152 THE PLANT LIKE OF MARYLAND 



Vegetation. 



Two topics of paramount interest present themselves in this re- 

 gion : The succession of types of forest growth and the salt marshes 

 with their transition to fresh marshes. Seldom does a hetter op- 

 portunity arise for observing the succession of groups of arborescent 

 growth which may cover an area. In southern Maryland many 

 areas which were highly cultivated prior to 1865 have for forty 

 years been neglected by man so that nature has been able to work 

 out her own methods which are of much interest. Moreover the 

 large number of estuaries and bays makes possible a thorough 

 study of the relation between halophytic and fresh water vegeta- 

 tion. Other topics are dealt with, as may be seen from a glance 

 at the table of contents. The forests will be first considered. 



Considering the proximity of the region to the nation's capital, 

 a surprisingly large portion of the surface is forest-covered. In 

 St. Mary's County fully half the area is uncultivated, for economic 

 reasons which do not need to be discussed here. It was hoped that 

 some areas of virgin forest might be found, hence inquiries and 

 search were made in many places. The nearest approach to orig- 

 inal conditions was seen on Lord Calvert's estate in Prince George's 

 County, on a tract two miles north of Harwood in Anne Arundel 

 County, at Leonardtown in St. Mary's County, and in the Zekiah 

 swamp in Charles County, but on none of these tracts does an un- 

 altered growth occur. They will be further considered in appro- 

 priate places. A fairly natural division of the forests into upland 

 and lowland may be made. 



Upland Forests. — An attempt is here made to arrange these into 

 ecological groups which will represent the order of development of 

 forests in accordance with the now well-accepted principle of suc- 

 cession, which may be stated thus: the vegetation found upon an 

 area does not represent a fixed or stable condition, but one of pro- 

 gressive change, dependent iipon the changing topography of the 

 region and on changes in soil, etc., brought about by the plants them- 



