Fig. 1 — Two species of duckweeds, Lemna minor (L) and Spirodela polyrhiza (R) share similar habitats, yet their different overwintering strategies and temperature optima allow them to coexist.

Fig. 1 — Two species of duckweeds, Lemna minor (L) and Spirodela polyrhiza (R) share similar habitats, yet their different overwintering strategies and temperature optima allow them to coexist.

Fig. 2 —  The coexistence of two species of duckweed appears to be due to a combination of relative differences in their thermal response curves (serving to equalize long-term average fitnesses), and stabilization from the effects of both dormant life history stages (fluctuation-dependent) and negative frequency-dependent growth (fluctuation-independent).

Fig. 2 —  The coexistence of two species of duckweed appears to be due to a combination of relative differences in their thermal response curves (serving to equalize long-term average fitnesses), and stabilization from the effects of both dormant life history stages (fluctuation-dependent) and negative frequency-dependent growth (fluctuation-independent).

Experimental approaches to coexistence & succession

For my postdoctoral research, I am using both aquatic duckweed plants (Lemnaceae) and environmental bacterial isolates to experimentally quantify the importance of various coexistence mechanisms. For instance, I study how dormant life stages (e.g., spores, seeds, turions) allow organisms to persist in fluctuating environments via the storage effect and relative nonlinearities. This work is important for our understanding of communities' responses to environmental perturbations.

Fig. 3 — Bacterial isolates can be evolved to express biomarkers (e.g., antibiotic resistance) for the purposes of tracking low-abundance individual cell lines in mixed cultures.

Fig. 3 — Bacterial isolates can be evolved to express biomarkers (e.g., antibiotic resistance) for the purposes of tracking low-abundance individual cell lines in mixed cultures.