Forest mensuration is a branch of forestry focused on determining the dimensions, form, age, and increment of trees and stands. Its objectives include providing a basis for the sale and management of timber, facilitating research, and aiding in planning for future timber demands. Key measurement techniques discussed include diameter and height measurements, with emphasis on their importance for estimating tree volume and site productivity.

1. FOREST
MENSURATIO
N
DR. INDRESH
KUMAR

2. FOREST MENSURATION
Definition of Forest Mensuration
Forest Mensuration is that branch of
forestry that deals with the determination
of dimensions (e, g; diameter, height,
volume etc.), form, age, and increment of
single trees, stands or whole woods, either
standing or after felling.

3. OBJECTIVES OF
FOREST
MANSURATION
Forest Mensuration serves
the following objects:
1. Basis for sale
2. Basis of management
3. Measurement for research
4. Measurement for planning

4. • Basis for sale
Before any sale and purchase, the quantity
of timber or other produce and their prices
are estimated.
• Basis of management
For proper management, knowledge of the
quantity of timber standing in forest and its
increment on every year or in a period of
years is necessary. This leads to the
development of methods of preparing forest
inventories using satellite imageries.

5. • Measurement for research
In order to find out which treatment and
method of management would maximize
production, it is necessary to layout
experiments to compare the results of different
treatments. This requires the layout of sample
plots and their periodic measurements.

6. Measurement for
planning
With the steeply(तेजी से) increasing
population and rising standards of living every
year, the gap between the demands and
supplies of timber and other forest products .
For this purpose, fast-growing species have to
be introduced.
Thus, Forest Mensuration supplies basic
statistical data to plan for the future and serves
to check the viability of projects.

7. Diameter and girth measurements
• to estimate stem cross-sectional area
• Diameter through the stem
(bole) perpendicular to stem long axis

8. Diameter Measurement
• Dendrometer: general term used
for instruments designed to measure
diameter.(place tape flat, tight, &
level at 1.37 m above ground )
Calipers
Diameter Tape

9. Calipers
 average of two measurements
taken at right angles. DBH = (D1+
D2)/2
 useful if stem non-circular

10. Diameter Tape
measures circumference, but tape
calibrated in diameter. Relationship
of Diameter (D) and
circumference Girth(G) of a
circle: G=𝝅D, where
𝝅=22/7 or 3.142 that is D=G/ 𝝅

11. methods show measure diameter outside
bark (DBH ob)
if inside bark diameter is needed (DBH
ib) measure two bark thicknesses and
subtract from DBH ob

12. Special Cases
 Slope: “ground level” is on uphill side
of tree
Deformity at 1.37m:
(a)shift to nearest normal
position on tree
(b)if shift >15cm, average
two measures (one above & one
below)
•

13. DBH Measurement – Special Cases

14. DBH Measurement – Special Cases

15. HIEGHT MEASUREMENT
OF TREES
Total height of the tree is the straight
line distance from the tip of the
leading shoot (or from the highest
point of the crown where there is
no leader) to the ground level,
usually measured on slopes from
the uphill side of the tree.

16. Objective
• To find out tree volume
• To read volume tables,
form factor table, yield
tables, etc
• To find out productive capacity
of the site
• To find out the site quality of a

17. Different Heights of Tree
• Bole Height: The distance between ground
level and Crown Point is called bole
height, Crown Point is The position of the
first crown forming living ordeal branch.
• Commercial Bole Height: If the height
of bole that is usually fit for utilization
as timber called commercial bole
height.
• Height of Standard Timber Bole : Height
of the standard timber bole is from the
ground level to diameter over bark

18. Stump height: The height of the top of the stump
above ground which gives the tree stem is lift
attached to the ground after felling ( 20 to 30
cm), called stump height. Value of standing tree
before felling is called stumpage value.
Crown length: The vertical measurement
of the crown of the tree from the tip to the
point half way between the lower green
branches forming green crown all round
and the lowest green branch on the bole,
called crown length.

19. THANK