A population Analysis of Juniperus in The Missouri River Basin: Taxonomic Interrelationships Between Juniperus scopulorum Sarg. and J. virginiana L. in Missouri River Basin

Juniper has been used since early pioneer days in the protective tree plantings established on the windswept Great Plains. More recently juniper has been used as a basic component of the shelter belt plantings which, by the thousands, dot the prairies of the Great Plains from Texas to Canada. Research to improve the quality of Plains tree planting materials, including Juniperus) is proposed or is now in progress. In the fall of 1965, 72 native stands of Juniperus were sampled throughout the Missouri River Basin-an area encompassing most of the Central and Northern Great Plains. The purpose was to determine the occurrence and extent of variation in this Juniperus population and to clarify some of the interrelationships between Juniperus scopulorum Sarg. and J. virginiana L., thus establishing a sounder foundation upon which to begin improvement of the planting stock with respect to characteristics desirable in Plains forestry. The study was based on a taxonomic evaluation of 38 gross morphological, foliage, cone and seed, and infrared characters of 675 trees. Separate analyses involved 675 ovulate and staminate trees with 16 characters, 343 ovulate trees with 24 characters, and 142 ovulate trees with 38 characters in common. Frequency distributions of character values, correlation coefficients of all possible character combinations, hybrid indices and percent germ plasm distributions were determined to characterize the population. IBM 7040 and 360 electronic computers were utilized as an aid in the analysis. Analyses suggested the Juniperus population throughout the Missouri River Basin to be of hybrid derivation with neither parental type being found. A strong tendency toward bimodality within the population was demonstrated, however, indicating the presence of two different species-]. scopulorum and J. virginiana. The analyses demonstrated an introgressive trend between southeast and northwest over the Basin from the reported range of J. virginiana into that of J. scopulorum

A population Analysis of Juniperus in The Missouri River Basin: Taxonomic Interrelationships Between Juniperus scopulorum Sarg. and J. virginiana L. in Missouri River Basin

Juniper has been used since early pioneer days in the protective tree plantings established on the windswept Great Plains. More recently juniper has been used as a basic component of the shelter belt plantings which, by the thousands, dot the prairies of the Great Plains from Texas to Canada. Research to improve the quality of Plains tree planting materials, including Juniperus) is proposed or is now in progress. In the fall of 1965, 72 native stands of Juniperus were sampled throughout the Missouri River Basin-an area encompassing most of the Central and Northern Great Plains. The purpose was to determine the occurrence and extent of variation in this Juniperus population and to clarify some of the interrelationships between Juniperus scopulorum Sarg. and J. virginiana L., thus establishing a sounder foundation upon which to begin improvement of the planting stock with respect to characteristics desirable in Plains forestry. The study was based on a taxonomic evaluation of 38 gross morphological, foliage, cone and seed, and infrared characters of 675 trees. Separate analyses involved 675 ovulate and staminate trees with 16 characters, 343 ovulate trees with 24 characters, and 142 ovulate trees with 38 characters in common. Frequency distributions of character values, correlation coefficients of all possible character combinations, hybrid indices and percent germ plasm distributions were determined to characterize the population. IBM 7040 and 360 electronic computers were utilized as an aid in the analysis. Analyses suggested the Juniperus population throughout the Missouri River Basin to be of hybrid derivation with neither parental type being found. A strong tendency toward bimodality within the population was demonstrated, however, indicating the presence of two different species-]. scopulorum and J. virginiana. The analyses demonstrated an introgressive trend between southeast and northwest over the Basin from the reported range of J. virginiana into that of J. scopulorum

Genetic variation in Douglas-fir : a 20-year test of provenances in eastern Nebraska

Twenty-year-old Douglas-fir trees in provenances from Arizona, New Mexico, and southern Colorado survived better and grew taller; but incurred more winter injury in eastern Nebraska than trees from provenances from northern Colorado, southern and western Montana, northern Idaho, Canada, and eastern Washington. However, surviving trees from Pacific Coast, and northern and central Rocky Mountain provenances increased in percent of plantation mean height during the past 9 years, whereas trees from southern Rocky Mountain provenances decreased. Age /age correlations indicate provenances expressing superior height growth can be identified at age 6.Keywords: Pseudotsuga menziesii var. glauca, P. menziessii, provenance, seed source, age /age correlation, winter injur

RB246 Trees and shrubs For Noise Abatement

Excessive noise is a form of environmental pollution. The continual increase in the community noise level during the past two decades indicates a future noise problem comparable to the current air pollution problem of our large industrial centers. Trees and other forms of vegetation are known to have some effect on the transmission of sound but precise information on their use as noise screens is rather meager. In this study, we attempted to derive accurate, useful information for the above purpose, and to add to knowledge about outdoor sound propagation. Actual plantings of trees and shrubs in the form of shelterbelts and windbreaks on the Nebraska plains, and screen plantings of shrub-tree combinations within the city were studied

Genetic variation in ponderosa pine : a 15-year test of provenances in the Great Plains /

no.26

Effects of treatment and seed source on germination of eastern redcedar seed /

no.26