ABSTRACT 
A study of the effect of nutria on marsh vegetation was made 
in southwestern Louisiana from 1954 to 1956 by means of plant 
transects, exclosures, and indices to nutria abundance. Plant 
species studied included saltmeadow cordgrass, Olney's three- 
Square, big cordgrass, reed, and sawgrass. Nutria had a pronounced 
effect, except for limited areas, only on big cordgrass. It is 
concluded that nutria did not have a major effect on the marsh 
vegetation as a whole, and did not create extensive bare areas. 
It is pointed out that the marsh habitat is dynamic and complex 
and many factors are undoubtedly involved in the changes that 
have occurred. 
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