Degree Name

Master of Science (MS)

Semester of Degree Completion


Thesis Director

Eugene B. Krehbiel


Terrestrial, shell-bearing gastropods were collected at Rocky Branch Nature Preserve, Clark County, Illinois. A total of three hundred nineteen specimens were collected representing five families and fifteen species. Two species of the family Endodontidae, eight species of the family Polygyridae, three species of the family Zonitidae, and one species in each of the families Pupillidae and Succineidae were collected.

In addition, an attempt was made to find the relationship between species diversity and dominant woody vegetation and soil quality. The land at Rocky Branch Nature Preserve ranges from lowland flood plain to high second growth forest. The dominant trees of the lowland were maple and elm, which produce an alkaline soil with high concentrations of calcium. The dominant trees of the second growth upland forest are oak and hickory, which produce an acid soil and lower calcium concentrations. More specimens of land snails were collected (one hundred and ninety-nine) from the upland forest than from the flood plain (one hundred twenty) .

There seemed to be a direct relationship between calcium and pH, but relationship of these two physical properties to organic matter is more complex. Quantitative levels of organic matter appeared meaningless without qualitative data of the tree species involved.