Gene flow in Uroctonus mordax and potential impacts of high-intensity, high-acreage wildfires on population dynamics

Wednesday, November 16, 2022

10:36 AM – 10:49 AM PT

Location: Vancouver Convention Centre, Meeting Room 109

Presenting Author(s)

Jacob A. Gorneau

Graduate Student
California Academy of Sciences
San Francisco, California

Co-author(s)

ES

Eric O. Stiner

California Academy of Sciences
San Francisco, California
PK

Pooneh Kalhori

California Academy of Sciences
San Francisco, California
Katherine O. Montana

Graduate Student
California Academy of Sciences
San Francisco, California
DP

Diana Phan

California Academy of Sciences
San Francisco, California
RQ

Rachel Quock

California Academy of Sciences
San Francisco, California

Co-Author(s)

LE

Lauren A. Esposito

California Academy of Sciences
Oakland, California

The Western forest scorpion (Uroctonus mordax) is a moisture-sensitive microhabitat specialist found in forested regions along the Cascade, Coast Ranges, and the Sierra Nevada in the western United States. Previous work employing RADSeq SNP data discovered a deep divergence among northern (Washington, Oregon, parts of northern California) and southern (California) clades, as well as distinct population structuring within these two clades. In the years since this study has been published, some of the most intense wildfires in the history of California have occurred in areas overlapping with the range of U. mordax. Understanding the potential effects of severe wildfires may improve our ability to proactively manage regions of high diversity or preserve unique populations. We conducted an initial analysis examining barriers to gene flow and potential corridors using the estimated effective migration surfaces (EEMS) analysis and visually compared this with recent wildfire history prior to the sampling dates of this study as a baseline. We then used three isolation by resistance models on simulated post-fire molecular data to examine the explanatory power of landscape variables on the genetic variation present in this species. These data show the Cascades, Coast Ranges, and the Sierra Nevada to be barriers to gene flow and the valleys of these ranges to be corridors to gene flow. Our initial analysis and landscape genetic simulations provide a baseline evaluation and example data against which we can test future evidence to examine the effects of wildfire on the survival and population health of this iconic woodland species.