322 BOTANICAL SURVEY OF DISMAL SWAMP REGION. 



form the plant covering of the region as a whole. As the character of 

 the assemblage which occupies each limited tract is, of course, largely 

 determined by conditions of the physical environment there prevail- 

 ing, it is easily seen how closely related are these two lines of investi- 

 gation. On its purely scientific side, the first is, indeed, merely an 

 aspect of the second. 



Tie- study of the native growth upon different soils presupposes 

 some knowledge of the soils themselves. To supply this knowledge 

 a special chapter upon the soils of the region has been contributed to 

 the present report by Mr. Frank Gardner, through the kindness of 

 Professor Whitney, of the Bureau of Soils. Mr. Gardner mad*' a 

 careful personal examination of the soils of the Dismal Swamp itself, 

 and has also studied other soils in the neighboring territory. Two 

 principal types of soil, the most valuable of the region, were especially 

 considered in this part of the investigation— the light, sandy soils in 

 the neighborhood of salt water,, which are devoted to market garden- 

 iimor "truck" growing, and the rich soils thai have been reclaimed 

 from ihe wooded swamps by felling the timber and by drainage, upon 

 which Ihe principal crops are corn and potatoes. 



The principal agricultural products of (he region are detailed and 

 briefly described by way of preface to that section of the report 

 which deals with the problem of Ihe relation between soils and the 

 native growth upon them. T< was found thai the solution of this 

 problem presents considerable difliculty in Ihe country investigated, 

 owing to the lack of important chemical differences in the agricultural 

 soils. Water content of the soil, depending largely upon the fineness 

 of its particles and upon the drainage, was found to be the principal 

 element in determining the character of the native growth. As this 

 fact or varies greatly within narrow limits, il soon became evident that 

 it would be impossible to map the soils of the region by (he forest 

 growth upon them, as was originally intended. Yet it is believed that 

 such positive results as were obtained will be useful in Ihe further 

 prosecution of this interesting and important but by no means simple 

 line of investigation, and thai even the negative results are not with- 

 out value. Both contribute toward determining just how far a farmer 

 may rely upon the quality of the native growth on his land as an in- 

 dication of its value for this or that crop. It is hoped thai the inquiry 

 maybe resumed in some region in which the natural conditions will 

 admit of obtaining more definite results. 



The purely scientific section of this report is largely devoted to a 

 description of the several assemblages which make up the plant cov- 

 ering of the region as it actually occurs. To supplement the descrip- 

 tions, which necessarily convey but a limited conception of the actual 

 relations and appearance of the vegetation, numerous photographs 

 are reproduced. A discussion of the character of the environment 

 and the most striking modifications which apparently adapt plants 



