Red spruce reproduces exclusively by seed. The first cone crop is usually produced when the crown first reaches direct light [27,39]. Therefore, red spruce can bear cones as early as 15 to 20 years of age; cone production peaks about 15 years later. In dense, even-aged stands, full cone crops are rare until the trees are 40 to 50 years old . Good seed crops are produced every 3 to 8 years, with light crops in intervening years. Cones are dropped shortly after they are mature . The seeds are wind or rain disseminated. The maximuim distance for dispersal by wind is approximately 201 feet (61 m) . Seeds do not exhibit dormancy. Most germinate the spring following dispersal; occasionally germination will occur in the fall soon after seeds drop from the tree. Seeds are usually not viable after 1 year. Germination is largely controlled by moisture availability. Seeds will germinate in almost any medium except sod. Seeds that germinate in thick duff are subject to overheating and/or drought mortality. Drought and frost-heave are the major causes of seedling mortality the first year . Successful reproduction appears to depend more on seedling survival than on germination requirements . Seedling establishment is usually best on shallow, less fertile soils that discourage competitive hardwoods . The primary roots of red spruce seedlings do not penetrate litter and forest duff to any depth . Red spruce seedlings have a root system of finely branched rootlets and no strong laterals; they depend entirely on the humus for nutrients and water .
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- 38. Klein, Richard M.; Perkins, Timothy D.; Tricou, Jeffery; [and others]
- 39. Korstian, Clarence F. 1937. Perpetuation of spruce on cut-over and burned lands in the higher Southern Appalachian Mountains. Ecological Monographs. 7(1): 125-167. 
- 57. Moore, Barrington. 1917. Some factors influencing the reproduction of red spruce, balsam fir, and white pine. Journal of Forestry. 15(7): 827-853. 
- 87. Wright, Henry A.; Bailey, Arthur W. 1982. Fire ecology: United States and southern Canada. New York: John Wiley & Sons. 501 p. 
- 9. Blum, Barton M. 1990. Picea rubens Sarg. red spruce. In: Burns, Russell M.; Honkala, Barbara H., technical coordinators. Silvics of North America. Volume 1. Conifers. Agric. Handb. 654. Washington, DC: U.S. Department of Agriculture, Forest Service: 250-259.