Life Sciences Commons^™

Denitrification And Oxygen Consumption In Sediments Of Two South Texas Estuaries, Won Bae Yoon, Ronald Benner

Faculty Publications

Spatial and temporal variations in rates of denitrification and oxygen consumption were measured in sediments of the Nueces and Guadalupe Estuaries in southern Texas, USA. Denitrification rates varied from 4.0 to 71.1 µmol N₂ m^-2 h^-1 in the Nueces Estuary and from 4.6 to 34.7 µmol N₂ m^-2 h^-1 in the Guadalupe Estuary. Denitrification accounted for 29 to 80% of total benthic N flux in the study areas. Oxygen consumption rates ranged from 176 to 818 µmol O₂ m^-2 h^-1 in Nueces Estuary and from 208 to 550 µmol O_{2 …}

Bacterial Numbers And Activity, Microalgal Biomass And Productivity, And Meiofaunal Distribution In Sediments Naturally Contaminated With Biogenic Bromophenols, Charles C. Steward, James L. Pinckney, Yvette Piceno, Charles R. Lovell

Faculty Publications

Sediment cores were collected inside and outside of a bed of a bromophenol-producing marine polychaete, Notomastus lobatus, and examined for impact of the bromophenols on sediment microflora and meiofauna around N. lobatus burrows. No significant differences were found between microbial parameters measured inside and outside of the N. lobatus bed. Integrated 6 cm cores taken adjacent to N. lobatus burrows contained 1.2 x 10⁹ bacteria ml^-1. Cell numbers were similar at control sites within the bed, but away from burrows, and not significantly different from cell numbers (1.0 X 10⁹ cells ml^-1) at a …

Enhanced Bacterioplankton Production And Respiration At Intermediate Salinities In The Mississippi River Plume, Gerardo Chin-Leo, Ronald Benner

Faculty Publications

Bacterial abundance and production (thymidine and leucine incorporation) were measured along a salinity gradient from the Mississippi River (0 %₀) to the open waters of the Gulf of Mexico (36 %₀) during July-August 1990 and February 1991. Bacterial production in surface waters was maximal at intermediate salinities (15 to 30 %₀). Nutrient enrichment experiments suggested that bacterial growth near the outflow of the river was C limited whereas bacteria in plume waters of intermediate salinities were P and N limited. Rates of plankton community oxygen demand measured during winter were also maximal at intermediate …

Nuclear Dna Content Variation Within The Rosaceae, E. E. Dickson, K. Arumuganathan, Stephen Kresovich, J. J. Doyle

Faculty Publications

Nuclear DNA content has been estimated using flow cytometry for 17 species and eight cultivars of Malus and for 44 species of 29 other genera within the Rosaceae. Compared to other angiosperms, diploid genome sizes vary little within the family Rosaceae and within the genus Malus. C-values of genera within the subfamilies Spiraeoideae and Rosoideae are among the smallest of flowering plants thus far reported. In general, the Maloideae have the largest diploid genomes of the family, consistent with their higher chromosome numbers and presumed polyploid origin.

A Break-Even Study Of In-Woods Merchandising Opportunities For Hardwoods In The Alabama-Mississippi-Tennessee Region, David Kinbrough, Steven H. Bullard

Faculty Publications

In most areas of Alabama, Mississippi, and Tennessee the recent arrival and dramatic growth of the hardwood chipping industry has created concerns among some members of the hardwood manufacturing industry. Hardwood sawmill and furniture manufacturing personnel are concerned that marginal sawlog/pulpwood material is increasingly processed as chips rather than sawn into lumber. The potential exists for increased in-woods merchandising of hardwoods, and this paper evaluates how transportation costs and pricing differences between hardwood pulpwood and sawlogs affect merchandising and hauling decisions. A model was developed to assist individual users in evaluating their merchandising and transportation options.

Effects Of Fall Fertilizer Applications Of Mitotic Index And Bud Dormancy Of Loblolly Pine Seedlings, Hans Michael Williams, David B. South

Faculty Publications

A series of studies examined the effects of fall fertilization with diammoniwn phosphate (DAP) on mitotic index and bud donnancy [as measured by mean days to budbreak (DBB)] of two half-sib seed sources of loblolly pine. The first study tested different rates of DAP (0, 67, and 202 kg Nlha), the second study compared DAP with ammoniwnnitrate, and the third study examined the effect of different application dates (September 28, October 19, and November 9). An increase in mitotic index of unfertilized seedlings was observed during October and was due to developmental activity which follows initial budset. Differences in mitotic …

Raw Materials Use By Mississippi Furniture Manufacturers, 1989, Mark A. Glaeser, Steven H. Bullard, Larry Doolittle, Philip Steele

Faculty Publications

Mississippi's furniture industry has grown rapidly in recent years and now ranks nationally in production of specific types of furniture. Furniture pmducers in the state use many types of wood and nonwood raw materials. Raw materials expenditures were almost $330 million for 92 firms that responded to a 1989 survey. The survey included upholstered and nonupholstered furniture producers as well as hardwood dimension and frame producers. Substantial amounts of these raw materials were obtained from suppliers within the state.

