of microbes in the warmer temperatures (and faster consumption of nectar sugars), or by completely killing off microbes in extreme heat waves, microbes are sensitive to environmental temperatures. I also am the first to find that nectar-inhabiting microbial communities correlate with pollinator communities in field realistic settings. These results indicate that climate change will affect pollinator visitation and pollination success in ways previously not considered. Objective #1 was completed within the first year of the project. Objective #2: There were some changes applied to this goal due to the COVID-19 pandemic. These changes have been detailed in the next "Changes/Problems" section. For this goal, I conducted a lab experiment looking at: The effect of temperature on microbial community of nectar. The interaction of nectar-inhabiting microbial and temperature on nectar sugars Pollinator preference I inoculated sterile lab-made nectar with the same wild nectar-inhabiting microbial community. I then grew this community up at two different temperatures: 27°C representing the average spring-time high in the area, and 32°C representing a climate change predicted temperature. I then characterized the microbial communities looking for any changes in the community between the two different temperature treatments. I also measured changes in nectar sugars and quantified bacterial cells in the nectar using quantitative PCR. This nectar was then offered to bumble bees as a choice assay. This preliminary data was presented in the proposal, but I was able to expand upon this project during the Pandemic. After the three-day incubation period, artificial nectar sugars were significantly reduced when microbes werepresent (Kruskal-Wallis chi-squared = 13.391; N = 50,p<0.0001).There was an interaction effect of temperature and treatment on fructose levels (F1,36=38.8, p<0.0001). There was more fructose in the in the 27°C compared to 32°C(Tukey HSD, p<0.0001), and significantly more in the sterile nectar compared to nectar with microbes (Tukey HSD, p<0.0001).When presented with the four nectar treatment choices,B. impatiensconsumed significantly more synthetic nectar inoculated with microbes (GLMM; t=6.854,df=207, p< 0.0001) and incubated at 27°C - the representative ambient temperature (GLMM; t=-4.190,df=207, p< 0.0001), than all other nectar choices.Across all samples, aFructobacillus(Leuconostocaceae) ASV was the most abundant bacterium and dominated the communities regardless of temperature treatment, with a significantly higher total abundance of bacteria in the temperature treatment of32°C compared to the 27°C treatment(t=-3.804, df=43.97, p < 0.0001). Temperature treatment affected overall microbial density within nectar which in turn, affected nectar sugar composition and ultimately pollinator preference. Nectar sugars decreased when microbes were present, but overall sugar levels by themselves did not explain bumble bee preference. Fructose levels were lowest with microbes present at the warmest temperature, which agrees with our microbial community data. Our synthetic nectar microbial communities were dominated byFructobacillus,and bacteria were more abundant in the warmer (32°C) incubation temperature.As its name implies,Fructobacillusis a fructophilic lactic acid bacteria that uses fructose as its main carbohydrate source, indicating that increasingFructobacillusabundance drives the decrease in fructose at the warmest temperature. A key outcome for this goal is a change of knowledge.Overall, our data indicate that the microbial community within nectar is important for pollinator choice and is mediated by abiotic factors such as temperature. As temperatures increases due to climate change, alterations to nectar microbiomes may have adverse effects on pollinator choice. Objective #3: There were some changes applied to this goal due to the COVID-19 pandemic. These changes have been detailed in the next "Changes/Problems" section. For this goal, I conducted a large-scale field experiment looking at: Effect of elevation (temperature) gradient on nectar-inhabiting microbial community How changes to the microbial community within nectar due to extreme temperatures affected pollinator visitation. For this experiment, plots ofPenstemon heterophylluswere set up along a 2000 m elevation gradient in the San Jacinto, California mountains. There were four sites at four different elevations each subjected to different temperatures in the area. Nectar was collected from each site weekly for 6 weeks and pollinators were observed, collected and identified twice a week from each site. Nectar-inhabiting microbial community was characterized for each site/time point, as were nectar sugars and nectar volume. There was a significant difference in alpha diversity of nectar microbial communities between elevations (Kruskal- Wallis χ2= 14.81,P= 0.005). Average weekly temperature affected microbial community beta-diversity (F1,287=11.22, R2=0.037, p=0.002). There was a significant interaction effect of pollinators by elevation and collection date (ANOVA: F2,30=84.88, P=0.002) andsignificant correlations between pollinator and nectar bacterial communities (r=0.06, P=0.004). Nectar-inhabiting microbial communities and nectar properties shifted along the elevational gradient, suggesting that elevated temperatures caused by climate change may influence the interplay between nectar sugar, volume, and microorganisms. Both elevation and weekly average temperatures affected nectar microbial communities, suggesting that optimal temperatures may govern microbial assembly within nectar.A key outcome for this goal is a change of knowledge.I also noted a correlation between pollinator and microbial communities along the elevational gradient. Pollinator identity and visitation rate drives assembly of nectar microbial communities,and to my knowledge these data are the first to show that pollinator and nectar microbial communities are correlated.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2021
Citation:
Russell, K.A., and McFrederick, Q.S. Climate change may affect nectar microbial abundance, nectar sugars, and bumble bee foraging preference. Accepted to Microbial Ecology
- Type:
Journal Articles
Status:
Under Review
Year Published:
2021
Citation:
Russell, K.A., and McFrederick, Q.S. Climate change is more likely to affect floral nectar microbial communities via extreme temperature events compared to background warming.
