1. What is a Site Index Calculator?

Definition: This calculator estimates the site index (a measure of forest productivity) based on tree height and age.

Purpose: It helps foresters and land managers evaluate site quality and predict future tree growth.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( SI \) — Site index (height in feet at age 50)
• \( H \) — Measured tree height (feet)
• \( A \) — Tree age (years)

Explanation: The formula projects current height to what it would be at the standard index age of 50 years.

3. Importance of Site Index

Details: Site index is crucial for forest management, helping determine timber yield potential, species suitability, and management strategies.

4. Using the Calculator

Tips: Enter the tree height in feet and age in years. Both values must be > 0. For best results, measure dominant or co-dominant trees.

5. Frequently Asked Questions (FAQ)

Q1: What is site index?
A: Site index is the height of dominant trees at a standard index age (typically 50 years for many species).

Q2: Why use age 50?
A: Age 50 is a common standard, but some species use different index ages (25 for fast-growing species, 100 for slow-growing).

Q3: How do I measure tree height?
A: Use a clinometer or laser hypsometer, or estimate using a stick method (requires practice).

Q4: How do I determine tree age?
A: Count rings from a core sample (increment borer) or stump, or estimate from growth rates.

Q5: Does this work for all tree species?
A: This is a general formula. Some species may require different calculations or site index curves.