Influence of Habitat Type and Prescribed Burning on Feral Swine Depredation of Artificial Quail Nests

Feral swine (Sus scrofa) have increased both spatially and numerically in the Rolling Plains of northwest Texas. Resource managers have little information on the interrelationships between feral swine and native species such as the northern bobwhite (Colinus virginianus). Nest predation by feral swine could adversely affect bobwhite reproduction. Honey mesquite (Prosopis glandulosa) and redberry juniper (Juniperus pinchotii) are the dominant woody plants in northwestern Texas and prescribed burning is used to manage both species. Two experiments were conducted to determine the extent of feral swine depredation on artificial quail nests. In 1992-93, we monitored nest loss in mesquite and juniper habitats for six weeks. Total depredation reached 85 and 98% after three and six weeks respectively, during 1992, compared to 60 and 92% in 1993. Feral swine depredation of artificial bobwhite nests was 33% across years and was evenly distributed between vegetation types. During three-week periods in June and July 1994, depredation was greater (P\u3c0.001) in an unburned (90%) pasture than in unburned areas within a burned (32%) pasture. Decreased predator activity in the burned pasture was probably due to temporary prey displacement and less forage. Feral swine depredation of artificial bobwhite nests was 14% in 1994. Feral swine could potentially have negative impacts for northern bobwhites in mesquite and juniper habitats of northwest Texas

Utility of Satellite and Aerial Images for Quantification of Canopy Cover and Infilling Rates of the Invasive Woody Species Honey Mesquite (Prosopis Glandulosa) on Rangeland

Woody plant encroachment into grasslands and rangelands is a world-wide phenomenon but detailed descriptions of changes in geographical distribution and infilling rates have not been well documented at large land scales. Remote sensing with either aerial or satellite images may provide a rapid means for accomplishing this task. Our objective was to compare the accuracy and utility of two types of images with contrasting spatial resolutions (1-m aerial and 30-m satellite) for classifying woody and herbaceous canopy cover and determining woody infilling rates in a large area of rangeland (800 km<sup>2</sup>) in north Texas that has been invaded by honey mesquite (<em>Prosopis glandulosa</em>). Accuracy assessment revealed that the overall accuracies for the classification of four land cover types (mesquite, grass, bare ground and other) were 94 and 87% with kappa coefficients of 0.89 and 0.77 for the 1-m and 30-m images, respectively. Over the entire area, the 30-m image over-estimated mesquite canopy cover by 9 percentage units (10 <em>vs.</em> 19%) and underestimated grass canopy cover by the same amount when compared to the 1-m image. The 30-m resolution image typically overestimated mesquite canopy cover within 225 4-ha sub-cells that contained a range of mesquite covers (1–70%) when compared to the 1-m image classification and was not suitable for quantifying infilling rates of this native invasive species. Documenting woody and non-woody canopy cover on large land areas is important for developing integrated, regional-scale management strategies for rangeland and grassland regions that have been invaded by woody plants

Optimization viewpoint on Kalman smoothing, with applications to robust and sparse estimation

In this paper, we present the optimization formulation of the Kalman filtering and smoothing problems, and use this perspective to develop a variety of extensions and applications. We first formulate classic Kalman smoothing as a least squares problem, highlight special structure, and show that the classic filtering and smoothing algorithms are equivalent to a particular algorithm for solving this problem. Once this equivalence is established, we present extensions of Kalman smoothing to systems with nonlinear process and measurement models, systems with linear and nonlinear inequality constraints, systems with outliers in the measurements or sudden changes in the state, and systems where the sparsity of the state sequence must be accounted for. All extensions preserve the computational efficiency of the classic algorithms, and most of the extensions are illustrated with numerical examples, which are part of an open source Kalman smoothing Matlab/Octave package.Comment: 46 pages, 11 figure

Influence of a montmorency cherry juice blend on indices of exercise-induced stress and upper respiratory tract symptoms following marathon running—a pilot investigation

Background: Prolonged exercise, such as marathon running, has been associated with an increase in respiratory mucosal inflammation. The aim of this pilot study was to examine the effects of Montmorency cherry juice on markers of stress, immunity and inflammation following a Marathon. Methods: Twenty recreational Marathon runners consumed either cherry juice (CJ) or placebo (PL) before and after a Marathon race. Markers of mucosal immunity secretory immunoglobulin A (sIgA), immunoglobulin G (IgG), salivary cortisol, inflammation (CRP) and self-reported incidence and severity of upper respiratory tract symptoms (URTS) were measured before and following the race. Results: All variables except secretory IgA and IgG concentrations in saliva showed a significant time effect (P < 0.01). Serum CRP showed a significant interaction and treatment effect (P < 0.01). The CRP increase at 24 and 48 h post-Marathon was lower (P < 0.01) in the CJ group compared to PL group. Mucosal immunity and salivary cortisol showed no interaction effect or treatment effect. The incidence and severity of URTS was significantly greater than baseline at 24 h and 48 h following the race in the PL group and was also greater than the CJ group (P < 0.05). No URTS were reported in the CJ group whereas 50 % of runners in the PL group reported URTS at 24 h and 48 h post-Marathon. Conclusions: This is the first study that provides encouraging evidence of the potential role of Montmorency cherries in reducing the development of URTS post-Marathon possibly caused by exercise-induced hyperventilation trauma, and/or other infectious and non-infectious factors

Endurance performance is influenced by perceptions of pain and temperature: Theory, applications and safety considerations.

