The recruitment trends of whitebark pine (Pinus albicaulis Engel.) were investigated in 18 recently burned stands in the Canadian Rockies and the North Cascades. Whitebark pine recruitment in recently burned stands (fires < 60 years prior) was compared to that on paired control stands (no recent fire) to determine if fire was necessary for successful recruitment. Recruitment in recently burned stands was compared with ecological and seed source variables. Along a chronosequence, whitebark pine recruitment was compared with precipitation and with Pacific Decadal Oscillation (PDO). Field sampling consisted of systematic plots established in sampling grids in both burned and control stands. In each plot ecological data was collected as was data regarding whitebark pine age, height, and disease status. Recent fire was not found to be a requirement for recruitment. Both distance to and size of seed source were important predictors of whitebark pine recruitment. Whitebark pine regeneration densities were low on warm steep rocky sites. High whitebark pine recruitment on cooler aspects suggested that whitebark pine could establish on cooler sites when competition was removed by fire. Most stands were composed of mixed conifers, but only lodgepole pine appeared to limit the growth of whitebark pine. Whitebark pine recruitment was episodic on all stands, and recruitment years were correlated among many stands separated by large distances. Episodic recruitment may be due to more than cone masting as recruitment in several stands was also correlated with growing season precipitation and positive PDO values, which may increase the length of growing season. A logistic regression model suggested that infection by white pine blister rust is most likely on older seedlings. The percentage of whitebark pine trees infected by white pine blister rust on a site increased with time since fire. Prescribed fires and wildfires should address retention of whitebark pine seed trees on site. Fires that remove competition from mesic-submesic stands may result in the most rapid recruitment of whitebark pine. With the exception of stands heavily stocked with lodgepole pine, all recently burned stands in this study would benefit from increased stocking of whitebark pine by planting.

The recruitment trends of whitebark pine (Pinus albicaulis Engel.) were investigated in 18 recently burned stands in the Canadian Rockies and the North Cascades. Whitebark pine recruitment in recently burned stands (fires < 60 years prior) was compared to that on paired control stands (no recent fire) to determine if fire was necessary for successful recruitment. Recruitment in recently burned stands was compared with ecological and seed source variables. Along a chronosequence, whitebark pine recruitment was compared with precipitation and with Pacific Decadal Oscillation (PDO). Field sampling consisted of systematic plots established in sampling grids in both burned and control stands. In each plot ecological data was collected as was data regarding whitebark pine age, height, and disease status. Recent fire was not found to be a requirement for recruitment. Both distance to and size of seed source were important predictors of whitebark pine recruitment. Whitebark pine regeneration densities were low on warm steep rocky sites. High whitebark pine recruitment on cooler aspects suggested that whitebark pine could establish on cooler sites when competition was removed by fire. Most stands were composed of mixed conifers, but only lodgepole pine appeared to limit the growth of whitebark pine. Whitebark pine recruitment was episodic on all stands, and recruitment years were correlated among many stands separated by large distances. Episodic recruitment may be due to more than cone masting as recruitment in several stands was also correlated with growing season precipitation and positive PDO values, which may increase the length of growing season. A logistic regression model suggested that infection by white pine blister rust is most likely on older seedlings. The percentage of whitebark pine trees infected by white pine blister rust on a site increased with time since fire. Prescribed fires and wildfires should address retention of whitebark pine seed trees on site. Fires that remove competition from mesic-submesic stands may result in the most rapid recruitment of whitebark pine. With the exception of stands heavily stocked with lodgepole pine, all recently burned stands in this study would benefit from increased stocking of whitebark pine by planting.

The purpose of this project is to determine landowners’ perceptions on the use of prescribed fire as a management tool. The majority of Texas rangelands are privately owned, and the sustainable management of almost all of the state’s rangelands is contingent upon private land management decisions. Therefore, it is imperative for policy makers and extension agencies to understand landowners’ perceptions, interests and concerns about alternative land management techniques. This is especially important for the use of prescribed fire, which has been identified as a critical management tool for maintaining the productivity of most Texas rangelands yet many landowners do not include it as an integral practice in managing their land. A better understanding of landowners’ perspective of the use of fire could facilitate the increased use of this management tool through the development of effective educational, costshare and fire planning programs. The study reported here consisted of a mail survey of all 185 members of the Edwards Plateau Prescribed Burn Association (EPPBA) and 600 landowners in six counties in Texas. Four of those counties were located in the Edwards Plateau (Sutton, Schleicher, Mason, Llano) and two counties were located in the Rolling Plains (Throckmorton, Shackleford). In each county, 100 landowners possessing at least 50 acres of land were randomly selected for inclusion in the survey. The mail survey approach followed Dilman’s five-step mailing procedure. Fire is an important rangeland management tool, but in a state where the majority of the land is privately owned fire suppression is still a dominant perspective. Our study suggests that important efforts to increase the use of prescribed fire include, educational programs about use of fire by landowners, increased assistance with prescribed fire plans, cost-sharing programs for fire implementation, and reduction in the legal liability associated with fire that burns out of control. Encouraging agencies to back educational programs and help teach landowners about the effects and uses of fire (burn plan assistance), and developing a resource pool to underwrite fire policies could increase the interest in and risk associated with the use of prescribed fires to more effectively manage rangelands in Texas, and elsewhere.

