The natural forests of Maryland: an explanation of the vegetation map of Maryland
The forests of Maryland have been mapped at a scale of 1:250 000 on the basis of 15 regional associations: (1) tamarack, (2) bald cypress, (3) hemlockâ€šÃ„Ã®yellow birchâ€šÃ„Ã®black birch, (4) river birchâ€šÃ„Ã®sycamore (5) sycamoreâ€šÃ„Ã®green ashâ€šÃ„Ã®box elderâ€šÃ„Ã®silver maple, (6) shingle oak, (7) chestnut oakâ€šÃ„Ã®post oakâ€šÃ„Ã®blackjack oak, (8) chestnut oakâ€šÃ„Ã®bear oak, (9) chestnut oak, (10) loblolly pine, (11) basket oakâ€šÃ„Ã®loblolly pine, (12) willow oakâ€šÃ„Ã®loblolly pine, (13) basket oak, (14) sugar mapleâ€šÃ„Ã®basswood, and (15) tulip poplar. The associations differ from each other in species composition and in abundances of species common to many associations. Each was identified in the field by the presence of relatively few common discontinuous tree species referred to as characteristic species. Correlations between forest associations and geologic, topographic, and soils units mapped at a similar scale suggest that patterns of available water are important in controlling distribution of woody species throughout Maryland.