Bulkley Valley Research Centre - Science in the Public Interest

Year 2 - Effect of Site Type on Competitive Interactions Among Trees in Complex-Structured Mixed Species Sub-boreal Forests

Project Reference Number: 2007-06

Project Status: Complete

Led by: Dave Coates, PhD, Research Silviculturist, Ministry of Forests and Range, Smithers

Aaron Trowbridge, and other Bulkley Valley Research Centre personnel; Geomorphic Environmental Services, Smithers

Funder: Forest Investment Account - Forest Science Program

This project investigates how interspecific competitive interactions of different tree species vary across site types in complex stands. The methodology applies remote sensing technology that creates large stem-mapped areas and statistical techniques that allow for spatially-explicit analysis of individual-tree competitive interactions among tree species across resource gradients. These statistical techniques allow tight linkage between field data and parameterization of forest dynamics models.

Current Year Objectives:

  • To sample individual trees and their competitive neighbourhoods in stem-mapped plots,
  • To test how well aerial photography and image processing routines can be used to produce stem-maps,
  • To test alternate hypotheses that may explain competitive interactions among tree species across resource gradients,
  • To produce a draft manuscript related to stem-mapping with aerial photography and image processing routines,
  • To produce a draft manuscript related to competitive interactions among trees species across resource gradients.

There has been one addition to the experimental design and methods section. In the initial proposal, it was proposed to use imagery (aerial photographs) obtained during summer. During the initial year of the project, we discovered that it likely is beneficial to use imagery obtained during winter conditions (snow on the ground creates greater contrast). Thus, this project will include a comparison of stem-maps derived from imagery taken in summer conditions and winter conditions. It is best to obtain winter condition imagery in early spring (late March). Consequently, the component of the project that relates to testing the remote sensing technology will be extended further into 2007-2008 than indicated in the initial proposal. This addition to the experimental design will not alter the experimental design or methods outlined in the initial full proposal.

Related Reports

Publication Date Report Title Authors
2013 Competitive interactions across a soil fertility gradient in a multispecies forest K. David Coates, Erica B. Lilles and Rasmus Astrup
April 2008 Effect of Site Type on Competitive Interactions Among Trees in Complex-Structured Mixed Species Sub-boreal Forests - Executive Summary Dave Coates, Rasmus Astrup, Erica Close and Aaron Trowbridge