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• 1. [Article] A preliminary investigation into the use of the tarif system and three tree selection methods for obtaining Douglas-fir stand and stock tables from large-scale aerial photography

  As a preliminary step toward the establishment of a 70 mm. aerial photo timber inventory system capable of generating accurate stand tables, stock tables, and gross volume estimates, this project focuses ...

  Citation × Citation Citation Abstract Copy Title: A preliminary investigation into the use of the tarif system and three tree selection methods for obtaining Douglas-fir stand and stock tables from large-scale aerial photography Author: McCadden, Richard Jay As a preliminary step toward the establishment of a 70 mm. aerial photo timber inventory system capable of generating accurate stand tables, stock tables, and gross volume estimates, this project focuses on the development of a system which (1) eliminates the need to measure tree height on the photos through use of the tarif system and, (2) incorporates the use of three distinct tree selection methods-- fixed plot, variable plot, and line transect sampling. The methodology is developed and applied to a 346 acre parcel of Douglas-fir forestland. The accuracy of individual tree predictions for diameter at breast height, volume, tarif number, and tree height (which is derived without traditional photo measurement) are evaluated by ground subsampling a 206- tree validation set and comparing actual and predicted values. The results show that an average underprediction of ground-measured tarif number by about 5% occurs, which in turn results in similar underpredictions of tree volume and height. The accuracy of the stand tables, stock tables, and gross volume estimates are examined by comparison to independently derived ground measurements. The photo estimates of mean gross volume per acre, using each of the three photo tree selection methods, are all within 5% of the ground-derived estimates; in all cases the 68% confidence intervals of the ground and photo estimates overlap. Graphic comparisons of the photo and ground-derived stand and stock tables are presented; they are similar, except for the inability of the photo method to accurately predict the stocking of trees less than twelve inches in stem diameter. The aerial photo system, using each of the three tree selection methods, demonstrates an ability to produce results comparable to those derived from conventional ground inventory techniques. Future research is recommended, and specific needs for this research are identified. Title: A preliminary investigation into the use of the tarif system and three tree selection methods for obtaining Douglas-fir stand and stock tables from large-scale aerial photography Author: McCadden, Richard Jay As a preliminary step toward the establishment of a 70 mm. aerial photo timber inventory system capable of generating accurate stand tables, stock tables, and gross volume estimates, this project focuses on the development of a system which (1) eliminates the need to measure tree height on the photos through use of the tarif system and, (2) incorporates the use of three distinct tree selection methods-- fixed plot, variable plot, and line transect sampling. The methodology is developed and applied to a 346 acre parcel of Douglas-fir forestland. The accuracy of individual tree predictions for diameter at breast height, volume, tarif number, and tree height (which is derived without traditional photo measurement) are evaluated by ground subsampling a 206- tree validation set and comparing actual and predicted values. The results show that an average underprediction of ground-measured tarif number by about 5% occurs, which in turn results in similar underpredictions of tree volume and height. The accuracy of the stand tables, stock tables, and gross volume estimates are examined by comparison to independently derived ground measurements. The photo estimates of mean gross volume per acre, using each of the three photo tree selection methods, are all within 5% of the ground-derived estimates; in all cases the 68% confidence intervals of the ground and photo estimates overlap. Graphic comparisons of the photo and ground-derived stand and stock tables are presented; they are similar, except for the inability of the photo method to accurately predict the stocking of trees less than twelve inches in stem diameter. The aerial photo system, using each of the three tree selection methods, demonstrates an ability to produce results comparable to those derived from conventional ground inventory techniques. Future research is recommended, and specific needs for this research are identified. Close

• 2. [Article] Probability proportional to size sampling of Douglas-fir from aerial photography

  This experiment was designed to investigate the use of volume estimations from aerial photography and probability proportional to size (PPS) sample selection in the development of a practical sampling design ...

