Invasive Species

We are studying how herbicides sprayed onto soil to prevent the establishment of exotic annual grasses such as cheatgrass may impact the health, growth resources and microbiota of soils in sagebrush-steppe, where herbicide use is an important and common tool. Our findings will help make herbicide applications more successful.

Pre-emergent herbicides applied to soil are a primary tool for reducing exotic annual grasses, such as cheatgrass, in sagebrush steppe rangelands. Effective herbicide application can allow existing perennials to grow and spread to outcompete cheatgrass, preventing reinvasion, but most perennials are slow-growing and require more years of relief from annual-grass competition than standard...

In order to break the annual grass fire-cycle in the sagebrush steppe, land managers use pre-emergent herbicides to reduce annual grass populations and seeding to increase fire-tolerant perennials. These tools must be applied to the same soils in ways that are not counterproductive, and their application must therefore be staggered in time, which we refer to as layering. Livestock grazing can also...

Management partners have identified a major need to understand the short and long-term consequences of altered wildfire patterns, vegetation change, climate change, and management actions for the carbon cycle. This project aims to quantify carbon storage and greenhouse gas emissions in sagebrush rangelands. Researchers will link findings to the Sagebrush Conservation Design Framework and provide...

Seeding and herbicide treatments are a key aspect of the strategy used to break the annual grass-fire cycle in sagebrush steppe. However, past studies report considerable variability in the effectiveness of seeding and herbicide treatments. To generate a more consistent interpretation of post-fire herbicide and seeding effects, we are compiling, reviewing, and synthesizing findings from past...

This interdisciplinary project combines expert judgment on treatment costs with spatially explicit ecological modeling to estimate the financial resources needed to address the threat of invasive annual grass across the entire sagebrush biome. Results of the assessment will provide economic insights that can inform cost-effective resource allocation to efficiently achieve sagebrush conservation...

Within areas of overlapping sagebrush and pinyon-juniper ecosystems, wildlife populations are declining due to habitat fragmentation and degradation, changing climate, and human development. However, management to bolster species associated with one ecosystem may result in negative consequences for species associated with the other. Thus, land managers are challenged with balancing which system to...

Prescribed fire is used in grasslands throughout the Northern Great Plains National Park Service units (parks) to manage fuel loads, control nonnative species, and maintain a vital ecosystem process. Questions about its effects in areas with invasive annual brome grasses require answers to ensure its application produces desired results. Using an experimental approach at two parks in South Dakota...

Big sagebrush plant communities are important and widespread in western North America and are crucial for meeting long-term conservation goals for greater sage-grouse and other wildlife of conservation concern. Yet wildfire is increasing in the West, turning biodiverse, shrub-based ecosystems dominated by sagebrush into grasslands containing invasive species such as cheatgrass and less overall pla

Mitigation of ecological damage caused by rangeland wildfires focuses on conservation of ecosystem function through reducing soil erosion and spread of invasive plants. The overall effectiveness of these treatments is variable, and their necessity has been debated recently. We conduct research projects and synthesize findings to determine if mitigation treatments: 1) protect ecosystems against...

Fuel conditions and fire regimes in western forests and deserts have been altered due to past land management, biological invasions, and recent extreme weather events and climate shifts. These changes have created extreme fire risk to local and regional communities, threatening their economic health related to wildland recreation, forest production, livestock operations, and other uses of public...