Botany 2012 - The Next Generation
Phragmites australis (common reed) consists of a native North American group with several genetic forms, and a non-native and highly invasive introduced group with a single genetic form. Little is known about the environmental factors that affect the distribution of native and non-native populations, and it is difficult to differentiate between the two based on physical characteristics alone. The west Michigan region provides an excellent opportunity to evaluate the relationship between environmental gradients and the spread of Phragmites. The Lake Michigan coast presents a strong temperature gradient from the north to the south, whereas a strong moisture gradient is found along the east-west axis from the Lake Michigan shoreline inland. Thus, the goals of this study are to: 1) determine the genetic composition of common reed populations along the west Michigan coast from southern (warmer) to northern (cooler) Lake Michigan, 2) determine the genetic composition of common reed populations along an east-west (wetter-drier) gradient from the west Michigan coast to more inland locations, 3) determine the current distribution of the exotic Phragmites in western Michigan, and 4) evaluate the importance of genotype in the distribution and abundance of the native common reed. Examination of 44 populations of Phragmites australis throughout western Michigan yielded only the non-native haplotype in the southern regions and a mixture of native and non-native haplotypes in the northern regions. A single population contained individuals of both haplotypes. No trends have been observed along the east-west axis.