Ecosystem-scale biodiversity monitoring across California

Sierra Nevada

How do disturbances like fire, forest restoration and fuels management, and drought-induced tree mortality affect biodiversity? What environmental features (and at what spatial scales) determine the spatial structuring of biodiversity? What are the population trends of key focal species across their range? These questions are now within reach!

The Sierra Nevada monitoring effort began with a two-species focus: understand the ongoing Barred Owl invasion to conserve the California Spotted Owl (read more here). Yet the advent of the BirdNET algorithm has opened up research possibilities for much of the rest of the Sierra Nevada bird community. Initial work focused on additional focal species, such as conducting the first study of Mountain Quail in over 30 years, and numerous studies of the Hermit Warbler, Clark’s Nutcracker, and Olive-sided Flycatcher.

Movement toward community-level projects began with a Before/After – Control/Impact study of how 67 species respond to a recent megafire (2020 North Complex Fire).

We have also used the community-level data to build a decision support tool for the US Forest Service in collaboration with the University of Washington with funding from NASA. FACET (Forest-Avian Communities Evaluation Tool) is freely available here; a screenshot is below.

Survey coverage in 2021

Southern California

Biodiversity in the steep, arid mountains of Southern California is highly structured: there are distinct plant and animal communities in the upland forests and narrow riparian corridors. We are developing monitoring efforts in both ecotypes to support conservation efforts for a range of at-risk bird species.

In montane forests, understanding the distribution of the Spotted Owl is a top priority. The Southern California-Coastal population segment of the California Spotted Owl is likely to be listed as Endangered under the Endangered Species Act, based in part on findings that one of the presumed strongholds of this population has declined by over 50% over the last 30 years. Little is known about the owl outside of several long-term monitoring areas, which challenges both owl conservation and the implementation of urgently needed forest restoration to reduce the risk of large, severe fires.

Riparian areas in Southern California are under immense pressure from climate change (drought), fire, invasive species, and the needs of the massive population of greater Los Angeles. Point counts have been conducted sporadically throughout Southern California riparian areas, but there is no statistically powerful and easy-to-implement biodiversity survey protocol. We are meeting that need by developing a scalable passive acoustic survey protocol. At present, focal species include the Least Bell’s Vireo, Wrentit, and Bullock’s Oriel.