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Crop-tree Release Thinning in 65-year-old Commercial Cherry-maple Stands (5-year Results)

出版	U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station, 1994
URL	http://books.google.com.hk/books?id=0RVbbz__wJEC&hl=&source=gbs_api
EBook	FULL_PUBLIC_DOMAIN

註釋Crop trees were selected and released in a 65-year-old cherry-maple stand in north central West Virginia. Six crop-tree treatments were evaluated. Crop trees were selected based on potential for quality sawtimber and veneer products. Initially, released crop trees averaged 12.5 inches d.b.h. and 80 feet tall and were released an average of 13 feet from the edge of their crown. Five-year stand growth, mortality, and in growth are discussed for the treatments. Tree quality as related to butt-log grade and epicormic branching also are discussed. Detailed information is given for d.b.h. growth as related to degree of crown release. In general, black cherry, free-to-grow crop trees for the 40 and 60 crop-trees-per acre treatments grew 1.0 inch in 5 years. Similar crop trees in the control areas, where tree crowns were not released, grew 0.6 inch during the same period. Growth response increased with an increase in number of sides of the tree crowns released. After 5 years, less than 2 percent of the released crop trees had a reduction in butt-log quality due to epicormic branching.