The North American Forestry Assoc. estimates that a 50-year-old urban tree
annual yields $75 in soil erosion and storm water control, $75 in
cooling services and $50 in air pollution control. Compounded at
5% interest over a tree's 50-year life, this adds up to $57,151.
warren@wsu.edu -- (509) 335-6456 -- Fax (509) 335-3818
(208) 882-7691 (home phone and fax)
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