Throughout the Great Plains, aboveground annual net primary productivity (ANPP) is a critical ecosystem service supporting billions of dollars of commerce and countless stakeholders. Managers and producers struggle with high interannual change in ANPP, which often varies 40% between years due to fluctuating precipitation and drought. To quantify ANPP trends and evaluate interannual and spatial variation, we created the Rangeland Production Monitoring Service (RPMS), a spatially explicit database with automatic annual updates of ANPP for all rangelands in the conterminous United States. The RPMS establishes relationships between normalized difference vegetation index (NDVI) from remote sensing data and ANPP from soil ecological site descriptions. These relationships were applied to NDVI data in each year from 1984 to present, although the present assessment focuses on the period from 1984 to 2017. Validation metrics include an r² of 89% between predicted and observed ANPP at three locations in the Great Plains. For this special issue, we assess data from the RPMS to quantify trends and variation of ANPP in the Great Plains region for four major grassland types, smaller-scale ecological subsections, and national grassland units. Significant (α ≤ 0.05) increases in ANPP since 1984 were observed across all major grassland types in the Great Plains, particularly the northern mixed-grass prairie, which also had the greatest interannual variation (21%) from 1984 to 2017. Corresponding significant increases (P < 0.1) in growing season precipitation were found in all grassland types except the shortgrass steppe. Spatial variation decreases from west to east and tallgrass prairie exhibited the lowest temporal and spatial variation of 8% and 21%, respectively, from 1984 to 2017. Grazing allotments in the National Grasslands exhibit differential recovery after drought ranging from about 15% to 350%.

The Great Plains region plays an important role in providing water and land resources and habitat for wildlife and livestock, crops, energy production, and other critical ecosystem services to support rural livelihoods. The semiarid conditions of the region and tight coupling of livelihood enterprises with ecosystem services creates a situation of increased sensitivity to climate changes and enhanced vulnerability among the rural communities and Native American nations across the region. Recent climate conditions associated with warming trends, and altered atmospheric flows have resulted in rapid onset of drought conditions and other extreme weather events across the region that are changing seasonal patterns of temperature and precipitation and warming trends. Projected climate changes provided in the fourth US National Climate Assessment indicate that potential warming and variability of precipitation will further increase drought and extreme weather events.

Recent research and assessment efforts of current and projected climate changes in the Great Plains indicate that rural communities and ecosystems are becoming more vulnerable to changes associated with warming trends, droughts, and increased variability in precipitation. These climate changes are having differential impacts on ecosystem services that are critical to livelihood enterprises. Strategies for how resource managers and the research community can better collaborate and more effectively codesign and coproduce efforts to understand and to respond to these challenges are needed.

Ranchers and other land managers of central and northern Great Plains rangelands face recurrent droughts that negatively influence economic returns and environmental resources for ranching enterprises. Accurately estimating annual forage production and initiating drought decision-making actions proactively early in the growing season are both critical to minimize financial losses and degradation to rangeland soil and plant resources. Long-term forage production data sets from Alberta, Kansas, Montana, Nebraska, North Dakota, South Dakota, and Wyoming demonstrated that precipitation in April, May, and June (or some combination of these months) robustly predict annual forage production. Growth curves from clipping experiments and ecological site descriptions (ESDs) indicate that maximum monthly forage growth rates occur 1 mo after the best spring month (April to June) precipitation prediction variable. Key for rangeland managers is that the probability of receiving sufficient precipitation after 1 July to compensate for earlier spring precipitation deficits is extremely low. The complexity of human dimensions of drought decision-making necessitates that forage prediction tools account for uncertainty in matching animal demand to forage availability, and that continued advancements in remote sensing applications address both spatial and temporal relationships in forage production to inform critical decision dates for drought management in these rangeland ecosystems.

Fire ecology has a long history of empirical investigation in rangelands. However, the science is inconclusive and incomplete, sparking increasing interest on how to advance the discipline. Here, we introduce a new framework for qualitatively and quantitatively understanding the ranges of variability in fire regimes typical of experimental investigations in rangeland fire science compared with the range of conditions that actually occurred during contemporary social-ecological times. We implement this framework for one of rangelands' most pyrogenic systems—the Great Plains of North America. We identify four social-ecological fire eras that have epitomized people's relationship with wildland fire in the Great Plains since the last glacial maxima. These cultural fire eras include the now-extinct coexistence era (indigenous fire use), the suppression era (extermination of wildland fire occurrence), the shadow era (localized prescribed burning groups), and the emerging wildfire era (resulting from wildland fire management failures, continued decoupling of human-fire ignitions, and global change). Our synthesis demonstrates that experimental fire conditions have not explored the types and ranges of variation in fire regime components responsible for shaping rangeland vegetation—now, in the past, or into the future. Instead, scientific investigations have focused largely on controlling and minimizing sources of uncertainty and experimental variation, essentially eliminating ranges of variation that underpin the functioning of fire in modern social-ecological systems. Yet a series of scientific investigations exist that targeted a wider range of variability in fire regime components, leading to major advancements and the rejection of a number of long-standing rules of thumb in rangeland science and management. These include 1) the manipulation of fire return interval, 2) the pyric herbivory experiments, and 3) the extreme fire trials. We discuss the general philosophy shared among these studies, introduce scientific standards needed to avoid common pitfalls, and highlight opportunities to better understand how rangeland pattern and process correspond to critical ranges of variation in the human-fire relationship.

