Kirk W. Davies

Agricultural Research Service | ARS · Eastern Oregon Agricultural Research Center

Re-establishing native plants while controlling invasive species is a challenge for many dryland restoration efforts globally. Invasive plants often create highly competitive environments so controlling them is necessary for effective establishment of native species. In the sagebrush steppe of the United States, invasive annual grasses are commonly...

There are concerns about the negative consequences of non‐native livestock grazing of sagebrush communities, especially since these communities are experiencing unpreceded threats from invasive annual grasses, altered fire regimes, and climate change. The narrative around grazing often focuses on the effects of heavy, repeated growing season use th...

Exotic annual grass invasion is a widespread threat to the integrity of sagebrush ecosystems in Western North America. Although many predictors of annual grass prevalence and native perennial vegetation have been identified, there remains substantial uncertainty about how regional‐scale and local‐scale predictors interact to determine vegetation he...

On the Ground • In recent decades rangeland science has moved from a “command and control” framework to one that values heterogeneity, recognizes rangelands as social-ecological systems, and seeks to integrate complexity. • This new framework recognizes management as fundamentally site-specific, but rangeland science has not provided clear princip...

Ecological restoration is critical for recovering degraded ecosystems but is challenged by variable success and low predictability. Understanding which outcomes are more predictable and less variable following restoration can improve restoration effectiveness. Recent theory asserts that the predictability of outcomes would follow an order from most...

There is limited knowledge of grazing impacts on longer term plant community dynamics following fire in sagebrush steppe. This study evaluated vegetation response to different intensities of deferred rotation cattle grazing over 16 years (2007–2022) on burned Wyoming big sagebrush ( Artemisia tridentata ssp. wyomingensis (Beetle & Young) Welsh) ste...

Sagebrush ecosystems of western North America are experiencing widespread loss and degradation by invasive annual grasses. Positive feedbacks between fire and annual grasses are often invoked to explain the rapid pace of these changes, yet annual grasses also appear capable of achieving dominance among vegetation communities that have not burned fo...

In this chapter, we summarize the ecology and conservation issues affecting greater (Centrocercus urophasianus) and Gunnison (C. minimus) sage-grouse, iconic and obligate species of rangelands in the sagebrush (Artemisia spp.) biome in western North America. Greater sage-grouse are noted for their ability to migrate, whereas Gunnison sage-grouse lo...

The invasive annual grass medusahead infests rangelands throughout the West, from the Columbia Plateau to the California Annual Grasslands and the Great Basin. Dominating secondary succession in the sagebrush steppe, medusahead can degrade the habitat of threatened species such as the greater sage-grouse. This research explores the potential of dor...

Billions of dollars are spent annually on ecological restoration efforts around the world and yet successful attainment of restoration targets still falls short in many regions. Globally, ecosystem restoration is becoming increasingly challenged with changes in climate. Years with extreme climatic events that limit plant establishment, such as seve...

Fire regimes in sagebrush (Artemisia spp.) ecosystems have been greatly altered across the western United States. Broad-scale invasion of non-native annual grasses, climate change, and human activities have accelerated wildfire cycles, increased fire size and severity, and lengthened fire seasons in many sagebrush ecosystems to the point that curre...

For nearly a century, invasive annual grasses have increasingly impacted terrestrial ecosystems across the western United States. Weather variability associated with climate change and increased atmospheric carbon dioxide (CO2) are making even more difficult the challenges of managing invasive annual grasses. As part of a special issue on climate c...

Over the last +150 years, increases in woody vegetation in drylands and associated declines in herbaceous vegetation have led to widespread interest in reversing this trend. However, the effects of native, non‐charismatic herbivores, such as lagomorphs, on these efforts are largely unknown. For 11 years post‐treatment, we quantified the effects of...

Billions of dollars are spent annually on ecological restoration efforts around the world and yet successful attainment of restoration targets still falls short in many regions. Conditions in which to restore global ecosystems are becoming increasingly challenging with changes in climate. Years with extreme climatic events, such as severe drought,...

