Two soil associations are recognized on the island 

 (SCS 1973) . The southeastern portion adjacent to the 

 IWW (excluding the spoil banks) is classified as the 

 Ponzer-Belhaven-Wasda association: very poorly drained 

 soils with moderately thick to thin organic surface 

 layers. Most of the western, northern, and eastern 

 portions are classified as the Dare-Pungo-Dorovan associ- 

 ation: very poorly drained soils with thick to moderately 

 thick organic surface layers. 



No detailed soil mapping has been done on Roper Island; 

 however, based on soils information from similar areas along 

 the Alligator River in Dare County, the deeper peats are 

 probably the Pungo series (Barnes 1981) . 



Ingram and Otte (1982) have mapped the peat deposits 

 of Roper Island as part of a study of deposits throughout 

 the Pamlimarle Peninsula. Depths of 8-10 feet are prevalent 

 along the Alligator River and gradually thin towards the in- 

 terior of the island. Relatively small areas of peaty sand 

 or sandy peat are mapped near the IWW. About 75% of the 

 island is underlain by peat 2 feet or more in depth. 



THE VEGETATION 



A brackish marsh community is located along the Alligator 

 River in the southwestern portion of Roper Island. It extends 

 along both sides of the river from the confluence with the IWW 

 downstream (north-northeast) for about 7.5 river miles. The 

 most extensive marshes are located at the extreme southwestern 

 corner of the island near the IWW and gradually become narrower 

 and more shrub-dominated towards the northern end of the island 

 before the Northwest Fork confluence. 



The brackish marsh community (780 acres) is dominated by 

 narrow-leaved cattail ( Typha angustifolia ) with some sawgrass 

 ( Cladium jamaicense ) intermixed. The primary community type 

 is Typha angustifolia (narrow-leaved cattail; CT 1) although 

 in some areas sawgrass is frequent enough to be considered a 

 codominant. Along the back edges of the marsh shrubs such as 

 groundsel tree ( Baccharis halimifolia ) and seashore mallow 

 ( Kosteletskya virginica ) are common with shrub-sized loblolly 

 pine ( Pinus taeda ) , red maple ( Acer rubrum ) , and some Atlantic 

 white cedar ( Chamaecypar i s thyoides ) . The shrub marsh zone 

 becomes more prominent in the downstream sections, particularly 

 past Kilkenny Landing, where it extends from the riverbank in- 

 land until grading into various forested wetland communities. 



70 



