Giant Sequoia Insect, Disease, and Ecosystem Interactions
Individual trees of giant sequoia (Sequoia gigantea [Lindl.] Decne.) have demonstrated a capacity to attain both a long life and very large size. It is not uncommon to find old-growth giant sequoia trees in their native range that are 1,500 years old and over 15 feet in diameter at breast height. The ability of individual giant sequoia trees to survive over such long periods of time has often been attributed to the species high resistance to disease, insect, and fire damage. Such a statement, however, is a gross oversimplification, given broader ecosystem and temporal interactions. For example, why isn't there a greater representation of young-growth giant sequoia trees throughout the mixed-conifer belt of the Sierra Nevadas? What other factors, in addition to physical site characteristics, limit giant sequoia to its present range and grove boundaries? How does fire and fire frequency affect disease and insect interrelationships in the giant sequoia/ mixed-conifer ecosystem? Are current forest management strategies (e.g., fire suppression, prescribed burning programs) affecting these interactions? Giant sequoia trees are subject to the same natural forces (e.g., insect and disease organisms) as other tree species. An attempt is made in this paper to discuss some of the more common insect and disease associates of giant sequoia and their significance in relation to the more complex temporal (e.g., succession, aging and other time related events) and ecosystem inter-relationships at work in the giant sequoia/mixed-conifer ecosystem.
Douglas D. Piirto. "Giant Sequoia Insect, Disease, and Ecosystem Interactions" Proceedings for the Symposium on Giant Sequoias: Their Place in the Ecosystem and Society, Visalia, CA.. Jun. 1992.
Available at: http://works.bepress.com/dpiirto/12