Sources:
https://www.conifers.org/pi/Picea_sitchensis.php
https://www.fs.fed.us/database/feis/plants/tree/picsit/all.html
https://www.nps.gov/articles/loggingolympicwwii.htm
https://www.nps.gov/articles/spruceproductiondivision.htm
https://www.oregon.gov/ODF/Documents/ForestBenefits/SitkaSpruce.pdf