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Over the past several decades, the management of historically frequent-fire forests in the western United States has received significant attention due to the linked ecological and social risks posed by the increased occurrence of large, contiguous patches of high-severity fire. As a result, efforts are underway to simultaneously reduce potential fire and fuel hazards and restore characteristics indicative of historical forest structures and ecological processes that enhance the diversity and quality of wildlife habitat across landscapes. Despite widespread agreement on the need for action, there is a perceived tension among scientists concerning silvicultural treatments that modify stands to optimally reduce potential fire behavior (fuel hazard reduction) versus those that aim to emulate historical forest structures and create structurally complex stands (restoration). In this work, we evaluated thinning treatments in the Black Hills National Forest that exemplify the extremes of a treatment continuum that ranges from fuel hazard reduction to restoration. The goal of this work was to understand how the differing three-dimensional stand structures created by these treatment approaches altered potential fire behavior. Our results indicate that restoration treatments created higher levels of vertical and horizontal structural complexity than the fuel hazard reduction treatments but resulted in similar reductions to potential crown fire behavior. There were some trade-offs identified as the restoration treatments created larger openings, which generated faster mean rates of fire spread; however, these increased spread rates did not translate to higher levels of canopy consumption. Overall, our results suggest that treatments can create vertical and horizontal complexity desired for restoration and wildlife habitat management while reducing fire hazard and that they can be used in concert with traditional fuel hazard reduction treatments to reduce landscape scale fire risk. We also provide some suggestions to land managers seeking to design and implement prescriptions that emulate historical structures and enhance forest complexity.

We conducted a 2 y study of survival and cause-specific mortality of elk (Cervus elaphus) calves to determine the current status of elk occupying the southwestern region of the Black Hills National Forest, South Dakota and eastern Wyoming. We captured and fit 71 calves ≤10 d of age with expandable radiocollars during summer 2012 (n = 37) and 2013 (n = 34). We used known-fate analysis in Program MARK to estimate summer (15 May–25 Sep.) and annual (12 mo) survival for elk calves. The top model for summer survival was {S1–2wk,3–20wk} indicating mortality during 1–2 wk of age and 3–20 wk of age best explained survival; overall probability of surviving 20 wk was 0.79 (95% CI = 0.68–0.88). For annual (12 mo) survival, model {Sbirthweight} had the lowest AICc value indicating birth weight of elk calves best explained survival as heavier born calves had a higher probability of survival. The overall probability a calf survived to 12 mo of age was 0.75 (95% CI = 0.61–0.84). Cougar (Puma concolor) predation accounted for 81% of mortalities; remaining mortalities were from starvation (6.3%, n = 1) and unknown causes (6.3%, n = 1). Our results document high survival for calves likely due to productive habitats, an ecosystem-specific predator guild, and high alternative prey.

During the twentieth century, the North American porcupine (Erethizon dorsatum) was common in the Black Hills of western South Dakota and northeastern Wyoming. However, the low number of recent observations in the region has led to concern that porcupine populations have declined. We conducted systematic surveys to assess porcupine occurrence at two hundred and sixty-three 1-ha sites in the Black Hills National Forest, Custer State Park, Jewel Cave National Monument, Mount Rushmore National Memorial, and Wind Cave National Park during 2016–2017. We observed no porcupines or recent feeding sign. We also noted few recent observations in information compiled from online databases and from other natural resource surveys with which we have been involved in the South Dakota Black Hills. Given the apparent abundance of porcupines in this area in the twentieth century, our results suggest that populations have declined dramatically. Predation by mountain lions (Puma concolor), habitat loss, and human-caused mortality are potential contributing factors, but estimating the degree of population declines and assessing hypotheses about the causes are hindered by a lack of long-term data on the region's porcupine populations. Moreover, accounts of the region's mammalian fauna suggest that porcupines were not abundant in the region during the late 1800s but became common in the early twentieth century.

