Gap-based silviculture in a sierran mixed-conifer forest: effects of gap size on early survival and 7-year seedling growth

摘要: Experimental canopy gaps ranging in size from 0.1 to 1.0 ha (0.25 2.5 acres) were created a mature mixed conifer forest at Blodgett Forest Research Station, California. Following gap creation, six species planted wagon-wheel design and assessed for survival after two growing seasons. Study trees measured seven years describe the effect of on early growth trees. Giant sequoia had lowest mortality (2.4 – 5.0 percent), sugar pine, incense-cedar, ponderosa Douglas-fir all comparable levels (5.8 - 18.9 white fir highest level (35.7 47.2 percent). To rank candidate models according goodness fit while penalizing model complexity, we used an information-theoretic approach using Akaike Information Criteria. An asymptotic height was most commonly selected as best among set feasible priori models, although there some parity. As increased, gains tended diminish between 0.3 0.6 (0.75 1.5 acres). Shade tolerance classifications did not predict relative or functional responses size.