  Citation × Citation Citation Abstract Copy Title: Probability proportional to size sampling of Douglas-fir from aerial photography Author: Rogers, Roger Allan This experiment was designed to investigate the use of volume estimations from aerial photography and probability proportional to size (PPS) sample selection in the development of a practical sampling design for timber volume estimation on small land areas of Pacific Northwest Douglas -fir (Pseudotsuga menziesii, Franco). The major problem of measuring exact stand height to predict stand volume from aerial photos was overcome by the development of two new volume equations which use percent crown closure, visible crown diameter and height classes as the independent variables. By the use of height classes, the photo interpreter is required to separate stand heights as to tall, medium or short. Equations are presented for both board- and cubic-foot volumes. Two computer programs were developed which reduce office calculations to a minimum. The programs compute photo volumes per plot, total gross and net volume estimations per area, standard errors and select the field plots to be sampled. The sampling design was tested on four test areas, using both quarter- and one-acre photo plots, and quarter-acre fixed-area and variable-area field plots at four photo scales. Based on these results a sample of about 20 field measured quarter-acre field plots combined with a 100 percent photo cruise on 1:7,000 aerial photos would be expected to produce gross volume estimations for a forty-acre tract of + 10 percent. at a 68 percent confidence level. Title: Probability proportional to size sampling of Douglas-fir from aerial photography Author: Rogers, Roger Allan This experiment was designed to investigate the use of volume estimations from aerial photography and probability proportional to size (PPS) sample selection in the development of a practical sampling design for timber volume estimation on small land areas of Pacific Northwest Douglas -fir (Pseudotsuga menziesii, Franco). The major problem of measuring exact stand height to predict stand volume from aerial photos was overcome by the development of two new volume equations which use percent crown closure, visible crown diameter and height classes as the independent variables. By the use of height classes, the photo interpreter is required to separate stand heights as to tall, medium or short. Equations are presented for both board- and cubic-foot volumes. Two computer programs were developed which reduce office calculations to a minimum. The programs compute photo volumes per plot, total gross and net volume estimations per area, standard errors and select the field plots to be sampled. The sampling design was tested on four test areas, using both quarter- and one-acre photo plots, and quarter-acre fixed-area and variable-area field plots at four photo scales. Based on these results a sample of about 20 field measured quarter-acre field plots combined with a 100 percent photo cruise on 1:7,000 aerial photos would be expected to produce gross volume estimations for a forty-acre tract of + 10 percent. at a 68 percent confidence level. Close

• 3. [Article] Evaluation of 35mm vertical aerial photography for estimating tree mortality

  Evaluation of four 35 mm film:lens combinations for estimating conifer mortality showed that large-scale true color images obtained with Kodak High Speed Ektachrome and color infrared images obtained with Kodak ...

  Citation × Citation Citation Abstract Copy Title: Evaluation of 35mm vertical aerial photography for estimating tree mortality Author: United States. Forest Service. Northern Region. State & Private Forestry, Williams, Ralph E. Evaluation of four 35 mm film:lens combinations for estimating conifer mortality showed that large-scale true color images obtained with Kodak High Speed Ektachrome and color infrared images obtained with Kodak Ektachrome Infrared, both exposed through a 135 mm lens were best. Higher correlation coefficients were found for the true color:135 combination than color IR:135 combination. Correlation between ground counts and photo counts of stereoscopically examined Kodacolor prints was no better and possibly not as good as correlations between ground counts and enlarged images of projected 35 mm transparencies. * This type and format of photography, as with other types and formats, has its advantages and disadvantages, and would be useful in determining 41 mortality rates or making mortality counts on areas where full coverage is not desired. Other innovations are discussed. Survey designs in which plot selection is based on probability proportional to size (numbers of trees) are apparently more efficient than methods employing simple random selection. An estimated mortality rate 41 of 1.5 trees per acre was indicated, and estimates of 9.8 dead goodtopped trees per acre plus an additional 9.5 green high-risk trees per acre were found. Most mortality and tree decline were associated with disease agents, and continuing or accelerated disease-caused decline is expected in the area. Western white pine,lodgepole pine, and Douglasfir accounted for over 90 percent of the recent and older mortality. The widespread occurrence of destructive root pathogens, including Armillariella me flea and Poria weirii (identified on high-risk trees during the survey), indicates that even though tested control measures are unavailable, best available alternatives discussed herein should be considered in management of the area. Title: Evaluation of 35mm vertical aerial photography for estimating tree mortality Author: United States. Forest Service. Northern Region. State & Private Forestry, Williams, Ralph E. Evaluation of four 35 mm film:lens combinations for estimating conifer mortality showed that large-scale true color images obtained with Kodak High Speed Ektachrome and color infrared images obtained with Kodak Ektachrome Infrared, both exposed through a 135 mm lens were best. Higher correlation coefficients were found for the true color:135 combination than color IR:135 combination. Correlation between ground counts and photo counts of stereoscopically examined Kodacolor prints was no better and possibly not as good as correlations between ground counts and enlarged images of projected 35 mm transparencies. * This type and format of photography, as with other types and formats, has its advantages and disadvantages, and would be useful in determining 41 mortality rates or making mortality counts on areas where full coverage is not desired. Other innovations are discussed. Survey designs in which plot selection is based on probability proportional to size (numbers of trees) are apparently more efficient than methods employing simple random selection. An estimated mortality rate 41 of 1.5 trees per acre was indicated, and estimates of 9.8 dead goodtopped trees per acre plus an additional 9.5 green high-risk trees per acre were found. Most mortality and tree decline were associated with disease agents, and continuing or accelerated disease-caused decline is expected in the area. Western white pine,lodgepole pine, and Douglasfir accounted for over 90 percent of the recent and older mortality. The widespread occurrence of destructive root pathogens, including Armillariella me flea and Poria weirii (identified on high-risk trees during the survey), indicates that even though tested control measures are unavailable, best available alternatives discussed herein should be considered in management of the area. Close