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Site Classification of Ponderosa Pine Stands Under Stocking Control in California

出版	Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station, 1978
URL	http://books.google.com.hk/books?id=ymc1eC8kFToC&hl=&source=gbs_api
EBook	FULL_PUBLIC_DOMAIN

註釋Existing systems for estimating site index of ponderosa pine (Pinus ponderosa Laws.) do not apply well to California stands where stocking is controlled. A more suitable system has been developed using trends in natural height growth, derived from stem analyses of dominant trees in California. This site index system produces polymorphic patterns of height development to 80 years of age. Using a second system, site index can be predicted in stands where dominants have reached a breast-height age of at least 4 years but have not attained a height of 20 feet. Accuracy of estimates by this method can be strongly influenced by soil type. Accordingly, a separate equation is presented for stands on soils formed from skeletal schists. Yield tables based on the first system will be issued separately.