Restoration of native shrub species is challenging but direly needed in arid and semiarid rangelands globally as native shrubs provide critical habitat for wildlife and livestock forage. Restoration of antelope bitterbrush (Purshia tridentata Pursh DC), a wildlife-important shrub, is often a priority on western US rangelands. One challenge to bitte...

High interannual variability in production occurs in many semiarid rangelands, including the perennial-dominated sagebrush steppe, in response to variable weather conditions. Describing the effects of weather on the dynamics of sagebrush steppe has implications for a broad set of management objectives including forage and wildlife habitat. Here, we...

Livestock grazing is the most extensive land use in Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis [Beetle & A. Young] S.L. Welsh) steppe and its effects on plant community characteristics have been greatly debated. However, most of the studies used to support grazing removal evaluated the impacts of excluding historic grazing, rathe...

Exotic annual grasses invasion across northern Great Basin rangelands has promoted a grass-fire cycle that threatens the sagebrush (Artemisia spp.) steppe ecosystem. In this sense, high accumulation rates and persistence of litter from annual species largely increase the amount and continuity of fine fuels. Here, we highlight the potential use and...

Wildfire activity is accelerating on many rangelands worldwide, yet the potential for grazing to be used as a fire management tool remains largely unknown. Particularly, little is known about the influence of grazing on ignition and initial spread of fire, as well as how these vary by differences in grazing management. We investigated effects of gr...

Wildfires are increasingly impacting ecosystem processes and ecological services provided by sagebrush rangelands in the western United States. Mitigating this problem involves actions taken before, during, and after fire. In recent years, there has been increased emphasis on prefire fuel management, including fuel breaks. Cattle grazing can be use...

Limiting fire in Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis [Beetle & A. Young] S.L. Welsh) steppe is often a management priority as fires threatens its ecological integrity and rural economies that depend on it. However, the Wyoming big sagebrush steppe is vast and occurs in different community states from intact (sagebrush-bunc...

Spatial and temporal dynamics of rangeland fuels is a primary factor driving large wildfires. Yet detailed information capturing variation in fine fuels has largely been missing from rangeland fire planning and fuels management. New fuels-based maps of Great Basin rangeland fire probability help bridge this gap by coupling dynamic vegetation cover...

Wildfires are a growing management concern in western US rangelands, where invasive annual grasses have altered fire regimes and contributed to an increased incidence of catastrophic large wildfires. Fire activity in arid, nonforested ecosystems is thought to be largely controlled by interannual variation in fuel amount, which in turn is controlled...

Seed-based restoration of wildlife-important shrubs following wildfire is a management priority in many ecosystems. However, postfire restoration success is spatiotemporally variable and establishment from seed frequently fails in arid and semiarid rangelands. There may be opportunities to improve restoration success by taking advantage of small-sc...

Restoration in dryland ecosystems is hindered by low establishment of seeded species. As such, evaluations of current seeding methods are critical to understanding limitations and barriers to seeding success. Drill seeding is perceived as an optimal seeding strategy in many dryland ecosystems, but broadcast seeding is more commonly used as a seedin...

Exotic annual grass invasion and dominance of sagebrush-bunchgrass steppe is a concern because it decreases biodiversity and promotes frequent wildfires. Management is needed to reduce exotic annual grasses to prevent sagebrush-bunchgrass communities from transitioning to annual grasslands. Grazing during the off season (fall-winter) has shown prom...

Exotic annual grass invasion is a pressing concern in sagebrush rangelands of the western United States. Overgrazing and fire have historically both been implicated in the rise of annual grasses, but experiments that compare the effect of grazing versus fire are lacking, particularly for contemporary grazing practices such as off-season (fall and w...

