Date of Award
Corkum, L. D.
CC BY-NC-ND 4.0
This study was designed to examine distributions of freshwater mussels in relation to riparian vegetation within the drainage basin. Three rivers were chosen with grassy riparian zones (Avon R., McGregor Cr., Whirl Cr.) and three rivers were selected with forested riparian zones (Ausable R., Dingman Cr., Saugeen R.). In total, 17 unionid species were found within the study area. Grassy rivers with narrow, grass-dominated riparian zones were characterised by Pyganodon grandis and Strophitus undulatus whereas forested rivers with wider riparian zones were characterised by Elliptio dilatata, Lampsilis radiata, Lampsilis cardium and Fusconaia flava. Basin types did not differ in mean species numbers, however, a shift towards dominance by a single species was found in grassy rivers with over 60% of individuals in these rivers being P. grandis. Unionid distribution patterns were modelled using Multiple Discriminant Analysis to determine if species distributions could be predicted on the basis of physical features of the riparian zone. Discriminant analysis on the basis of mussels species abundances confirmed a priori classification in 100% of cases whereas classification on the basis of physical riparian characteristics confirmed 85% of classifications. The discriminant model was tested using an additional 16 sites that were not used during the initial development of the model. Growth rates were examined as potential controlling agents of unionid distributions. Analyses of long term growth patterns on the basis of regular growth rests in the unionid shell revealed two distinct growth patterns. Species which characterize forested rivers (e.g., Elliptio dilatata) show slow growth throughout the life whereas species which characterize grassy rivers (e.g., Pyganodon grandis) show rapid growth during early life and achieve a smaller maximum size at a younger age. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1996 .M66. Source: Masters Abstracts International, Volume: 34-06, page: 2297. Adviser: Lynda D. Corkum. Thesis (M.Sc.)--University of Windsor (Canada), 1996.
Morris, Todd James., "Landscape influences on the distribution and growth of freshwater mussels (Bivalvia: Unionidae) in southern Ontario." (1996). Electronic Theses and Dissertations. 2567.