A phytosociological study of weed communities on the southwestern Coastal Plain of North Carolina

The lower River Bend Formation at the Martin Marietta New Bern quarry in Craven County, North Carolina, contains a diverse and abundant moldic molluscan fauna. This fauna, reconstructed by latex casts, suggests a Vicksburgian or a post-Vicksburgian, pre-Chickasawhayan age for the New Bern exposure. Forty-one molluscan species and subspecies are presently identified from the lower River Bend Formation, 11 of which are new: Turritella caelatura alani, Turritella neusensis, Galeodaria britti, Phalium newbernensis, Cymatium planinodum, Oocorys vadosus, Ecphora wheeleri, Lyria concinna, Scaphella saintjeani, Turricula (Orthosurcula) aequa, and Lucina (Stewartia) micraulax. This fauna is virtually identical at the generic level and similar at the species level to the Vicksburgian faunas of the Gulf Coastal Plain. About 37 percent of the New Bern species also occur in the Vicksburgian of Mississippi, although many of these species reach considerably larger sizes at New Bern. Apparent evolutionary transitions between previously known Vicksburgian and Chickasawhayan mollusks suggest a time of deposition intermediate between these two Oligocene stages.Moderately high molluscan diversity, the abundance of characteristically warm-water genera, and associated carbonate-rich sediments suggest that the lower River Bend Formation represents a subtropical, open-marine, predominantly carbonate environment immediately seaward of a nearshore lagoonal or barrier island complex.The lower River Bend Formation at New Bern differs faunally, climatically, and sedimentologically from the upper River Bend Formation in quarry exposures near Belgrade, North Carolina. The upper River Bend Formation contains a lower diversity molluscan fauna with marked dominance diversity and few warm-water taxa. It represents a slightly cooler nearshore, open-marine environment in a transitional siliciclastic-carbonate sedimentary regime. The considerable taxonomic and sedimentologic differences between the lower and upper parts of the River Bend Formation corroborate microfossil evidence suggesting that they represent temporally distinct depositional cycles.

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The 1909 North Carolina Drainage Act and Agricultural Drainage Effects in Eastern North Carolina

Journal of North Carolina Academy of Science ◽

10.7572/2167-5880-128.3.59 ◽

2012 ◽

Vol 128 (3-4) ◽

pp. 59-73 ◽

Cited By ~ 3

Author(s):

Michael A. O'Driscoll

Keyword(s):

North Carolina ◽

Coastal Plain ◽

Management Practices ◽

Stream Water ◽

Agricultural Drainage ◽

Agricultural Lands ◽

Stream Water Quality ◽

Agronomic Management ◽

Effective Drainage ◽

Eastern North Carolina

Abstract Over the last two centuries, agricultural drainage in eastern North Carolina has transformed extensive wetlands to productive croplands. At the start of the drainage movement in the early 1900s, approximately 200,000 hectares (one half million acres) of drained agricultural lands existed in North Carolina. The 1909 North Carolina Drainage Act allowed for more extensive drainage projects. Drainage districts provided effective drainage outlets for farms and reduced flooding for the district. The districts dramatically increased the extent of drained lands during the 20th century. Currently, it is estimated that over 2 million hectares (five million acres) of drained agricultural lands exist in North Carolina, with the majority in the Coastal Plain. Agricultural drainage has contributed to huge gains in agricultural productivity in the region. However, this drainage has contributed to regional stream water quality impairment, altered stream hydrology, and wetland conversion. Over the last three decades, much work has been focused on reducing watershed nutrient exports in eastern North Carolina. Several major strategies have been used to decrease the environmental impacts of agricultural drainage, including: agronomic management practices; controlled drainage; riparian and wetland buffers; and channel alterations. Management of agricultural drainage during the 21st century will play a crucial role in regional stream, wetland, and coastal ecosystem health.

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