Approximate time required to produce different wood crops (U. S. Forest

Service)

Forest Yields 107

1 Species tolerant of shade which should show better results in second growth.

2 Species growing under favorable conditions when measured.

Yield of white pine per acre in southern New Hampshire (Margolin)

Quality I

Age

Number of Trees

Basal Area

Mean Height

Volume

Current Annual Increment

Mean Annual Increment

Years

 

Square ft.

Feet

Cubic ft.

Cubic ft.

Cubic ft.

25

2,430

190

33

3,100

124

124

30

1,840

215

41

4,367

253

145

35

1,250

230

48

5,850

296

167

40

870

238

56

7,033

236

176

45

640

243

64

8,000

193

177

50

510

246

70

8,767

153

175

55

430

249

75

9,475

141

172

60

380

252

80

10,100

125

168

65

340

255

84

10,633

106

164

70

310

258

87

11,100

93

158

75

280

261

90

11,567

93

154

80

260

263

93

12,000

86

150

85

240

266

95

12,383

76

146

90

220

268

97

12,767

76

142

Quality II

25

2,430

163

31

2,700

108

108

30

1,840

183

38

3,700

200

123

35

1,250

195

45

4,850

230

139

40

870

212

52

5,800

190

145

45

640

221

59

6,600

160

147

50

510

228

65

7,300

140

146

55

430

233

71

7,925

125

144

60

380

236

76

8,500

115

142

65

340

238

80

9,000

100

138

70

310

241

84

9,450

90

135

75

280

244

87

9,900

90

132

80

260

247

89

10,300

80

129

85

240

250

91

10,650

70

125

90

220

253

93

11,000

70

122

Quality III

25

2,430

150

28

2,300

 

92

30

1,840

165

35

3,033

146

101

35

1,250

176

42

3,850

163

110

40

870

185

48

4,567

143

114

45

640

191

54

5,200

126

116

50

510

197

60

5,833

126

116

55

430

201

66

6,375

108

116

60

380

205

71

6,900

105

115

65

340

208

75

7,367

93

113

70

310

211

79

7,817

90

112

75

280

213

83

8,233

83

110

80

260

216

85

8,600

73

107

85

240

218

88

8,917

63

105

90

220

221

89

9,233

63

103

Second growth

Age

Volume

Quality I

Quality II

Quality III

Years

Board feet

Board feet

Board feet

20...........

4,600

3,150

1,700

25...........

8,400

5,900

3,450

30...........

15,100

10,800

6,550

35...........

24,950

18,050

11,200

40...........

33,550

25,000

16,450

45...........

40,750

31,450

22,150

50...........

47,450

37,800

27,650

55...........

52,350

42,550

32,750

60...........

57,300

47,400

37,500

65...........

61,850

51,850

41,850

70...........

65,900

55,800

45,700

75...........

69,750

59,500

49,250

80...........

73,300

62,850

52,400

85...........

76,700

66,000

55,300

90...........

80,050

69,000

57,950

Volume in board feet is round-edged box board material. White pine thinnings

Quality I

Quality II

Quality III

Age

Total Thinning per Acre

Trees under 5 Inches in Diameter Breast-high

Total Thinning per Acre

Trees under 5 Inches in Diameter Breast-high

Total Thinning per Acre

Trees under 5 Inches in Diameter Breast-high

Years

Cubic feet

Board feet

Cubic feet

Cubic Board feet feet

Cubic feet

Cubic feet

Board feet

Cubic feet

25

1,350

2,000

830

900 750

750

600

 

600

30

1,730

4,500

660

1,380 3,300

600

1,090

2,200

500

35

1,980

6,800

480

1,680 5,600

450

1,440

4,300

400

40

2,120

8,700

270

1,900 7,500

300

1,640

5,800

300

45

2,240

10,100

60

,2,040 8,900

150

1,750

6,900

200

50

2,280

11,200

 

2,100 9,900

 

1,800

7,600

80

55

2,280

12,000

 

2,100 10,400

 

1,780

8,100

 

60

2,260

12,300

 

2,000 10,600

 

1,700

8,300

 

65

2,200

12,300

 

1,850 10,300

 

1,590

8,200

 

70

2,100

11,900

 

1,630 9,500

 

1,420

7,800

 

75

1,950

11,100

 

1,300 8,000

 

1,200

6,900

 

80

1,700

9,500

 

860 5,000

 

920

5,600

 

85

     

200 1,200

 

650

4,000

 

90

   

-----

   

370

2,300

 

Life of Fence-Posts and Shingles

Durability of fence posts in Minnesota (Green).

Years

Red cedar.....................      30

White cedar (quartered 6 in. face).............    10-15

White oak (6 in. round)................ 8

Red and black oak.................. 4

Tamarack (red wood)................. 9

Elm.......................      6-7

Ash, beech, maple.................. 4

Black walnut....................      7-10

Prolonging the life of fence-posts (Willis).

Measures for posts named in ascending order of efficiency: —

Peeling and seasoning.

Charring.

Painting.

At best, surface brush paintings are not very durable. Some of the substances which may be applied with a brush are whitewash, petroleum-tar creosote, coal-tar creosote, and various patented products of coal tar and petroleum tar. Paint and whitewash are inferior to antiseptic preservatives; products of coal tar (creosote, etc.) are the best. These are best applied hot, in two or more coats. A barrel (50 gallons) of creosote should be sufficient to paint at least 300 posts with three coats for the butts and two for the tops.

Dipping.

One defect of brush treatment is that the preservative does not enter readily the cracks and checks. This defect may be overcome by dipping the posts in the preservative. Another advantage of dipping, as compared with painting, is a saving in labor. On the other hand, dipping requires a larger quantity of preservative, and, in addition to the amount consumed, there must be enough surplus to keep the barrel or tank filled to the proper depth. This usually forbids the use of any expensive preservative for dipping. Petroleum tar, coal tar, and the creosotes, however, may often be advantageously employed.

Posts have been treated by dipping the butt in cement. This is hardly satisfactory, owing to the ease with which the protective covering may be broken; moisture is absorbed after treatment; and causes the wood to expand and crack the cement.

Cold-bath treatment.

This differs from dipping because penetration of the wood is secured by leaving the post in the bath for ten hours or more. As a rule, only the cheaper preservatives can profitably be used in the cold-bath treatment. Coal tar is so ropy and sticky that it will scarcely penetrate even the most easily treated woods. Crude petroleum enters the wood rather readily, but lacks strong antiseptic qualities. A long bath in crude petroleum may, however, prove a feasible method of treatment where petroleum is very cheap and the woods used are readily impregnated. Creosote is usually the best preservative to employ. Coal-tar creosote requires a slight heating to liquefy it. Water in the wood cells resists the penetration of the oil. Thorough seasoning before treatment, therefore, is necessary to allow the oil to penetrate readily and to prevent checking after treatment. The cold-bath method of treatment has not yet been thoroughly investigated. It is probable, however, that it will impregnate but few woods. The woods which are likely to prove most suitable are beech, cottonwood, the gums, pin and red oaks, the pines, sycamore, and tulip tree.