Wetlands on the Lake Michigan Coast
Location
Hager-Lubbers Exhibition Hall
Description
PURPOSE: Wetlands in dune landscapes provide important breeding habitat for amphibians along the Lake Michigan Coast. Unfortunately, these unique habitats and the corresponding amphibian metapopulations are understudied and threatened. The aim of this study is to determine what variables influence amphibian species richness and community composition in dune wetlands. SUBJECTS: We measured a number of variables at 16 permanent and ephemeral wetlands along the coast of Lake Michigan in Grand Haven, MI. METHODS AND MATERIALS: Species richness, wetland area, terrestrial habitat type, depth, hydroperiod, shade, and degree of isolation were measured from April to September of 2017. ANALYSES: Non-metric multidimensional scaling (NMDS), Least cost modeling (LCM), Principle components analysis (PCA), and Correlation testing were used. RESULTS: Nine species of amphibian were found in these wetlands; Green Frogs and Spring Peepers were most abundant, while Fowler’s Toad was the rarest. LCM allowed us to determine the shortest navigable route between wetlands to determine wetland isolation, NMDS revealed that smaller wetlands in open dunes had different species assemblages than larger wetlands in forested habitat. PCA showed the correlations between hydroperiod, area, and depth; and correlation testing confirmed the strong positive relationship between species richness, area, and hydroperiod, and negative relationship between species richness and isolation. CONCLUSIONS: Species richness was higher in larger wetlands, with longer hydroperiods. However, some small temporary wetlands situated in the open dunes harbored rare species not found in other wetlands—highlighting the importance of protecting all of these habitats from land development, fragmentation and degradation.
Wetlands on the Lake Michigan Coast
Hager-Lubbers Exhibition Hall
PURPOSE: Wetlands in dune landscapes provide important breeding habitat for amphibians along the Lake Michigan Coast. Unfortunately, these unique habitats and the corresponding amphibian metapopulations are understudied and threatened. The aim of this study is to determine what variables influence amphibian species richness and community composition in dune wetlands. SUBJECTS: We measured a number of variables at 16 permanent and ephemeral wetlands along the coast of Lake Michigan in Grand Haven, MI. METHODS AND MATERIALS: Species richness, wetland area, terrestrial habitat type, depth, hydroperiod, shade, and degree of isolation were measured from April to September of 2017. ANALYSES: Non-metric multidimensional scaling (NMDS), Least cost modeling (LCM), Principle components analysis (PCA), and Correlation testing were used. RESULTS: Nine species of amphibian were found in these wetlands; Green Frogs and Spring Peepers were most abundant, while Fowler’s Toad was the rarest. LCM allowed us to determine the shortest navigable route between wetlands to determine wetland isolation, NMDS revealed that smaller wetlands in open dunes had different species assemblages than larger wetlands in forested habitat. PCA showed the correlations between hydroperiod, area, and depth; and correlation testing confirmed the strong positive relationship between species richness, area, and hydroperiod, and negative relationship between species richness and isolation. CONCLUSIONS: Species richness was higher in larger wetlands, with longer hydroperiods. However, some small temporary wetlands situated in the open dunes harbored rare species not found in other wetlands—highlighting the importance of protecting all of these habitats from land development, fragmentation and degradation.