and its annual cycle of growth and decay. The growth of Spartina 

 was studied with harvest and other techniques in salt marshes near 

 Beaufort, N. C, Standing crop at maturity (in the fall) apd annual 

 production were estimated to average 545 to 650 g dry wt/m^, or 208 

 and 248 g C/m^, respectively. Spartina production approached one-third 

 the total phytoplankton net production of adjacent estuaries, and thus 

 was potentially important in estuarine food chains. Zinc, manganese, 

 and iron all had markedly higher concentrations in dead Spartina 

 than in live, and averaged 22, 200, and 5000 ppm (dry wt), respectively, 

 in the dead material. The unusually high iron content of the dead 

 material suggested that the Spartina detritus may be especially important 

 in the movement of radioisotopes of iron from water and sediment into 

 estuarine animal populations. (L.H.) 



Keywords: food chain, minerals, Spartina alterni flora . North Carolina 



II-B-20 



Stroud, L.M., and A.W. Cooper. 1968. Color-infrared aerial photographic 

 interpretation and net primary productivity of a regularly-flooded 

 North Carolina saltmarsh. North Carolina Water Resources Research 

 Institute Report No. 14, North Carolina State University, Raleigh. 86 pp. 



A study was made of the net primary productivity of salt marsh communities 

 in a 2000-acre, regularly flooded marsh in Brunswick County, N. C. 

 Color infrared aerial photographs were used to determine acreages of 

 community types. Acreages were: short Spartina alterniflora (cordgrass) 

 - 837; medium cordgrass - 195; tall cordgrass - 110; Juncus roemerianus 

 (black needlerush) - 161; water - 474; other - 118. Net primary 

 productivity estimates were based on harvest method data. Observed 

 harvest data were fitted to a fourth-degree polynomial in time in order 

 to express the average behavior of the standing croo through the year. 

 Net productivity was determined by two methods: (1) use of living 

 standing crop only, and (2) use of changes in living and dead standing 

 crop. Estimates of net primary productivity using changes in living 

 and dead standing crops based on the prediction equation were: short 

 cordgrass - 1106 kcal/m^/yr; medium cordgrass 1856 kcal/m^/yr; ,. 

 tall cordgrass - 6471 kcal/m^/yr; black needlerush - 5346 kcal/m I'jt. 

 Over the entire marsh net primary productivity was estimated to be 

 1534 kcal/m^/yr. These values were lower than similar values from 

 Georgia, but were close to other estimates of net primary productivity 

 for salt marsh vascular plants in North Carolina. (A. A.) 



Keywords: primary productivity, infrared photography, Spartina 

 alterniflora, Juncus roemerianus. North Carolina 



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