Biological soil crusts (BSCs), or biocrusts, are composed of fungi, bacteria, algae, and bryophytes (mosses, etc.) that occupy bare soil, entwining soil particles with filaments or rootlike structures and/or gluing them together with polysaccharide exudates to form a consolidated surface crust that stabilizes the soil against erosion. BSCs are common in arid and semiarid regions where vascular plant cover is naturally sparse, maximizing the exposure of surface-dwelling organisms to direct sunlight. Although less prominent and less studied there, BSC organisms are also present in more mesic areas such as the Great Plains where they can be found in shortgrass and mixed-grass prairie, in the badlands of several states, where burrowing animals have created patches of bare soil, on damaged road-cuts, strip-mines, gas and oil drill pads, military training areas, heavily grazed areas, and burn scars. Even where BSCs are not readily visible to the naked eye, many of the organisms are still present. BSC organisms are passively dispersed to the Great Plains as airborne organismal fragments, asexual diaspores, or sexual spores that accompany windblown dust from as far away as northern China and Mongolia. BSCs can best be studied and managed by 1) acknowledging their presence; 2) documenting their diversity, abundance, and functional roles; and 3) minimizing unnecessary disturbance, particularly when the soils are dry. This paper describes the current knowledge of Great Plains BSCs in an effort to heighten awareness of these cryptic but crucial ecosystem components and to encourage new research initiatives to better understand and manage them in this biome. Some specific actions may include refined taxonomic and ecologic studies of BSC organisms in underexplored areas, particularly those previously less or not recognized as BSC habitat, and incorporation of techniques to sample airborne organisms.

Recent global declines of pollinator populations have highlighted the importance of pollinators, which are undervalued despite essential contributions to ecosystem services. To identify critical knowledge gaps about pollinators, we describe the state of knowledge about responses of pollinators and their foraging and nesting resources to historical natural disturbances and new stressors in Great Plains grasslands and riparian ecosystems. In addition, we also provide information about pollinator management and research needs to guide efforts to sustain pollinators and by extension, flowering vegetation, and other ecosystem services of grasslands. Although pollinator responses varied, pollinator specialists of disturbance-sensitive plants tended to decline in response to disturbance. Management with grazing and fire overall may benefit pollinators of grasslands, depending on many factors; however, we recommend habitat and population monitoring to assess outcomes of these disturbances on small, isolated pollinator populations. The influences and interactions of drought and increasingly variable weather patterns, pesticides, and domesticated bees on pollinators are complex and understudied. Nonetheless, habitat management and restoration can reduce effects of stressors and augment floral and nesting resources for pollinators. Research needs include expanding information about 1) the distribution, abundance, trends, and intraregional variability of most pollinator species; 2) floral and nesting resources critical to support pollinators; 3) implications of different rangeland management approaches; 4) effects of missing and reestablished resources in altered and restored vegetation; and 5) disentangling the relative influence of interacting disturbances and stressors on pollinator declines. Despite limited research in the Great Plains on many of these topics, consideration of pollinator populations and their habitat needs in management plans is critical now to reduce future pollinator declines and promote recovery.

The Great Plains of North America encompass approximately 1,300,000 km² of land from Texas to Saskatchewan. The integrity of these lands is under continual assault by long-established and newly-arrived invasive plant species, which can threaten native species and diminish land values and ecological goods and services by degrading desired grassland resources. The Great Plains are a mixture of privately and publicly owned lands, which leads to a patchwork of varying management goals and strategies for controlling invasive plants. Continually updated knowledge is required for efficient and effective management of threats posed by changing environments and invasive plants. Here we discuss current challenges, contemporary management strategies, and management tools and their integration, in hopes of presenting a knowledge resource for new and experienced land managers and others involved in making decisions regarding invasive plant management in the Great Plains.

The Great Plains is a mixture of cropland and grassland mainly used for agricultural purposes, with grasslands under continual threat of conversion to cropland. Agriculturists are advocating for the integration of crop-livestock systems (ICLS) to recouple nutrient cycles, improve biodiversity, and increase resilience of agricultural operations. We address the benefits of ICLS in the Great Plains, contending that focus on improving soil health and financial stability of agricultural operations should reduce the conversion of grasslands to cropland. Using US Department of Agriculture National Agricultural Statistics Service Census of Agriculture survey data from the 1925–2017 category “cropland used only for pasture or grazing,” which represents land that had been cropped but converted to annual/perennial pasture and grazed, we showcase that the number of farms and the land area in this category is a reasonable proxy of ICLS. As expected, ICLS dramatically decreased in the entire United States from 1925 to 1945, but from 1945 to 2002 in the Great Plains ICLS remained relatively constant, providing evidence of sustained crop-livestock integration. Consistent high numbers of beef cows during this period and the wide availability of forages and crop residues for ruminants facilitated opportunities for producers to use ICLS on their individual operations (within farm) or among operations where row crop farmers and forage-based producers integrated beef cattle use across the landscape (among farms). This integration, however, was decoupled from 2006 to 2013, a period of high grain prices. As a result, economic value of grasslands was decreased and conversion to cropland was increased. Thus, conservation efforts in the Great Plains for grasslands should focus on keeping grasslands intact for provision of multiple ecosystem goods and services by emphasizing incorporation of ICLS within and among farms to reduce the risk of converting grassland to cropland.

