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Estimating loblolly pine size-density trajectories across a range of planting densities

Informally Refereed

Abstract

Size-density trajectories on the logarithmic (ln) scale are generally thought to consist of two major stages. The first is often referred to as the density-independent mortality stage where the probability of mortality is independent of stand density; in the second, often referred to as the density-dependent mortality or self-thinning stage, the probability of mortality is related to stand density. Within the self-thinning stage, segments of a size-density trajectory consisting of a nonlinear approach to a linear portion, a linear portion (maximum size-density relationship dynamic thinning line), and a divergence from the linear portion are generally assumed. Estimates of the ln of quadratic mean diameter and ln of trees per acre where the two stages of stand development and the three phases of self-thinning begin and end were obtained from segmented regression analyses and used as response variables predicted as a function of planting density. Predicted values allow for size-density trajectories to be estimated for any planting density.

Parent Publication

Citation

VanderSchaaf, Curtis L.; Burkhart, Harold E. 2013. Estimating loblolly pine size-density trajectories across a range of planting densities. In: Guldin, James M., ed. 2013. Proceedings of the 15th biennial southern silvicultural research conference. e-Gen. Tech. Rep. SRS-GTR-175. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 207-212.
https://www.fs.usda.gov/research/treesearch/43593