. A primer on stand and forest inventory designs. Forests and forestry Mensuration; Forest surveys. Discussion—This technique is very common in the United States, particularly by the USDA Forest Service Forest Inventory and Analysis Units (Beltz 1984, Cost 1984, Hahn 1984, Born 1984, and Ohmann 1984). Stratified double sampling is particularly useful where aerial photography exists and large areas must be covered in a short period of time. Some attention to the ages of photographs and to the classification of points versus areas of photographs could improve the estimates obtained from the tech
. A primer on stand and forest inventory designs. Forests and forestry Mensuration; Forest surveys. Discussion—This technique is very common in the United States, particularly by the USDA Forest Service Forest Inventory and Analysis Units (Beltz 1984, Cost 1984, Hahn 1984, Born 1984, and Ohmann 1984). Stratified double sampling is particularly useful where aerial photography exists and large areas must be covered in a short period of time. Some attention to the ages of photographs and to the classification of points versus areas of photographs could improve the estimates obtained from the technique. Unfortunately, stratified double sampling is too often applied as if there were no differences in ages of photography and the point classification. These problems are minor though they probably should be considered for applications where areas are the most important factor in the inventory. Lund (1974) also used this technique for forest inventories in the Department of Interior Bureau of Land Man- agement, and Lund and Kniesel (1975) used the same process to inventory multiresource values, including herb- age production, soil surface factors, soil cover, and deer- days use. The Northeast FIA unit uses a modification of this tech- nique and sampling with partial replacement (Barnard 1984). Sampling with partial replacement (SPR) is very Forest Boundary. Figure 20—Mapping showing measured (*), stratum average (s), and Density Classes Forest average (a) volume (ccf) per acre based on the stratified double ? 0-30% sample of photo points. Each hexagon approximately represents 191 31-60% acres. fj 61 + % 47. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Lund, H. Gyde; Thomas, Charles E. (Charles Eugene), 1940-; United States. Forest Service. [Washington, D. C. ?] : U. S. Dept. of Agriculture, Fo
Size: 1675px × 1491px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorunitedstatesforestservice, bookcentury1900, bookpublis
