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    Author(s): Philip M. McDonald; Celeste S. Abbott
    Date: 1994
    Source: Res. Paper PSW-RP-220. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture; 13 p
    Publication Series: Research Paper (RP)
    Station: Pacific Southwest Research Station
    PDF: View PDF  (1.2 MB)


    Forty-eight openings of 30, 60, and 90 feet in diameter were created in previously unmanaged mixed conifer-hardwood stands on a high-quality site in northern California in 1963. They were an attempt to convert an essentially even-aged forest to an uneven-aged arrangement and comprised the initial cut in the group-selection system. Five conifers and three hardwoods produced 36 seed crops that ranged from very light to heavy during the 10-year study period (1964-1973). Sound seed for four conifer species combined (not sugar pine) for 10 years amounted to the equivalent of more than 302,900 seeds per acre and, in general, did not differ significantly among opening sizes. Shade and roots from bordering trees were major influences on seedling survival and development in the openings. Density of established conifer and hardwood seedlings (at least 4 years old) ranged from 12 per acre for incense-cedar in 90-foot openings to about 9,600 ponderosa pines per acre in 60-foot openings after 10 years, and did not differ significantly among opening sizes. Conifer seedling heights ranged from 0.8 to 1.7 feet after 9 years. Average height of ponderosa pines and hardwoods differed significantly between the largest and smallest opening size with height being best in the largest. Normally multi-stemmed and wide-crowned shrubs were conspicuous by their single spindly stems.

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    McDonald, Philip M.; Abbott, Celeste S. 1994. Seedfall, regeneration, and seedling development in group-selection openings. Res. Paper PSW-RP-220. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture; 13 p


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    conifers, hardwoods, seed crops, seedling density, seedling development, management implications

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