UNITED STATES DEPARTMENT OF AGRICl 



- BULLETIN No. 1059 



jfVJ^^Wl. 



Contribution from the Forest Service 

 WILLIAM B. GREELEY, Forester 



Washington, D. C. 



May 19, 1922 



RESEARCH METHODS IN THE STUDY OF FOREST 



ENVIRONMENT. 1 



By Carlos G. Bates, Silviculturist in Charge of Fremont Forest Experiment Station, 



and Raphael Zon, Forest Economist. 



CONTENTS. 



Page. 



11 



11 

 12 



Introduction 



Object 



Scope 



Sample plot method 



Need for a permanent organization in 

 forest investigations 



Forest experiment stations 



Short-term studies. . : 



The simple physico-physiological concept . 

 .Icasurement of environmental conditions 



affecting vegetation H 



Climatic characteristics of locality 



Natural climatic regions 



Data obtained by the Weather Bureau. . 



Knowledge of existing stations necessary 



Periods of growth and rest 12 



Special observations on climate and soil of 



locality 13 



Location of instruments for study of 



growth 13 



Location of instruments for study of 



reproduction * 3 



Air temperatures 15 



Problems 



Exposure of thermometers 



Standardizing thermometers 18 



Maximum, minimum, and current 

 temperatures 



Hourly temperatures 19 



• Frosts 24 



Mean temperatures 24 



Annual summary 



Instruments 



Soil temperatures 



Purposes to be served 



Problems 



Time of observations 28 



Daily mean soil temperatures 



» Revised, August, 1922. 



10163— 22— Bull. 1059 1 



Page. 



Measurement of environmental conditions af- 

 fecting vegetation— Continued. 

 Special observations on climate and soil of 

 locality —Con tinued . 



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