2 

 The community mean net areal productivity is 1388 g/m /yr. More than 



90 percent of the intertidal marsh net areal production is removed to 



the estuary as organic detritus, and net area! production in the high 



marsh is rapidly incorporated into marsh soil. It is estimated that 



approximately 56 percent of all net areal production on West Island is 



transported to the estuary by the tides. It is recommended that salt marshes 



be preserved in their natural state and new salt marshes be created to 



ensure the continued high productivity of estuarine ecosystems in 



Oregon. (A. A.) 



Keywords: salt marsh, salt marsh plants, biomass, productivity, tidal 

 marsh, Oregon 



II-B-2 



Mahall, B.E., and R.B. Park. 1976. The ecotone between Spartina foliosa 



Trin. and Salicornia virginica L. in salt marshes of northern San Francisco 

 Bay. I. Biomass and production. Journal of Ecology 64:421-433. 



One of the most striking characteristics of tidal salt-marsh vegetation 

 is its frequent division into distinct zones. Northern San Francisco 

 Bay is an ideal location in which to study salt marsh zonation because 

 of its heavy winter rainfall, uniform soil composition, geographically 

 uniform shoreline, and simple zonation at mean high water (MHW) level 

 between two monospecific communities of Spartina foliosa and Salicornia 

 virginica . 



Measurements were made of the standing crop and net production above 

 and below ground in 1972 along two transects: one on the Petal uma 

 River and one on Mare Island. The height of the aboveground standing 

 crop and the net production of Spartina generally decreased landward 

 and decreased greatly at the middle of the ecotone. The height of the 

 aboveground crop and the net production of Salicornia also decreased 

 toward the ecotone, but at Mare Island, Salicornia was more productive 

 per unit biomass in the Spartina zone than in the Salicornia zone. 



The authors conclude that there is little competition between the 

 two species at the ecotone and that the primary limitations are physical 

 and physiological. (B.W.) 



Keywords: marsh plants, productivity, Spartina , Salicornia virginica , 

 California 



34 



