GROWTH AND YIELD OF SITKA SPRUCE ON AFOGNAK ISLAND, ALASKA IS LOW OR IS IT?

Sitka spruce (Picea sitchensis Bong, Carr.) is the only tree that naturally inhabits Afognak Island, Alaska. Commercial harvesting on Afognak Island has generated interest for foresters and land managers of the Kodiak archipelago. Although Sitka spruce has been thoroughly studied in its most product...

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Bibliographic Details
Main Author: Hansen, Devin
Format: Text
Language:unknown
Published: Digital Commons @ ESF 2018
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Online Access:https://digitalcommons.esf.edu/etds/52
https://digitalcommons.esf.edu/cgi/viewcontent.cgi?article=1051&context=etds
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Summary:Sitka spruce (Picea sitchensis Bong, Carr.) is the only tree that naturally inhabits Afognak Island, Alaska. Commercial harvesting on Afognak Island has generated interest for foresters and land managers of the Kodiak archipelago. Although Sitka spruce has been thoroughly studied in its most productive regions, Afognak and surrounding islands have been excluded from these studies due to unique growth and habit. A network of 90 permeant continuous forest inventory plots on Afognak Island were established in 2010. Four common non-linear growth equations, logistic, Gompertz, Richards and Weibull, were fit to tree age-height and age-volume data. Site index for Afognak Island was found to be 80. All age-height equations accounted for at least 26 % of variation on Afognak Island. The Richards equation accounted for 90% of the variation in tree volume. Average site productivity class was found to be 9,075 cubic feet per acre at an age of 100 years.