Energy is an integral part of society. The major US energy sources of fossil fuels (coal, oil, natural gas); biofuels (ethanol); and wind are concentrated in grassland ecosystems of the Great Plains. As energy demand continues to increase, mounting pressures will be placed on North American grassland systems. In this review, we present the ecological effects of energy development and production on grassland systems. We then identify opportunities to mitigate these effects during the planning, construction, and production phases by using informed methodology and improved technology. Primary effects during energy development include small- and large-scale soil disturbance and vegetation removal as small patches of grasslands are used to host oil or gas wells, wind turbine pads, associated roadways, and pipelines or through the conversion of large grassland areas to biofuel croplands. Direct habitat loss or habitat fragmentation can affect wildlife directly through increased mortality or indirectly through reduction in habitat quantity and quality. During energy production, air and water quality can be affected through regular emissions or unplanned spills. Energy development can also affect the economy and health of local communities. During planning, energy development and production effects can be reduced by carefully considering effects on grasslands during siting and even by selecting different energy source types. During construction, effects on soil and plant systems can be minimized by eliminating weed populations before disturbance, salvaging and stockpiling topsoil for future revegetation, and harvesting native local seed for postsite restoration. During energy production operations, noise and road traffic reduction plans and atmospheric monitoring will enable more informed mitigation measures. Continued research on energy development effects and mitigation measures is necessary to establish best management practices beneficial to grassland health while providing needed energy for the United States.

The Great Plains provide a major portion of US beef cattle production, and beef cattle represent the largest sector of the regional agricultural economy. Cattle producers regularly contend with climate variability, but the consequences of this variability are less well understood than for cropping systems. A retrospective analysis of US Department of Agriculture AgCensus data was conducted to assess the extent to which climate variability (1978 – 2017) has affected the spatial and temporal distribution of beef cow numbers throughout the Great Plains. Cow numbers were remarkably stable, declining only 3.1% between 1978 and 2017. However, beef production increased 30% during this period, in response to a steady increase in live animal slaughter weight. Cow numbers decreased during droughts in the late 1980s and the early 2010s but recovered before the subsequent 5-yr census. Cow numbers decreased 5.1%, 8.8%, and 4.0% in the Northern, Central, and Southern Plains, respectively, between the 1982 and 1987 censuses, even though annual precipitation only decreased in the Northern Plains. The reduction in cow numbers during the 2010s drought, which is assumed to portend future extreme droughts, was greatest in the Southern Plains (– 17.6%) followed by the Central (– 11%) and Northern Plains (– 4.9%), compared with the 2007 census. The relative increase in beef cow numbers in the Northern Plains may represent an emerging signal of climate variability on rangeland beef production. This may be a consequence of weaker correlations between cow numbers and mean annual precipitation and temperature established by lower mean annual temperatures in the Northern Plains. This retrospective analysis indicates that continued climate warming and drying will adversely affect rangeland beef production, it identifies a large knowledge gap between climate variability and sustainable rangeland beef production, and it provides a reference to begin assessing the vulnerability of rangeland beef cattle production in future climates.

Fauna of North America's Great Plains evolved strategies to contend with the region's extreme spatiotemporal variability in weather and low annual primary productivity. The capacity for large-scale movement (migration and/or nomadism) enables many species, from bison to lark buntings, to track pulses of productivity at broad spatial scales (> 1 000 km²). Furthermore, even sedentary species often rely on metapopulation dynamics over extensive landscapes for long-term population viability. The current complex pattern of land ownership and use of Great Plains grasslands challenges native species conservation. Approaches to managing both public and private grasslands, frequently focused at the scale of individual pastures or ranches, limit opportunities to conserve landscape-scale processes such as fire, animal movement, and metapopulation dynamics. Using the US National Land Cover Database and Cropland Data Layers for 2011–2017, we analyzed land cover patterns for 12 historical grassland and savanna communities (regions) within the US Great Plains. On the basis of the results of these analyses, we highlight the critical contribution of restored grasslands to the future conservation of Great Plains biodiversity, such as those enrolled in the Conservation Reserve Program. Managing disturbance regimes at larger spatial scales will require acknowledging that, where native large herbivores are absent, domestic livestock grazing can function as a central component of Great Plains disturbance regimes if they are able move at large spatial scales and coexist with a diverse array of native flora and fauna. Opportunities to increase the scale of grassland management include 1) spatial prioritization of grassland restoration and reintroduction of grazing and fire, 2) finding creative approaches to increase the spatial scale at which fire and grazing can be applied to address watershed to landscape-scale objectives, and 3) developing partnerships among government agencies, landowners, businesses, and conservation organizations that enhance cross-jurisdiction management and address biodiversity conservation in grassland landscapes, rather than pastures.

