2l8 FLORIDA GEOLOGICAL SURVEY I3TH ANNUAL REPORT 



CENSUS OF TIMBER TREES. 



In contrast with the great diversity of vegetation, the species 

 of trees in central Florida are rather few. About two dozen that 

 are widely distributed in the eastern United States reach their 

 southern limits a little north of our area, while a much larger num- 

 ber of tropical species do not extend quite so far north. 



In the following table the large trees already mentioned in the 

 regional descriptions are brought together in a single list, with a 

 column for each region filled with symbols showing the relative 

 abundance of each species there. The writer's observations are 

 hardly complete enough yet to warrant assigning percentages to 

 every species, but those over 20 are indicated by numbers, and those 

 under 20 by easily remembered letters corresponding to groups of 

 percentages, as follows : — 



10-20%, A (abundant) 

 3-10%, C (common) 

 1-3%, F (frequent) 

 0.1-1%, O (occasional) 

 0.01-0.1%. R (rare) 



It will be noticed that these letters are in alphabetical order, 

 so that in the table the letters nearest the beginning of the alpha- 

 bet indicate the highest percentages. Where the occurrence of a 

 given species is probable but not proved an interrogation point 

 is used, and where it is believed to be entirely absent the space is 

 left blank.* 



The smaller and rarer trees are omitted, as are all the shrubs 

 and herbs, because they are hardly important enough to justify 

 taking up much space with them, and also because their relative 

 abundance cannot be determined so accurately. 



At the top of each column is given the estimated percentage of 

 evergreens in the forests, which is believed to be pretty closely 

 correlated with soil fertility. 



*A similar scheme was used for the trees of southern Alabama in Geol. 

 Surv. Ala. Special Report No. n, pp. 102-104. Aug., 1920. 



