This document discusses forest mensuration, which involves determining dimensions, form, age, and growth of trees and forests. It has four main objectives: basis for sale, basis of management, measurement for research, and measurement for planning. Specific measurements discussed include diameter, which is typically measured at breast height, and total tree height. Diameter can be measured using calipers or diameter tapes. Special cases for diameter measurement are discussed. Tree height is also defined. Different heights within a tree like bole height and crown length are defined.

1. FOREST
MENSURATION
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
1.37

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
locality

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 20cm.

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 YOU