ON 
APPENDIX A. 
METHODS OF STUDY. 
AREAS STUDIED. 
The characteristics and the reproduction of Douglas fir have been studied 
by the Wind River Forest Experiment Station staff for the past 10 years. 
Field studies have been made, and laboratory results have been verified 
throughout the Douglas fir region of Oregon and Washington. 
Not only has a general survey been made of most of the large forest burns 
and a number of smaller burns in the Douglas-fir region of Oregon and Wash- 
ington, but also a close study of about 875,000 acres located in various parts of 
the region, including large and small burns has been made. The effects of one 
forest fire and one or more reburns on the same area were analyzed as well as 
the effects of season and methods of slash burning and of one or more slash 
fires on the Same area. 
THE TRANSECT. 
In the field studies the belt transect, 83 feet wide, was generally used. On 
these transects the age, species, and condition of each seedling found were noted. 
The rod-square plot was also used to a large extent both for permanent and 
temporary records. 
For an intensive study of an area, belt transects were run 24 chains apart 
over the entire area, and in this way an actual examination of 5 per cent of 
the total area was made. For an extensive study two transects were run 24 
chains apart over the parts of the area that obviously afforded the best average 
conditions. A total of 1,223 temporary and permanent rod-square plots and 
109.9 miles of belt transect 8: feet wide formed the basis for the conclusions 
reached through field studies. 
INSTRUMENTS. 
All records of temperature in fires and in the heat treatment of seeds or 
cones were taken with the Leeds and Northrup portable potentiometer. In the 
field the iron-constantin lead wire was used and the iron-constantin and chromel- 
alumel thermocouples. The chromel-alumel and ecopper-constantin thermo- 
couples were used in the laboratory, but no lead wires were required. The 
potentiometer, thermocouples, and wire were tested and standardized by the 
Bureau of Standards at Washington, D. C. The copper-constantin thermo- 
couples were used for some of the readings in tests of cones and inflammability. 
For the inflammability tests the same inflammability apparatus was used that 
had been used in the tests at the Forest Products Laboratory of the Forest 
Service at Madison, Wisconsin. Standard thermometers were used for soil and 
air temperatures. Evaporation records were taken with the Forest Service 
Evaporimeter and by the open tank method. For the laboratory tests of heat 
resistance of seeds in cones, the inflammability point of needles and twigs, and 
the heat resistance of bark, the apparatus was arranged as shown in Plate 
XVIII. 
- 57 
