Ben Pecci
Research Mentor: Alain Isabwe
Mentor Department: Environmental Science, Not Available
Author(s): Ben Pecci, Alain Isabwe, PhD
Session: Session 1 (9:00 AM – 9:50 AM)
Presentation Type: Poster 54
Abstract
Freshwater microbial communities can exhibit strong biogeographic structure, but it
remains unclear whether functional guilds follow the same latitudinal patterns as
taxonomic diversity. Using 18S rRNA metabarcoding datasets from subtropical,
temperate, and Arctic/subarctic lakes, we assigned amplicon sequence variants (ASVs)
to ecological guilds using curated FAMITAX database annotations and compared
functional composition across latitude. Although taxonomic richness increased toward
higher latitudes, functional guilds did not follow this trend. Instead, guild structure
differed sharply among zones: Arctic and temperate lakes were dominated by
autotrophic and phagotrophic guilds, while subtropical lakes showed reduced functional
diversity and a higher proportion of unassigned or stress‑tolerant guilds. These
contrasting patterns indicate that functional and taxonomic diversity are decoupled
across latitude, suggesting that environmental filtering and ecosystem characteristics
shape functional roles independently of richness. Our findings highlight the importance
of integrating functional perspectives when evaluating large‑scale ecological patterns.
