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An analysis of design and technique of cluster point sampling in coastal Alaska old-growth forests

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dc.contributor.advisor Dilworth, John R.
dc.creator LaBau, Vernon J.
dc.date.accessioned 2009-02-02T20:35:43Z
dc.date.available 2009-02-02T20:35:43Z
dc.date.issued 1967-06-00
dc.identifier.uri http://hdl.handle.net/1957/10325
dc.description Graduation date: 1967 en_US
dc.description.abstract This study was a test of eight basal area factors and five point sampling cluster patterns in a computer oriented sampling study of coastal Alaska old-growth spruce-hemlock stands. It was an attempt to learn which basal area factor and which type of point sample cluster pattern should be used in such stands. A. test of the effect of stand density on point sampling was also made. All trees 3. 0 inches d. b. h. and larger on ten 3. 5 acre areas were measured and mapped in the field. Five of the areas had crown densities of from 40 to 69%, and the other five had crown densities of 70% or more, as determined from aerial photographs. The computer measured basal areas per acre for all forty of the basal area factor/sample cluster combinations on each of the stem mapped areas. These average basal areas were summarized for the five sampled areas in each density and analyzed in two ways. Analysis of variance was used to test for significant difference of precision and accuracy among the eight basal area factors, among the five sample cluster patterns, and between the two density classes. A chi-square analysis was used to determine the relative accuracy of the designs under test. Results of the analysis of variance indicated that there were highly significant differences among the variances of the basal area factors tested and a significant difference among the variances of the sample cluster patterns tested. There was no significant difference between the variances of the two stand density classes tested. No significant interaction was observed among the sample variances for the sets of variables tested. There were highly significant differences among the accuracies obtained with each of the basal area factors and with each of the sample cluster patterns tested. There was no significant difference between accuracies of the density classes tested. A significant interaction was observed between the accuracies of the basal area factors tested and the accuracies of the cluster patterns tested. The data of this study indicated that samples from full density stands measured with large basal area factors tended to overestimate the true basal area of the stand. This overestimate increased as size of basal area factor increased. For that reason, and until further study denies that this bias exists, maximum basal area factors of 30 and 40 are recommended for sampling in medium and full density stands respectively. The data also indicate that, of the five cluster patterns tested, a 15 point cluster pattern provided the most accurate and most precise measure of basal area per acre. en_US
dc.language.iso en_US en_US
dc.subject.lcsh Forests and forestry -- Measurement en_US
dc.title An analysis of design and technique of cluster point sampling in coastal Alaska old-growth forests en_US
dc.type Thesis en_US
dc.degree.name Master of Science (M.S.) in Forest Management en_US
dc.degree.level Master's en_US
dc.degree.discipline Forestry en_US
dc.degree.grantor Oregon State University en_US
dc.description.digitization Master files scanned at 600 ppi (256 Grayscale) using Capture Perfect 3.0 on a Canon DR-9080C in TIF format. PDF derivative scanned at 300 ppi (256 B+W), using Capture Perfect 3.0, on a Canon DR-9080C. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR. en_US

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