N'ebe ugwu nke Oregon, ebe obibi ya na-agbatị n'ime ala n'akụkụ mmiri iyi, ma ọ dịghị ebe ebe obibi ya na-agbatị karịa 80 km (50 mi) site na Oké Osimiri Pacific na ọwa mmiri ya. Sitka spruce na-etolite n'ụsọ oké osimiri ọdịda anyanwụ nke Norway, ebe a na-ewere ya dị ka ụdị invasive. Ajụjụ: Gịnị bụ ókèala ugwu ọdịda anyanwụ nke Sitka spruce?
Kenai Peninsula, Alaska