The endangered Puerto Rican parrot (Amazona vittata) has been bred in captivity for decades, and since 2000, over 50 parrots have been released into native habitats to rebuild wild populations in Puerto Rico. One group of 21 parrots was released into Río Abajo Forest in the karstic region of Puerto Rico in November 2006, where high quality habitat resources exist, but the management of sustainable food resources, such as the fruit of Prestoea montana (sierra palm) and Roystonea borinquena (royal palm), is imperative. An inventory of accessible regions in Río Abajo Forest was conducted to assess differences in size and abundance of P. montana and R. borinquena palms between three forest community types and fruiting patterns under differing growing conditions. Twenty palms in each of three size classes of both palm species were located in Río Abajo Forest and approximately half were supplied with a controlled-release formula of inorganic NPK fertilizer with micronutrients to investigate potential soil nutrient limitations to growth of palms. Thirty R. borinquena seedlings were located in artificial canopy gap plots previously created in abandoned Hibiscus elatus (mahoe) plantations in Río Abajo Forest and approximately half were supplied with the same fertilizer formula to evaluate combined soil and light limitations on seedling growth. In the size and abundance inventory, seedlings were the most abundant size class of both palm species. No significant difference in size or abundance existed between any size classes of either palm species in different forest community types. P. montana seedling size and abundance were correlated with moderate shade, available soil P and other micronutrients, and relatively alkaline soils. Seedling height and diameter significantly increased with the addition of NPK and micronutrients to surrounding soil. Wet soils appeared most important to fruit production of mature P. montana. In the size and abundance inventory, R. borinquena seedling success was correlated to sites containing relatively high soil micronutrient concentrations and seedlings and mature R. borinquena palms exhibited larger size, abundance, and fruit production in open canopies. R. borinquena seedling height significantly increased with the addition of N-P-K and micronutrients to surrounding soil. Diameter significantly increased with the addition of fertilizer to soil surrounding seedlings in artificial canopy gap plots. Mortality was decreased in R. borinquena seedlings with the addition of fertilizer, under the full canopies of fertilizer experiments and in the open canopies of artificial canopy gap plots. Management to increase abundance and fruit production of these palm species in RAF may initially include techniques to provide increased light availability and nutrients to mature R. borinquena. Strategic management objectives may include provision of the same resources to smaller R. borinquena and increased soil moisture and nutrients to P. montana of all sizes.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-05012007-121725 |
| Date | 16 July 2007 |
| Creators | Malone, Meredith B. |
| Contributors | Daniel J. Robison, Jaime A. Collazo, Thomas R. Wentworth |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-05012007-121725/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dis sertation, 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 NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, 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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