CONTENTS: 
introduction: spai's sys ee ee reas 
Aeimdistoreelit es eae ie 
Direct and diffused light ....-..-. 
Overhead side vandienectedsiolt=) (2) oe same oe I Ae 
Light intensities and tree growth.... 
Minimum intensities............ 
Optimum intensities. ........-- 
Rolerance and sintolerancevoistreesey sie ee ee ee een ora 
Lubimenko’s experiments....... 
Grafe’s experiments.......-... 
Factors influencing tolerance. ...... 
Clima tees Meee Uk Geers Pee oh 
PeNI RES OOK) Sah apo eee a capa Cian 
Soil moisture. ees ye Gel oe oe 
Solbientilityse Gwe Se Ne 
Age, vigor, and origin of the tree 
Measure of tolerance. ............-- 
Scales of tolerance.............. 
i i i i i i re 
racucalivaltievolrerherscalesiens. enum tee CMe me Nani Ne See ER 
Methods of determining tolerance. . - 
Bmpiricalimethods?..2 2222 2252.- 
Density of crown...... 
Selicprumines 2 5.2. cy: 
Numiberoiioranicheordergies est ban sare nee eM ce Ee nye a ee 
Natural thinning of stand -. 
Condition of reproduction. . 
Relativetmeiohties =. £25 25%. 
Artificial shading........... 
Se ee 
Anatonmmcalfand omy siolovicalvimernodss 2.80) 2255 6. ee 
Structure of leaves........- 
Assimilative capacity of leaf 
Physical methods... 25 ies. 
Measurement of luminous light intensity....... 
Measurement of chemical light intensity....-.-. 
Wse of photographic paper-. 92.2.2... 22... 
‘‘Normal shade” and ‘‘normal paper”... --- 
Wiesnensmmsolatoruwod i fae UNO a 
Clements; photometer: 22 42 ee 
Absolute and relative light intensity.....-.. 
Method of making measurements.......... 
Measurements of direct and diffused light. . - 
Se ee ee 
Whiesnermsrimvestiontloms a. focOu ue eh Ne cea set yw) 
Clementspaimvestigationsas =. 2 Vinnie ice Ek a se oes 
iHlorest Senvaice imvestigationss 5222 5-5 ue ese ee ae eee 
Defects of the method. - 
eee eee eee eee eee ee te ee tt ee et ee ee ee tt ee ee 
Spectroscopic measurement of light intensity. .......--..-.--------- 
Zederbavler- samvesticationss so sss 5. see eet aE ie tei: 
Wiesner’s investigations 
Relative value of different methods. 
SORTA. hava stele alciaiuars © elelsmiale s 
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