Grassland organisms evolved alongside the interaction of fire and grazing, but modern management often decouples these disturbances. In order to analyze the effects of reintroducing this interaction, we implemented four treatments. Two of these treatments were variations of patch-burn grazing, one was modified rest-rotation grazing, and one was season-long grazing. We chose to monitor the butterfly response to these treatments because butterflies have short generations, require a wide variety of resources, and are easily identifiable as adults. We quantified both the butterfly community and the behavioral time budgets of two species. We found that the butterfly community is more species-rich and abundant in treatments including fire than in treatments without fire. We found no difference in time budgets between treatments. Overall, we suggest that managers implement a carefully-planned patch-burn grazing regime in order to support grassland butterflies and other organisms.

Tree diameter, bark thickness and texture, litter bulk density and chemistry, and sprouting ability are a few, species-specific adaptations and properties that may be related to an individual tree stem's potential fire resistance. Based upon these features and others, trees exhibiting similar characteristics have been broadly classified as pyrophytic or pyrophobic. To our knowledge, few if any, research studies have been conducted to determine if tree buds may exhibit speciesspecific fire or heat tolerance. Understanding potential relationships between bud characteristics and fire tolerance may assist prescribed fire managers as they target control of specific undesired tree species while promoting desired tree species. Buds of six common hardwood species in the southeastern U.S. were harvested and exposed to different heat dosages using a propane gas tube burner: red maple (Acer rubrum L.), yellow-poplar (Liriodendron tulipifera L.), American beech (Fagus grandifolia Ehrh.), mockernut hickory (Carya tomentosa Lam.), scarlet oak (Quercus coccinea Münchh.), and chestnut oak (Quercus montana Willd.). These species are commonly categorized as pyrophobic (American beech, red maple, yellow-poplar) and pyrophytic (chestnut oak, mockernut hickory, scarlet oak). Using electrolyte leakage of heated and unheated buds, the mean difference in bud percent mortality between heated and unheated buds was compared by species, functional group, and differing heat dosages. The mean difference in bud percent mortality differed between the heated and unheated buds by species (p < 0.0001). Heated buds of yellow-poplar, mockernut hickory, and chestnut oak displayed similar percent mortality; however, the presumed pyrophytic species had greater heated bud percent mortality (34.0 %) than the pyrophobic species (26.8 %) (p = 0.0003). Heated bud percent mortality differed based upon differing heat dosage levels (height above the propane burner and heat exposure time) and their species-specific interactions. Fire tolerance, as assigned and assessed by features such as bark texture and thickness, may not be directly related to mid-story tree bud physical properties (i.e. length, mass, and diameter) or fire tolerance. Research including additional species, heat dosages, and different sampling times (i.e. late fall vs. late winter) would be valuable for investigating these dynamics further. Deploying a similar, field-scale experiment before and after prescribed burns would be useful to determine how tree buds may respond to different heat dosages that could be exacted during prescribed burns. / Master of Science / Prescribed fire is utilized on millions of acres per year in the southeastern United States. These burns are conducted for a variety of reasons, including: wildlife habitat establishment, restoration, and maintenance; aesthetics; hazardous fuel reduction; and the control of undesired vegetative species. Factors that may influence an individual species' response to fire include, but are not limited to: bark thickness and texture, litter bulk density and chemistry, and resprouting strategy. These traits may differ by species and by the age of a given stem. Few studies have investigated these characteristics in younger tree stems within the southeastern United States. Additionally, few research studies in any ecosystem have investigated potential species-specific tree bud responses to increased heat. Determining if undesired tree species respond differently to heating than desired tree species may provide additional information to assist prescribed fire managers in many locations where vegetation control is a management objective. As a result of this knowledge gap, a research study was designed to investigate these dynamics in the southeastern United States for six common, hardwood tree species: red maple (Acer rubrum L.), yellow-poplar (Liriodendron tulipifera L.), American beech (Fagus grandifolia Ehrh.), mockernut hickory (Carya tomentosa Lam.), scarlet oak (Quercus coccinea Münchh.), and chestnut oak (Quercus montana Willd.). The results suggested that percent bud mortality may be species-specific, but few relationships appeared to be present to relate bud physical characteristics to bud mortality. Additionally, supposed heat tolerance groups assigned to older tree stems based upon traits, such as bark thickness and texture, did not provide a valid assessment of bud mortality. Additional research is needed to understand these dynamics further, including burning under different heat dosages, evaluating additional tree species, and assessing bud mortality resulting from in-the-field prescribed fires.