|
Progress 07/01/19 to 06/30/21
Outputs
Target Audience: Academic:The academic audience this work is targeted toranges from scientists interested broadly in insects and agriculture, to those specifically interested in pollination in agricultural systems and pollinator health. This work was presented at general entomology meetings as well as specific meetings focusing on polliantor health. Agricultural: These projects were intended to aid growers and bee keepers in understanding how polliantor health will be affected by the interaction of climate change and plant microbial communities.The results of this work were discussed at targeted bee keeping meetings which are attended by growers and honey and native bee keepers. General Public: The methods, results, and overall background of this research has been presented at a virtual insect fair and virtual outreach events. These events were mainly designed for K-12 students. In general, these events are geared toward getting the general public excited about science, however, I have utilized this to teach people of the community about agriculture, pollination, and microbiology. Changes/Problems:Due to the COVID-19 Pandemic, there were substantial changes to the methods in which I went about answering the same questions proposed in the initial proposal. Goal #2 stated: "Elucidate nectar chemistry shifts under temperature treatments-to understand if plants can mediate nectar colonization under climate change conditions. As temperatures change, plants rapidly respond in many ways including adjusting water content of nectar and altering nectar sugar concentrations. Comparing plants with sterile flowers to those with flowers inoculated with a microbial community will tease apart what impact nectar microbes have on plant nectar compared to how the plant alone alters nectar with climate change." Changes: This goal was written with the intention of using shared equipment in the department. I intended to use sterile growth chambers shared by many labs. However, due to the pandemic, it was no longer possible to use this equipment. Therefore, this experiment was slightly changed to consist of a more manipulative lab experiment. Here instead of using sterile plants, I used lab generated sterile nectar. The results of this study are detailed in the previous "Accomplishments" section and have been accepted for publication in Microbial Ecology. Goal #3 stated: "Characterize nectar-inhabiting microbes' volatile emissions and determine their attractiveness to pollinators. As microbes within nectar metabolize nectar resources, they can emit volatiles which can be detected in the floral headspace. I will characterize volatile emissions under climate change predicted conditions by incubating commonly found nectar microbes to different heat treatments and reading volatile emissions, then presenting them to bumble bees in choice assays." Changes: This goal was written with the intention of collaborating with Dr. Kerry Mauck and using her lab's equipment and reagents. Due to the COVID-19 pandemic, labs were limited on the number of people allowed to work at any given time, and this displaced our collaborative work. However, instead I set up a large-scale field study addressing a similar issue as stated in goal #1: "Determine the effects of climate change on nectar-inhabiting microbes, using manipulative field experiments. In this experiment I will use passive heating devices to warm plants while allowing pollinators to visit and naturally occurring microbes to inhabit the nectar. This will allow the real time determination of the nectar-inhabiting microbial community on plants experiencing an increase in temperature." I was able to use a natural elevation gradient to compare nectar properties, nectar-inhabiting microbial communities, and pollinator visitation on plants subjected to different temperatures. I used a natural elevation gradient instead of the passive heating technique used in goal 2, in order to get a more representative temperature gradient. This experiment led to field realistic results that better address the question of how climate change will affect plants, pollinators, and their associated microbes. These results are detailed in the previous "Accomplishments" section. What opportunities for training and professional development has the project provided? This funding has allowed me to work one-on-one with the PM on the project on enhancing my skills in bioinformatics, statistics, and experimental design. All of these skills are necessary for achieving my ultimate career goal, a tenure-track teaching/research position at a university. I have also been able to take courses in GIS and statistical analysis using R. Other intended training activities were cancelled due to the COVID-19 Pandemic. How have the results been disseminated to communities of interest? The results of this work have reached a broad target audience including academics, the general public, and growers. Academic presentation: The results of these projects have, so far, produced two academic papers (one accepted and one in review), with a third in preparation. They were presented at the Pacific Branch Entomological Society of America regional meeting in San Diego as a presentation in 2019. A further extension of these results was later presented at the International Pollinator Conference in UC Davis as a poster presentation. Lastly, at the end of 2019 and 2020results were presented at Annual Student Seminar Day at the University of California, Riverside, Entomology department.This audience of academics ranges from scientists interested broadly in insects and agriculture, to those specifically interested in pollination in agricultural systems and pollinator health. General Public: The methods, results and overall background of this research has been presented at insect fairs and outreach events aimed at the general public. These events are aimed at K-12 students, their parents, and even community college students. In general, these events are geared to getting the general public excited about science, however, I have utilized this to teach people of the community about agriculture and pollination. Growers: I was able to attend the Blue Orchard Bee conference at the University of California, Riverside. Although I did not present here, I did network with growers and share the results of this research. