Norway spruce develops two types of needles. Eight or nine cotyledons are present in germinating seedlings in the first year. True needles are produced throughout the life of the tree and are borne singly and spirally arranged on the twig. The needles are 25 to 35 mm long, about 1 mm wide, and rhomboid in cross section. Needle lifespan averages 4 years in lowland sites and often exceed 5 years or more in high-elevation and high-latitude sites (KAWECKA
1977; Wachter 1985). The needles are attached to the shoot on woody, peglike projections (sterigmata) that persist on the twig after needle fall. BURGER (1953) noted that a 152 year-old individual had an estimated 25 million needles with total surface area of 1,410 m2 and mass of 290 kg. Growing in stands, Norway spruce exhibits a relatively high leaf area index (ratio of leaf area to ground area), estimated at 10.5 in one study (Bolstad and GOWER 1990).
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