Predicting wildfire activity has been a major concern for fire weather forecasters and fire managers in recent decades. Identifying mid-tropospheric circulation patterns that are conducive to higher rates of spread has been widely employed as a predictive tool. This study classifies circulation patterns at the 500 mb level for 3865 fire days from 1970 through 2004 in the central hardwood region of the Midwestern United States. Several circulation patterns were identified that are associated with enhanced fire activity relative to other patterns. All patterns with elevated fire activity were associated with either flow from dry air source regions, or patterns that placed the region on the periphery of a high pressure system. Weather variables associated with each type of circulation pattern were also analyzed and were found to vary among patterns. Circulation patterns with greater fire activity were identified as being drier than patterns with lesser activity. The findings of this study provide crucial information to fire managers and forecasters, which can help them achieve their ultimate goal of minimizing loss of life and property.

Overbrowsing by ungulates decimates plant populations and reduces diversity in a variety of ecosystems, but the mechanisms by which changes to plant community composition influence other trophic levels are poorly understood. In addition to removal of avian nesting habitat, browsing is hypothesized to reduce bird density and diversity through reduction of insect prey on browse-tolerant hosts left behind by deer. In this study, we excluded birds from branches of six tree species to quantify differences in songbird prey removal across trees that vary in deer browse preference. Early in the breeding season, birds preyed on caterpillars at levels proportional to their abundance on each host. Combining these data with tree species composition data from stands exposed to experimentally controlled deer densities over 30 years ago, we tested whether overbrowsing by white-tailed deer reduces prey biomass long after deer densities are reduced. Our analysis predicts total prey availability in the canopy of regenerating forests is fairly robust to historic exposure to high deer densities, though distribution of prey available from host species changes dramatically. This predicted compensatory effect was unexpected and is driven by high prey abundance on a single host tree species avoided by browsing deer, Prunus serotina. Thus, while we confirm that prey abundance on host trees can act as a reliable predictor for relative prey availability, this study shows that quantifying prey abundance across host trees is essential to understanding how changes in tree species composition interact with ungulate browse preference to determine prey availability for songbirds.

Bottomland hardwood stands of the Mid-South region of the United States are some of the most productive forests in the country. A large percentage of these stands are owned by nonindustrial private forest landowners, who have little information on which to base management decisions. These stands are, therefore, a largely unmanaged and under-utilized reserve of high quality hardwoods. To provide landowners with a decision-making tool for comparing management scenarios, a growth and yield study was initiated in 1981. One hundred and fifty permanent plots were installed in red oaksweetgum stands. The study has been remeasured three times over the past 35 years. New plots were added when losses occurred due to natural disasters or harvesting. Stand level (Iles 2008), log grade volume distribution (Banzhaf 2009), and diameter distribution (Howard 2011) models were developed as component models of the overall growth and yield system. This study completes the modeling effort by developing individual tree equations for percent annual diameter growth and survival. Equations were constructed using linear, non-linear, and logistic regression techniques. The best set of developed equations was selected based on biological consistency, joint behavior when inserted into the growth and yield computer model, and the performance of each plot’s predicted future yield when compared to its observed data at the next projection period. Final independent stand level variables for the two models included age, diameter at breast height, trees per acre, and average height of dominant trees. Percent diameter growth and survival equations exhibited high fit statistics and when coupled with the other equations in the computer model, produced estimates for trees per acre, basal area, arithmetic and quadratic mean diameters with low bias and root mean squared error. The resulting growth and yield simulator implemented in Microsoft Visual Basic® Editor within Microsoft Excel® enables forest professionals and landowners to make better management decisions for their red oak-sweetgum mixture bottomland hardwood stands by projecting current forest inventories into the future, predicting average yields, and evaluating and comparing forest management scenarios.