Forestry-prescribed fires have been essential for managing forestland and reducing the risk of catastrophic wildfires. However, the use of prescribed fires has also raised concerns about their potential environmental and social impacts, leading to the development of various statutes and regulations that govern their implementation. This study explores the evolving legislative efforts related to forestry prescribed fire in managing forests and reducing wildfire risks to assess their dynamic nature. Determinants behind these legislative patterns are examined using qualitative content analysis and a binary logit model. A total of 199 legislative bills related to forestry prescribed fire were identified from 1995 to 2023 across the United States. The Southern United States reported the highest number of legislative bills. The passing rate of those legislative bills stands at 46.7%. This study contributes to a comprehensive understanding of the legislative effort surrounding forestry prescribed fires and informs ongoing discussions on effective forest management practices.

Dry mixed conifer forests of southwestern North America are projected to be particularly vulnerable to ongoing persistent warm drought conditions, and related increases in wildfire frequency, size and severity, due in part to consequences of over a century of fire exclusion. Prescribed fire is applied actively in many landscapes to reduce hazardous fuel loads and continuity, restore forest community composition and structure, and increase tree resilience to drought stress. However, fire can also adversely affect tree growth by damaging cambial, root, and canopy tissues, leading to tradeoffs in the use of fire as a tool for forest resilience. Radial growth is an indicator of climatic and ecological stress and can thus provide a relative measure of resilience to stress and disturbances; but, the mechanisms driving tree resilience to prescribed fire and concurrent drought are poorly understood. Thinning effects of prescribed fire may increase tree resilience to drought by increasing water, light and nutrient availability and production of defense mechanisms. However, trends over the last century indicate warming temperatures are increasing tree sensitivity to fire by reducing post-fire growth (lower resilience) and increasing the likelihood of mortality. Trees can be resistant to fire exposure, and where growth changes occur they can be transient or persistent. We studied the interactions between tree- and stand-level fire effects on the growth responses of surviving Abies concolor, Pinus jefferyi, Pinus ponderosa, and Pseudotsuga menziesii over 24 years of variable climatic conditions in ten National Parks across the western and southwest United States. We used linear mixed effects models to identify mechanisms influencing resistance and resilience responses to fire and interannual climate, using climatic water deficit (CWD) as an index of climatic stress. Compared to pre-fire growth, trees exposed to fire increased growth during periods of greater water deficits. Tree growth responses were variable among and within species and size classes, but contingent on time-since-fire and the climate during the recovery period. Negative fire effects on tree resistance were generally transient, while climate and pre-existing stand conditions were persistent controls on tree resilience. These results suggest that antecedent and subsequent climate conditions modulate post-fire forest response. Consideration of climate variation could improve the strategic use of prescribed fire for tree resilience to drought, and a deeper understanding of factors contributing to prefire growth may elucidate the mechanisms driving post-fire growth responses.

