102 THE PLANT LIFE OF MARYLAND 



Eastern Shore, yet the character of the soils is of very great impor- 

 tance in this respect. In Kent County near the Limit of the Loblolly 

 Pine it occurs only on Elkton Clay and Meadow,* while in Worcester 

 and Wicomico counties it occurs on soils of every texture from clay 

 i" sand. In the northern part of Wicomico < !ounty and the southern 

 part of Talbot County occur loams which supporl a forest largely 

 made up of deciduous species, and on similar soils in northern Queen 

 Anne's and in Kent counties is a similar foresl made up exclusively 

 of deciduous species. While the general distribution of the Loblolly 

 Pine is determined by historical and climatic factors, yet its relative 

 abundance at different localities within its area is determined by the 

 character of the soil. While it grows on a diversity of soils 100 

 miles south of its limit, yet it extends to its limit chiefly on the soils 

 which are everywhere most favorable to its dominance. The occur- 

 rence of deciduous forests on loam at points 50 miles smith of pure 

 stands of Loblolly Pine on Elkton Clay shows the great importance 

 of soils in sorting and rendering locally dominant or rare the various 

 species of the arborescent flora. 



As already pointed out in the introduction, the soils of the Eastern 

 Shore fall into two classes of very distinct texture a) the heavy 

 Elkton Clay, Meadow and related soils (locally known as "while oak 

 soil") and b) the various types of sand and sandy loam. While the 

 distinctness of the physical texture of these two classes of soils i^ the 

 primary factor in determining the character anil distribution of 

 vegetation in the upland, nevertheless the topography plays a second- 

 ary role in determining the average moisture content of both the 

 heavy and the light classes of soils. In the River Swamps and 

 Marshes the topographic position, conditioning as it does a saturation 

 of the soil, reduces the importance of its physical texture to a negli- 

 gible minimum. Yet in the Upland Swamps the character of the 

 soil does cause differences of vegetation in spite of its high moisture 

 content, because of the more favorable conditions for the movement 

 and aeration of the soil water in the Sandy Loam Upland Swamps as 

 contrasted with the ('lay Upland Swamps. Indeed the differences 

 in the vegetation of the heavy ami lighl ^>ils here should not he 



*The term "Meadow" is here employed in the technical sense in which it is 

 used by the United States Soil Bureau. 