Hydrologic dysfunction associated with desertification of grazing lands likely depends on two opposing biophysical drivers, compaction by livestock and bioturbation by plant roots and soil biota. To understand which is most important, we conducted a long-term field experiment. We tested the effects of phytobiomass (control vs. herbicide treated) and three ungulate disturbance treatments (none, once, and twice disturbed) on soil water transport in northern mixed-grass prairie. Field-saturated hydraulic conductivity (i.e., infiltration) was primarily reduced by the most severe (twice disturbed) ungulate disturbance treatment. To a lesser degree, ungulate disturbance and phytobiomass interacted, and similar levels of hydrologic dysfunction were detected for plots annually treated with herbicide and disturbed by a single livestock disturbance event (and while soils were dry and resistant to compaction) and naturally vegetated plots that had been twice disturbed (including while soils were wet and susceptible to compaction). Our findings suggest hydrologic dysfunction in grazing lands is mainly due to compaction by ungulates, especially when grazing at high stocking rates and while areas are vulnerable to compaction (e.g., fine soils, wet soils, not well vegetated).

Significant interest exists in the potential for specialized grazing systems, including adaptive multipaddock (AMP) grazing, to enhance grassland health and function. However, specific pasture management practices associated with AMP grazing at the ranch level remain poorly understood in comparison with more regionally representative management systems. As part of a larger study examining grazing effects on soil carbon, greenhouse gases, and other ecosystem attributes, here we report on differences in disturbance history and grazing management practices on a sample of AMP operators and their neighboring (n-AMP) ranches at 32 paired sites across the prairie provinces of western Canada. Most ranches studied (77.5%) relied on pastures composed of introduced (seeded) forage. On average, the AMP ranches surveyed were larger in size, supported greater animal numbers, and were more likely to use seeded forages comprising diverse mixes. Relative to n-AMP ranches, AMP ranches used 18.6-fold higher average stock densities in smaller paddocks (22.3 vs. 120.7 ha) while grazing over a grazing season that was 76 d longer, although computed stocking rates remained similar (P ≥ 0.10). AMP operators specifically used much shorter grazing periods (2.8 d) during the early growing season (i.e., before August 1) that were followed by a prolonged rest period (69 d) and could be used to compute a rest-to-grazing ratio for the first half of the grazing season for all ranches. This ratio, along with cattle stock density computed at the pasture scale, exhibited the greatest potential to differentiate the two groups of ranchers. Finally, both groups, and in particular ranchers within the AMP group, demonstrated high variability in management practices among individual operators, highlighting the importance of using specific management metrics rather than generalized descriptors of “grazing system type” to interpret their influence.

State-and-transition models (STMs) are tools used in rangeland management to describe linear and nonlinear vegetation dynamics as conceptual models. STMs can be improved by including additional ecosystem services, such as wildlife habitat, so that managers can predict how local populations might respond to state changes and to illustrate the tradeoffs in managing for different ecosystem services. Our objective was to incorporate songbird density into an STM developed for sagebrush rangelands in northwest Colorado to guide local management of sagebrush birds. The STM included two shrub-dominated community phases, a native grassland state, and a shrubland and grassland phase within an exotic-dominated state. We surveyed plots for songbirds, collected a suite of vegetation indicators at each plot, and quantified songbird habitat relationships with count-based regression models. We then used the estimated models to predict songbird density based on average vegetation conditions per state or community phase. Moderate or increasing shrub cover were important predictors for shrubland-associated species, and responses to understory components varied by species. In the STM, we predicted higher densities of shrubland-associated bird species in the shrub-dominated phases and higher densities of grassland-associated bird species in the state and phase lacking shrub cover. No single state or phase captured the highest density for all songbirds, illustrating the value of alternative states. Our results also demonstrate the utility of displaying traditional wildlife count models against the range of vegetation conditions associated with each state or phase to understand how wildlife density can vary within states and phases. Our approach can assist land managers to gauge the potential impacts of land-use decisions and natural vegetation variability on wildlife, especially for species of conservation concern.

Grazing, a defining use of rangelands, can have immediate and legacy impacts in ecosystems with short evolutionary histories of grazing and where climatic conditions are marginal and variable. In arid rangelands of the Colorado Plateau, domesticated ungulates were introduced in the 1800s at high densities and grazing has been maintained in the region at variable stocking rates for approximately the past 150 yr. Historic grazing practices, combined with a marginal climate, may have caused an irreversible shift in the vegetation community leading to limited recovery with cessation of grazing. Using three exclosures ranging from 12 to 50 yr of age, we evaluated vegetation composition, diversity, and cover inside the exclosures and compared them with directly adjacent, actively grazed areas outside of the exclosures in the fall and spring of 2018 and 2019. We then asked 1) How do exclosures and their adjacent unexclosed sites differ in vegetation diversity, composition, and cover? and 2) Are there significant differences in cover of key forage species in exclosed versus unexclosed areas? Overall, there were significant differences in vegetation communities inside and outside of exclosures in both seasons. Composition, alpha, and beta diversity differed between grazed and exclosed sites, with higher alpha and beta diversity in the 50-yr exclosure in the fall. Composition was significantly different between exclosures and unexclosed sites at all sites and in all seasons. Cover of several important forage grasses (Achnatherum hymenoides, Hilaria jamesii, Elymus elymoides) was higher in exclosed areas, while cover of Scleropogon brevifolius and Bouteloua gracilis was higher in unexclosed areas. Taken together, these results indicate limited recovery of vegetation in the absence of grazing, with exclosures exhibiting higher plant diversity, as well as cover of some desirable forage species, suggesting this area has not undergone irreversible state change but recovery may require > 50 yr of grazing cessation.

