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Restoration of degraded Acacia koa forests in Hawaii often involves mechanical scarification to stimulate germination of seed buried in the soil ecological importance for native forest birds (Scott et al., 1986). Acacia koa A. Gray, a high-value endemic timber species, dominated upland forests but was extensively logged to defray between 1200 and 1800 m elevation—the heart of the historical distribution of mesic A. koa forests (Mueller-Dombois and Available online at www.sciencedirect.com Forest Ecology and Management 2degradation. Conversion of forests to non-forest use began about 500 A.D. when the islands were first colonized by Polynesians, and accelerated greatly after 1798 with the arrival of Europeans (Cuddihy and Stone, 1990). Lowland forests were cleared for agriculture while the cooler drier uplands were converted to pastures (Tummons, 2002). Today most native forests occur in precipitation belts too wet or cool for agriculture or pasture. Little remains of native low or hig