Synthesis Paper: Assessment of Research on Rangeland Fire as a Management Practice

Rangelands are fire-dependent ecosystems severely altered through direct fire suppression and fuels management. The removal of fire is a dominant cause of ecological sites moving across thresholds with the majority of North American rangelands currently showingmoderate or high departure from reference conditions. Recognizing the need to restore fire on rangelands and incorporate prescribed fire into management plans, the Natural Resource Conservation Service initiated the Conservation Effects Assessment Project (CEAP) to evaluate the validity current practices through peer-reviewed scientific literature. We updated the CEAP review and broadened the discussion of prescribed fire as a global management practice. We reviewed and summarized prescribed fire literature available through Web of Science using search terms in the title. The majority of literature (40%) evaluated plant responses to fire with fire behavior and management (29%), wildlife and arthropods (12%), soils (11%), and air quality (4%) evaluated less frequently. Generally, fire effects on plants are neutral to positive and the majority of negative responses lasted less than 2 years. Similarly, soil responses were recovered within 2 yr after burning. However, most studies did not report how long treatments were in place (62%) or the size of experimental units (52%). The experimental literature supporting prescribed burning is in need of greater managerial relevance that can be obtained by directly addressing spatial scale, temporal scale, and interaction with other disturbances, including drought and grazing. Reliance on information from single fires applied on small plots tracked for a relatively short time interval greatly constrains inferences and application to ecosystem management and information should be applied with caution. Therefore, conservation purposes need to incorporate temporal dynamics to the extent that this information is available. The complex interaction of scientific knowledge, social concerns, and variable policies across regions are major limitations to the successful and critical restoration of fire regimes. © 2016 The Society for Range Management. Published by Elsevier Inc. All rights reserved.The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information

Response of Northern Bobwhite Movements to Management-Driven Disturbance in a Shrub-Dominated Ecosystem

Despite inhabiting fire-adapted grasslands and shrublands across much of their continental distribution, northern bobwhite (Colinus virginianus, hereafter bobwhite) behavior relative to disturbance (e.g., fire) is poorly understood, especially in the western fringe of their distribution. We assessed bobwhite movement and space use following dormant season burning (January-March 2013-2014) in a sand shinnery oak (Quercus havardii, hereafter shinnery oak) plant community. We captured and radio-marked bobwhites (n=369) and monitored them via radiotelemetry across burn treatments (averaging 254 ha) ranging from 0 to 12, 13 to 24, 25 to 36, and >36 months post fire (hereafter, time since fire [TSF]) at the Packsaddle Wildlife Management Area in western Oklahoma, United States. Mean covey home range size was 76.6 ha ± 5.9 [SE] (range; 12-270 ha) (n = 61 coveys), which is substantially larger than covey home ranges reported for other regions. Prescribed fire affected space use of coveys (F4, 54 = 2.95, P 36 TSF (78.9 ha [± 6.54]). Generalized linear mixed models demonstrated that neither spring dispersal (movements or area traversed) were correlated with TSF, age, or sex (n = 114), further demonstrating aminimal effect of prescribed fire; however, dispersal areas were greater in 2013 than in 2014 (P < 0.05). Our research shows that prescribed fire applied at a landscape scale had limited effects on short-term bobwhite movement and space use. These findings also suggest that in shinnery oak vegetation communities land managers can use prescribed fire across large spatial extents without substantially altering the space use or movement of bobwhites. © 2016 The Society for Range Management.The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information

Pyric-Herbivory and Hydrological Responses in Tallgrass Prairie

Pyric-herbivory is the spatial and temporal interaction of fire and grazing on area resources that results in site selection by animals on recently burned areas. Pyric-herbivory promotes heterogeneity by increasing bare ground on some patches and litter and aboveground biomass on other patches. The influences of this heterogeneity on hydrological properties and sediment transport are not well documented. We monitored the pattern of cattle occupancy on annually burned and patch burned pastures under moderate stocking rates of steers in the Tallgrass Prairie Preserve and quantified surface runoff and sediment transport for simulated rainfall of 10-year return storm intensity applied to different phases of the fire-grazing interaction in 2011 and 2012. Results showed that patch burn altered grazing distribution with cattle spending 70% of their time within the most recently burned areas. Our rainfall simulation results showed the high-intensity grazing following a spring fire did not have a prolonged, ecologically meaningful detrimental impact on hydrological properties of the burned patch in comparison with annually burned grazing pasture. Instead, the increased spatial and temporal heterogeneity of hydraulic properties could potentially enhance resource conservation through runoff and runon interactions within the patch-burned pasture. Further study focusing on quantifying pyric-herbivory effects on runoff and sediment transport at watershed scale will provide needed insights for managing tallgrass prairie for improving ecosystem services. © 2016 Society for Range Management. Published by Elsevier Inc. All rights reserved.The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information