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Pollinator populations are declining due to pesticide use, habitat loss, pathogen spread, and climate change. For the sake of global crop production and protection of ecosystem functions, high priority has been placed on the study of pollinator health and decline in the context of these four factors. I proposed here to understand the effects of climate change on plants, pollinators, and their associated microbes. Microbes (fungus and bacteria) play an important role in pollination because microbes can persist in nectar. Nectar, a sugar solution produced by flowers, is considered a main attractant for pollinators. Some microbes found in nectar have been associated with a positive response from insect pollinators. For example, bumble bees prefer nectar that has yeast in it (even if the yeast has consumed some of the nectar sugars), to nectar that is sterile and more sugar rich. I conducted a lab-based study and two field experiments to answer the question "How does climate change affect the tripartite interaction between plants, nectar-inhabiting microbes, and pollination success?" Overwhelmingly, I found that temperature does influence nectar-inhabiting microbial communities. Whether by allowing for faster growth of microbes in the warmer temperatures (and faster consumption of nectar sugars), or by completely killing off microbes in extreme heat waves, microbes are sensitive to environmental temperatures. I also am the first to find that nectar-inhabiting microbial communities correlate with pollinator communities in field realistic settings. These results indicate that climate change will affect pollinator visitation and pollination success in ways previously not considered. Objective #1 was completed within the first year of the project. Objective #2: There were some changes applied to this goal due to the COVID-19 pandemic. These changes have been detailed in the next "Changes/Problems" section. For this goal, I conducted a lab experiment looking at: The effect of temperature on microbial community of nectar. The interaction of nectar-inhabiting microbial and temperature on nectar sugars Pollinator preference I inoculated sterile lab-made nectar with the same wild nectar-inhabiting microbial community. I then grew this community up at two different temperatures: 27°C representing the average spring-time high in the area, and 32°C representing a climate change predicted temperature. I then characterized the microbial communities looking for any changes in the community between the two different temperature treatments. I also measured changes in nectar sugars and quantified bacterial cells in the nectar using quantitative PCR. This nectar was then offered to bumble bees as a choice assay. This preliminary data was presented in the proposal, but I was able to expand upon this project during the Pandemic. After the three-day incubation period, artificial nectar sugars were significantly reduced when microbes werepresent (Kruskal-Wallis chi-squared = 13.391; N = 50,p<0.0001).There was an interaction effect of temperature and treatment on fructose levels (F1,36=38.8, p<0.0001). There was more fructose in the in the 27°C compared to 32°C(Tukey HSD, p<0.0001), and significantly more in the sterile nectar compared to nectar with microbes (Tukey HSD, p<0.0001).When presented with the four nectar treatment choices,B. impatiensconsumed significantly more synthetic nectar inoculated with microbes (GLMM; t=6.854,df=207, p< 0.0001) and incubated at 27°C - the representative ambient temperature (GLMM; t=-4.190,df=207, p< 0.0001), than all other nectar choices.Across all samples, aFructobacillus(Leuconostocaceae) ASV was the most abundant bacterium and dominated the communities regardless of temperature treatment, with a significantly higher total abundance of bacteria in the temperature treatment of32°C compared to the 27°C treatment(t=-3.804, df=43.97, p < 0.0001). Temperature treatment affected overall microbial density within nectar which in turn, affected nectar sugar composition and ultimately pollinator preference. Nectar sugars decreased when microbes were present, but overall sugar levels by themselves did not explain bumble bee preference. Fructose levels were lowest with microbes present at the warmest temperature, which agrees with our microbial community data. Our synthetic nectar microbial communities were dominated byFructobacillus,and bacteria were more abundant in the warmer (32°C) incubation temperature.As its name implies,Fructobacillusis a fructophilic lactic acid bacteria that uses fructose as its main carbohydrate source, indicating that increasingFructobacillusabundance drives the decrease in fructose at