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NATURALIST'S GUIDE TO THE AMERICAS 



weeks difference in the appearance of 

 spring between the southern and the 

 northern part of the state and in the 

 higher portions of the Allegheny Moun- 

 tains this is increased almost two 

 additional weeks. 



The average annual rainfall varies 

 from 30 to 55 in., with the larger amounts 

 of rain in the extreme western part of the 

 state (in Garrett County), in the north- 

 central portion of the state (in Harford 

 and Carroll counties) and in the south- 

 central part of the eastern shore (in 

 Dorchester and Wicomico counties). 

 The greater part of the state receives an 

 average annual precipitation of 40 to 

 45 in. The precipitation is more or less 

 equally distributed throughout the 

 months, when the means for a long term 

 of years are taken. 



The original biota 



Maryland lies in a region in which the 

 dominant vegetation was the deciduous 

 forest, and before settlement by the 

 white man, the state was undoubtedly 

 covered by continuous forests. Only 

 here and there were there restricted 

 areas of marshes, bogs, bare rocks, or 

 sandy areas, in which local conditions 

 were not favorable for tree growth. 

 The forests differed from place to place 

 in their vegetational landscape aspects. 

 Shreve^ in his Vegetational Map of the 

 United States, divides the state into 

 four regions. These are, beginning 

 with the southernmost portion of the 

 state and extending north and westward, 

 the Southeastern Mesophytic Evergreen 

 forest, the Deciduous forest, the North- 

 ern Mesophytic Evergreen forest, and 

 the Northeastern Evergreen Deciduous 

 Transition forest. These vegetational 

 landscape aspect regions in Maryland 

 correspond- — fairly closely^ — respectively 

 to the Louisianian, Carolinian, and 

 AUeghenian zones of Verrill and to the 

 Lower Austral, Upper Austral and the 

 Transition Life-zones of Merriam. 



Since, in the undisturbed condition, 

 Maryland was originally largely covered 



' Shreve, Forrest, Vegetational Map of the United 

 States, Geographical Review, February, 1917. 



with deciduous and evergreen forests, 

 the animal life must have largely corre- 

 sponded to that generally found in 

 forests of that type. There was, no 

 doubt, considerable difference in the 

 southeastern and the northwestern parts 

 of the state due to the differences in the 

 climate and the physiography. These 

 differences in the animal and plant 

 biota will be discussed according to the 

 various vegetat.onal landscape aspect 

 regions as given by Shreve, Chrysler, 

 Blodgett and Besley.^ 



The Southeastern Mesophytic Forest 



This region includes the area south 

 and eastward from a line extending from 

 the Delaware Bay across the middle of 

 Delaware, through Caroline and Queen 

 Anne counties in Maryland to Baltimore 

 City, from there to the District of Co- 

 lumbia, and thence across the eastern 

 one-third to one-half of Virginia, North 

 Carolina, South Carolina, and south- 

 ward. This area was largely a forest of 

 evergreen needle-leaved trees with a 

 subordinate admixture of evergreen 

 broad-leaved and deciduous species. 

 Extensive areas in Maryland were pure 

 stands of loblolly pine {Pinus taeda) 

 in open formation, nearly devoid of 

 shrubs and carpeted with grasses and 

 herbaceous plants. Most of this area 

 has but little elevation, only in a few 

 places rising above 150 ft. Many 

 swamps, marshes and bogs were common 

 along the low lying shore of the Chesa- 

 peake Bay and its tributaries. The 

 marshes of the Eastern Shore aggregate 

 many acres in area and are most ex- 

 tensive in Dorchester and Somerset 

 counties, and have probably changed 

 but little from their original condition. 

 These marshes are of both the salt and 

 the fresh water kind. 



The plant life of the salt marshes is 

 limited to those plants which have 



- Shreve, Forrest, Chrysler, M. A., Blodgett, 

 Frederick and Besley, F. W. The Plant Life of 

 Maryland. Maryland Weather Service. Special 

 publication. No. Ill, 1910. Pp. 533. 



This publication is a very valuable piece of work 

 and should be consulted by anyone interested in 

 the ecological plant life of Maryland. It has served 

 as the basis for much of the information regarding 

 plants contained in this report. 



