A BOLD CHALLENGE - ASSESSING WILD BEE OCCURRENCE IN FORESTS THAT DIFFERED IN STAND AGE AND FIRE SEVERITY AT LARGE SPATIAL SCALES.

Katie M Moriarty; Senior Research Scientist; kmoriarty@ncasi.org; Lincoln Best, Jesse Fan Brown, Rose McDonald, Felix Bruner, Rebecca Hayes, Leithen M’Gonigle, Hanna Jackson, Lauren Ponisio

Bees provide pollination services that influence floral diversity, abundance, and overall ecosystem productivity. Although research exists in agriculture or urban areas, few studies have investigated diversity and abundance of bees in conifer forests of the Pacific Northwest. We present preliminary results from three studies focused on bee occurrence in both forested systems and recently burned fires, explore predictions related to distribution, and highlight opportunities to enhance managed or burned landscapes. We surveyed 202 stands (2020-2023), hand-netting or passive trapping (3-6 occasions/year, >2 years). For bees netted by hand, we recorded the flower the bee was pollinating and followed netting protocols suitable for lab-based pathogen identification and DNA metabarcoding of pollen. We collected and identified ~100,000 bees to species. In the coast range, bee abundance and richness increased in stands where forest canopy had recently been removed through thinning or cut forests. In burned forest, floral richness and diversity decreased with severity. Bee richness and abundance increased with increasing floral resources. Preliminarily, native floral enhancements were effective in burned slash piles and increased bumble bee abundance and diversity. Our data, combined with ongoing efforts by the Oregon Bee Atlas, can help inform elusive bee distributions, floral associations, and restoration actions.

Natural History of Invertebrates