42 REPORT OF NEW JERSEY STATE MUSEUM. 



RKI.ATIONSIIIP BETWEEN THE FLORA OE THE COASTAL PLAIN AND 

 THAT OE THE PIEDMONT REGION. 



The line separating the coastal plain from the Piedmont region 

 to the west of it is known as the fall line and is marked through- 

 out its extent by a more or less abrupt change of level. As 

 already stated there is an appreciable difference in climatic con- 

 ditions as we pass east or west of this line, and a more striking 

 difference in soil conditions, the coastal plain being for the most 

 part covered with sand and gravel in marked contrast to the 

 heavier soils of the Piedmont. There are also frequent rock 

 outcrops and rapid tumbling streams in the latter region, which 

 are entirely lacking in the flat stretches of southern New Jersey. 

 Historically, too, there are ample reasons for differences between 

 I he two regions, as the vastly older land of the Piedmont area 

 was undoubtedly covered with vegetation before the coastal 

 plain was elevated above the sea. 



Hence it is not surprising that we should find a decided differ- 

 ence in the plant life of these two areas. 



In the life-zone maps issued by the United States Department 

 of Agriculture, and based mainly upon the distribution of birds 

 and mammals, we shall notice that the line of demarcation be- 

 tween the Transition and Carolinian Zones is much further back 

 towards the mountains than the line separating the coastal plain 

 flora from that of the uplands. It is, however, well known that 

 Carolinian birds and mammals are everywhere taking advantage 

 of deforestation and cultivation to push northward, so that it is 

 quite conceivable that the tv/o lines may have been much more 

 nearly identical in Pennsylvania and New Jersey under primeval 

 conditions. 



Whether the fall line ever did form the boundary between the 

 faunal zones, there is no question but that it still marks a great 

 change in plant life. 



Farther south, however, it seems that a great many coastal 

 plain plants range far west of the fall line, so that its effect 

 upon distribution is less potent southward or else it coincides in 

 the north more nearly with a line of demarcation in plant life 

 due to other influences. 



