402 



CORRELATION OF DISTRIBUTIONAL FEATURES. 



Table 26. — Climatic extremes for the grassland — deciduous-forest transition. 



Plate 

 34 

 35 

 36 

 37 

 38 

 39 

 40 

 41 

 43 

 44 

 45 



46 

 47 

 48 

 49 

 60 

 61 

 52 



63 



54 



58 

 59 

 60 



63 



65 

 66 



68 



69 



70 



71 



72 



Plate 

 34 

 35 

 36 

 37 

 38 

 39 

 40 

 41 

 43 

 44 

 45 



46 



47 

 48 

 49 

 50 

 61 

 62 



Temperature: 



Days in normal frostless season (/s) 



Hot days, fs 



Cold days, fs 



Remainder summation above 32°, year (thousands) 



Remainder summation above 39°, fs (thousands) . . 



Exponential summation, fs (hundreds) 



Physiological summation, fs (thousands) 



Absolute minimum 



Normal daily mean, coldest 14 days of year (°F.) . 



Normal daily mean, hottest 6 weeks of year (°F.) . 



Normal daily mean, year (°F.) 



Precipitation: 



Normal daily mean, fs (inch) 



Normal No. rainy days (over 0.10 inch), fs 



Normal No. dry days (0.10 inch or less), fs 



Dry days, percentage of total, fs (per cent) 



Days in longest normal rainy period, fs 



Days in longest normal dry period, fs 



Mean total, year (inches) 



Evaporation: 



Daily mean, 1887-88, fs (inch) 



Total annual, 1887-88 (inches) 



Moisture ratios: 



Normal P/E, fs 



Normal irjfE, fs 



Normal P/E, year 



Vapor pressure: 



Normal mean, fs (hundredths inch) 



Humidity: 



Normal mean, fs (per cent) 



Normal mean, year (per cent) 



Wind: 



Normal mean hourly velocity, fs (miles) 



Sunshine: 



Normal total duration, fs (hours) 



Moisture-temperature indices: 



Normal P/E X T, fs, remainder method 



Normal P/E X T, fs, exponential method 



Normal P/E X T, fs, physiological method 



Low. 

 125 

 0" 

 



10.0 

 3.0" 

 3.0-" 

 6.0« 

 -48 

 5-" 



64.4 



35 



.080 

 58 

 28 

 19 

 18 

 12 

 30- 



.115 



20« 



.51 

 .64 

 .65 



350 -« 



64.5 

 66.6 



6.0 



1,300- 



300" 

 5,373 

 J,000- 



Table 27. — Climatic extremes for the deciduous-forest. 



Temperature: 



Days in normal frostless season (fs) 



Hot days, fs 



Cold days, fs 



Remainder summation above 32°, year (thousands) 



Remainder summation above 39°, fs (thousands) . . 



Exponential summation, fs (hundreds) 



Physiological summation, fs (thousands) 



Absolute minimum 



Normal daily mean, coldest 14 days of year (°F.) . . 



Normal daily mean, hottest 6 weeks of year (°F.) . 



Normal daily mean, year (°F.) 



Precipitation: 



Normal daily mean, fs (inch) 



Normal No. rainy days (over 0.10 inch), fs 



Normal No. dry days (0.10 inch or less), fs 



Dry days, percentage of total, fs (per cent) 



Days in longest normal rainy period, fs 



Days in longest normal dry period, fs ; 



Mean total, year (inches) 



Low. 

 128 

 63 





 11.5 



3.7 



3.8 



6.1 

 -27 

 21 



71.6 

 45 



.091 

 26 

 19 

 11 

 17 

 4 

 30- 



High. 

 276 

 173 

 150+" 



18.0 

 9.3 



10.3 



19.2 

 +4 



51 



78.8 + 



70 



.135 

 151 

 211 



78 

 136 



59 



40 



.166 

 52.4 



1.03 

 1.14 

 1.02 



540 



70.7 

 75.0 



12.3 



2,343 



611 

 4,734 

 9,716 



High. 

 323 

 218 

 117 

 18.0 

 8.1 

 8.9 

 16.5 

 + 15 

 47 

 78.8 

 70 



.147 

 225 

 250" 



80 

 174 



91 



60 + 



