Habitat and the effects of elevation, salinity and drought on Amaranthus pumilus Rafinesque (Amaranthaceae) / by Cass A. Wigent.
| Author/creator | Wigent, Cass A. author. |
| Other author | Jolls, Claudia Lee, degree supervisor. |
| Other author | East Carolina University. Department of Biology. |
| Format | Theses and dissertations |
| Production | 2006. |
| Description | 96 leaves : illustrations, maps ; 28 cm |
| Supplemental Content | Access via ScholarShip |
| Subjects |
| Summary | Habitat loss causes most species extinctions; to preserve a species' habitat, the species' ecological limiting factors must be defined. I used field transplants, salinity and water growth chamber experiments, and geographic information systems (GIS) to assess maritime strand habitat of the threatened annual Amaranthus pumilus, at Cape Lookout and Cape Hatteras National Seashores. At elevations below 0.7 m relative to mean high water, only 10 % of the transplants survived. Yet, these plants grew twice as much as plants in the 0.7 and 2.0 m elevation range. The transplant data suggest overwash disturbance and physiological stress may restrict distributions of A. pumilus at low and high elevations, respectively. Final growth chamber germination was [less-than-or-equal-to] 12% in salinities [greater-than-or-equal-to] 10 ppt. Half of the plants survived the most extreme salinity and water treatments, yet essentially no growth occurred in salinities [greater-than-or-equal-to] 20 parts per thousand (ppt) or in watering regimes [greater-than-or-equal-to] 3 days without water. Thus, salinity and water availability may be able to influence germination, survival, and growth of A. pumilus. Naturally occurring plants were highly clumped. Habitat area and area/shoreline at Cape Hatteras were half that at Cape Lookout and, therefore, may be variable, at least at this larger scale. This habitat analysis provides another example of the utility and challenges in application of remotely sensed data and GIS to ecological questions. Information provided here about relationships among elevation and plant success, salinity and drought tolerance, and GIS habitat analysis may be used by resource managers in identification and preservation of the highly dynamic habitat of A. pumilus and other threatened maritime dune species. |
| General note | Presented to the faculty of the Department of Biology. |
| General note | Advisor: Claudia L. Jolls |
| Dissertation note | M.S. East Carolina University 2006 |
| Bibliography note | Includes bibliographical references (leaves 87-96). |
| Genre/form | Academic theses. |
| Genre/form | Academic theses. |
| Genre/form | Thèses et écrits académiques. |