the warmest temperature. A key outcome for this goal is a change of knowledge.Overall, our data indicate that the microbial community within nectar is important for pollinator choice and is mediated by abiotic factors such as temperature. As temperatures increases due to climate change, alterations to nectar microbiomes may have adverse effects on pollinator choice. Objective #3: There were some changes applied to this goal due to the COVID-19 pandemic. These changes have been detailed in the next "Changes/Problems" section. For this goal, I conducted a large-scale field experiment looking at: Effect of elevation (temperature) gradient on nectar-inhabiting microbial community How changes to the microbial community within nectar due to extreme temperatures affected pollinator visitation. For this experiment, plots ofPenstemon heterophylluswere set up along a 2000 m elevation gradient in the San Jacinto, California mountains. There were four sites at four different elevations each subjected to different temperatures in the area. Nectar was collected from each site weekly for 6 weeks and pollinators were observed, collected and identified twice a week from each site. Nectar-inhabiting microbial community was characterized for each site/time point, as were nectar sugars and nectar volume. There was a significant difference in alpha diversity of nectar microbial communities between elevations (Kruskal- Wallis χ2= 14.81,P= 0.005). Average weekly temperature affected microbial community beta-diversity (F1,287=11.22, R2=0.037, p=0.002). There was a significant interaction effect of pollinators by elevation and collection date (ANOVA: F2,30=84.88, P=0.002) andsignificant correlations between pollinator and nectar bacterial communities (r=0.06, P=0.004). Nectar-inhabiting microbial communities and nectar properties shifted along the elevational gradient, suggesting that elevated temperatures caused by climate change may influence the interplay between nectar sugar, volume, and microorganisms. Both elevation and weekly average temperatures affected nectar microbial communities, suggesting that optimal temperatures may govern microbial assembly within nectar.A key outcome for this goal is a change of knowledge.I also noted a correlation between pollinator and microbial communities along the elevational gradient. Pollinator identity and visitation rate drives assembly of nectar microbial communities,and to my knowledge these data are the first to show that pollinator and nectar microbial communities are correlated.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2021
Citation:
Russell, K.A., and McFrederick, Q.S. Climate change may affect nectar microbial abundance, nectar sugars, and bumble bee foraging preference. Accepted to Microbial Ecology
- Type:
Journal Articles
Status:
Under Review
Year Published:
2021
Citation:
Russell, K.A., and McFrederick, Q.S. Climate change is more likely to affect floral nectar microbial communities via extreme temperature events compared to background warming.
|
Progress 07/01/19 to 06/30/20
Outputs
Target Audience:The results of this work have reached a broad target audience including academics, the general public, and growers. Academic presentation: The results of this research were presented at the Pacific Branch Entomological Society of America regional meeting in San Diego as a presentation in 2019. A further extension of these results was later presented at the International Pollinator Conference in UC Davis as a poster presentation. Lastly, at the end of 2019 results were presented at Annual Student Seminar Day at the University of California, Riverside, Entomology department. This audience of academics ranges from scientists interested broadly in insects and agriculture, to those specifically interested in pollination in agricultural systems and pollinator health. General Public: The methods, results and overall background of this research has been presented at insect fairs and outreach events aimed at the general public. These events are aimed at K-12 students, their parents, and even community college students. In general, these events are geared to getting the general public excited about science, however, I have utilized this to teach people of the community about agriculture and pollination. Growers: I was able to attend the Blue Orchard Bee conference at the University of California, Riverside. Although I did not present here, I did network with growers and share the results of this research. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Training activities- This funding has allowed me to work one-on-one with the PM on the project on enhancing my skills in bioinformatics, statistics, and experimental design. All of these skills are necessary for achieving my ultimate career goal, a tenure-track teaching/research position at a university. I have also been able to take courses in GIS and statistical analysis using R. Along with these technical skills I have been able to learn with this funding, I was also able to attend The Bee Course, put on by the American Museum of Natural History in association with the Southwestern Research Station in Portal, Arizona. This is a competitive course, which teaches proper bee collection, curation, and identification techniques. Professional development - This funding has given me the opportunity to attend 4 conferences and even organize a symposium. The results of this research were presented at the Pacific Branch Entomological Society of America regional meeting in San Diego as a presentation in 2019 in the