CLIMATE AND PLANT GROWTH. 



63 



6.10 



63 '' 



A. 



2.0 



501 







\ 



49.0 



5.7 



FIG. 



< GROWING SEASON * 



~~~ Physiological Temperature efficiency 



Wheat 



Brome -grass 



Evaporation 



35. Relation between increments of leaf expansion rate and temperature, spruce-fir 



type. 



