Lennon Lab
Microbial Biodiversity


Research Projects

Microbial seed banks

In nature, most individuals live in unpredictable environments and experience conditions that are suboptimal for growth and reproduction. When faced with biotic or abiotic stress, many organisms hedge their bets by entering a reversible state of reduced metabolic activity, or dormancy. Transitions into dormancy create a "seed bank" that represents a reservoir of taxonomic, genetic, and functional biodiversity. We use simulation modeling and molecular tools to better understand how dormancy and environmental cues structure microbial communities in natural, engineered, and host-associated ecosystems.

Eco-evolutionary dynamics

Microbes are critical components of ecosystem structure and function. However, ecosystem processes can be rapidly altered by the underlying evolutionary forces that structure microbial populations. The effects of such dynamics can be detected across biological scales, from molecules (e.g. nucleotide substitution rates) to ecosystem processes (e.g. predator-prey dynamics and resource utilization). In our laboratory, we use a combination of experimental manipulation and an "-omics" driven systems approach to study the eco-evolutionary feedbacks of starvation, stoichiometry, and seed banks on microbial populations and communities.

Microbial community ecology and biodiversity

The last decade has revolutionized the way we study microbial diversity. However, the mechanisms and processes by which microbial communities are structured remain poorly resolved. We investigate microbial community responses (e.g., community composition, biodiversity patterns, function, stability) along environmental gradients (e.g., resources, moisture, and connectivity), to understand the importance of constraints, such as ecosystem residence time, in structuring natural, managed, and host-related microbial communities using lab- and field-based experiments alongside ecological theory, individual-based modeling, and macroecological analyses of global-scale data sets.

Ecosystem processes

Microorganisms regulate the flow of energy and materials in natural and managed ecosystems. For example, microbes alter the concentration and composition of resources (e.g., carbon) in ways that influence food webs and the physical environment (e.g., lakes, soils, caves). In our laboratory, we address questions related to ecosystem processes at scales from individual-level variation in physiology to ecosystem fluxes at the landscape. To address these issues, our work integrates molecular and biogeochemical techniques ranging from laboratory investigation and comparative surveys to whole-ecosystem manipulations.

Microbial traits

Traits refer to the physiological, morphological, and behavioral characteristics of individuals. Over the past decade, plant and animal ecologists have made major advances in understanding patterns of biodiversity by exploring functional traits. Although traits have historically been difficult to study for microbes, our lab has been using a combination of culture-dependent and culture-independent (e.g., sequencing and flow cytometry) approaches to understand how contemporary and deeply conserved traits evolve, shift along environmental gradients, structure communities, and influence ecosystem processes.