86 



J'OREST INFLUENCES. 



The range is exagQerated in tlie glade as comi>ave<l with the]>lain by 

 0°.3G. The niiiiitua are also exaggerated in the ])lain hy (K'.54, but it 

 ai)pears that in this ease the niaxininin is reduced. 



The disajjpearance of this feature of glade temperatures is doubt 

 less dne to the large size of some of the glades, and also to the high 

 latitude of the st.ations, giving a low latitude to the meridian sun. 

 The relatively large reduction of the maxima causes the mean temper- 

 ature of the glade to be 0^.30 loMer than that of the plain. It ajtpears, 

 therefore, that the glade climate is l)y a small (iuantity more rigorous 

 than the climate of open plains. The forest tends, in so far, to exagger- 

 ate or sharpen the diurnal changes of temperature. 



Fig. 45 also shows the values of W—G and W—P for soil tempera- 

 tures at the depths of 20 inches and of 5 feet. Tlie temperatures are 

 slightly higher under plains; G — F at both depths = +0°.l. 



Fig. 40 shows the monthly values of ^y-G, W-P, and G-P. The 



MINIMA. 



MEAN. 



MAXIMA. 



Plfi. 4C. — Differences of ;iir- ti'iii])erataire in fore.st, glade, ami ]il!iiii (Swedisli). 



stations are not necessarily the same for the three figures nor the same 

 as for the i)receding. Tlie first curve is of the same character as the 

 temperature figures in the j^receding sections, and shows the same gen- 

 eral features. The cooling etfe(;t is much more marked in the spring 

 than lias been the case with any examined before. The second shows 

 an exaggeration of the features of the first, except for tiie line of 

 minima, and these ai)pear in si)ring and summer to be much the same 

 in forest and jdain. 