Plateau zokor (Eospalax baileyi) is a native subterranean rodent living in alpine rangeland on the Qinghai–Tibet Plateau. The zokors excavate soil in their tunnels and push it out to form the zokor mound, which is secondary bare land on the ground. In the alpine rangeland ecosystem, the bare lands emit greenhouse gases and reduce carbon sequestration. However, little is known about the greenhouse gas emissions from the zokor mounds with bare soil. In this study, we used a gas analyzer in situ combined with a closed static chamber to monitor the emissions of CO₂ and CH₄ from new mounds, seminew mounds, old mounds, and the pasture without mounds. The biomass bacteria, fungi, and actinomycetes in the 0-to 20-cm soil layer of the mounds and the pasture without mounds were simultaneously investigated. To explore the source of the CO₂ and CH₄ emissions, we compared the differences of CO₂ and CH₄ flux in the zokors' active tunnels, tunnel-free soil, and mound-free pasture. The results showed that 1) the highest flux of CO₂ and CH₄ emissions in the same month was from new mounds, followed by seminew mounds, old mounds, and the pasture without mounds; 2) CO₂ and CH₄ emissions from the different mounds in 4 mo were significantly influenced by months and mound types, although there was no significant interaction between these factors; and 3) the flux of CO₂ and CH₄ emissions from the zokor mounds were significantly positively correlated with their total biomass of microbes and the flux of CO₂ and CH₄ inside the zokor active tunnels. The CO₂ and CH₄ inside the zokor active tunnels had more contributions to CO₂ and CH₄ emissions from the zokor mounds than the soil microbes' biomass in the mounds.

Rangeland degradation is a global concern that is exacerbated by soil loss through water erosion. A deeper understanding of rainfall and runoff dynamics can assist in the development of sustainable management strategies. Current methods to measure surface runoff (e.g., natural runoff plots, rainfall simulation and overland flow experiments, modeling approaches) have many advantages but can be prohibitively expensive, may require considerable maintenance, and/or result in significant disturbance during installation. To address these limitations, we assessed a relatively new and underused method for monitoring runoff, the Upwelling Bernoulli Tube (UBeTube). The UBeTube is a low-cost, passive runoff monitoring method that estimates runoff from the height of water flowing out of a slot machined in the side of a vertical tube. In this study, we evaluated the UBeTube across a range of flow rates with three specific objectives: 1) calibrate the UBeTube measurements using clean water, 2) assess the impacts from varying sediment loads on UBeTube measurement accuracy, and 3) evaluate accuracy under conditions similar to those on undisturbed and disturbed rangelands. We found that properly calibrated UBeTubes could be a relatively accurate runoff monitoring method on rangelands (mean percent error = 7.7% clean water calibration, 34.1% sediment loading, 35.2% undisturbed overland flow, 17.7% disturbed overland flow). UBeTubes provide an alternative method to monitor runoff on rangelands that can augment current methods by providing near real-time measurements of runoff generated during natural precipitation events. Easily and rapidly deployed across the landscape, UBeTubes could allow for the relative measurement of spatially variable hydrologic dynamics and serve as another source of information for management decision-making processes and the creation of sustainable strategies for rangeland development.

Livestock guarding dogs reduce livestock predation by excluding carnivores and altering herbivore behavior through their presence. In Patagonia, invasive European hares compete with livestock for forage but change their behavior when exposed to native predator odors. In this experiment, we aimed to test if livestock guarding dog odor triggers fear in this herbivore and reduces hare presence in different habitats of sheep grazing lands of Chilean Patagonia, where these lagomorphs are an invasive species. The results showed that European hares reduce their visits to scented places with and without horizontal vegetation. We also discovered that this invasive species reduced foraging time when the odor was present in places with dense horizontal vegetation. These results suggested that livestock guarding dogs could also serve as a European hare deterrent and decrease competition with livestock, allowing greater production and supporting sustainable livestock farming.

Woody plant encroachment into rangeland ecosystems is a widespread and often unwelcomed circumstance affecting rangeland management decisions worldwide. In the rangeland management profession, varying philosophies have been employed in the management of woody plant encroachment. Following World War II, total eradication of woody plant cover was commonly practiced, eventually giving way to a mosaic approach that benefits livestock, wildlife, and recreational objectives, with cover increasing or even stabilizing in many areas. Cultural practices such as land fragmentation, lifestyles not dependent on agricultural income, and shifts in herbivory from predominately browsers to grazers may also be contributing factors. Modern image analysis technologies, such as object-oriented feature extraction and patch metric analyses, can shed light on past paradigm shifts through spectral and textural assessment of modern and historical aerial photography. In this study, woody plant cover and patch metrics were analyzed for a period spanning from 1938 to 1940 through 2018 in the Bennett and Sulphur Creek watersheds of the Lampasas Cut Plain of Central Texas. Object-based feature extraction was used to calculate woody plant cover, and Fragstats was used for landscape patch metrics. Total woody cover was compared with past stewardship paradigms. There was a net decrease of total woody plant cover from 1938 to 1940 through 2018, with variation in between as management paradigms shifted. A pattern of decline, regrowth, and stabilization, like that observed in other research, was noticed for the Bennett Creek watersheds but was not apparent in Sulfur Creek. Patch size/shape varied as well, but fractal patch complexity was relatively stable through time. Raster algebra analysis showed that < 10% of the initial woody cover from 1938 to 1940 remained in 2018, although total cover went through various expansion/reduction phases. This research underscores the importance of long-term datasets and locally based knowledge in the application and interpretation of historical management paradigms.

