Current Appointments & Affiliations
Professor of Biology
·
2015 - Present
Biology,
Trinity College of Arts & Sciences
Recent Publications
Nitrogen fixation in Arctic lichens and mosses: A survey across circumpolar subzones.
Journal Article The Science of the total environment · October 2025 Nitrogen bioavailability frequently constrains primary production in the Arctic with tundra communities vulnerable to ecological and metabolic disruption from climate variability. Diazotrophs associated with lichens and mosses are the primary source of new ... Full text CiteRapid Radiations Outweigh Reticulations During the Evolution of a 750-Million-Year-Old Lineage of Cyanobacteria.
Journal Article Molecular biology and evolution · October 2025 Species are a fundamental unit of biodiversity. Yet, the existence of clear species boundaries among bacteria has long been a subject of debate. Here, we studied species boundaries in the context of the phylogenetic history of Nostoc, a widespread genus of ... Full text CitePeltigera lichen thalli produce highly potent ice-nucleating agents
Journal Article Biogeosciences · April 29, 2025 From extracellular freezing to cloud glaciation, the crystallization of water is ubiquitous and shapes life as we know it. Efficient biological ice nucleators (INs) are crucial for organism survival in cold environments and, when aerosolized, serve as a si ... Full text CiteRecent Grants
Collaborative Research: Leveraging historical collections and new surveys to characterize foundational shifts in vital symbioses in the threatened Arctic
ResearchPrincipal Investigator · Awarded by National Science Foundation · 2020 - 2026Digitization TCN: Collaborative Research: Building a global consortium of bryophytes and lichens: keystones of cryptobiotic communities
ResearchCo-Principal Investigator · Awarded by National Science Foundation · 2020 - 2025Spatio-temporal factors shaping symbiotic networks: a case study with cyanolichens
ResearchPrincipal Investigator · Awarded by National Science Foundation · 2019 - 2024View All Grants
Education, Training & Certifications
Duke University ·
1995
Ph.D.
Ottawa University ·
1990
M.S.
Grinnell College ·
1987
B.S.