Ecologists continue to find innovative uses for natural history collections. Jasper Ridge houses over 5,300 collections of dried, pressed plants collected in or around the preserve, in the Oakmead Herbarium, and this research team will leverage these and other natural history collections. Researchers aim to quantify the variation of nectar microbial communities in sticky monkeyflowers, Diplacus aurantiacus, across space and time.

They will combine microbial DNA recovered from crystallized nectar of herbarium specimens with standardized field collections of fresh nectar to investigate the following:

1. Do nectar microbial communities (yeast or bacteria) cluster by space, time, or both?
2. Has microbial alpha diversity (richness) changed through time, and does this change differ for yeasts vs bacteria?
3. What are the predictors of microbe compositional beta diversity? (e.g. climate, land use, pollinator community, geographic distance)

Plants and herbarium collections will be sampled from the full latitudinal range of D. aurantiacus in California, and herbarium specimens as far back as 1950 will be sampled. By integrating historical herbarium specimens with fresh field sampling, researchers will develop a reproducible methodological framework for retrospective nectar microbiome analyses alongside a California statewide assessment of how environmental change has altered plant–pollinator–microbe interactions in D. aurantiacus. Read more about how Herbaria unlock tripartite pollination responses to anthropogenic change in this publication by Puleo, Fukami, Daru (2026).

This project is funded by an AW Mellon grant for student research.