NSF PRFB FY23: Temperature effects on community assembly: a case study in nectar microbes of a western north American native plant

Mcguire, Rosa M, Los Angeles CA

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment, and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. Despite the threat of climate change, the effects of temperature on major ecological processes are still not well understood. Community assembly is a process in which biotic and abiotic factors interact, giving rise to the group of species that make up a community. This research aims to understand the link between temperature and community assembly. The project will combine experimental and theoretical methods. The model system consists of the native North American plant Pedicularis densiflora and its nectar microbes. Flowers and their nectar begin as a sterile environment. Over time, microorganisms arrive, transported by pollinators like insects and birds. The first goal of this project is to measure the temperature responses of nectar microbes. Then, community assembly in the laboratory and the field will be studied. The project will also develop new theory for the effects of temperature on community assembly. The temperature responses of life history traits are conserved among many life forms. Therefore, studies on nectar microbes can provide insights about the effects of climate change in other communities. Nectar microbe communities consist of a small set of bacteria and yeast species. They can be cultured, and their populations quantified in laboratory settings. This makes them an ideal system to disentangle the effects of climate change on community assembly. The project will first measure thermal reaction norms of growth rate. Growth rate will be quantified in terms of death and birth with the goal of building a parameterized model for each species. The second phase of this project involves studying the outcomes of assembly by building experimental communities in the lab and in the field subject to different temperature regimes. The experimental data will be used to calculate interaction strengths between species and build a theoretical model for community assembly that incorporates temperature. Finally, the consequences of different nectar communities on pollination preference and fecundity of P. densiflora will be studied. The fellow will gain expertise in bacterial methods, molecular techniques, and mathematical modeling. Broader impacts of this project include facilitating research experiences for undergraduates and developing workshops on the use of simulations in R to learn ecological models. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.