Researchers seek to address how changing climate alters community composition via weakened priority effects by studying the temporal variation in microbial communities of sticky monkeyflower (Diplacus aurantiacus).

Priority effects are an important process that dictates the composition of ecological communities, where early arriving species outcompete late-arriving ones. One well-known system in which to study community assembly are nectar-inhabiting microbes. Perturbations in climate can alter the interactions between nectar microbes, as the strength of priority effects can be influenced by environmental variation. As a result, climate change can affect nectar composition and subsequently interactions with other species, like pollinators that benefit from said nectar. Individual species' growth rates may be affected by temperature and in turn affect dynamics in community assembly.

Rosa and her team are focusing on the interaction between yeast, bacteria, and temperature by inoculating flowers of sticky monkeyflower (Diplacus aurantiacus) with varying concentrations of competing species. Plants span a wide diversity of microclimates and environmental conditions within the preserve. For example, plants located at the top of the ridge are expected to experience warmer, drier conditions compared with plants located alongside Searsville Reservoir. To account for microclimatic variation, a temperature logger is located next to each experimental plant to record ambient temperature over the course of the experiment. Once inoculated, the flowers are harvested and transported to the lab to measure pH and nectar volume and to harvest nectar for identification of nectar microbes using tools such as genetic sequencing and other lab protocols established in the Fukami lab. As of spring 2025, this project is now in its second iteration of experimental manipulations.