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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effects of coppice thinning on growth and yield of Emory oak sprouts in southeastern Arizona.

Touchan, Ramzi January 1991 (has links)
Emory oak (Quercus Emoryi) is a dominant tree species in San Rafael Valley in southeastern Arizona. However, basic information about the effects of coppice thinning on the growth and yield of this species is lacking. Thus, objectives of the study were to measure the effects of coppice thinning on Emory oak survivor growth, ingrowth, and mortality, which are the basic components of a growth budget. This study determined gross growth, net growth, and yield estimates. In addition, this study evaluated the mean annual growth (MAG) values in relation to the biological rotation age of Emory oak in southeastern Arizona. Coppice thinning treatments were applied to sprouts of different ages. Height and diameter at root collar measurements were taken immediately after thinning and again 5 years later. Sprouts were classified into 5 age groups, 4 stump diameters, and 3 level of coppice thinnings and an unthinned control. The interactions of these treatments and their effect on growth and yield were analyzed. Stump diameters did not significantly affect the growth components, growth estimates, or yield estimates. The number of residual sprouts significantly affected the growth components, growth estimates, and yield estimates. Survivor growth, gross growth, net growth, and yield were lowest for 1 residual sprout, except for net growth of 8-year-old sprouts. There were no significant differences in net growth between the different coppice thinning treatments. At age 8-year-old sprouts, the mean annual growth of individual sprouts increased as the number of residual sprouts per stump reduced. Based on this relationship, it is recommended that 1 residual sprout be left when thinning sprouts. Age of sprouts significantly affected growth. There was an increase in the mortality of the control sprouts in the 6th year. Based on those results, it is recommended that thinning be conducted in the 5th year of the sprout's growth. Proper timing of thinning can reduce the rotation age of Emory oak sprouts, if the rotation is based on achievement of a specified diameter. To draw firm conclusions about the effects of thinning on shortening the rotation age, the study measurement needs to be continued into the future.
2

Effects of Quercus emoryi trees on microclimate, precipitation distribution, and herbs in a semi-arid savanna

Haworth, Kathryn, January 1992 (has links) (PDF)
Thesis (M.S. - Renewable Natural Resources)--University of Arizona. / Includes bibliographical references (leaves 96-107).
3

First year effects of thinning coppice on Quercus emoryi in southeastern Arizona

Bennett, Duane Anthony, 1956- January 1990 (has links)
This study was conducted to measure the effects of thinning coppice on Emory oak (Quercus emoryi). Thinning treatments were applied to sprouts of different ages. Height and diameter measurements were taken immediately after thinning and again one year later. Sprouts were classified into 5 age groups, 4 stump diameter groups, and 4 residual sprout groups. The interactions of these treatments and their effect on volume growth were analyzed. The results showed volume growth per stump was directly related to the number of sprouts per stump; volume growth per sprout was inversely related to the number of sprouts per stump; volume growth per stump and per sprout were both significantly affected by the age of the sprout at the time of thinning; and that stump diameter size had no significant effect on volume growth.
4

Sampling efficiency evaluation in Emory oak woodlands of southeastern Arizona

Zanga, Ambroise, 1956- January 1989 (has links)
A forest inventory was made by a two-man team in the Emory oak (Quercus emoryi) woodlands, near the Huachuca Mountains, in southeastern Arizona. Two plot sizes, 1/10th, and 1/25th hectare, and three basal area factors, 2, 4 and 6 (square meters per hectare) were used. Tree tally time was recorded, but the travelling time between plots was not recorded. Total number of trees, total basal area, and total volume of trees per hectare were measured, summarized, and analyzed. Significant differences were noted between plot sampling and point sampling. Results suggested that with plot sampling, 1/25th hectare plot was more efficient than 1/10th hectare plot for all measures of forest densities. With point sampling, basal area factor 6 had the highest relative sampling efficiency in terms of trees per hectare. Basal area factor 2 had the highest relative sampling efficiency in terms of basal area and volume per hectare. From this information, more efficient forest inventories of the Emory oak woodlands can be designed.
5

First year coppice regeneration of Quercus emoryi and Quercus arizonica in the Huachuca Mountains, Arizona

Meyer, John William, 1958- January 1988 (has links)
Emory oak (Quercus emoryi) and Arizona white oak (Q. arizonica), currently being harvested for fuelwood in encinals of southern Arizona, usually regenerate through stump sprouting. Adjacent to a Huachuca Mountains fuelwood cutting area, 3 replications of four thinning treatments (25%, 50%, 75%, and 100% intensity) were established in January, 1986. Regeneration was assessed one year later by examining the effects of thinning intensity, partial or complete stem cluster cutting, and tree characteristics. Clearcutting greatly increased the proportion of stumps that sprout for Emory oak and increased sprout volume production for both species in comparison to thinned plots. Partially cut multi-stemmed tree clusters were less likely to sprout and have less sprout volume growth after one year than completely cut clusters. Regression models were developed to estimate sprout volume production based on thinning intensity, percent stem basal area cut, tree vigor, number of tree stems, and heart rot.
6

Effect of soil salinity and acidity on the germination of Quercus emoryi and Robinia neo-mexicana seeds

Al-Hazzouri, Abbas Ahmad, 1949- January 1987 (has links)
The purpose of the study was to determine the effect of four salt concentrations and four acid levels of soil solution on the germination of Quercus emoryi and Robinia neo-mexicana seeds, and to study the effects of the cation concentration changes in solution (Na, Ca, Mg, K) and exchangeable cation concentration. The solution extracts and exchange phases of both soils, salt accumulation in the soil increased by increasing the salinity and acidity of the water applied. Exchangeable sodium was related directly to the SAR of the applied solutions. The soil responded differently to the salty water and acid water. Both soil treatments released Ca, Mg and K to the soil solution from the dissolution of the primary minerals and cation exchange reaction.
7

Site quality indices for the Emory oak woodlands of southeastern Arizona.

Callison, James Charles. January 1989 (has links)
Site index curves were constructed for the Emory oak (Ouercus emoryi) woodlands of the San Rafael Valley in southeastern Arizona. The woodlands primarily consisted of trees that were of sprout origin. Growth was rapid for 10 years, moderate from 10 to 20 years, and slow after 20 years. No trees in the study area were more than 40 feet tall. Stepwise regression analysis was used to analyze the relationship between site index and site factors. Important variables included available soil water holding capacity, percent volume of coarse fragments, radiation index, percent sand, litter depth, and soil pH. Two models were developed; the r² values were 0.56 and 0.49, respectively. Analysis of variance was used to test for differences between site index on different soil types and slope positions. All statistical tests were conducted using a 0.10 level of significance. The sample consisted of 100 trees. Most of the factors were involved with availability of water to the tree roots. Emory oak grows in a dryland area where water is a limiting factor. Therefore, the effect that soil and terrain has on the availability of water to tree roots is an important impact on the site index for Emory oak woodlands.

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