| Abstract Detail
Recent Topics Posters Frank, Margaret, H. [1], Palmer, Matthew, I. [2]. Life history of Rhynchospora knieskernii, a rare early-successional sedge, in the New Jersey Pine Barrens. An understanding of population dynamics is fundamental to developing sound management plans for rare early-successional plants. The life history of Rhynchospora knieskernii, a federally threatened wetland sedge endemic to the Pine Barrens of southern New Jersey, is essentially unknown. Understanding the dynamics of R. knieskernii populations is an essential component to designing effective conservation plans. We studied the spatial structure of R. knieskernii populations at two field sites and measured soil attributes and hydrology to characterize the habitat. Seeds from R. knieskernii and three other Rhynchospora species were collected and subjected to scarification and stratification treatments to investigate their germination dynamics. R. knieskernii seedlings were grown in the greenhouse at six depths from 2 cm below to 2.5 cm above a constant water table in order to correlate hydrology with growth, survival, and reproduction. Natural populations of R. knieskernii had variable density, size class distribution, and reproduction both within and across sites. Their habitats were characterized by variable hydrology and sandy soils with low pH, organic matter content, ammonium concentrations and conductivity. R. knieskernii seeds were significantly more likely to germinate when scarified (7.5% for scarified vs. 3.7% for intact seeds), but showed no significant response to stratification. Survivorship of R. knieskernii seedlings was 31% after 11 weeks at 2 cm underwater (i.e., the most flooded treatment), which was significantly lower than all other positions on the hydrologic gradient, which had survivorship ranging from 72% to 84%. The results from these experiments can inform the design of an effective management plan for R. knieskernii, and will contribute to further research on the population dynamics of rare early-successional plants.
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1 - Barnard College, Biology, 3001 Broadway, New York, NY, 10027, USA
2 - Columbia University, Ecology, Evolution, and Environmental Biology, 1200 Amsterdam Ave, New York, NY, 10027, USA
Keywords:
Germination
Cyperaceae Family
population dynamics
Wetland Plants.
Presentation Type: Recent Topics Poster
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P79004
Abstract ID:2533 |
