areas, fertilization initially increased the standing crop of Distichlis 

 spicata but this was later replaced by Spartina patens . S^. alterniflora 

 did not respond to fertilization in the high marsh. 



The amount of dead matter in both high and low marsh was highest 

 in the fall, after death of the sward, and decreased slowly to a low 

 point in midsummer. The amount of dead matter was never equal to 

 peak live biomass, implying decomposition or tidal export. The 

 production achieved by the most heavily fertilized plots were among 

 the highest recorded for marsh plants, except that of tall form 

 S. alterniflora in exceptionally favorable sites. 



Treatments converted low marsh vegetation, consisting mainly of 

 dwarf form S_. alterniflora . into a sward approaching the biomass and 

 morphology of tall form. The authors conclude that the so-called 

 "forms" are a response to nitrogen supply. 



The effect of sludge fertilizer on the net annual production (gm ) 

 and peak aboveground biomass (gm"^) on low marsh and high marsh vegetation 

 for each of three years was determined: 



(Author's summary) 



Keywords: productivity, saltmarsh plants, biomass, nutrients, Spartina , 

 Distichlis , high salt marsh, Massachusetts 



64 



