A recent study suggested that 22.6% of the best-studied pollinator groups are at an elevated extinction risk, with bees and a substantial number of butterflies and moths being the most at risk (1). One of the largest drivers of this decline is the loss and degradation of habitat. With growing concerns about declines in insect biodiversity, habitat restoration and reconstruction are one way to add additional floral resources and nesting sites to the landscape.
This trend can be seen in Iowa, with tallgrass prairies being planted across the state to restore native plant diversity and provide essential nectar resources for pollinators. However, diversity for some groups of pollinators remains higher in remnants, prairies that have never been plowed, compared to reconstructions.
New research suggests that there are several differences between prairie reconstructions and remnants, including microbial communities (2). Indeed, it has been established that microbes can significantly affect plant health and alter nectar rewards and scent, potentially influencing insect health and behavior (3). With this in mind, the Kral-O’Brien and Crowley-Gall Labs set out to understand potential floral microbial differences between remnant and reconstructed prairies.
Emma Donahey, a monarch intern for the Iowa Monarch Conservation Consortium, collected floral samples from five remnant prairies and three reconstructed prairies across central Iowa. All flowers sampled were chosen due to their high prevalence in Midwest prairies and their association with bees and butterflies.
Throughout the past year, Donahey created stock solutions for each microbial isolate and then, using PCR and Sanger sequencing, was able to identify 55 distinct microbes found across the sites. Preliminary results show that reconstructions tended to have greater total microbial diversity and richness compared to remnants. Interestingly, there was more variation in the microbial community compositions between the remnant sites, whereas the reconstructed prairies had a more uniform microbial community between sites.
The Crowley-Gall lab is currently working on submitting floral microbial samples for Illumina sequencing, which will provide additional insight into the microbial community makeup of the two site types. The isolates collected during the Summer of 2026 have all been stored and will later be utilized to test how environmental microbes may impact insect health and behavior.
This summer, the monarch interns, the Kral-O’Brien, and Crowley-Gall labs will be completing an additional round of floral sampling with two more added sites to further build the isolate library and better characterize the differences between remnants and reconstructed prairies. With a growing understanding of the role of microbes in insect-floral interactions, it is essential to assess their function in critical habitats for pollinator conservation.
References:
- T. Cornelisse,D.W. et al, Elevated extinction risk in over one-fifth of native North American pollinators, Proc. Natl. Acad. Sci. U.S.A. 122 (14) e2418742122, https://doi.org/10.1073/pnas.2418742122 (2025).
- Ramakrishnan, D.K., Jauernegger, F., Hoefle, D. et al. Unravelling the microbiome of wild flowering plants: a comparative study of leaves and flowers in alpine ecosystems. BMC Microbiol 24, 417 (2024). https://doi.org/10.1186/s12866-024-03574-0
- Rachel L. Vannette. 2020. The Floral Microbiome: Plant, Pollinator, and Microbial Perspectives. Annual Review Ecology, Evolution, and Systematics. 51:363-386. https://doi.org/10.1146/annurev-ecolsys-011720-013401
Photo credits:
- Katherine Kral-O'Brien
- Katherine Kral-O'Brien
- Emma Donahey
- Emma Donahey