46 research outputs found
Computer-aided instruction in dendrology: Preparation for distance learning
Many state legislatures are increasing public access to higher education by establishing more two-year institutions with lower tuition and fees than four-year institutions. This will likely increase the number of students enrolling in two-year institutions and later transferring to a four-year institutions. Transfer students presently comprise more than 30% of the University of Arkansas at Monticello\u27s (UAM) undergraduate forestry majors. These students arrive commonly deficient in six required freshman and sophomore forestry courses and facing four years at UAM to complete their baccalaureate degree. Prospective transfer students need access to freshman- and sophomore-level forestry courses. Forestry majors need tutorials aiding the development of skills and knowledge in plant morphology, identification, nomenclature and silvics. At UAM, experiences to a broader range of learning styles than traditional instruction alone. When combined with distance learning technologies, this approach can potentially reach prospective transfer students. Resolution of course deficiencies reduces problems for transfer students and academic advisors, and homogenizes levels of preparedness leading to higher quality instruction, student understanding and academic success. This paper introduces a series of PC-based tutorials and a format for electronic discussion groups in dendrology intended as part of a package for both resident and distant students. The user friendly tutorials provide easy access to approximately 120 species of native and exotic woody trees, shrubs and vines of the upper Coastal Plain of the Western Gulf Region. The self examination segment of the software allows students to pretest their skill and knowledge in the morphology, identification, and nomenclature of forest species as part of their preparation for actual examinations. The electronic discussion groups helps students learn from each other while catering to diverse learning styles and study schedules. This approach to dendrology is nontraditional and appeals to students either literate or illiterate in computer usage without reduced participation in traditional classroom experiences
Genetic Family and Stock Type Influence Simulated Loblolly Pine Yields from Wet Sites
Planting adapted families or a bulked seedlot of bare-root and container-grown-seedlings of loblolly pine (Pinus taeda L) were contrasted as cost effective alternatives for regenerating Arkansas\u27 wet sites. Survival data from two wet sites were used to simulate 15 years of growth. Containerized seedlings provided 17% greater survival than bare-root seedlings, but yielded a lower present net worth than bare-root seedlings. Planting families adapted to excessive moisture provided 7% greater survival and yielded a greater present net worth than planting a bulked seedlot consisting of adapted and poorly adapted families
Survival and Growth Two Years After Control of Herbaceous Competitors in Newly Planted Seedlings of Loblolly Pine
Early or late over-the-top applications of herbicides were used to control herbaceous competition in machine planted loblolly pine (Pinus taeda L) seedlings at two locations in a pasture near Alleene and hand planted seedlings on a bedded site near Fouke. Sites were selected for diverse competitors. None of the treatments controlled weeds for the entire growing season. Only glyphosate + sulfometuron methyl produced seedling survival and growth below the check plots. The best over-the-top treatments were sulfometuron methyl alone or sulfometuron methyl + hexazinone
Control of Herbaceous Competitors in Progeny Tests Using Container-grown Seedlings
Container-grown and May-planted seedlings of loblolly and shortleaf pines were treated with herbicides for control of herbaceous competitors. Weed control and seedling growth were evaluated. Competitor control was good for all treatments. Survival and growth of pines differed by species and herbicide treatment. The best treatment for both species included covering seedlings and spraying competitors with glyphosate. Both species showed decreased survival and growth when treated with medium and high rates of hexazinone + sulfometuron methyl
Effects of Broad-Scale Conservation on Northern Bobwhite Populations in Agricultural Landscapes
Private land initiatives such as the Conservation Reserve Enhancement Program (CREP) are avenues for broad-scale northern Bobwhite (Colinus virginianus) conservation. The CREP in Kentucky established 40,468 ha of native prairie grasses and riparian corridors in the Green River Basin. Northern bobwhite responses to similar conservation measures at local scales (i.e., the site of implementation) have been positive; however, the geographic extent of the influence of private land initiatives on populations is less understood. Our objectives were to investigate landscape-scale effects of CREP on northern bobwhite populations. Using a stratified random sampling design, 254 roadside point counts were performed over 5 years throughout the Green River Basin along a gradient of landscape-scale CREP density. Local-scale (500 m radius) CREP density was held constant at monitoring points. We analyzed data using an openpopulation distance sampling model that included estimators of appropriate landscape scale and strength of density dependence. Population response to the CREP was positive and outweighed conservation footprint. Our results suggest that broad-scale conservation can influence wildlife populations outside of targeted areas. Concurrently, because the majority of land in the Eastern U.S. is privately owned, private land conservation initiatives present an effective strategy for promoting wildlife population recovery across large areas. Our future directions with this research include improving model estimators, determining mechanisms behind landscape-scale effects of CREP, and determining the influence of the spatial arrangement of landscape features on local populations