The greater bilby (Macrotis lagotis) once occupied much of Australia's mainland. Bilbies are now listed as vulnerable and only occur in 20% of their former range. Operation Rangeland Restoration aims to to restore an ex–pastoral lease; reintroduce several species of locally extirpated fauna, including the bilby; and maintain the area in perpetuity for the conservation of Australian arid zone species. Bilbies were reintroduced to the Matuwa Indigenous Protected Area between 2007 and 2010 and, with ongoing landscape-scale control of feral predators, herbivores, and fire, have thrived. Here, we present a detailed account of the methods used during the reintroduction, showing that between 2007 and 2019 there has been an 88% increase in the area of occupancy by bilbies at Matuwa. The results of 2-ha track plot surveys conducted by the traditional owners of Matuwa suggest that the reintroduced bilbies are emigrating out of Matuwa. In addition, in 2018 and 2019 we used 120 camera-traps over 18 mo and occupancy analysis to confirm the widespread presence of bilbies across Matuwa and define significant habitat correlates. Bilbies were more likely to be detected on sandplains with Eucalyptus species as overstorey vegetation and Triodia as understorey vegetation. Bilbies were not detected in habitats with ≥ 75% bare ground. We attribute the success of the bilby reintroduction at Matuwa to the consistent implementation of landscape-scale control of feral predators.

In many mesic grasslands, such as the central Great Plains in North America, frequent fire is a key regulator of ecological processes. Long periods of infrequent fire facilitate the conversion of herbaceous-dominated grassland to woody-dominated shrubland or woodland. At the Konza Prairie Biological Station in northeast Kansas, one infrequently burned portion of the landscape has undergone transformation from grassland to woodland after nearly 30 yr without fire. In Spring 2017, a prescribed burn was implemented to assess fire effectiveness on woody plant mortality. A postfire census of 3 000+ individual woody plants identified the distribution of species by size (height), topographic position, and slope on the landscape. Mortality and canopy fire damage were calculated for each individual. In lowland locations with near-continuous shrub cover (30.7% of the landscape), woody plants were unaffected by fire. However, in upland and slope locations, where shrubs and trees were sparser, survival probability varied by topographic position and species. In these locations 68% of all woody individuals experienced 90% or greater fire damage to the canopy, with 56% of these individuals exhibiting new canopy regrowth within 2 mo after the fire. The two most abundant woody shrubs, Cornus drummondii and Rhus aromatica, showed high survival at all height classes and landscape positions. The two abundant tree species, Gleditsia triacanthos and Juniperus virginiana, showed increased survival probability with tree height that varied by landscape position. Survival of J. virginiana also varied according to proximity and size of neighboring clonal shrubs, providing a mechanism for persistence of this fire-sensitive tree species even at small height classes. The probability survival curves developed here are useful for managers assessing when to prescribe fire to maximize mortality for J. virginiana and provide insight relevant for broader ecological understanding of woody encroachment within grasslands throughout the world.

The Qilian Mountain Grassland is an important animal husbandry production base in northwestern China. Horses, cattle, and sheep are the main livestock, which are widely distributed in the desert grasslands and alpine meadows around the Qilian Mountains. Grazing livestock produce large amounts of feces, and the germinable seeds in feces constitute the seed banks. Research on the size, plant species composition, and distribution of livestock dung seed banks in the Qilian Mountain grasslands may help understand the interactions between grass species and livestock and inform the comprehensive management practices for grazing livestock. In mid-October 2018, we collected the dung of horses, cattle, and sheep in the alpine meadows and desert grasslands of the Qilian Mountains and estimated the composition and size of the dung seed bank by the greenhouse germination method. Seeds of aboveground vegetation in the same location were also collected to determine the relationships between the size and composition of dung seed banks and the seed traits (i.e., mass and shape). A total of 30 plant species germinated from the dung seed banks of the three livestock species, of which 22 species (73%) were perennial. The seedling densities for horse, cattle, and sheep dung were 11.91, 10.80, and 7.60 seedlings per gram dung, respectively. The species richness, species diversity, and Jaccard coefficients of similarity between dung seedling and aboveground vegetation of horse dung were significantly greater than that of cattle and sheep dung. Regression analyses indicated that medium-sized (10–30 mg) and spherical (0.04–0.10 shape index) seeds had the greatest germination potential. Our study suggests that, of the three livestock species tested, the horse dung seed bank contributes most to grassland recovery and restoration of the Qilian Mountains.