Master of Science / Department of Animal Sciences and Industry / K C Olson / The largest intact remnant of the tallgrass prairie, the Flint Hills ecoregion, is currently under threat from the invasive weed sericea lespedeza (Lespedeza cuneata [Dumont] G. Don; SL). The objectives of this research were to evaluate the efficacy of late-season prescribed burning and fall herbicide application, alone and in concert, for comprehensive control of sericea lespedeza and to assess their broader treatment impacts on native plant communities. A 31-ha native tallgrass pasture with a light to moderate infestation of SL was divided into 16 subunits for this experiment. Each subunit was randomly assigned to 1 of 4 treatments: negative control, spray-only, burn-only, or burn-plus-spray. A prescribed burn was conducted on burn-only and burn-plus-spray subunits in early September 2016. Following the re-emergence of SL, spray-only and burn-plus-spray subunits received a broadcast application of metsulfuron methyl (Escort XP, DuPont, Wilmington, DE) at a rate of 70.1 g ˖ ha⁻¹ in late September. Frequency and vigor of SL, total forage biomass, soil cover, and plant species composition were measured along permanent 100-m transects in each subunit prior to treatment application and again 12 mo later, in 2017 (i.e., 1 YAT). In 30 x 30-cm plots at 1-m intervals along each transect, the presence or absence of SL was noted. Where SL was present, crown maturity and maximum stem length of the SL plant nearest to the transect were recorded. Presence of multiple stems in plots was also recorded. Prior to treatment application, SL comprised 1 ± 2.0% of total basal cover and was not different between treatments (P = 0.38). One YAT, SL was more abundant (P ≤ 0.02) in negative control subunits than in spray-only, burn-only, or burn-plus-spray subunits, which were not different (P ≥ 0.95) from one another. Aerial frequency of SL, abundance of mature SL crowns, and incidence of plots with multiple SL stems were greatest (P ≤ 0.03) for negative controls, although not different (P ≥ 0.50) between the other 3 treatments. The change in forage biomass production 1 YAT did not differ (P = 0.16) between treatments. A tendency (P = 0.06) for a shift from litter cover to bare soil was noted when the spray-only, burn-only, and burn-plus-spray treatments were compared to the negative control. Graminoid basal cover was greater (P < 0.01) in the spray-only and burn-plus-spray treatments than in the negative-control and burn-only treatments 1 YAT. Conversely, forb basal cover was less (P = 0.01) in spray-only and burn-plus-spray treatments than in negative-control and burn-only treatments. The evenness component of diversity decreased in the burn-plus-spray treatment relative to the negative control (P ≤ 0.01). These data indicate that each of these strategies were effective in reducing SL populations. Although late-summer prescribed burning produced no detected negative responses within the native plant community, fall herbicide application, alone or in conjunction with prescribed burning, resulted in collateral damage to forb populations. A late-summer prescribed burn alone is recommended for low-cost comprehensive control of a light to moderate sericea lespedeza infestation.

No description available.

African American landownership is decreasing in the southeastern United States. At the same time, prescribed fire use, research, and outreach are increasing. This disparity between changing landowner demographics and a renewed interest in a historically prevalent land management tool has prompted a broader conversation about diversity and inclusion in outreach programs and land management preferences. Therefore, an exploratory qualitative study was conducted using semi-structured interviews with African American non-industrial private landowners (NIPLs) in southern Alabama, northern Florida, and southwestern Georgia. The objectives of this study were to address the following questions: 1) Do African American NIPLs use prescribed fire?; 2) Why do they choose or refuse to use prescribed fire?; 3) What potential constraints discourage African American NIPLs from using prescribed fire? Twenty-one African American landowners within these states were interviewed from May through August 2019. Analysis of these interviews was completed using rapid rural appraisal, a method used to quickly gather data from individuals in rural settings. The results suggested that 81% of the African American NIPLs interviewed used prescribed fire to accomplish specific land management objectives, such as hazardous fuel reduction, undesired vegetation control, timber stand improvement, pest and disease reduction, and aesthetics. These individuals faced unique potential limitations including a lack of relevant information regarding prescribed fire permits, smoke management, safety, and burning smaller parcels. These individuals also desired opportunities to retain land within their own families and also felt they were underrepresented within land management organizations and extension programs. In the future, policymakers' efforts may benefit from an intentional focus on building relationships with individual landowners, enhancing educational programming and access for landowners maintaining small and large parcels, and striving for diverse and inclusive representation within land management organizations. / Master of Science / During a period of time when the use of prescribed fire (i.e. intentionally ignited fires by land managers and professionals) has increased in the southeastern United States, African American non-industrial private landownership has decreased. When surveyed alongside white and Hispanic landowners within this region, African American private landowners expressed negative attitudes toward prescribed fire and responded at lower rates than others. The combined issues of land loss, minority representation, and the need for prescribed fire on private lands has generated questions about diversity and inclusion in landowner assistance and fire outreach programming. To address these issues, first-hand accounts were necessary to understand land management perspectives from African American private landowners within this region. Therefore, a research study was conducted to interview African American private landowners in southern Alabama, northern Florida, and southwestern Georgia. The objectives of this study were to determine what African Americans know about prescribed fire and if African American private landowners use prescribed fire for land management. Through personal interviews, African American landowners were asked to describe what influenced their use or lack of use of fire and what relationships they had formed with outreach and educational organizations. These individuals were also asked how they believed their prescribed fire perspectives and usage connected to their ancestral heritage. Twenty-one interviews were conducted and the results suggested that seventeen interviewees used prescribed fire at communal, historical, and organizational levels, but limitations to prescribed fire use did exist. Agency and organizational policymakers should focus on building relationships with individual landowners while offering better educational access that focuses on maintaining land legacies, particularly those that would be considered small parcels. Additionally, most of the landowners interviewed believed they were underrepresented within organizational leadership. There is indeed a cultural fabric that cannot be erased from current African American private landowners. Their practices and views are key to the inclusive and diverse conversations that should guide southeastern prescribed fire into the future.