Models of endurance performance now recognise input from the brain, including an athlete’s ability to cope with various non-pleasurable perceptions during exercise, such as pain and temperature. Exercise training can reduce perceptions of both pain and temperature over time, partly explaining why athletes generally have a higher pain tolerance, despite a similar pain threshold, compared with active controls. Several strategies with varying efficacy may ameliorate the perceptions of pain (e.g. acetaminophen, transcranial direct current stimulation and transcutaneous electrical stimulation) and temperature (e.g. menthol beverages, topical menthol products and other cooling strategies, especially those targeting the head) during exercise to improve athletic performance. This review describes both the theory and practical applications of these interventions in the endurance sport setting, as well as the potentially harmful health consequences of their use

Vertical Brush Sculpting for Heterogeneity in Mesquite Savanna: Implementation and Effect on Grass Production

Managing woody species that have encroached into grasslands and can resprout following top-kill has become an increasing problem. Treatments that yield complete mortality (i.e., “root-kill”) such as mechanical grubbing are often too costly at landscape scale. Less expensive treatments that only top-kill are problematic if treatments are not applied frequently to maintain regrowth suppression. More sustainable strategies are needed. Previous research found that a low rate (0.28 kg·ha−1) of clopyralid-only herbicide root-killed some honey mesquite (Prosopis glandulosa) but importantly caused partial top-kill (PTK) in surviving trees that maintained apical dominance and prevented basal sprouting. This management approach, referred to as “vertical brush sculpting,” increased herbaceous productivity compared with top-killed mesquite with dense resprouting. Here we determined if higher rates of clopyralid could increase mesquite root-kill and maintain the PTK physiognomy in surviving plants. We evaluated effects of clopyralid at 0.28, 0.42, and 0.56 kg·ha−1 (C28, C42, and C56, respectively) and a mixture of clopyralid (0.28 kg·ha−1) + triclopyr (0.28 kg·ha−1) (C + T) on mesquite physiognomy. Averaged over two sites at 6 yr post treatment (YPT), root-kill was 0%, 20.0%, 42.8%, 58.9%, and 65.6% in untreated, C28, C42, C56, and C + T, respectively. Among surviving trees, percent PTK with no basal sprouts was greatest in clopyralid-only treatments; percent top-killed with basal sprouting was greatest in C + T. Grass production, measured in untreated, C28, and C + T, ranged from 110% to 215% greater in treated than untreated at 2 YPT. We developed a model to project stand-level mesquite competitive impact on grasses in all treatments over 30 yr. Mesquite competitive impact values were lowest in C42 and C56 due to high root-kill, and most survivors had noncompetitive PTK physiognomy. We viewed C42 as the best option due to lower cost. Vertical brush sculpting offers a method to reduce woody competition with grasses yet maintain landscape heterogeneity.This article is published as Ansley, R. James, and Michael J. Castellano. "Vertical Brush Sculpting for Heterogeneity in Mesquite Savanna: Implementation and Effect on Grass Production." Rangeland Ecology & Management 88 (2023): 12-21. doi:10.1016/j.rama.2023.01.007. Posted with permission.This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Comparison of Ground-Measured and Image-Classified Mesquite (Prosopis glandulosa) Canopy Cover