Lignocellulosic ethanol production currently uses expensive and harsh methods to extract wood sugars from small-diameter hardwood trees that otherwise would have little or no marketability. A byproduct that adds no value to the conversion process results, thus alternative methods are needed to make this fuel source cost-effective. This dissertation proposes only partially hydrolyzing southern hardwoods, extracting some polysaccharides for ethanol fermentation while leaving behind a modified wood material which could be used as furnish for manufacturing strand-based wood composites. Three treating solutions, 1% sulfuric acid, water, and 1% sodium hydroxide, along with untreated controls, were utilized in a partial hydrolysis at 150°C for 30 minutes. The treatments’ effects were measured by testing the mechanical, physical, surface, and durability properties of red oak, sweetgum, and yellow-poplar miniature beams (3 mm x 15 mm x 150 mm, t x r x l). These properties were then correlated to the polysaccharide content of the modified woods following treatment. All treatments provided a significant mass loss, with sweetgum’s mass loss being significantly greater than the other species. The initial effect of the partial hydrolysis on modulus of elasticity (MOE) showed water reduced MOE the least for each species. Sweetgum produced a higher reduction in MOE in all three solutions. Specific modulus was calculated to eliminate the density effect between the treatment combinations for measuring bending properties at oven-dry conditions. Sweetgum produced a lower SM in all treatments, and only the water treatment consistently reduced SM across all species. Wettablility was measured by dynamic contact angle analysis via the Wilhelmy plate technique in four probe liquids. Surface energies were then calculated by the geometric mean procedure. Acid and water treatments improved the wettability for all species. Alkaline treatment effects were species-specific. All treatments improved the surface energy of red oak. The AWPA E1-09 no-choice termite test determined mass loss due to Reticulitermes flavipes Kollar. Yellow-poplar averaged a significantly higher mass loss while wood treated in water or NaOH showed a higher degree of termite degradation compared to the controls. Polysaccharide content significantly correlated with mass loss due to treatment and specific modulus.

Red oaks (Quercus spp.; Section Erythrobalanus) produce acorns which are valuable forage for wildlife especially mallards (Anas platyrhynchos) and wood ducks (Aix sponsa). Scientists have limited information on amount, timing, and persistence of these acorns in the Mississippi Alluvial Valley (MAV). Conservation planners rely on precise estimates of acorns and other forage to estimate habitat needed by waterfowl in the MAV and other regions. My study provided premiere landscape-scale, multi-year estimates of red oak acorn yield and on-ground abundance in the MAV. Mean yield of acorns was 534 kg(dry)/ha (42.3 acorns/ m2) across all sites, years (falls-winters 2009-2012), and oak species. Yield varied more within years (CV = 11 - 29%) than when data were combined across years (CV = 11%). Yield was not synchronized in any year among MAV sites. However, yield usually was synchronized among species within sites suggesting local factors influenced acorn yield more than landscape-scale factors. Among sites and years, acorn abundance generally was greatest in January (sample mean = 371 kg/ha) and least in November (198 kg/ha). Acorns persisted to February only in years of above-average yield. Except for Nuttall oak (Quercus texana), acorn persistence generally was stable regardless of yield from parent trees. Nuttall oak acorn persistence increased with yield perhaps revealing an evolutionary pressure that encourages masting. Red oak acorn abundance was linearly related to percentage of red oaks in the overstory, but this relationship differed in years of above- and below-average yield. Currently, conservation planners use 166 kg/ha as a forage estimate of red oak acorns, moist-soil seeds, and aquatic macro-invertebrates in bottomland hardwood forests with 100% red oak canopy. I sampled at 5 sites throughout the MAV over 3 years; therefore, I recommend conservation planners consider adopting my predicted estimate of 247 kg of acorns/ha of forest land with 100% red oak canopy. Because acorns persist through most winters and generally reach peak abundance in January, often concomitant with peak abundance of mallards and other ducks in the MAV, biologists and conservation planners may have undervalued the potential of bottomland hardwood forests to support ducks in mid-late winter.

No description available.

Land disposal of municipal wastewater is considered ecologically acceptable and cost effective. The success of land treatment systems, however, requires proper functioning of all ecosystem components. The impact of municipal wastewater irrigation on the structure and function of an Appalachian hardwood forest in Virginia was investigated. Four irrigation rates (17.5, 35, 70, and 140 em yr⁻¹ ) were applied in this hardwood forest, and their effects on forest nutrient cycling were monitored for two years. Tree growth, seedling reproduction, tree mortality, species diversity, and N sequestering by vegetation were not changed significantly. Herbaceous ground cover increased due to irrigation, except for the 140 cm yr⁻¹ treatment where the heavy spray caused physical damage to the cover. Depending on the rate applied, the mature hardwood forest system sequestered only -3.4 to 8.2 kg N ha yr⁻¹ in the above ground biomass. Therefore, the fate of added N to the system became a function of N transformation processes in the soil. Nitrogen mineralization and nitrification increased as irrigation increased. Denitrification rates were not affected by irrigation; the process of denitrification did not constitute a significant N output from the forest system. The additional soil nitrate (N0₃) was left to leach because of the low assimilation by the plant/soil system and the low denitrification rate. Nitrogen storage decreased in the forest floor due to the increase in litter decomposition, and increased in the surface soil due to the increase in microbial N assimilation. Total soil N increased on the low irrigation sites and decreased on the high irrigation sites, indicating that high rates of irrigation stimulated N loss from the soil by enhancing soil N transformations. The health of the forest ecosystem was not adversely affected during this period, but the forest did not serve as a net sink for N. There was little opportunity for N sequestering in this mature hardwood forest. Without harvesting and regeneration, the system is likely to lose system N when wastewater is applied. When wastewater is applied to lands, N sequestering and denitrification should be maximized in order to minimize the pollution potential of N0₃ leaching to groundwater systems. / Ph. D.