We evaluated plant community succession following prescribed fire on Artemisia arbuscula var. arbuscula (Nutt.) McMinn (low sagebrush) steppe in southeastern Oregon. Treatments were prescribed burned (burn; fall 2012) and unburned (control) A. arbuscula steppe, and the study design was a randomized complete block with 4 replicates per treatment. He...

Management of areas invaded by cheatgrass (Bromus tectorum) continues to be one of the greatest challenges for US Great Basin ecosystems. Targeted cattle grazing in the fall and winter has shown positive results as a management tool to reduce dormant fine fuel biomass within cheatgrass-invaded areas, but management of targeted grazing within large...

On public lands grazing allotments in the western US sagebrush steppe, cattle are generally excluded from burned pastures for 2 yr post fire. If only a portion of a pasture burns, the burned area may be fenced, allowing for cattle grazing to resume in the unburned portion. However, traditional wire-based fencing is often not an option due to expens...

On the Ground •Wildfires and incidents of large fires have increased substantially in the past few decades, in part from increases in fine, dry fuels. Fine fuel management is needed, and grazing is likely the only tool applicable at the scale needed to have meaningful effects. •Moderate grazing decreases wildfire probability by decreasing fuel amo...

Spatial heterogeneity in plant communities promotes coexistence and diversity by providing a variety of niches for different species. In shrub-steppe communities, shrubs create distinct microsites under their canopies (canopy microsites) compared to areas between their canopies (interspace microsites). This creates spatial heterogeneity in soil nut...

Restoration efforts in dryland systems are often limited by a complex range of environmental variables and chronically low establishment of seeded native species. Methods for restoring large tracts of degraded drylands in the western United States and southwestern Australia have not advanced substantially since the early 1900s despite continuous ef...

Aim In the western United States, sagebrush (Artemisia spp.) and salt desert shrublands are rapidly transitioning to communities dominated by exotic annual grasses, a novel and self‐reinforcing state that threatens the economic sustainability and conservation value of rangelands. Climate change is predicted to favour annual grasses, potentially pus...

Grazing and fire are both independently important drivers of plant community dynamics; however, their interactive effects may be even more influential. Little is known about prefire grazing effects on postfire plant community dynamics. We investigated the effects of dormant-season, moderate prefire grazing by cattle on postfire plant community resp...

Restoration of degraded drylands is urgently needed to mitigate climate change, reverse desertification and secure livelihoods for the two billion people who live in these areas. Bold global targets have been set for dryland restoration to restore millions of hectares of degraded land. These targets have been questioned as overly ambitious, but wit...

A full list of affiliations appears at the end of the paper. R estoration ecology is rapidly advancing in response to the ever-expanding global decline in ecosystem integrity and its associated socioeconomic repercussions 1-4. Nowhere are these dynamics more evident than in drylands, which help sustain 39% of the world's human population 5 but rema...

Exotic annual grass invasion and dominance of rangelands is a concern across western North America and other semiarid and arid ecosystems around the world. Postfire invasion and dominance by exotic annual grasses in sagebrush communities is especially problematic as there are no cost-effective control strategies available for the vast acreages alre...

Wildfires are a growing management concern in western US rangelands, where invasive annual grasses have altered fire regimes and contributed to an increased incidence of catastrophic large wildfires. Fire activity in arid, non-forested ecosystems is thought to be largely controlled by interannual variation in fuel amount, which in turn is controlle...

Exotic annual grasses dominate millions of hectares and increase fire frequency in the sagebrush ecosystem of North America. This devastating invasion is so costly and challenging to revegetate with perennial vegetation that restoration efforts need to be prioritized and strategically implemented. Management needs to break the annual grass-fire cyc...

Crist, M.R., Belger, R., Davies, K.W., Davis, D.M., Meldrum, J.R., Shinneman, D.J., and Mayer, K.E. 2021. Chapter J. Altered Fire Regimes. Pages 79-98 in: Remington, T.E., Deibert, P.A., Hanser, S.E., Davis, D.M., Robb, L.A., and Welty, J.L., Sagebrush conservation strategy—Challenges to sagebrush conservation: U.S. Geological Survey Open-File Repo...

