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Basic Tree Queries

This section contains tree enumeration and counting queries based on EVALIDator SQL Queries.

Queries in this Section

1. Oregon Total Live Trees

EVALID: 412101 (Oregon 2021) Result: 10,481,113,490 live trees (357.8 trees/acre)

A comprehensive example of EVALIDator-style tree counting that demonstrates: - Proper adjustment factors (MICR/SUBP/MACR) based on tree diameter - Population expansion factors (EXPNS) for statistical estimates - Exact Oracle EVALIDator query structure - Forest area calculation: 29,292,380 acres

Key Concepts Demonstrated

  • Diameter-based Adjustment Factors: Trees are counted differently based on their size
  • Population Expansion: Converting plot-level data to population estimates
  • Status Filtering: Focusing on live trees in forest conditions
  • EVALID Usage: Proper statistical grouping for estimates

EVALIDator Methodology

These queries follow Oracle EVALIDator methodology exactly: - Uses TPA_UNADJ (trees per acre, unadjusted) as the base metric - Applies diameter-specific adjustment factors - Multiplies by expansion factors for population estimates - Filters appropriately for live trees and forest conditions

Usage Notes

  • Always verify EVALID values match your analysis needs
  • Understand that different EVALIDs represent different time periods and methodologies
  • Results represent statistical estimates, not exact counts
  • Plot counts provide context for sample size and reliability