An analysis of the environmental factors determining the distribution of Scirpus acutus and S. americanus in Cecil Bay marsh.

Abstract

The physical environment, especially the soil conditions, were analyzed to determine the distribution of S. acutus and S. americanus in Cecil Bay marsh, located near Mackinaw City, Michigan. Three transects were conducted running parallel through the marsh. One-meter plots were sampled every five to ten meters; stem counts were made, soil texture and its thickness in the soil profile was determined, the percentage cover of cobbles on the surface was recorded and a soil core was taken for bulk density analyses. The results showed that S. acutus was dominant on finer textured soils, especially those high in organic matter content, and on shallow sandy soils overlying clay. Conversely, S americanus was dominant mainly on sandy soils greater than 4 cm deep, in soils of low organic matter content and in soils where cobbles were present. These findings and their relevance to recent literature are discussed.