Abstract Understanding the effects of contemporary cattle grazing on herbaceous perennial communities in big sagebrush steppe is important for managing for wildlife habitat, plant diversity, and productivity, yet potentially complicated by legacy impacts of historic, often higher intensity, livestock grazing. Here, we evaluate whether recovery of h...

Perennial grasses are often seeded after disturbances to provide ecosystem services and prevent invasive plant dominance. However, there is widespread disagreement over the use of native compared to introduced grasses. In Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & A. Young) communities, introduced wheatgrasses are...

Restoring degraded plant communities is a global challenge and a major priority for land managers and conservationists. Degraded Wyoming big sagebrush communities (Artemisia tridentata ssp. wyomingen-sis [Beetle & A. Young] S.L. Welsh) have high sagebrush cover with a depleted perennial herbaceous understory. They are widespread in western North Am...

Operational satellite remote sensing products are transforming rangeland management and science. Advancements in computation, data storage and processing have removed barriers that previously blocked or hindered the development and use of remote sensing products. When combined with local data and knowledge, remote sensing products can inform decisi...

Dryland ecosystems represent a significant portion of global land area, support billions of people, and suffer high rates of land degradation. Successfully restoring native vegetation to degraded drylands is a global priority and major challenge – highlighting the need for more efficient and successful restoration strategies. We introduce the conce...

Aim In the western US, sagebrush ( Artemisia spp.) and salt desert shrublands are rapidly transitioning to communities dominated by exotic annual grasses, a novel and often self-reinforcing state that threatens the economic sustainability and conservation value of rangelands. Climate change is predicted to directly and indirectly favor annual grass...

Pre‐emergent herbicides are frequently used to control exotic annual plants prior to seed‐based restoration, but seeding must generally wait until herbicide toxicity has waned. The emerging seed‐enhancement technology of herbicide protection pods (HPP) allows for simultaneous seeding and herbicide application by protecting desirable seeds inside po...

Revegetation of exotic annual grass−invaded rangelands is a primary objective of land managers following wildfires. Controlling invasive annual grasses is essential to increasing revegetation success; however, preemergent herbicides used to control annual grasses prohibit immediate seeding due to nontarget herbicide damage. Thus, seeding is often d...

Operational satellite remote sensing products are transforming rangeland management and science. Advancements in computation, data storage, and processing have removed barriers that previously blocked or hindered the development and use of remote sensing products. When combined with local data and knowledge, remote sensing products can inform decis...

Restoration of non-sprouting shrubs after wildfire is increasingly becoming a management priority. In the western U.S., Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young) restoration is a high priority, but sagebrush establishment from seed is sporadic. In contrast, planting seedlings often successfully restores sag...

Post‐fire restoration of foundation plant species, particularly non‐sprouting shrubs, is critically needed in arid and semi‐arid rangeland, but is hampered by low success. Expensive and labor intensive methods, including planting seedlings, can improve restoration success. Prioritizing where these more intensive methods are applied may improve rest...

Sage‐grouse (Centrocercus spp.) are influencing rapidly evolving land management policy in the western United States. Management objectives for fine‐scale vegetation characteristics (e.g., grass height >18 cm) have been adopted by land management agencies based on resource selection or relationships with fitness proxies reported among numerous habi...

We assessed plant community succession following prescribed fire on ungrazed Wyoming big sagebrush steppe, eastern Oregon. Treatments were burned (Burn; September and October, 2002) and unburned (Control) sagebrush steppe. Herbaceous yield, vegetation canopy cover and density were compared between treatments after fire (2003–18). Herbaceous yield i...

Fire frequency has decreased in many shrub-steppe communities. Re-introducing fire may be needed to increase spatial and temporal variability in vegetation, but is often hindered by concerns of undesired vegetation shifts. These concerns arise, in part, because long-term effects of fire re-introduction in these communities after prolonged fire excl...