We evaluated changes in forest structure related to fire severity after a wildfire in ponderosa pine forests of the Black Hills, South Dakota, where 25% burned at low, 48% at moderate, and 27% at high severity. We compared tree mortality, fine (FWD) and coarse woody debris (CWD) and tree regeneration in areas burned under different severity. With low severity, mortality was limited to small trees (<15 cm dbh) with no reduction in basal area (BA) compared with unburned areas. FWD and CWD were 60% less than the unburned forest. With moderate severity, 100% mortality of small trees and significant large tree mortality resulted in an approximately 50% reduction in BA and an open stand structure dominated by a few large trees. After 5 years, FWD and CWD recovered to unburned levels. With high severity, a lack of seed source makes regeneration unlikely. After 5 years, FWD equaled levels in unburned stands and CWD loads exceeded the unburned forest by 74%. The future landscape will be a mosaic of patches with forest structures determined by developmental trajectories set in motion by different fire severities. There will be patches of fully stocked, single canopy forest, multistory forest, and persistent grass- and shrub-dominated communities. High fuel loads in moderate and high severity areas remain a concern for management as does the lack of regeneration in high severity areas.

Two determinants of crown fire hazard are canopy bulk density (CBD) and canopy base height (CBH). The Fire and Fuels Extension to the Forest Vegetation Simulator (FFE-FVS) is a model that predicts CBD and CBH. Currently, FFE-FVS accounts for neither geographic variation in tree allometries nor the nonuniform distribution of crown mass when one is estimating CBH and CBD. We develop allometric equations specific to ponderosa pine (Pinus ponderosa Dougl. ex Laws.) in the Black Hills to predict crown mass and use the Weibull distribution to model the vertical distribution of crown mass within individual trees. We present parameter prediction models that, in turn, predict the vertical distribution of crown mass based on stand- and tree-level attributes. With use of an FFE-FVS executable incorporating local crown mass equations and the parameter prediction models, new estimates of CBD and CBH were produced. Locally derived biomass equations predicted substantially greater estimates of foliage mass than currently predicted by FFE-FVS. The increase in CBD resulting from the local biomass and vertical distribution models averaged 78% over original estimates. Our results suggest that locally derived crown mass equations in addition to nonuniform estimates of crown mass distribution be used to calculate CBH and CBD as used in fire prediction models.

The Mountain Pine Beetle Response (PBR) Project on the Black Hills National Forest demonstrates how resource professionals and the public can collaborate, anticipate, and apply a suite of silvicultural tools across large landscapes to more effectively respond to quickly changing ecosystems within the legal framework governing national forests. Across the West, bark beetle epidemics have been outpacing the ability of resource managers to respond with traditional approaches. In the Black Hills, it was time for a change, especially because local communities and stakeholders had become anxious and eagerly supported new approaches. Borrowing the best from research and practical experiences and with a fresh eye on the future, foresters developed the PBR Project across a million acre landscape in western South Dakota and northeastern Wyoming, with adaptive features to more swiftly address expanding pine beetle populations and reduce hazardous fuels.

Ruffed grouse (Bonasa umbellus) are a popular game bird and the management indicator species for quaking aspen (Populus tremuloides) in the Black Hills National Forest (BHNF), which requires development of a robust monitoring protocol to evaluate trends in ruffed grouse populations. We used roadside drumming surveys in spring 2007 and 2008 to estimate ruffed grouse occupancy and detection probabilities in the BHNF while simultaneously assessing the influence of sampling and site covariates on these processes. Ruffed grouse occupancy estimates were constant between spring 2007 and 2008 (ψ; = 0.12, SE = 0.03) and were positively influenced by the amount of aspen surrounding the site. Detection probability estimates were constant between spring 2007 and 2008 (p = 0.27, SE = 0.06) and were influenced by survey date in a quadratic form and negatively influenced by wind speed and time of the survey. Collectively, our results demonstrated that ruffed grouse occupancy and detection probabilities in the BHNF were low. Occupancy could be increased by increasing the extent of aspen. To improve monitoring efficiency and maximize probability of detecting ruffed grouse, ruffed grouse monitoring should be conducted during the peak of drumming (mid-May), during favorable weather conditions such as low wind speeds and little precipitation, and during early morning, near sunrise.