symposium I organized called "Working out the Bugs:Multidisciplinary Approaches to Unraveling Insect-Microbe Symbioses". A further extension of these results was later presented at the International Pollinator Conference in UC Davis and the Annual Student Seminar Day at the University of California, Riverside, Entomology department. I was also able to attend the Blue Orchard Bee Association annual conference and network with growers interested in this research. How have the results been disseminated to communities of interest?The results of this research were presented at the Pacific Branch Entomological Society of America regional meeting in San Diego as a presentation in 2019. A further extension of these results was later presented at the International Pollinator Conference in UC Davis as a poster presentation. Lastly, at the end of 2019 results were presented at Annual Student Seminar Day at the University of California, Riverside, Entomology department.I was also able to attend the Blue Orchard Bee conference at the University of California, Riverside. Although I did not present here, I did network with growers and share the results of this research. This audience of these academics seminars/conferensesranges from scientists interested broadly in insects and agriculture, to those specifically interested in pollination in agricultural systems and pollinator health, as well as growers. The methods, results and overall background of this research has been presented at insect fairs and outreach events aimed at the general public. These events are aimed at K-12 students, their parents, and even community college students. In general, these events are geared to getting the general public excited about science, however, I have utilized this to teach people of the community about agriculture and pollination. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Pollinator populations are declining due to pesticide use, habitat loss, pathogen spread, and climate change. For the sake of global crop production and protection of ecosystem functions, high priority has been placed on the study of pollinator health and decline in the context of these four factors. I proposed her to understand the effects of climate change on plants, pollinators, and their associated microbes. Microbes (fungus and bacteria) play an important role in pollination because microbes can persist in nectar. Nectar is considered the main attractant plants use to bring in pollinators for propagation. Some microbes found in nectar have been associated with a positive response from bees. For example, bumble bees prefer nectar that has yeast in it (even if the yeast has consumed some of the nectar sugars), to nectar that is sterile and more sugar rich. I conducted a field study where I artificially heated plants in the field. I found that pollinators preferred non-heated plants and that increases in temperature affect the nectar sugars and the microbes living in the nectar. Mainly, an intense heatwave will select for heat tolerant microbes in the nectar. This is important as the Earth continues to experience increases in global temperature. If we can predict how these increases in temperature will negatively affect pollinator populations, we can potentially mitigate these responses and protect the pollinators. Objective 1 Determine the effects of climate change on nectar-inhabiting microbes, using manipulative field experiments. In this experiment I will use passive heating devices to warm plants while allowing pollinators to visit and naturally occurring microbes to inhabit the nectar. This will allow the real time determination of the nectar-inhabiting microbial community on plants experiencing an increase in temperature. This objective has been completed and the manuscript for this project is in preparation. A manipulative field experiment was set up at the Agricultural Operations on the University of California, Riverside's campus. This plot consisted of Penstemon plants being subjected to heated plexiglass treatments or control treatments to artificially increase heat on some plants compared to others. Nectar was collected from these plants and pollinator visitation was recorded. Nectar sugar concentrations were recorded, then DNA was extracted from each nectar sample. This DNA was sequenced for microbial strains. The microbial DNA extracted from these samples was minute and needed a new protocol than that previously established in the lab. I was ableto extract this DNA using a modified phenol/chloroform method which has now been disseminated to all lab mates to increase the knowledge of novel protocols in the field. The results of this study have shown that increases in temperature do effect nectar-inhabiting microbial as well as sugar concentrations. An interesting result was due to an unexpected heatwave in the area of the experiment. In the middle of the nectar collections, average daily highs increased about 15°F. This rapid increase in temperature selected for heat tolerant microbes in the nectar. As temperatures leveled out, a new microbial community established in the nectar, different from the original communities. To date, research in this area has stated that priority effects take place in these nectar-inhabiting microbial communities. We are the first to show drastic increases in temperature will disrupt this priority effect and shift community structure. *Due to the effects of COVID-19 the goals for Objectives 2-3 have been slowed as there is no/limited access to on-campus laboratory settings.
Publications
|