Recipient Organization
NORTH CAROLINA STATE UNIV
(N/A)
RALEIGH,NC 27695
Performing Department
Applied Ecology
Non Technical Summary
Pollinators play key roles in maintaining the diversity and health of native and managed ecosystems. The majority of flowering plants, including wild and agricultural plants, rely on insects (especially bees) and other animals for pollination, making it an important ecosystem service, and pollination by native bees alone provides billions annually in agricultural and forestry-related products. Moreover, plant-pollinator interactions provide some of the best-known examples of mutualisms and exploitation, and evolutionary and co-evolutionary relationships, and bees in particular have been model organisms in the study of optimal foraging theory, competitive displacement, and thermoregulation. Growing concerns about declines in the abundance and diversity of bees worldwide may have alarming consequences on the ecosystem services they provide. In my research, I combine concepts and techniques from studies of plant-pollinator and plant-herbivore interactions to understand the ecological and evolutionary consequences of pollination mutualisms and how they will respond to environmental change. More broadly, I am interested in how biological communities affect ecological and microevolutionary patterns, processes, and services, and how microevolution can in turn shape and constrain biodiversity and species interactions. I use a diversity of approaches in my work, including biodiversity surveys, observations and experiments in the field, and simple models, and I collaborate not only with other ecologists and evolutionary biologists both also with economists and natural product chemists to study and develop sustainable solutions to environmental challenges.
Animal Health Component
40%
Research Effort Categories
Basic
60%
Applied
40%
Developmental
0%
Goals / Objectives
The major goals of my research are to:1) Explore how major drivers of global environmental change, including urbanization, invasive species, and climate change, affect pollinator biodiversity, plant-pollinator interactions, and plant and pollinator health.2) Test how secondary metabolites naturally produced by plants affect pollinator health through changes in their interactions with pollinator parasites with implications for pollination in agricultural systems.3) Investigate how pollen species identity affects bee health and disease and the mechanisms involved.4) Explore the importance of landscape context and pollination mutualisms in the reproduction of rare North Carolina plants.Finally, as part of this 5-year plan, I will also write up results from prior research from goals 1-4, continue mentoring students, and also write up results from research exploring the behavioral ecology of larcenous bee behaviors.
Project Methods
In all areas of science in my lab, we develop hypotheses a priori and then test those hypotheses using observations, experiments and/or models. Goal 1) Explore how major drivers of global environmental change, including urbanization, invasive species, and climate change, affect pollinator biodiversity, plant-pollinator interactions, and plant and pollinator health? Our major methods involve surveying habitats for bee biodiversity every two weeks throughout the activity season. We sample using pan traps and netting. Bees are then pinned, databased, and identified to species or morphospecies. We quantify land-use change around sites using GIS. We measure plant-pollinator interactions using observations of these interactions at flowers. Pollination limitation is assessed through experimental hand-pollinations of focal plant species. Pollinator abundance is estimated using catch rates. We also manipulate drivers of global environmental change using small-scale experiments, such as removals of invasive species or snow removals to simulate early snow-melt timing under climate-change scenarios. We then measure subsequent plant-pollinator interactions and plant reproduction. We estimate plant reproduction by counting fruits and seeds. The climate change research is funded by a current grant from the National Science Foundation. Goal 2) Test how secondary metabolites naturally produced by plants affect pollinator health through changes in their interactions with pollinator parasites with implications for pollination in agricultural systems.We are studying the common eastern bumble bee, Bombus impatiens, and its gut parasite Crithidia bombi. We can experimentally infect bumble bees in the lab and use laboratory experiments to test the benefits of nectar and pollen secondary metabolites on parasite loads vs. the direct consumptive costs on bee performance. We do so using microcolonies of queenless workers. We are also testing whether bees self-medicate on nectar secondary metabolites when they are parasitized using flight cage experiments in the lab as well as observations of wild-flying bees in the field. We are testing how parasitized bees affect pollination services using field experiments. Are also exploring various aspect of host-parasite ecology and interspecific host switches using a trait-based approach. This work is currently funded by the National Institutes of Health.3) Investigate how pollen species identity affects bee health and disease and the mechanisms involved.We are again studying the common eastern bumble bee, Bombus impatiens, and its gut parasite Crithidia bombi. We have discovered that sunflower pollen (Helianthus annuus) dramatically reduces the prevalence and intensity of infection in bees. We are scaling this work up to whole-colony manipulations exploring how supplementing colonies with sunflower mixed with wildflower pollen affects colony level disease and health in laboratory and field settings. We are also using manipulative experiments to discover the mechanism(s) by which sunflower pollen affects bee disease. These include mechanisms associated with pollen chemistry, nutrition, and morphology, and interactions between pollen and host, including host physiology, the immune system, and the microbiome. Using pollen collections informed by the Asteraceae phylogeny and pollen morphology in other plant families, we are using experimental manipulations to understand how widespread this medicinal effect is. This work could open up new avenues for managing bee disease and health in commercial rearing facilities and field settings. This work is funded by two grants from the USDA. In the "Proposal" section of this Hatch submission, I uploaded one of the funded USDA proposals to provide an example of the research we conduct and a detailed description of our methodology associated with bee health. The uploaded proposal only covers a portion of this research objective. The uploaded proposal involves myself (Rebecca Irwin) as PD, Dr. Lynn Adler of UMass-Amherst as co-PD, and Dr. Quinn McFrederick of University of California-Riverside as co-PD.4) Explore the importance of landscape context and pollination mutualisms in the reproduction of rare North Carolina plants.We are studying the pollination biology of rare North Carolina plants, including Venus Flytrap and Smooth Purple Coneflower. We are using experimental hand-pollinations to explore plant mating system and pollen limitation. We are using pollinator observations and insect identification to understand the most common pollinators and pollinator effectiveness. For Smooth Purple Coneflower, we are using a habitat manipulation to understand how forestry practices and fire affect insect communities, pollination success and plant reproduction. This work is funded by a NCSU CALS Dean's Enrichment Stakeholder Collaborative Grant.In all of this research, we use standard statistical analyses for hypothesis testing using SAS, JMP, and/or R statistical software.