High levels of dissolved SO₄ in drinking water can adversely affect livestock performance. Some plant species may help to remove SO₄ and cleanse drinking water, especially S-hyperaccumulators. However, little is known about the capacity of S-hyperaccumulators to grow in rangeland wetland environments. Here we measured plant properties, S concentration, and S mass of nine plant species. Plants were grown in a wetland environment on an artificial floating island (AFI) in a mesocosm supplied with high SO₄ water (2 430–4 730 parts per million [PPM]) from a rangeland reservoir. Water properties were measured throughout the experiment. We also used our data and data from the literature to parameterize simulations and estimate the number of plants (per L) needed to reduce the SO₄ concentration from 2 000 PPM to a recommended limit of 1 000 PPM. The average sulfur concentration of the nine species was 3.8 times greater than the average of 39 species from the literature. Among the nine species, Brassica napus L., B. napus var. pabularia (DC.) Rchb., and Brassica septiceps (L. H. Bailey) L. H. Bailey tended to have the greatest shoot S concentrations. The total S mass per plant was 5 times greater for B. septiceps (44 mg × plant^–1) than B. juncea (L.) Czern. We found no other appreciable differences in total S mass among species. The simulations suggest that ≥ 1.9 plants × L^–1 of B. septiceps or ≥ 0.6 plants × L^–1 of B. oleracea L. would be needed to reduce the water's SO₄ concentration from 2 000 PPM to the recommended limit. Given the small amount of S removed (per plant) relative to the vast amount of dissolved SO₄ possible in rangeland water sources, planted AFIs are not likely to be a practical tool for reducing SO₄ in livestock drinking water. Conversely, water treatment systems may be justified in some cases.

Increased agricultural intensification and extensive woody plant encroachment are having widespread effects on the functioning of grass-dominated systems at multiple spatial scales. Yet there is little understanding of how the provisioning of biodiversity-based ecosystem services might be altered by these ongoing changes. One fundamental ecosystem service that is decreasing globally, especially in human-altered landscapes, is scavenging that regulates disease processes, alters species distributions, and influences nutrient cycling. Accordingly, our goal was to understand how facultative scavenging, particularly that of mesocarnivores, was affected by landscape heterogeneity and woody encroachment in tropical-grassy savannas within an agricultural landscape mosaic. We baited (using chicken carcasses) plots across a gradient of land cover heterogeneity in areas with an open and closed canopy and subsequently measured scavenging rates. We found that scavenging efficiency of mesocarnivores and other small vertebrates was dependent on environmental variation at multiple spatial scales within our savanna agroecosystem. Mesocarnivores removed more bait when the overstory canopy at the plot (i.e., exact location of bait station) was more closed; in contrast, mesocarnivore scavenging was less efficient when patches (50 × 50 m area around the bait station) within the site had a higher density of shrubs. At the landscape scale, increased land cover fragmentation resulted in decreased amounts of scavenging by mesocarnivores. This study demonstrates that a relatively transformed agroecosystem can support the provision of important ecosystem services and offer an important buffer against loss of ecosystem services. Our results suggest that targeted woody encroachment control, protection of large trees, and management or mitigation of extreme levels of fragmentation can help maintain ecosystem service provision and biodiversity.

Grasslands across the world are transitioning to woody-dominated states with major consequences for ecosystem service provisioning. Managers have consequently turned to woody plant removal or “brush management” as a tool for grassland restoration. Yet the lifespan of brush management treatments depends on rates of re-encroachment, which are often unknown and seldom considered in restoration planning. In this study, we determine the rate of re-encroachment for Juniperus virginiana L. after 16 yr of fire-based restoration actions in the Loess Canyons Experimental Landscape in Nebraska. In this experimental landscape, reclamation fires are used to collapse J. virginiana woodlands and have been applied almost every yr since 2002 as part of a regional restoration initiative. We observed rapid rates of re-encroachment after fire-based restoration. Seedlings re-established within 1–2 yr and reached densities similar to unburned woodlands in 5–11 yr. Cover was low and stable 8–10 yr after restoration and then transitioned to a rapid growth phase as trees escaped the herbaceous layer. The tallest trees reached heights associated with the onset of seed production after 7–11 yr, marking a demographic transition in the re-encroachment process as restoration sites become sources of seed exposure. These results suggest that single restoration treatments are likely to be short-lived. A key implication is that follow-up J. virginiana treatments are needed to maintain restored grasslands at fairly regular intervals.

While considerable research has quantified effects of grazing management and precipitation on plant communities, less is known about how seasonal effects influence extrusa diet quality selected by grazing ruminants. We tested effects of cattle grazing to two residual herbages (600 kg [moderate] or 300 kg [low] animal unit mo [AUM]/ha) and two grazing seasons (summer and fall) on 20 indicators of ruminant extrusa diet quality over a 6-yr period. We found no effect of residual herbage on 13 indicators of diet extrusa quality (P ≥ 0.13) and no effect of season on 4 indicators of extrusa diet quality (P ≥ 0.0773). We did, however, detect effects of yr on extrusa diet quality metrics and nutrients, likely due to variation in annual precipitation, which ranged from 63.9% to 138.6% of the long-term average. Most noticeably, the mineral Mn in extrusa was substantially lower in yrs with higher precipitation (P < 0.0001). While grazing intensity had divergent effects on forage quality in the summer versus fall, annual precipitation was often important. Crude protein was lowest in fall of 2013 (6.5%) and 2018 (7.78%), two high-precipitation yrs, but it was also low in fall of 2015 (7.30%), a low-precipitation yr (P < 0.0001). Forage extrusa Cu, an important catalyst in ruminant metabolism, exhibited a yr × season interaction. Copper in fall of 2018 was greater compared with all other yrs and seasons in the study (P < 0.0001), 35.7% greater than summer of 2018, a high-precipitation yr, and 82.9% and 43.5% greater than summer and fall of 2013, another high-precipitation yr. Seasonal variation in diet nutrients and quality indicators were complex and complicated by yr effects, which sometimes related to precipitation amounts.

