Researchers from the U.S. Geological Survey are reviewing, summarizing, and analyzing what is currently known about changes happening in pinyon-juniper ecosystems in the western U.S. in response to tree removal treatments. Although tree removal can help restore sagebrush ecosystems, these treatments also impact wildlife, wildfire fuels, and invasive plants. This project will help identify key science gaps that, when addressed, will inform future land management planning.
Background
The expansion of pinyon pine and juniper woodlands into sagebrush ecosystems has been a major focus of restoration for land management agencies in the western U.S. Tree removal treatments are in progress across the region to reduce wildfire fuels and restore habitat for species of conservation concern, especially the greater sage-grouse. However, there are also species that rely on woodlands for habitat, such as the pinyon jay.
In addition, wildfire and drought die-off events can reduce pinyon-juniper woodlands and affect the species that depend on them. While each of these agents of change—tree removal, drought, and wildfire—have been major topics of research on their own, there is a critical need to synthesize and compare their impacts on ecosystems and wildlife.
Assessing how different types of disturbance alter woodlands, and how responses vary across a wide geographic area, is critical to designing and optimizing management strategies for the diverse wildlife species that occupy western rangelands.
Objectives and Methods
Through a systematic review of the scientific literature, we will summarize and analyze what is currently known about pinyon-juniper ecosystem change in response to tree removal treatments, drought, and wildfire.
We are investigating how each disturbance type influences:
- Stand structures: vertical and horizontal structure of woodlands
- Fuel loads: amount of vegetative wildfire fuel available, which translates to fire risk
- Plant community composition: presence and distribution of native and invasive plants
- Landscape-scale patterns and processes
These observed effects will be compared to known wildlife habitat needs, with a focus on sage-grouse and pinyon jay. This literature review builds upon an existing review that assessed the effects of pinyon-juniper removal treatments on plants, wildlife, and other environmental attributes across the western U.S. By comparing among additional disturbance types, this new review project will help land managers better predict likely outcomes based on management action or inaction.
For example:
- How will tree removal treatments, wildfire, or drought impact exotic annual grass invasion patterns?
- How do the different disturbance types impact the availability of food for sage-grouse and pinyon-jay?
- Do these disturbance effects vary among environmental settings, or in areas with different land use histories?
Where the literature is not adequate to answer all of these types of questions, we will highlight key science gaps, with a focus on those that are most valuable to land managers.
Learn more about our team.
Fire Ecology in Dynamic Ecosystems Team (FRESC)
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Ecological effects of pinyon-juniper removal in the Western United States—A synthesis of scientific research, January 2014–March 2021
We are working with the following partners on this project, visit their websites to learn more.
- Overview
Researchers from the U.S. Geological Survey are reviewing, summarizing, and analyzing what is currently known about changes happening in pinyon-juniper ecosystems in the western U.S. in response to tree removal treatments. Although tree removal can help restore sagebrush ecosystems, these treatments also impact wildlife, wildfire fuels, and invasive plants. This project will help identify key science gaps that, when addressed, will inform future land management planning.
Background
The expansion of pinyon pine and juniper woodlands into sagebrush ecosystems has been a major focus of restoration for land management agencies in the western U.S. Tree removal treatments are in progress across the region to reduce wildfire fuels and restore habitat for species of conservation concern, especially the greater sage-grouse. However, there are also species that rely on woodlands for habitat, such as the pinyon jay.
In addition, wildfire and drought die-off events can reduce pinyon-juniper woodlands and affect the species that depend on them. While each of these agents of change—tree removal, drought, and wildfire—have been major topics of research on their own, there is a critical need to synthesize and compare their impacts on ecosystems and wildlife.
Assessing how different types of disturbance alter woodlands, and how responses vary across a wide geographic area, is critical to designing and optimizing management strategies for the diverse wildlife species that occupy western rangelands.
Objectives and Methods
Through a systematic review of the scientific literature, we will summarize and analyze what is currently known about pinyon-juniper ecosystem change in response to tree removal treatments, drought, and wildfire.
We are investigating how each disturbance type influences:
- Stand structures: vertical and horizontal structure of woodlands
- Fuel loads: amount of vegetative wildfire fuel available, which translates to fire risk
- Plant community composition: presence and distribution of native and invasive plants
- Landscape-scale patterns and processes
These observed effects will be compared to known wildlife habitat needs, with a focus on sage-grouse and pinyon jay. This literature review builds upon an existing review that assessed the effects of pinyon-juniper removal treatments on plants, wildlife, and other environmental attributes across the western U.S. By comparing among additional disturbance types, this new review project will help land managers better predict likely outcomes based on management action or inaction.
For example:
- How will tree removal treatments, wildfire, or drought impact exotic annual grass invasion patterns?
- How do the different disturbance types impact the availability of food for sage-grouse and pinyon-jay?
- Do these disturbance effects vary among environmental settings, or in areas with different land use histories?
Where the literature is not adequate to answer all of these types of questions, we will highlight key science gaps, with a focus on those that are most valuable to land managers.
- Science
Learn more about our team.
Fire Ecology in Dynamic Ecosystems Team (FRESC)
Understanding how fire and other disturbances affect ecosystem health and resiliency is critically important for land managers and for society as a whole. - Publications
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Ecological effects of pinyon-juniper removal in the Western United States—A synthesis of scientific research, January 2014–March 2021
Executive SummaryIncreasing density of pinyon (Pinus spp.) and juniper (Juniperus spp.) woodlands (hereinafter “pinyon-juniper”), as well as expansion of these woodlands into adjacent shrublands and grasslands, has altered ecosystem function and wildlife habitat across large areas of the interior western United States. Although there are many natural and human-caused drivers of woodland infillingAuthorsDouglas J. Shinneman, Susan K. McIlroy, Sharon A Poessel, Rosemary L. Downing, Tracey N. Johnson, Aaron C. Young, Todd E. Katzner - Partners
We are working with the following partners on this project, visit their websites to learn more.