RESULTS AND DISCUSSION 



Substrate 



Results of analyses of substrate samples from lie Grande indicated 

 important differences among sites which affect plant growth. Samples 

 from relatively undisturbed areas of marsh from which transplants were 

 taken and from the root mat of marsh killed by oil but with no surface 

 manipulation, had relatively high ammonium, phosphorus and organic 

 matter concentrations and low volume weight and pH values compared to 

 substrate below the undisturbed root mat and that exposed by the 

 cleanup operations (Table 1 ) . The low ammonium and phosphorus 

 concentrations of the subsurface material definitely were limiting to 

 plant growth. Data to be presented later in the report indicate that 

 fertilizer materials were necessary for significant plant growth in 

 these disturbed substrates. 



TABLE 1. Values for five substrate variables for seven sites (source 

 of transplant sites for four species, two strata of marsh 

 without vegetation but with surface not removed, upper 

 stratum of a creek bank without vegetation but with surface 

 not removed, and a site from which the marsh surface was 

 removed) at lie Grande. 



Site 



Puccinellia site 



Triglochin site 



Juncus site 



Spartina site 



Marsh without vegetation 3 



upper 10 cm (root mat) 



below root mat 

 Creek bank (upper 10 cm) a 

 Site with marsh removed 13 



a Marsh vegetation removed as a result of cleanup operations but 

 marsh surface not removed; examples of site in Figures 1 and 16. 



Marsh surface including root mat was removed during cleanup 

 operations. 



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