Self-thinning in Prince Rupprecht's Larch (<i>Larix principis-rupprechtii</i> Mayr) Stands

Abstract

AbstractPrince Rupprecht's larch (Larix principis-rupprechtii Mayr) stands growing at three different densities were investigated to determine characteristics of self-thinning. Tree density decreased with increasing stand age, and the higher density stand had higher mortality than the lower one. Mean stem volume increased with increasing stand age, and the higher density stand had higher relative growth rate of mean stem volume than the lower one. Mean stem volume (ν) increased with decreasing tree density (ρ), resulting in self-thinning line being expressed as ln ν=ln K-α ln ρ, where K and α are coefficients. The slope of self-thinning line, ¯α, over the whole study period for all sites was similar with a mean value of ¯2.13. The ν-ρ trajectories before reaching the self-thinning slope of¯3/2 could be described by Tadaki's model. The phase self-thinning line tended to decrease toward a slope of¯3/2 with increasing stand age, which trends agreed with those of the published data of a Pinus strobus stand and P. densiflora stands.Key words: density-dependent mortalitymean stem volume-tree density trajectoryphase self-thinning linePrince Rupprecht's larchself-thinning law