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Full-Text Articles in Life Sciences
Mississippi’S Softwood Timber Potential: Private Nonindustrial Influences, Steven H. Bullard, G. H. Weaver, Willem W. S. Van Hees
Mississippi’S Softwood Timber Potential: Private Nonindustrial Influences, Steven H. Bullard, G. H. Weaver, Willem W. S. Van Hees
Faculty Publications
Mississippi's long-run softwood timber potential was estimated for three input situations under a common set of economic and biological assumptions. Economic goals for sustained pine production were estimated using the computer program GASPLY with no restrictions, with private nonindustrial upland hardwoods excluded from type conversion and with private nonindustrial lands excluded from active forest management altogether. Estimated price-quantity equilibria ranged from $301 per thousand cubic feet (MCF) and 966 million cubic feet (MMCF) in the unrestricted case, to $1,226/MCF and 479 MMCF in the example with passive private nonindustrial management. Widely diffel'ing potential goals for pine product-ion highlight the degree …
An Approach For Projecting Mixed-Species Forest Growth And Mortality, Steven H. Bullard
An Approach For Projecting Mixed-Species Forest Growth And Mortality, Steven H. Bullard
Faculty Publications
Mixed-species forests are common throughout the United States and growth and yield models are needed which reflect complex interrelationships. A stand-table projection approach with upgrowth and mortality components is presented for modeling growth and development in such forests. The method involves concepts previously used to model mixed-species diameter growth, in the upgrowth component of the projection system. Tentative equation forms arc presented to help clarify the general approach.
Root Diseases And Blister Rust Associated With Bark Beetles (Coleoptera: Scolytidae) In Western White Pine In Idaho, David Kulhavy, A.D. Partridge, R.W. Stark
Root Diseases And Blister Rust Associated With Bark Beetles (Coleoptera: Scolytidae) In Western White Pine In Idaho, David Kulhavy, A.D. Partridge, R.W. Stark
Faculty Publications
Root systems of western white pine, Pinus montieola Douglas, were excavated with explosives and examined for pathogens. Data were also recorded on portions of the crown killed by blister rust caused by Cronartium ribieola Fisch. Statistical tests revealed a significant association between the bark beetles Dendroetonus ponderosae Hopkins and Pityogenes fossifrons (LeConte), and the root pathogen Armillariella mellea. (Vah!. ex Fr.) Karst and between beetles and all root diseases. Ninety-two percent of the trees attacked by bark beetles had root diseases, and 97% had either root diseases or blister rust. A discriminant analysis correctly classified 88% of the sample trees …
Nantucket Pine Tip Moth (Lepidoptera: Tortricidae) Infestation Rates Related To Site And Stand Characteristics In Nacogdoches County, Texas, David Kulhavy, Richard N. Conner, Mark White
Nantucket Pine Tip Moth (Lepidoptera: Tortricidae) Infestation Rates Related To Site And Stand Characteristics In Nacogdoches County, Texas, David Kulhavy, Richard N. Conner, Mark White
Faculty Publications
Twenty-two pine stands with a variety of site and stand characteristics and management strategies were analyzed using discriminant analysis to determine factors which influence Nantucket pine tip moth infestations. A whole-tree sequential sampling scheme designed to estimate absolute infestation rates (±5%) was used. An 8% infestation rate was used as the dividing line between high and low tip moth infestations. A sequential sampling program was used in the field to estimate populations. Absolute infestation rates (P ± 5%), were obtained through random selection of pines for whole-tree sampling. Four equations were developed which gave 91% correct classification of initial …
Estimating Infestation Rates Of The Nantucket Pine Tip Moth (Lepidoptera: Tortricidae) Through Sequential Sampling, David Kulhavy, Paul C. Johnson, Bernard Andersen
Estimating Infestation Rates Of The Nantucket Pine Tip Moth (Lepidoptera: Tortricidae) Through Sequential Sampling, David Kulhavy, Paul C. Johnson, Bernard Andersen
Faculty Publications
Sequential sampling to estimate proportion from a binomially distributed population was used to estimate apparent and actual infestation rates of the Nantucket pine tip moth, Rhyacionia frustrana (Comstock), on loblolly, Pinus taeda, and shortleaf pine, P. echinata. Populations of R. frustrana, as measured by infested tips, increased from the overwintering generation through the second generation (July), then decreased rapidly for P. echinata. Populations of R. frustrana continued to increase through the season in P. taeda. Tip moth infestations were concentrated in the top one-half of the tree.
Effect Of A Prescribed Fire On Herbage Production In Southwestern Ponderosa Pine On Sedimentary Soils, Brian P. Oswald, W. Wallace Covington
Effect Of A Prescribed Fire On Herbage Production In Southwestern Ponderosa Pine On Sedimentary Soils, Brian P. Oswald, W. Wallace Covington
Faculty Publications
An area burned by prescription in 1977 and a nearby unburned area were measured in 1974 and 1980 to determine effects of the burn on herbage and forage production. Herbage production on the burned area increased significantly in 1980 over its 1974 level, in addition to being greater than the 1980 control production. However, the proportion of forage production to total herbage production in 1980 on the burned area decreased after the burn, and was significantly less than the control area forage production. This reduction in forage production can be attributed to the increase of nonforage species, notably bracken fern. …
Thinning Optimization In Mixed-Species Forests, Steven H. Bullard, W. David Klemperer
Thinning Optimization In Mixed-Species Forests, Steven H. Bullard, W. David Klemperer
Faculty Publications
An approach is summarized for estimating optimal thinning and final harvest age for existing, mixed-species stands. The method involves stand-table projection with upgrowth and mortality equations, formulated as an integer-nonlinear programming problem. Random search methods are proposed for estimating optimal cutting prescriptions. Such solution methods warrant further study in forestry, since their use enables broad application of stand-specific modeling results.
A Case For Heuristic Optimization Methods In Forestry, Steven H. Bullard, W. David Klemperer
A Case For Heuristic Optimization Methods In Forestry, Steven H. Bullard, W. David Klemperer
Faculty Publications
With rising competition for scarce resources, forest managers are increasingly concerned with estimating optimal solutions to complex problems. Heuristic procedures are often useful in solving such problems.
Promoting Soft Mast For Wildlife In Intensively Managed Forests, John J. Stransky, John H. Roese
Promoting Soft Mast For Wildlife In Intensively Managed Forests, John J. Stransky, John H. Roese
Faculty Publications
The fruit of woody plants is important as food for wildlife (Martin et al. 1951, Lay 1965). The relation of fruit production to southern forest stand conditions has been explored in only a few studies. Fruit production is greater in forest clearings than in closed forest stands (Lay 1966, Elalls and Alcaniz 1968). In Georgia slash pine (Pinus elliottii) plantations, fruit yields of shrubs are greatest in 4-yeas-old stands, and soil disturbance in site preparation greatly reduces fruit yields (Johnson and Landers 1978). Total fruit production is greatest in 5-year-old bedded loblolly pine (P. taeda) plantations …