Exercise 5 (forest mensuration)

Ma. Wella Portillo Dianne Nueva Anne Frances Buhay Francis Villamil Janelle San Juan

FRM 61 T-1L February 12, 2014

EXERCISE NO. 5 MEASUREMENT OF STANDING TREES

I. INTRODUCTION

Since a tree is shaped like a cylinder, its volume may be determined by measuring its diameter and height. Diameter of standing trees is measured by time-honored custom, at 4 feet and 6 inches above ground. This convenient way is abbreviated as DBH(diameter breast height). Some of the instruments instruments used in measuring diameter of a tree are biltmore stick, stick, meter stick, stick, diameter tape, caliper, ordinary meter tape, tree-fork, wheeler pentaprism, barr and stroud dendrometers and relascope. To avoid errors in using these instruments, terrain and tree characteristics (orientation and defects) must be taken into consideration (Carandang, 1996). To measure the tree height, instruments like haga altimeter, abney hand level, blume-leiss altimeter, suunto clinometer and hypsometers are used. II. OBJECTIVES

a. To learn the principles and techniques of diameter and height measurement of standing trees.  b. To practice the use of different diameter and height measuring equipment. III. MATERIALS AND EQUIPMENTS

a. diameter tape  b. meter tape c. biltmore stick d. tree caliper e. abney hand level f. haga altimeter IV. METHODOLOGY

Each group selected ten (10) (10 ) trees of different species and of varying diameters and h eights. Pictures of the general form of the trees measured (including the person who measured the tree) were taken by the group. To obtain the diameter and height of the selected trees, the following steps were conducted:  A. Diameter

1. The diameter (dbh) of the tree was measured using the diameter tape, meter tape,Biltmore stick and tree caliper 2. All measurements were recorded in tally form.  B. Height 1. The total height (to the nearest half-meter) of each tree using the abney hand level and haga altimeter was estimated. 2. All measurements were recorded in tally form.

VI. RESULTS

Table No. 1. Measurements of Diameter and Height DBH (cm)

Tree No. / Tree ID

Diameter Tape

1 Mahogany

75

2 3 4 5

63 40 30 32

Mahogany Biriba Amherstia Balitbitan

6 Banaba 7 Ilang-ilang 8 Mahogany 9 Mahogany 10 Sampaloc

67 80 92 61 47

Biltmore Stick

70 70 40 25 27.5

57.5 80 85 60 45

75 60 45 30 30

60 80 80 60 45

70 65 45 30 35

60 80 90 60 50

75 60 40 25 30

60 80 85 60 50

70 60 40 25 30

60 80 80 60 45

Tree Caliper

Meter Tape

70

2

60 40 29.5 29.75

1.9 1.25 0.75 0.95

63.25 74 78.5 60 47.5

1.2 2.5 2.9 1.9 1.5

Height (m) Abney Reading Haga (˚) Altimeter Rt Rb 54 0 32 48 2 37 43 -1 17 34 3 16 40 -9 14

41 41 41 37 47

COMPUTATIONS FOR TOTAL HEIGHT (ABNEY HAND LEVEL):

1. TH= (Tan 54) (30) = 41.29 m 2. TH= 30 (Tan 48  –  Tan 2)= 32.27 m 3. 4. 5. 6. 7. 8. 9. 10.

TH= 15 [ Tan (-1) + Tan 43 ] = 13.73 m TH= 15 ( Tan 34  –   Tan 3 ) = 9.33 m TH= 15 [ Tan (-9) + Tan 40 ] = 10.21 m TH= 15 [ Tan (-10) + Tan 41 ) = 10.39 m TH= 25 (Tan 41- Tan 3 ) = 21.69 m TH= 30 [ Tan (-2) + Tan 41= 25.03 m TH= 30 [ Tan (-4) + Tan 37 ] = 20.51 m TH= 15 [Tan (-5) + Tan 47]= 14.77 m

-10 3 -2 -4 -5

17 35 23 26 16

HD (m)

Total Height (m)

30

41.29

30 15 15 15

32.27 13.73 9.33 10.21

flat terrain tree with buttress leaning tree forking tree forking tree

10.39 21.69 25.03 20.51 14.77

tree with tumor leaning tree leaning tree leaning tree flat terrain

15 25 30 30 15

Remarks

VII. PHOTO DOCUMENTATION

VIII. REFERENCE

Carandang, M. G. (1996). FOREST BIOMETRY SYLLABUS. Department of Forest Resources Management College of Forestry U.P. Los Baños. pp.50-58.