548 forestry Quarterly. 



Forest Atlas. Geographic Distribution of North American 

 Trees. Part I, Pines. By George B. Sudworth. U. S. De- 

 partment of Agriculture, Forest Service. 1913. 



This is a series of maps, each containing the field of distribution 

 of one species, 36 species being represented. The only textual 

 addition outside of a short preface is the statement of the altitu- 

 dinal range on each map. In the preface the author admits that 

 "our present knowledge and published records of the geographic 

 range of North American trees is still very incomplete." Yet, 

 we think that in some instances it is more complete than ap- 

 pears on the maps. If, for instance, a scalloped outline on the 

 outskirts means a patchy or localized distribution (no explana- 

 tion is given as to its meaning), and that is all it may mean on 

 a small scale map, then it is difficult to see why Pinus strobus 

 should be so outlined and the P. resinosa outline appear solid : 

 the two unquestionably behave alike, indeed, they occur almost 

 invariably together in their northern range. In various cases it 

 remains doubtful as to whether a non-continuous field repre- 

 sents really definite information or is merely an indication of dis- 

 continuousness. If the former, then the scale of the maps is too 

 small to give to the information much value ; if the latter, then 

 many more solid color fields should have been broken. At least 

 an intimation as to whether generalized or specialized informa- 

 tion was intended, should have been given. 



We doubt very much from the bookmaker's point of view 

 whether the allotment of an entire map of the continent to each 

 species is desirable ; at least with such species as P. torreyana, 

 radiata, quadrifolia, balfoitriatta, apache ca, nuricata, which can 

 be indicated only by a dart or spot, this is not justified. On 

 the contrary, we believe, interest and value would be increased 

 by combining a number of fields on one map, for comparative 

 purposes, and also by representing merely portions of the map, 

 thus avoiding the unnecessary ballast of useless paper. 



As far as a superficial examination discloses, the information 

 is still only very general ; what is really much more needed and 

 would prove of exceeding value is the detail distribution on a 

 large scale map, even if it were of only a Hmited number of 

 species, and especially of their outskirts, when the ecology of 

 the species could be brought out with more satisfaction. 



If, however, this publication, as the author hopes, will stimulate 



