PLAN OF REGIONAL DESCRIPTIONS. 27 



The mixed pine and oak woods which constitute a very- 

 large proportion of the forests of Alabama and other 

 southeastern states occupy an intermediate position be- 

 tween the rich shady hardwood forests and the open 

 long-leaf pine forests with respect to fire. In these 

 woods fire often consumes the dry leaves in late fall, 

 and even though it does little harm to the trees it tends 

 to impoverish the soil by driving ofi" the nitrogen and 

 other organic matter contained in the leaves, so that it 

 does not seem to be good policy to set fire to such forests 

 purposely, at least where the land is likely to be used for 

 cultivation at some future time. 



Lists of trees. — The lists of trees for each region have 

 been prepared with considerable care, and are probably 

 not far from complete in most cases, for all but the rar- 

 est species. The species are arranged in the same order 

 in each list, beginning with the pines and ending with 

 those trees which are generally regarded by botanists as 

 most highly organized. This method does not bring out 

 the contrasts between the different regions quite as 

 plainly as it would to arrange the species in order of 

 abundance, but it is more convenient for fi.nding quickly 

 in any list the name of any particular tree. 



Each line in these lists begins with two numbers. The 

 first represents the proportion of the area of the original 

 forests of each region supposed to have been occupied by 

 each species, and the second shows the same thing for 

 the present forests. These ratios are expressed in per- 

 centages, and are given only to the nearest unit, so that 

 all percentages less than 1/2 ^^^ represented by 0. Species 

 which make up less than one-tenth of one per cent of the 

 forests of any region are usually omitted, as having lit- 

 tle significance. The first figure is more or less of a 

 rough estimate, while the second is derived from my 

 field-notes by a rather complex and laborious method, 

 which need not be explained here. Great accuracy can- 

 not be claimed for these figures, but they are much bet- 

 ter than what we have had before (viz., none at all) , and 

 perhaps none of them will prove to be more than double 

 or less than half the correct figures which may be ulti- 

 mately obtained. There are of course more precise 



