Inventory Analysis Reports

Introduction to Inventory Audit and Young Stand Monitoring Analyses

Inventory audit analysis

Inventory audit analyses provide comparative information on the VRI Phase 1 inventory, in order to assess its accuracy, by comparing ground sample attribute values, including volume, age, height, stand density, basal area and species composition, to corresponding photo interpreted values in the corporate database. The target population is the mature (51 years and older) vegetated treed component in a given management unit (TSA or TFL).  Inventory audit analysis reports include a description of the population of interest, data sources, the statistical methods that were used and key findings. The results may be used to provide adjustment ratios for some attributes in the Phase 1 inventory or, for example, as a guide for adjusting stand mortality due to mountain pine beetle or other forest health agents.

Young Stand Monitoring (YSM) Analysis

The intent of Forest Analysis and Inventory’s YSM program is to monitor the performance of young forest stands (50 years and younger), which is the target population. The primary goals of the YSM are to:

  1. Characterize the young stand population, including composition, structure, mortality, growth, yield, and health;
  2. Assess the accuracy of some Phase 1 Vegetation Resources Inventory (VRI) photo-interpreted polygon attributes (e.g., age, height, density and site index) for young stands;
  3. Assess the accuracy of site index estimates in the Provincial Site Productivity Layer (PSPL);
  4. Compare observed stand yields (e.g., basal area/ha and trees/ha) to predictions generated from TIPSY; and
  5. Once re-measurements are available, compare observed growth to forecasts from growth and yield models for the young stand population.

YSM analyses provide information on the target population, such as growth, species composition, stand density, mortality and forest health incidence which may be used to compare actual stand performance to predicted stand performance once re-measurement data becomes available.

Both inventory audit and YSM analyses are based on current VRI standards and procedures. The ground sample data is obtained from statistically unbiased random sampling that has been conducted in accordance with a sampling plan, and this information is considered to be the baseline for comparison with the calibrated and photo estimated VRI information. The ground sample data also has other applications; for further information on ground sampling, please visit Ground Sampling.