Treesearch

The recent introduction of the Asian gypsy moth (Lymantria dispar L.) into North America has necessitated the development of genetic markers to distinguish Asian moths from the established North American population, which originated in Europe. We used RAPD-PCR to identify a DNA length polymorphism that is diagnostic for the two moth strains. The polymorphism maps to an autosomal locus with codominant Mendelian inheritance. DNA sequence analyses of the Asian and North American forms enabled development of locus-specific primers so that this marker, designated FS-1, will be useful for strain...

The formation of few polyhedra mutants during serial propagation of baculoviruses in cell culture encumbers commercial scale production in this system. A Lymantria dispar nuclear polyhedrosis virus (LdMNPV) variant (isolate A21-MPV) has been isolated and the traits of budded virus (BV) production, synthesis of polyhedra, the percentage of cells that produce polyhedra, and the formation of few polyhedra (FP) mutants were investigated during serial passage of the variant in L. dispar 652Y cells. Isolate A21-MPV exhibited stable levels of BV production and polyhedra production and a small...

The Lymantria dispar nucleopolyhedrovirus (LdMNPV) gene encoding the 25K FP protein has been cloned and sequenced. The 25KFP gene codes for a 217 amino acid protein with a predicted molecular mass of 24870 Da. Expression of the 25K FP protein in a rabbit reticulocyte system generated a 27 kDa protein, in close agreement with the molecular mass predicted from the nucleotide sequence. The gene is located between 40.3 and 40.8 map units on the viral genome. It is transcribed in a counterclockwise direction with respect to the circular map at late times during the infection cycle from a...

Measurement of city tree cover can aid in urban vegetation planning, management, and research by revealing characteristics of vegetation across a city. Urban tree cover in the United States ranges from 0.4% in Lancaster, California, to 55% in Baton Rouge, Louisiana. Two important factors that affect the amount of urban tree cover are the natural environment and land use. Urban tree cover is highest in cities that developed in naturally forested areas (31%), followed by grassland cities (19%) and desert cities (10%), but showed wide variation based on individual city characteristics. Tree...

Logarithmic regression equations were developed to predict leaf area and leaf biomass for open-grown deciduous urban trees based on stem diameter and crown parameters. Equations based on crown parameters produced more reliable estimates. The equations can be used to help quantify forest structure and functions, particularly in urbanizing and urban/suburban areas.

This paper presents a step-by-step procedure for designing the "best" sequence of saw spacings for a fixed-blade gang ripsaw arbor. Using the information contained in a cutting bill and knowledge of the lumber width distributions to be processed, thousands of possible saw spacing sequences can be reduced to a few good ones.

Large-scale changes in the atmosphere associated with a globally changed climate and changes in climatic variability may have important regional impacts on the frequency and severity of wildland fires in the future.

The Regional Atmospheric Modeling System (RAMS) is a sophisticated computer model for the simulation of atmospheric processes on scales from a county to a country.

Carbon (C) storage in forest ecosystems is a significant part of the total terrestrial C pool, and may potentially be manipulated as an important C sink. The influence of management on C pools must be understood before guidelines can be suggested for maximizing C sequestration in forests. Studies of hardwood, red pine (Pinus resinosa Ait.), aspen and hybrid poplar stands located primarily in Minnesota, Wisconsin and Michigan have been and are currently being conducted to address the effects of common management practices on C storage. Factors studied include: (1) the effect of harvest...