Woody Plant Encroachment Mitigated Differentially by Fire and Herbicide

Woodland expansion is a global phenomenon that, despite receiving substantial attention in recent years, remains poorly understood. Landscape change of this magnitude has several impacts perceived as negative on landscape processes, such as influencing fire regimes, habitat for wildlife, and hydrological processes. In southern Great Plains, Juniperus virginiana has been identified as a major contributor to woodland expansion. Adding to the perplexity of this phenomenon is its evidence on numerous landscape types on several continents, documented under varying climates. Our study aimed to quantify a direct treatment to reduce or slow down woodland expansion in an experimental rangeland in central Oklahoma, United States under three treatments: 1) herbicide, 2) fire with herbicide, and 3) control (no fire, no herbicide) within areas classified as “open grassland” in 1979. Thereafter, we identified these same areas in 2010 with remotely sensed imagery (Light Detection And Ranging) to quantify 1) total encroachment and 2) total encroachment by three size classes: a) small 1 − 2.5 m, b) intermediate 2.5 − 4.5 m and c) tall > 4.5 m. Overall, of the total area classified as grassland in 1979 (277.64 ha), 31% had been encroached by 2010. Encroachment was greatest in the control treatments, followed by herbicide-only treatment application and lowest in the fire and herbicide treatment with minor differences in mean plant height (4.11 m ± 0.28). Encroached areas were mostly dominated by tall individuals (45 ± 3.5%), followed by the intermediate-height class (31.53 ± 1.10%) and the least recorded in the smallest-height class (23.46 ± 2.29%), suggesting expansion occurred during the initial phases of treatment application. The costly practice of herbicide application did not provide a feasible solution to control further woodland expansion. However, when using herbicide with fire, woodland expansion was reduced, highlighting the effectiveness of early intervention by fire in reducing encroachment. This further supports landscape-scale studies highlighting the effect of fire to reduce woodland expansion.The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information

A hierarchical perspective to woody plant encroachment for conservation of prairie-chickens

Encroachment of Great Plains grasslands by fire-sensitive woody plants is a large-scale, regional process that fragments grassland landscapes. Using prairie grouse (Tympanuchus spp.) of conservation concern,we apply hierarchy theory to demonstrate how regional processes constrain lower-level processes and reduce the success of local management. For example, fire and grazingmanagementmay be locally important to conservation, but the application of fire and grazing disturbances rarely cause irreversible fragmentation of grasslands in the Great Plains. These disturbance processes cause short-term alterations in vegetation conditions that can be positive or negative, but from a long-term perspective fire maintains large tracts of continuous rangelands by limiting woody plant encroachment. Conservation efforts for prairie grouse should be focused on landscape processes that contribute to landscape fragmentation, such as increased dominance of trees or conversion to other land uses. In fact, reliance on localmanagement (e.g.,maintaining vegetation structure) to alter prairie grouse vital rates is less important to grouse population persistence given contemporary landscape level changes. Changing grass height, litter depth, or increasing the cover of forbs may impact a fewremaining prairie-chickens, but itwill not create useable space at a scale relevant to the historic conditions that existed before land conversion and fire suppression.The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information

A hierarchical perspective to woody plant encroachment for conservation of prairie-chickens

Encroachment of Great Plains grasslands by fire-sensitive woody plants is a large-scale, regional process that fragments grassland landscapes. Using prairie grouse (Tympanuchus spp.) of conservation concern,we apply hierarchy theory to demonstrate how regional processes constrain lower-level processes and reduce the success of local management. For example, fire and grazingmanagementmay be locally important to conservation, but the application of fire and grazing disturbances rarely cause irreversible fragmentation of grasslands in the Great Plains. These disturbance processes cause short-term alterations in vegetation conditions that can be positive or negative, but from a long-term perspective fire maintains large tracts of continuous rangelands by limiting woody plant encroachment. Conservation efforts for prairie grouse should be focused on landscape processes that contribute to landscape fragmentation, such as increased dominance of trees or conversion to other land uses. In fact, reliance on localmanagement (e.g.,maintaining vegetation structure) to alter prairie grouse vital rates is less important to grouse population persistence given contemporary landscape level changes. Changing grass height, litter depth, or increasing the cover of forbs may impact a fewremaining prairie-chickens, but itwill not create useable space at a scale relevant to the historic conditions that existed before land conversion and fire suppression.The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information

The Combined Influence of Grazing, Fire, and Herbaceous Productivity on Tree–Grass Interactions

Although Juniperus communities are native to most regions of North America, they have proliferated in many areas of the Great Basin and Great Plains that historically supported grasslands, shrublands, and savannas. Explanations for the observed increases in Juniperus dominance, as well as other woody plant communities, ar

Nondestructive Estimation of Standing Crop and Fuel Moisture Content in Tallgrass Prairie

Accurate estimation of standing crop and herbaceous fuel moisture content (FMC) are important for grazing management and wildfire preparedness. Destructive sampling techniques have been used to accurately estimate standing crop and FMC, but those techniques are laborious and time consuming. Existing nondestructive methods for estimating standing crop in tallgrass prairie have limitations, and few studies have examined nondestructive estimation techniques for FMC in this environment. Therefore, our objective was to develop robust models for nondestructive estimation of standing crop and FMC in tallgrass prairie. We calibrated and validated stepwise multiple linear regression (SMLR) and artificial neural network (ANN) models for standing crop and FMC using data collected in tallgrass prairies near Stillwater, Oklahoma. Day of year (DOY), canopy height (CH), Normalized Difference Vegetation Index (NDVI), and percent reflectance in five wavelength bands were candidate input variables for the models. The study spanned two growing seasons and nine patches located within three pastures under patch burn management, and the resulting data set with > 3 000 observations was split randomly with 85% for model calibration and 15% withheld for validation. Standing crop ranged from 0 to 852 g m− 2, and FMC ranged from 0% to 204%. With DOY, CH, and NDVI as predictors, the SMLR model for standing crop produced a root mean squared error (RMSE) of 119 g m− 2 on the validation data, while the RMSE of the corresponding ANN model was 116 g m− 2. With the same predictors, the SMLR model for FMC produced an RMSE of 26.7% compared with 23.8% for the corresponding ANN model. Thus, the ANN models provided better prediction accuracy but at the cost of added computational complexity. Given the large variability in the underlying datasets, the models developed here may prove useful for nondestructive estimation of standing crop and FMC in other similar grassland environments. © 2018 Society for Range ManagementThe Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information