Density Effects on Giant Sequoia (Sequoiadendron giganteum) Growth Through 22 Years: Implications for Restoration and Plantation Management

作者：York Robert A^*; O'Hara Kevin L; Battles John J

来源：Western Journal of Applied Forestry, 2013, 28(1): 30-36.

DOI：10.5849/wjaf.12-017

• spacing study
• density management
• intraspecific competition

Giant sequoia were planted at various densities and tracked for 22 years to quantify the effect of growing space on diameter, height, stem volume, branch diameter, and branch density. Beginning after just 4 years and continuing through year 22, both stem diameter and height growth were highly sensitive to initial planting density (expressed in this case as horizontal growing space per tree) within the tested range of 3.7 to 28.4 m(2). Through 22 years, treatments allocating the greatest growing space per tree had greater volume per tree with no tradeoff yet observed in stand level volume growth. Branch diameter along the stem generally increased with growing space, but branch density did not change. To meet objectives, this study demonstrates that management strategies should be tailored to species' specific growth strategies. Giant sequoia is characterized by rapid early growth coupled with exceptionally low mortality, which has relevance in both native grove restoration as well as plantation management contexts. The measurements in this study suggest either planting at low density or thinning giant sequoia very early in dense stands if the objective is to increase individual tree growth rates without a corresponding reduction in stand volume. Young stands developing following high-severity fires may benefit from low-severity prescribed burns if objectives are to increase average stem growth or the rate of canopy recruitment.

• 出版日期2013-1