Remote sensing has long been recognized as a rapid, inexpensive, nondestructive, and synoptic technique to study rangeland vegetation and soils. With respect to the worldwide phenomenon of woody plant invasion on many grasslands and rangelands, there is increasing interest in accurate and cost-effective quantification of woody plant cover and distribution over large land areas. Our objectives were to 1) investigate the relationship between ground-measured and image-classified honey mesquite (Prosopis glandulosa Torr.) canopy cover at three sites in north Texas using high spatial resolution (0.67-m) aerial images, and 2) examine the suitability of aerial images with different spatial resolutions (0.67-m, 1-m, and 2-m) for accurate estimation of mesquite canopy cover. The line intercept method and supervised maximum likelihood classifier were used to measure mesquite cover on the ground and on images, respectively. Images all were taken in September when mesquite foliage was photosynthetically active and most herbaceous vegetation was dormant. The results indicated that there were robust agreements between classified and ground-measured mesquite cover at all three sites with the coefficients of determination (r2) >0.95. Accuracy of lower spatial resolution images ranged from r2=0.89-0.93, with the 2-m spatial resolution image on one of the sites at r2=0.89. For all sites, the overall, producer’s, and user’s accuracies, and kappa statistics were 92% and 97%, 91% and 99%, 85% and 96%, and 0.82 and 0.95 for 2-m and 0.67-m spatial resolution images, respectively. Results showed that images at all three spatial resolution levels were effective for estimating mesquite cover over large and remote or inaccessible areas./La técnica de sensores remotos ha sido reconocida como una técnica rápida, económica, no destructiva, y sinóptica para el estudio de la vegetación de los pastizales y suelos. Con respecto al fenómeno mundial de invasión de plantas leñosas praderas y pastizales, existe un creciente de interés en la cuantificación precisa y efectiva en costo, del alcance y distribución de las plantas leñosas en grandes extensiones de tierra. Nuestros objetivos fueron: 1) investigar la relación entre la medición en tierra y la clasificación de imágenes de la cobertura del mezquite (Prosopis glandulosa Torr), en tres sitios al norte de Texas, usando imágenes de alta resolución espacial (0.67-m), y 2) examinando las imágenes aéreas más apropiadas con diferentes resolución es espaciales (0.67-m, 1-m y 2-m) para una exacta estimación de la cobertura del mezquite. Se usaron el método de la línea de intercepción y el clasificador de máxima probabilidad para medir la cubierta del mezquite en el suelo en las imágenes respectivamente. Todas las imágenes se tomaron en Septiembre cuando el follaje del mezquite estaba fotosintéticamente activo y la mayoría de la vegetación herbácea perennes estaba inactiva. Los resultados indicaron que hubo sólidos coincidencias entre las medidas clasificadas y las del suelo en la medida de cobertura del mezquite en todos los sitios con coeficientes de determinación (r2)>0.95. La precisión de las imágenes espaciales de menor resolución, varían entre r2=0.89–0.93, con 2-m de resolución espacial de imagen en uno de los sitios a r2=0.89. En todos los sitios, en general, las cifras de precisión de los productores y usuarios y las estadísticas de kappa fueron 92% y 97%, 91% y 99%, 85% y 96%, y 0.82 y 0.95 para 2-m y 0.67-m en imágenes de resolución espacial, respectivamente. Los resultados mostraron que las imágenes en los tres niveles de resolución espacial fueron efectivas en la estimación de la cobertura del mezquite en áreas grandes, remotas o inaccesibles.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.Migrated from OJS platform August 202

Texas Wintergrass and Buffalograss Response to Seasonal Fires and Clipping

There is increased interest in the use of summer-season fires to limit woody plant encroachment into grasslands, but effects of these fires on grasses are poorly understood. We quantified effects of repeated winter fires, repeated summer fires, and clipping (to simulate grazing) on aboveground total yield, live yield, and percentage of live tissue of C3 Texas wintergrass (Nassella leucotricha [Trin. Rupr.] Pohl.), and C4 buffalograss (Buchloë dactyloides [Nutt.] Engelm.) in 2 experiments. Monospecific patches of each species were exposed to 1 of 3 fire treatments (no-fire, 2 winter fires in 3 years, or 2 summer fires in 3 years) and 1 of 2 clip treatments (no clip or clip once each spring). Experiment 1 evaluated effects of fire without grazing or clipping on late-growing season (late-season) yields. Late-season total yield of both species recovered from winter and summer fires within 1 or 2 growing seasons post-fire. By 3 years post-fire, Texas wintergrass late-season total yield was 2 times greater in the summer fire treatment than the winter fire or no-fire treatments, and buffalograss late-season total yield was 3 times greater in summer and winter fire treatments than in the no-fire treatment. Experiment 2 evaluated combined effects of fire and clipping the previous spring on spring-season yields. Clipping alone or with fire (summer or winter) reduced Texas wintergrass yields on more sample dates than occurred with buffalograss. By 3 years post-fire, buffalograss spring total yield was greater in all fire and fire + clip treatments than in the clip only or untreated controls. Results suggest: 1) both species were tolerant of summer fire, 2) fire in either season with or without clipping stimulated buffalograss production, and 3) buffalograss was more tolerant than Texas wintergrass to the combined effects of clipping + fire (either season). 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.Migrated from OJS platform August 202

Crested Wheatgrass Vigor as Affected by Black Grass Bug and Cattle Grazing

Light to moderate populations (50-200 per m2) of black grass bugs in a seeded monoculture of crested wheatgrass appeared to reduce plant vigor. Vigor of ungrazed plants was compared to plants grazed only by black grass bugs and plants grazed by black grass bugs and cattle. Generally, vigor decreased as levels of grazing increased. Leaf length, seedhead height, root crown nonstructural carbohydrates, and plant color correlated positively with vigor while functions of axillary tillering such as basal area and seedhead density correlated negatively with vigor. Cattle grazing was not in excess of intensities recognized as proper for the area.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202