| Abstrakt: |
One of the greatest challenges for biologists today is to protect biodiversity against a backdrop of widespread habitat loss. Helenium virginicum Blake (Virginia sneezeweed) is a federally threatened herb associated with sinkhole margins and wet meadows in the Shenandoah Valley of Virginia and in the Ozark Highlands of Missouri. In this study we evaluated the influence of seed source (maternal line), planting site, water regime, and weed exclusion on survivorship, growth, and fecundity of H. virginicum with the objectives: (1) to establish two viable populations on public land in Missouri, and (2) to formulate reintroduction protocols for the species. We collected seed from the one known population in the state of Missouri. Seeds were germinated under controlled conditions and then transplanted to two sites on public land. Maternal line was found to have no significant effects on seed germination or seedling survivorship in the greenhouse for the first year. Maternal line, site, water regime, and weed exclusion cloth had no effects on the survivorship of H. virginicum at field sites. Maternal line, along with site, water regime, and weed exclusion cloth had significant effects on height at time of flowering and number of flowers produced by H. virginicum. The results of this study address some of the unknowns regarding the biology of H. virginicum and will be used to guide future reintroduction projects as well as the ongoing development of state and federal recovery plans. [ABSTRACT FROM AUTHOR] |
