Transplants of Spartina alterniflora Loisel. (smooth cordgrass, Poaceae) are effective in stabilizing and protecting vulnerable coastal wetlands from erosion. However, the expense and labor associated with propagation and transplanting restrict the widespread use of S. alterniflora in coastal restoration and protection projects. As an alternative, seeding of S. alterniflora by aircraft has been proposed as a more useful and economical approach for revegetating denuded marsh sites. However, a period of stalled growth, which lasts for 12 or more weeks, has been observed in smooth cordgrass seedlings, and this increases their susceptibility to being washed away by inundating tides. This stalled growth period must be overcome before aerial seeding can be implemented.
As with any plant species, it is reasonable to assume that S. alterniflora has optimal nutritional requirements for seedling and mature plant growth. Previous nutritional research has involved only mature smooth cordgrass plants. These studies showed that applications of nitrogen and phosphorus fertilizers increased plant growth. The objectives of this study were to document the lag phase of seedling growth observed in field and greenhouse conditions; determine the possible role of soil microbes, including seed and seedling pathogens and mycorrhizal fungi, as a cause of delayed seedling growth; and investigate the role of nutrition in seedling growth.
This study confirmed the existence of stalled seedling growth in S. alterniflora and concluded that pathogens are not the cause of this lag period. Furthermore, supplemental N and P (240 kg N ha-1, 49.5 kg P ha-1) reduced the lag phase from over 100 days to less than 50 days under ideal greenhouse conditions. However, nutrient additions did not completely overcome stalled seedling growth. Future research possibilities include investigating the effects of plant growth regulators (hormones) and seed preconditioning treatments on seedling growth.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-04042007-213813 |
| Date | 10 April 2007 |
| Creators | Robertson, Clark Lane |
| Contributors | Marc A Cohn, Irv Mendelsshon, Stephen A Harrison, Raymond W Schneider |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-04042007-213813/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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