Permanent sample plots (PSP) shall be established 3 years after planting. The main purpose is to monitor growth and assess the potential yield on all planted tree species.

 

The following information can be developed from data collected from PSP.

1. Mean annual increment (MAI) and potential yield

2. Growth pattern and tree form

3. Growth rates of PCT and regenerations

4. Impact of pest attack and mortality rate

 

PSP shall be of standard size : 40m X 60m. To avoid road edge effect,PSP shall be located 100 meters (perpendicular) away from the secondary or feeder road.

a) PSP shall be demarcated on ground with GPS reading recorded.

b) All the trees shall be marked in running number and diameter of standing trees must be taken at breast height (1.3m). The point of measurement shall be marked for future reference. Measurement shall be recorded using standard form.

c) measurement shall be conducted yearly to determine MAI.

d) The stand volume increment can be determine without height information using valentine formula :

V:0.0026466*dbh˄2.279212554

e) Record of the data collected shall be summarized as below: