326 



SCIENCE 



[N. S. Vol. LIII. No. 1371 



any problem without a great deal of in- 

 ventiveness. Where necessary to indicate 

 species an initial following the symbol does 

 very well. 



Using these symbols the species of bearing 

 trees at each section comer can be transcribed 

 onto a sheet of cross section paper with one 

 centimeter or quarter inch squares. Where 

 correspondence between original and modern 

 surveys is sufficiently close it is sometimes 

 convenient to transcribe directly upon a 

 county road map or topographic sheet, as this 

 gives a ready guide for field checking. With 

 an assistant reading locations and species it 

 was found that an average county in Ohio 

 could be transcribed in from thirty to forty- 

 five minutes, while one man working alone 

 could do the job in one or two hours. 



If, for publication or other reasons, a map 

 in colors is desired, distinctive colors can be 

 assigned to each series, and the various shades 

 of these colors to the important species of the 

 respective series. The symbols may then be 

 transcribed by means of properly colored dots 

 upon two millimeter cross section paper. 



Finally and most important, it has been 

 amply demonstrated that this network of 

 specimen trees at one mile intervals affords a 

 workable map of native vegetation, even 

 within an area twenty miles square. One 

 concrete instance of the usefulness of such a 

 map within the Erie Basin of Ohio may be 

 cited. The climax forest of glaciated Ohio is 

 beech-maple, but there are considerable areas 

 whose native vegetation is oak-hickory and 

 also prairie. The map in question revealed 

 with great promptness a correlation whose 

 significance the reader may judge for him- 

 self; the beech-maple covers what was upland 

 during the recession of the postglacial lake, 

 the oak-hickory coincides with the great 

 shallow bays formed at various stages of 

 recession, and prairie (with occasional bog 

 centers) marks clearly the deeper baymouths. 

 These facts of course become especially illu- 

 minating when taken in connection with the 

 events of to-day, patent in and about San- 

 dusky and Matmiee bays. 



While stationed at Dorr Field, Arcadia, 

 Florida, in 1918, the writer had excellent op- 

 portunity to test the utility of the airplane 

 as an aid in vegetation reconnaissance and 

 mapping. It goes without saying that experi- 

 ence of this sort came as a by-product of 

 other duties which fairly filled the time. 



There are two basic facts to emphasize in 

 connection with airplane reconnaissance — first, 

 the tremendous increase in perspective made 

 possible, and second, the fact that each type 

 of vegetation preserves its distinctive shade 

 of color, and often a distinctive texture, so 

 long as it remains visible. 



Granted that vegetation types are distinc- 

 tive in shade and texture from considerable 

 altitudes, one has only to examine mosaic air- 

 plane maps made with one of the excellent 

 automatic cameras now available to realize 

 that this method can be just as useful for 

 mapping vegetation as for locating gunpits 

 or analyzing topography. Because of the cost 

 it is not likely that extensive photographic 

 maps will often be undertaken by individuals, 

 but pressure from individuals may be highly 

 instrumental in getting organized agencies to 

 undertake methodical mapping of this kind 

 while native vegetation still remains. 



For reconnaissance mapping, however, the 

 airplane should be of great service to the 

 individual. The ecologist who is engaged in 

 studying a given region ought to pause to 

 balance the time he will spend in planning ^ 

 and later in piecing together isolated field 

 studies to get their broad interpretation 

 against the expense involved in taking two 

 thirty-minute flights over the region. A min- 

 imum of two flights has been suggested be- 

 cause the first would permit intelligent plan- 

 ning of field studies while the second, taken 

 at the conclusion of these studies, would per- 

 mit their proper synthesis and criticism. 

 Since expense is not the only objection that 

 is likely to arise, it may not be amiss to 

 mention that straight flying is uniformly a 

 delightful experience and that notetaking or 

 even map sketching can be performed with 

 ease inside of the cockpit. 



