The influence of hydroperiod on competitive interactions among larval anurans / by Tracy Noel Rogers.
| Author/creator | Rogers, Tracy Noel author. |
| Other author | Chalcraft, David R., degree supervisor. |
| Other author | East Carolina University. Department of Biology. |
| Format | Theses and dissertations |
| Production | 2007. |
| Description | 44 leaves : illustrations ; 28 cm |
| Supplemental Content | Access via ScholarShip |
| Subjects |
| Summary | Few studies have examined how varying abiotic factors, such as hydroperiod, affect the strength of competition either within or between species. Competitive interactions play an important role in the ecology of larval anurans and many larval anurans occur in ponds that vary in their hydroperiod. Competitive interactions, coupled with the rapidly drying habitats amphibians inhabit, could have severe impacts on survivorship to metamorphosis and growth and development in the larval stage. Pressure to metamorphose faster and at smaller sizes may increase due to the decreased hydroperiod resulting in reduced food, space and refugia as well as the increases in encounters with potential competitors in the ponds. Therefore, I expected that pond drying will intensify intraspecific and interspecific competitive interactions of larval anurans resulting in reduced growth and development, thereby increasing the risk of desiccation I examined the effects of pond hydroperiod, intraspecific and interspecific competition between Bufo terrestris and Hyla squirella in a mesocosm experiment Ponds without tadpoles had greater amounts of periphyton but neither the identity nor abundance of tadpoles affected the amount of periphyton present. The amount of phytoplankton present was the same in all treatments. Pond hydroperiod did not directly affect growth, development or survivorship of either species. Furthermore, I did not observe effects of interspecific competition on growth and survivorship for either larval anuran species. Increasing density of H. squirella, however, reduced the mass at metamorphosis of H. squirella but did not affect either the larval period or survivorship of H. squireHa. Increasing density of terrestris did not affect the growth or development ofA terrestris. The effects of increasing density on survivorship of B. terrestris, however, depended on pond hydroperiod. Specifically, increasing the density of B. terrestris resulted in lower survivorship in short hydroperiod ponds but increased survivorship in permanent ponds. As a result, hydroperiod appears to cause the nature of intraspecific density dependent interactions in B. terrestris to switch from competitive interactions to facilitation. This suggests the length of time the pond holds water may have an impact on how intraspecific density dependent effects influence survival of B. terrestris in the larval stage. |
| General note | Presented to the faculty of the Department of Biology. |
| General note | Advisor: Dave Chalcraft |
| Dissertation note | M.S. East Carolina University 2007 |
| Bibliography note | Includes bibliographical references (leaves 25-28). |
| Genre/form | dissertations. |
| Genre/form | Academic theses. |
| Genre/form | Academic theses. |
| Genre/form | Thèses et écrits académiques. |