208 PHYSICAL ENVIEONMENT 



cold. A favorable exposure for any plant is one which 

 supplies the requisite amount of warmth, room, sunlight, 

 moisture, and plant-food, and immunity from severe winds 

 and other destructive agencies. Against the edge of a 

 forest (Fig. 356) or at the base of a cliff, certain plants 

 thrive unusually well. Note the plants of any kind grow- 



356. The flowering dogwood is seen at its best along the margins of the wood. 



ing in different exposures: observe that they vary in 

 stature, time of maturity, color of foliage and flowers, 

 productiveness, size of leaves and flowers, longevity. 



REVIEW. Contrast physical and organic environments. How are 

 plants modified by climate? Define acclimatization. Explain how time 

 of maturity is influenced by climate. How is germination influenced ? 

 Explain how climate influences stature. How do winds affect plants ? 

 How are plants influenced by soil ? By soil moisture ? Exposure ? 