Evaluating Hunting Success of Pen-Reared and Wild Northern Bobwhite in a Reclaimed Kentucky Mineland
Northern bobwhites (Colinus virginianus) have experienced severe population declines across their distribution. In order to address population declines and to continue providing hunting opportunities, multi-state efforts have been undertaken to stabilize and restore bobwhite populations. Ongoing efforts using the National Bobwhite Conservation Initiative’s quail focus area approach have so far demonstrated success throughout Kentucky. However, population increases in the Peabody Bobwhite Focal Area, in western Kentucky, have not been correlated to increases in perceived hunter success. Consequently, some sportsmen question the effectiveness of focal area conservation. In response to hunter concerns, we tested dog hunting ability with wild and pen-reared bobwhites. We also measured evasive behaviors of wild bobwhite using radiotelemetry. During the 2013–2014 and 2014–2015 hunting seasons we conducted 114 dog trials. Dogs detected bobwhite during 46 of 59 (78.0%) pen-reared trials and 16 of 55 (29.1%) wild bird trials. When dogs did not detect wild quail, birds ran away 64.1% of the time and remained motionless 20.5% of the time. Using an information-theoretic approach, we determined that bird type (wild vs. pen-reared) had a significant effect on bird detection, with dogs 8.62 times more likely to detect pen-reared birds than wild birds. We recommend that hunters be informed about differences in dog detection rates between pen-reared and wild bobwhite so that public support needed for wild bobwhite restoration can persist
Effects of Midrotation Intensive Silviculture on Forest Soils in East Texas: First-Year Results
Intensive forest management is becoming increasingly common in east Texas. Included in intensive management are such practices as mid-rotation fertilization, prescribed fire, and herbicide application. There is insufficient information about the effects of these treatments on soil physical, chemical, and biological properties when applied at mid-rotation. The objectives of this research are to evaluate the effects of these treatments on soil physical properties including organic matter content and bulk density; chemical properties including soil nitrogen and phosphorus; and on populations of resident earthworms. Five replications were installed in each of two loblolly pine (Pinus taeda L.) plantations aged 15 and 17. Both were thinned in 1998. Accord SP and Chopper emulsion were ground applied in the fall of 1999. The prescribed burn treatment occurred the following spring. Fertilizer was applied one to two weeks after completion of the burn to supply 224 kilograms per hectare of N and 28 kilograms per hectare of P. First-year results are presented
X-ray fluorescence analysis of long-term changes in the levels and distributions of trace elements in the rat brain following mechanical injury
This paper describes the results of the application of X-ray fluorescence microscopy to the qualitative, topographic and quantitative elemental analysis of nervous tissue from rats with neocortical brain injury. The tissue samples were analyzed with a 15 μm beam defined by the size of the polycapillary focus. Raster scanning of the samples generated 2D cartographies, revealing the distributions of elements such as P, S, Cl, K, Ca, Fe, Cu, and Zn. Special emphasis was placed on the analysis of the areas neighboring the lesion site and the hippocampal formation tissue. The results obtained for rats with mechanical brain injuries were compared with those recorded for controls and animals with pilocarpine-induced seizures. There were no significant differences in the elemental compositions of gray and white matter between injured and uninjured brain hemispheres. A higher level of Ca was observed in the gray matter of both of the hemispheres in brains with neocortical injuries. A similar relation was noticed for Fe in the white matter. A comparative study of hippocampal formation tissue showed a statistically significant decrease in the mass per unit area of P in the dentate gyrus (DG) and the hilus (H) of DG for animals with brain lesions in comparison with the control group. Analogous relations were found for Cu in the DG and Zn in sector 3 of Ammon’s horn (CA3) and the DG. It is important to note that identical changes in the same areas were observed for animals with pilocarpine-induced seizures in our previous study
Metallothionein (MT) -I and MT-II Expression Are Induced and Cause Zinc Sequestration in the Liver after Brain Injury
Experiments with transgenic over-expressing, and null mutant mice have determined that metallothionein-I and -II (MT-I/II) are protective after brain injury. MT-I/II is primarily a zinc-binding protein and it is not known how it provides neuroprotection to the injured brain or where MT-I/II acts to have its effects. MT-I/II is often expressed in the liver under stressful conditions but to date, measurement of MT-I/II expression after brain injury has focused primarily on the injured brain itself. In the present study we measured MT-I/II expression in the liver of mice after cryolesion brain injury by quantitative reverse-transcriptase PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) with the UC1MT antibody. Displacement curves constructed using MT-I/II knockout (MT-I/II−/−) mouse tissues were used to validate the ELISA. Hepatic MT-I and MT-II mRNA levels were significantly increased within 24 hours of brain injury but hepatic MT-I/II protein levels were not significantly increased until 3 days post injury (DPI) and were maximal at the end of the experimental period, 7 DPI. Hepatic zinc content was measured by atomic absorption spectroscopy and was found to decrease at 1 and 3 DPI but returned to normal by 7DPI. Zinc in the livers of MT-I/II−/− mice did not show a return to normal at 7 DPI which suggests that after brain injury, MT-I/II is responsible for sequestering elevated levels of zinc to the liver. Conclusion: MT-I/II is up-regulated in the liver after brain injury and modulates the amount of zinc that is sequestered to the liver