Surveys to detect damage on forested lands occur annually across the United States. Historically, much of these data have been collected by observers in aircraft documenting visible damage using a technique known as aerial detection survey (ADS) or sketchmapping. ADS is an efficient method but produces coarse scale data. We used one meter natural color imagery to conduct a photo interpretation survey (PIS) to compare the resulting data with the annual ADS data. The study area consists of a portion of the Black Hills National Forest that is currently experiencing mountain pine beetle-induced conifer mortality. Ground plots were used to compare how accurately each survey method delineated forest damage and results indicate a statistically significant difference (alpha 0.05) between ADS and PIS and a trend toward no significant difference when a buffer is considered. Substantial differences in the average size of polygons, total number of polygons, and total area mapped were observed. Our results indicate that current estimates of mortality intensity in our study area are low and remedies should be investigated. Photo surveys over the Black Hills National Forest are less efficient but yield damage polygons with higher accuracy and with fewer errors of commission than traditional ADS.

Wildlife conservationists design monitoring programs to assess population dynamics, project future population states, and evaluate the impacts of management actions on populations. Because agency mandates and conservation laws call for monitoring data to elicit management responses, it is imperative to design programs that match the administrative scale for which management decisions are made. We describe a program to monitor population trends in American beaver (Castor canadensis) on the US Department of Agriculture, Black Hills National Forest (BHNF) in southwestern South Dakota and northeastern Wyoming, USA. Beaver have been designated as a management indicator species on the BHNF because of their association with riparian and aquatic habitats and its status as a keystone species. We designed our program to monitor the density of beaver food caches (abundance) within sampling units with beaver and the proportion of sampling units with beavers present at the scale of a national forest. We designated watersheds as sampling units in a stratified random sampling design that we developed based on habitat modeling results. Habitat modeling indicated that the most suitable beaver habitat was near perennial water, near aspen (Populus tremuloides) and willow (Salix spp.), and in low gradient streams at lower elevations. Results from the initial monitoring period in October 2007 allowed us to assess costs and logistical considerations, validate our habitat model, and conduct power analyses to assess whether our sampling design could detect the level of declines in beaver stated in the monitoring objectives. Beaver food caches were located in 20 of 52 sampled watersheds. Monitoring 20 to 25 watersheds with beaver should provide sufficient power to detect 15-40% declines in the beaver food cache index as well as a twofold decline in the odds of beaver being present in watersheds. Indices of abundance, such as the beaver food cache index, provide a practical measure of population status to conduct long-term monitoring across broad landscapes such as national forests.

Northern flying squirrels (Glaucomys sabrinus) and red squirrels (Tamiasciurus hudsonicus) in the Black Hills National Forest (BHNF) of South Dakota represent isolated populations. Because data on both species in the region are limited, and because the northern flying squirrel in South Dakota and the Black Hills National Forest has species of concern status, we trapped throughout BHNF to determine relative abundance in different forest types for both populations. For northern flying squirrels, capture rate was higher in the northern and western hills compared to the southern and eastern hills, whereas for red squirrels, capture rate was higher in the western hills, followed by the southern and eastern hills. The northern hills are classified as mesic coniferous forest transitioning to a dry coniferous forest in the southern hills. In addition, the northern hills is characterized by a mixed coniferous-deciduous forest, whereas the southern and eastern hills are characterized by even-aged managed coniferous stands. Understanding the abundance of these two isolated squirrel populations in the different forest types of the BHNF is important in intensively managed forests, because management decisions can impact isolated populations.