Production costs and production rates for harvesting hardwood pulpwood in western Virginia were empirically studied. The harvesting operations of felling, bucking, skidding, loading and delay were individually and collectively analyzed. Forty operators were studied during the period July-September 1965. Average production time for all operators to process 1000 pounds of wood from the stump to a loaded transport device was 39.8 man-minutes, 8.0 power saw minutes, and 3.8 tractor minutes. Average cost for the total operation was $1.29 per 1000 pounds. Operators studied were stratified by amount of equipment used and productivity in truckloads per day. Variation within strata obscured most differences between strata. However, the data indicated that two load per day operators had a lower cost per 1000 pounds than the one load per day operators. Recommendations for improved harvesting efficiency center on improved organization of the harvesting processes, such as temporary storage, rather than on larger or different equipment. / M.S.

A model was developed to estimate the economic stock supply of primary wood products. Two hardwood products were recognized: logs and bolts. The supply model was used to evaluate the impacts of shifting primary product demands and increasing supply costs on delivered prices and quantities in southwest Virginia. Homogeneous supply response cells, identified from Forest Service forest survey data, were used to generate log and bolt supplies. Response cells define blocks of forest land with similar biologic, physiographic, and landowner characteristics. Yield equations estimate the volume of logs and bolts available. Harvesting and hauling costs depend on a response cell's physiographic characteristics. Stumpage owners set reservation price as a function of expected stumpage prices, future timber yields, and an alternative rate of return. Recovery cost per unit in a response cell equals the sum of harvesting and hauling costs and reservation price. The quantities of logs and bolts supplied are determined by comparing harvest revenues to recovery costs. If revenues are greater than or equal to costs in a particular response cell, then timber is harvested The demands for logs and bolts are derived from the demand for manufactured products. Log and bolt demand equations in the model were statistically estimated. For each time period, the model determines the delivered log and bolt prices which equate the quantities of logs and bolts supplied to the quantities demanded. The solution technique is iterative. The quantities demanded and supplied of logs and bolts are determined for the given delivered prices. If quantities supplied do not equal the quantities demanded, then delivered prices are adjusted, and the quantities are recalculated. Primary product supplies in southwest Virginia are price elastic because of extensive hardwood resources and relatively constant recovery costs. Expansions in primary product demands expected over the next 15 years should have little direct impact on delivered prices. Delivered prices, however, will be sensitive to production costs. These costs will rise if factor input prices, such as fuel prices, wage rates, or machinery costs, increase. / Ph. D.

U.S. manufacturers of wood household, wood office and upholstered furniture were surveyed to (1) assess wood material use for 1990 and estimate use for 1991, and 1992, and (2) to examine consumer perceptions of certain hardwood lumber and supplier attributes in order to ascertain which are most influential in consumer purchase decisions. This study also provided information about the respondents, RTA and unfinished furniture, and green lumber purchases. Total 1990 hardwood lumber used in wood furniture was estimated at over 2.4 billion board feet. Use was expected to increase 13% from 1990 to 1992. Softwood lumber used in wood furniture in 1990 was estimated at over 839 million board feet. A 6% increase in softwood lumber use was expected from 1990 to 1992. Red oak was the most commonly used hardwood species and southern pine was the most used softwood. Furniture manufacturers indicated a decrease in particleboard and MDF use, and an increase in hardboard and OSB/softwood plywood use from 1990 to 1992. Product consistency was the attribute which most influenced the purchase of hardwood lumber, followed by accurate grading, supplier's knowledge of lumber, correct orders, and shipping on time. The least influential attributes were square end trimming, square edges, protective wrapping, end coating and supplier's ability to surface. Just over 20% of the respondents manufactured Ready-to-Assemble furniture and just over 15% manufactured unfinished furniture. Overall, 26% of respondents purchased green hardwood lumber, most being larger firms. Most firms' purchases of green lumber either have not changed, or have increased, over the last 5 years. / Master of Science