A maximum living and dead biomass of salt hay for Maine marshes approached 

 3036 ± 506 g dry wt/m^ (Linthurst 1977). Values for Delaware and Georgia 

 marshes showed lower maximum biomass values ( 2000 g dry wt/m2). Above-ground 

 production of salt hay in Rhode Island at the end of the growing season was 

 430 g dry wt/m^ (Nixon and Oviatt 1973). 



Creek bank black rush had a maximum living and dead biomass in Maine of 1694± 

 190 g dry wt/m2 . High marsh black rush possessed a somewhat lower maximum 

 biomass of 676± 90 g dry wt/m^ (Linthurst 1977). 



Estimates of productivity attempt to reflect the production of a standing crop 

 of vegetation over an entire growing season, rather than the biomass at peak 

 standing crop. The net aerial primary productivity (NAPP) of the three 

 dominant species of emergent salt marsh vegetation in Maine was determined by 

 Linthurst (1977; table 5-16). NAPP was calculated by methods used by Smalley 

 (1959) and Weigart and Evans (1964). Linthurst (1977) used a combination of 

 these methods in estimating NAPP in the estuarine intertidal wetland. The 

 NAPP of salt hay in Maine was approximately double that of Delaware and also 

 higher than that reported for Georgia (table 5-16). 



NAPP values for creek bank black rush were much higher in Maine than in 

 Delaware; however, the NAPP for high marsh black rush in Maine was much lower 

 than that in Delaware (table 5-16). 



The annual above ground net productivity of cordgrass was 619 g/m2/year 

 (McGovern 1978). Of this, at least 223 g/m2 of organic material was later 

 stored as below ground tissue and at least 396 g/m2was left above ground as 

 detritus each year. 



The turnover rate of cordgrass in Maine was higher than that of Delaware and 

 Georgia, primaily because of the greater loss of dead plant material due to 

 greater tidal activity (Linthurst 1977). Maine salt marshes apparently supply 

 more energy per unit area of marsh to the estuarine ecosystem through the 

 detrital cycle than salt marshes further to the south. 



The below ground biomass of cordgrass at Herrick Bay salt marsh in Brooklin, 

 Maine (McGovern 1978), was 1422 g/m2 when first sampled in April but decreased 

 to a low of 909 g/m2 in August and then increased to 1646 g/m in December 

 (McGovern 1978). 



Because below ground biomass was 223 g/m2 greater in December than in April, 

 Herrick Bay cordgrass marshes required 223 g/m2 organic matter for respiration 

 and senescence of tissue during the winter. Since net above-ground 

 productivity was determined to be 619 g/m , McGovern (1978) estimated that at 

 a maximum, 396 g/m (2 tons/acre) of organic tissue potentially would become 

 detritus each year. This indicates a very productive system, one of the most 

 productive natural systems in the world (Teal and Teal 1969). 



Below-ground productivity makes a special contribution to salt marsh 

 productivity by providing primary production to infaunal organisms and 

 microbes. In addition, the below ground parts of plants help ward off erosion 

 and stabilize the marsh peats and bordering uplands. 



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