Direct Comparison Of Processing Technology In Hardwood And Softwood Sawmills, Philip Steele, Tony El-Radi, Steven H. Bullard

Faculty Publications

This study compares the sawing accuracy of 273 machines in hardwood sawmills to 291 machines in softwood sawmills. Characteristics compared were kerf width, sawing variation (within-board, between-board, and total), machining wood loss per sawline, and oversizing/undersizing practices. While results varied between machine types by region, hardwood sawmills generally performed as well as, or sometimes better than, softwood sawmills for many of the machine characteristics studied.

Relative Kerf And Sawing Variation Values For Some Hardwood Sawing Machines, Philip Steele, Michael W. Wade, Steven H. Bullard, Philip A. Araman

Faculty Publications

Information on the conversion efficiency of sawing machines is important to those involved in the management, maintenance, and design of sawmills. Little information on the conversion characteristics of hardwood sawing machines has been available. This study, based on 266 studies of 6 machine types, provides an analysis of the machine characteristics of kerf width, within-board, between-board, and total sawing variations and wood loss per sawline. Machine conversion efficiency was found to be explained by feedworks and setworks type, and sawblade thickness and type. This analysis of machine characteristics provides information for a rational choice of sawing machines for hardwood sawmills.

Estimating Hardwood Sawmill Conversion Efficiency Based On Sawing Machine And Log Characteristics, Michael W. Wade, Steven H. Bullard, Philip Steele, Philip A. Araman

Faculty Publications

Increased problems of hardwood timber availability have caused many sawmiller, industry analysts, and planners to recognize the importance of sawmill conversion efficiency. Conversion efficiency not only affects sawmill profits, but is also important on a much broader level. Timber supply issues have caused resource planners and policy makers to consider the effects of conversion efficiency on the utilization and depletion of the timber resource. Improvements in sawmill conversion efficiency would favorably impact sawmill profits, and would be equivalent in effect to extending existing supplies of standing timber. An equation was developed to estimate lumber recovery factor for hardwood sawmills based …

A Note On After-Tax Analysis Where Capitalized Costs Are Depreciated, Steven H. Bullard, Thomas J. Straka

Faculty Publications

Forest management often requires relatively long-term and capital intensive investments. Economic analysis of timber management alternatives can therefore be an extremely important aspect of decision-making. Investment analysis techniques are prominent in forest management texts and have also been the subject of many articles in the forestry literature.

Any forestry investment analysis involves several important aspects. Topics included in reports by Gunter and Haney (1984) and Bullard et al. (1986), for example, include the treatment of inflation, income taxes, risk, and the choice of an appropriate discount rate. In this article, we focus on a very specific aspect of after-tax investment …

Pine Tip Moth (Lepidoptera: Tortricidae) Infestation Rates As Influenced By Site And Stand Characteristics In Loblolly Pine Plantations In East Texas, James R. Meeker, David Kulhavy

Faculty Publications

Three young loblolly pine plantations grown on contrasting soil types produced quantitatively and qualitatively different host material for pine tip moths during 1985 and 1986. Amounts, periodicity, and availability of soil moisture regulated internal moisture conditions within host trees. Host xylem moisture potential in conjunction with soil nutrient status governed tree growth and influenced pine tip moth infestation rates.

Pines on a sandy site exhibited the poorest growth with lowest infestation rates, indicative of low-quality hosts with little if any tolerance to damage. A clayey site produced vigorous plant growth with moderate infestation rates. The less apparent hosts appeared capable …

Site Factors Affecting Growth Of Loblolly Pine In The Post Oak Belt, W. D. Hacker, M. Victor Bilan

Faculty Publications

A study was conducted in the Post Oak Belt of East Texas to determine which site factors affected height growth of loblolly pine (Pinus taeda L.). Height/age pairs were developed from stem analysis. Nonlinear regression was implemented to develop generalized height-age model. After curves were developed, stepwise regression was used to determine if an environmental variable impacted height growth. Environmental factors correlated with height growth included A horizon depth and those related to moisture relations including seasonal precipitation, average daily temperature, and texture of the A horizon. South.J. Appl. For. 16(4):197-200

Economics Of Direct Seeding And Planting For Establishing Oak Stands On Old-Field Sites In The South., Steven H. Bullard, John D. Hodges, Robert L. Johnson, Thomas J. Straka

Faculty Publications

On old-field sites in the South, oak stand may be established by direct seeding of acorns, or by planting seed- lings. Planting seedlings costs approximately 21/2 times the cost of direct seeding on a per acre basis, and based on our study of overall costs and returns, we conclude that in most cases the additional costs of planting are not justified by the additional benefits. Direct seeding is therefore an eco- nomically viable alternative to planting, although success with seeding requires careful selection of species/site combinations and proper seed handling and storage

Upholstered Expenditures: What U.S. And Canadian Consumers Plan To Spend On Upholstered Furniture, Gary M. Kellum, Eric J. Todd, Steven H. Bullard

Faculty Publications

Approximately 48 percent of U. S. households and 54 percent of Canadian households plan to buy some form of upholstered furniture in the near future. According to a recent survey, spending plans differ somewhat between U. S. and Canadian consumers, however. American consumers, for example, favor less expensive sofas, loveseats, and recliners, while Canadians prefer less expensive upholstered rockers and stationary chairs. Overall, Canadian households plan to spend more for each individual item than U. S. households.