New Science on Extent of Conifer Expansion and Management
Two newly published remote-sensing studies provide a comprehensive view of recent change in pinyon-juniper woodlands in the Great Basin and sage-grouse country. Taken together, these studies provide critical context for ongoing discussions about the extent of conifer management and further highlight the need for continuing collaborative efforts to implement targeted restoration in priority rangelands.
In the first study, Filippelli et al. (2020) find that even after 150 years of prior expansion, pinyon-juniper continue to replace shrublands and grasslands across the Great Basin. From 2000-2016, the amount of new pinyon-juniper ‘forest’ (>10% tree cover) increased >1.1 million acres at rate of 0.46% per year. Eighty percent of the increase in tree biomass documented was due to infill, supporting predictions of previous studies that pinyon-juniper continue to progress through the phases of woodland succession.
In the second study, Reinhardt et al. (2020) document patterns of conifer reduction across sage-grouse range over the past several years overlapping with concerted sage-grouse habitat restoration. They find total the area supporting tree cover decreased by 1.6%, with 2/3 attributable to active management and 1/3 due to wildfire. The study shows spatial targeting of conifer reductions has been successful: over half (53%) of treatments occurred within sage-grouse Priority Areas for Conservation (PACs) with additional reductions often addressing connectivity between PACs. Prioritization and collaboration were also evident in strong patterns of cross-boundary conifer reductions observed in key watersheds across the region. Eighty-seven percent of mapped conifer reductions occurred in three states (Utah, Oregon, and Nevada) where the extent of pinyon-juniper is most pronounced. Where targeted restoration has occurred, partners are successfully getting ahead of the curve in addressing conifer expansion. Going forward, the authors recommend scaling up comparable collaborative and strategic efforts in other priority landscapes to outpace ongoing rate of expansion (~0.4-1.5% per year).
This co-produced science was led by a research lab based at Colorado State University with support provided by Bureau of Land Management, Intermountain West Joint Venture, USDA Natural Resources Conservation Service’s Conservation Effects Assessment Project and Working Lands for Wildlife, NASA, and others.
Host: Great Basin Fire Science Exchange
Presenters: Jeremy Maestas, National Sagebrush Ecosystem Specialist, NRCS and Jason Tack, Wildlife Biologist, USFWS
Brief Description: This webinar highlights recent literature on wildlife response to pinyon-juniper management across the West, and new science and tools for considering sagebrush- and woodland-obligate songbirds, like pinyon jay, in conifer management. Knowledge gained from wildlife studies is put into context of emerging remote sensing analyses that provide a comprehensive picture of continued woodland change.
Replay URL: https://youtu.be/RW8ljbctKs0