Investigation of Forest Structure

In Article 12 of Circular 33/2018/TT-BNNPTNT on forest investigation, inventory, and monitoring of forest dynamics, effective from January 1, 2019, the regulations for forest structure investigation are prescribed as follows:

1. Content of forest structure investigation:

   - Average forest stand indicators, including: diameter at 1.3 m, total tree height, cross-sectional area, volume;

   - Forest composition structure;

   - Forest tree density structure;

   - Forest canopy structure;

   - Forest coverage degree;

   - Tree distribution by diameter;

   - Tree distribution by height;

   - Correlation between height and diameter.

2. Methods for forest structure investigation:

   - Utilize standard sample plots, typically arranged, with a minimum area of 2,000 m2 to survey forest structure;

   - Measure and collect indicators, including: tree name, diameter at 1.3 m, total tree height, height to first branch, crown diameter; draw cross-sectional and longitudinal profiles of the forest tree layer at a 1/100 scale;

   - Use mathematical methods and software to calculate the average forest stand indicators as stipulated in clause 1 of this Article.

3. Results of forest structure investigation:

   - The primary survey data system, summary tables of forest structure survey results according to Tables No. 01, 10, and Table No. 29 in Appendix II attached to this Circular;

   - Horizontal and vertical profiles of the spatial structure of the forest;

   - Report on the results of the investigation and evaluation of forest structure.

These are the regulations regarding forest structure investigation.

Respectfully!