544 



CORRELATION OF DISTRIBUTIONAL FEATURES. 



ratio. Owing to the extension of the northern edge into Canada it is 

 impossible to speak regarding its probable controls in that direction. 



TCM^CHATURC 



Durs IN NoKM<L Froitics* SuaoN ir. S.I 

 Hot Ouva, F. S. 

 Cold Days, F. S. 

 Phtiiolocical Summation. F. S. 



n 



Normal Daily Mean, colocst 14 days or Vcar C 



Normal Daily Mean, Year [ 



Precipitation 



Normal Daily Mean, F. S. [ 



Day* in LONQEar Normal Rainy Period, F. S. [ 



Days in lonqest Normal Dry Per^pd. F, S. | 



Mean Total. Year [ 



Cvaroration 



Daily Mean, IOST-B, F. S. [ 



Moisture Ratios 

 ' Normal P/E, F. S. C 



Normal ff/E, F. S. i 



Normal P/E, Vcah C 



Huhioitt 

 Normal Mean. F. S. I 



Sunshine >^ 



Normal Daily Duration. F. S. 



Moisture-Tehrerature Indices 



CZH 



Normal P/Z « T, F. S., Physiolocical Method C 



Fig. 52. Climatic extremes for Quercus alba. 



Quercus falcata (fig. 53). — This tree is found throughout the Atlantic 

 Coastal Plain and the southern Mississippi Valley, reaching its greatest 

 abundance in the Southeastern Mesophytic Evergreen Forest, but ex- 

 tending well into the Deciduous Forest region. It encounters extremely 



TCMPCflATURC 



Oavs in Normal Frostlcss Sca«on (f. S.i 



Hot Days, F. S 



Cold Days, F. S. 



Physiological Summation, F. S. 



Normal Daily Mcan, colocst 14 days or Ycar 



Normal Daily Mcan, Ycar 



Prccipitation 

 Normal Daily Mean. F. S. 

 Days in longest Normal Rainy Period, F. 5. 

 Days in longest Normal Dry Period, F. S. 

 Mean Total, Year 



cvaroration 

 Daily Mean, 1887-8. F. S. 



Moisture Ratios 

 Normal P/E, F. S. 

 Normal rr/E. F. S. 

 Normal P/E, Year 



Humidity 

 Normal Mean. F. S. 



Sunshine 

 Normal Daily Duration. F. S. 



Moisture-Temperature Indices 

 NoRHAL P/E X T. F. 5., Physiological Method 



Fig. 53. CI 



matic extremes for Quercus falcata. 



wide amplitudes of all but one of the temperature conditions here 

 dealt with, and its diminishing occurrence in southern Florida is 

 coincident with the maximum values for these conditions. This is one 



