Stockability, relative density and productivity: investigating their link in boreal mixedwoods

• Author / Creator

  Reyes-Hernandez, Valentin J

• I explore and evaluate the use of indicators of density and stand composition in analyzing key aspects of the dynamics of boreal stands comprised primarily by trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss. in western Canada. First, using repeated measures data, I examine static and dynamic maximum size-density relationships (MSDR) for both pure and mixed stands of these species. Then, I evaluate the usefulness of density indicators in explaining understory light availability in mid-rotation and mature boreal pure and mixed stands, including examination of stand density index (SDI) based on the MSDR previously developed. Furthermore, I also test the usefulness of SDI and other density indicators in explaining trembling aspen, white spruce, and stand periodic annual increment in volume. Finally, I evaluate the usefulness of stand characteristics, including density and composition, in predicting the probability of survival of individual trees and saplings in boreal stands experiencing self-thinning. Results show that MSDR can be developed for mixed and pure boreal stands, and that a three-dimensional surface is the most suitable approach for their development. Stand composition and site quality are factors influencing MSDR. I also found that understory light is fairly variable in these stands, and that density and/or SDI are able to explain about 30 % of this variation. Total periodic annual increment in volume appears to be determined by the maximum stockability of these stands, and decreases in either aspen or spruce stocking, or both, result in reductions in PAI. Finally, one-sided competition, rather than two-sided, is the determining factor affecting individual tree survival, regardless of species. While basal area and/or SDI of larger trees captures these effects, individual tree growth rates serve better as indicators of survival probability.

• Subjects / Keywords

  • Maximum size-density relationships
  • Stockability
  • Relative density
  • Reineke's SDI
  • Boreal mixedwoods
  • Density-dependent mortality
  • Productivity

• Graduation date

  Spring 2014

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R39W0966X

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.