Frequent, severe defoliation reduces grass production and can alter plant species composition in grasslands. Multipaddock rotational grazing has been proposed as a grazing strategy that may reduce the frequency and intensity of defoliation on palatable grass plants without altering stocking rates. Previous studies evaluated this hypothesis using small, homogeneous paddocks and nonadaptive rotation schedules and found small and inconsistent differences between continuous and rotational grazing systems. Using a stakeholder-driven collaborative adaptive management (CAM) framework, we conducted the first ranch-scale experimental investigation into tiller defoliation patterns in the context of adaptive multipaddock rotational grazing. We monitored tiller defoliation frequency and intensity in 10 paired 130-ha pastures assigned to either a collaborative adaptive multipaddock rotational grazing treatment (CARM, one livestock herd) or a season-long continuous grazing treatment (traditional rangeland management [TRM]; 10 separate herds) in shortgrass steppe. Consistent with previous studies, we observed that frequencies of grazing and regrazing on a palatable, cool-season grass (western wheatgrass, Pascopyrum smithii) were much more sensitive to stocking rate than grazing system. Under moderate stocking rates used in both CARM and TRM treatments, roughly two-thirds of western wheatgrass tillers remained ungrazed annually, regardless of grazing system. Thus, season-long rest is present in season-long continuous and rotational grazing systems. Frequencies of tiller regrazing were low (5–15%) and similar between CARM and TRM treatments. Although defoliation patterns were similar between treatments at the whole-ranch scale, CARM enhanced spatial and temporal heterogeneity in defoliation frequencies among individual pastures. Pastures grazed earlier in the season or for longer experienced more defoliation. Managers implementing adaptive, multipaddock rotational grazing could use this heightened and predictable variability to strategically manage impacts of grazing on western wheatgrass at the individual pasture scale. The CAM model enabled our team to identify and directly address key stakeholder hypotheses and resulted in coproduction of management-relevant research.

Conservation strategies that rely on umbrella species depend on spatial overlap with target species of concern, yet the temporal and spatial scale at which co-occurrence is assessed is rarely considered. In seasonal environments, shifts in space use across seasons could alter patterns of co-occurrence, especially at regional and local scales that are relevant to land management. Greater sage-grouse (Centrocercus urophasianus), which currently serve as an umbrella species for sagebrush ecosystems across the western United States, move between seasonal habitats. Our goal was to evaluate the degree to which sage-grouse general and seasonal habitats overlap with habitat for another sagebrush-dependent species of conservation concern, the pygmy rabbit (Brachylagus idahoensis). We created inductive species distribution models for both species in east-central Idaho. We used maximum entropy methods to build models incorporating environmental factors representing topography, vegetation, climate, and soil characteristics. Despite both species being sagebrush obligates, we documented a relatively modest degree of spatial overlap between these species across the region; only 49% of highly suitable habitat for pygmy rabbits overlapped with areas mapped as highly suitable for sage-grouse when considering general habitat, and overlap was lower (18–31%) when we evaluated seasonal sage-grouse distributions. Our models predicted that pygmy rabbits would also occur in narrow (1–2 km) sagebrush corridors between steep terrain features where sage-grouse are typically absent. This work suggests that additional habitat conservation for pygmy rabbits will be needed to support their long-term persistence, especially where their habitat falls outside of areas designated as primary habitat for sage-grouse. Our models provide useful information for land management and habitat restoration within the study region and also offer a cautionary tale for application of simplified conservation strategies like the designation of umbrella species. Incorporating spatial and temporal scales into assessments of co-occurrence may increase effectiveness of conservation strategies involving surrogate species.

To protect species of concern in rangeland systems, managers and policy makers must understand the human dimensions of the ecosystems those species rely on. Sagebrush (Artemesia spp. L.) ecosystems are among the most extensive rangelands in the western United States and have been of particular concern in recent years due to the decline of greater sage-grouse (Centrocercus urophasianus) and other sagebrush obligate species. While there is a substantial body of literature on the biophysical aspects of sagebrush ecosystems, the human dimensions of sagebrush management are not well understood and social science research is distributed throughout a wide range of journals and disciplines. We used systematic review principles to conduct a synthesis of literature to assess existent knowledge on the human dimensions of sagebrush management and conservation and to identify areas for future research. We cast a broad net to include studies from economics, political science, social psychology, sociology, governance, anthropology, and other fields. Using Web of Science and search terms sourced from our research questions and relevant stakeholders, we identified 78 studies meeting the following criteria: 1) the research was conducted within the distribution of North American sagebrush and 2) the research included social science methods. We coded the 78 studies to identify the focus of research on resource issue(s), social issue(s), geographical region, and additional research needs. The literature focused on resource issues primarily related to fire, land use, sage-grouse, and rangeland management, while social issues emphasized collaboration, stakeholder perceptions and attitudes, and modes of governance. Research gaps include assessments of the longevity and ecological impacts of collaboration, perceptions and attitudes surrounding wild horse and burro management, and governance approaches to managing invasives and ecological restoration. Research that includes input from Native Nations is lacking, and inclusive social science relevant to diverse stakeholders in sagebrush is overdue.