CLIMATE. 101 



to another for thousands of years, must have had a marked 

 influence in leaching the soils of the southern and eastern 

 counties (and at the same time making the ground-water 

 purer and more constant there than in the northwestern 

 portions). 



In the late summer rain area most of the rain falls in 

 the daytime, while in the rest of the State, where there is 

 more winter and spring rain, a larger proportion of it falls 

 during the night. Tornadoes are most frequent in those 

 parts of the country that have the greatest excess of early 

 over late summer rain (such as Kansas), and hurricanes 

 at the other extreme, typified by southern Florida; but 

 neither kind of windstorm is as common in southern Ala- 

 bama as it is farther from the line of equilibrium, which 

 passes through our area.* 



Vegetation. 



This whole area, except for bodies of water, marshes, 

 dunes, and a few prairie spots, was presumably originally 

 covered with forests, with pines of various species predomi- 

 nating and oaks next in abundance. The percentage of 

 evergreens increases as the soil fertility diminishes, from 

 about 45 per cent in the northwestern portions to 95 per 

 cent in the coast strip. 



The percentage of forest now remaining likewise varies 

 in different regions with soil fertility (for naturally the 

 richer soils are cleared first by the farmers), ease of tillage, 

 etc., from about 50 per cent to nearly 100 per cent. In the 

 more fertile areas land was cleared faster than the timber 

 could be utilized, and millions of fine trees were girdled and 

 left to die standing, or else cut down, rolled into heaps and 

 burned. This practice has also prevailed even in the poorer 

 regions, in places remote from railroads and navigable 

 streams by which the timber could be gotten to market (evi- 

 dences of it can now be seen especially in the southern part 

 of Monroe County), but as a rule in the long-leaf pine 

 country the lumberman has preceded the farmer and laid 



*For a discussion of the relations of the ratio between early and 

 late summer rain to soil, vegetation, water-power, floods, tornadoes, 

 hurricanes, and a few other things see Science II, 48:208-211. Aug. 

 30, 1918. 



