Multiple causes of seedling rarity in scrub plum,Prunus geniculata(Rosaceae), an endangered shrub of the Florida scrub

Autor: Amy E. Faivre, Carl W. Weekley, Eric S. Menges, David N. Zaya
Rok vydání: 2010
Předmět:
Zdroj: American Journal of Botany. 97:144-155
ISSN: 1537-2197
0002-9122
DOI: 10.3732/ajb.0900106
Popis: Conservation of an imperiled plant often requires an understanding of its reproductive ecology. Scrub plum ( Prunus geniculata ) is an endangered Florida shrub endemic to pyrogenic xeric uplands. Although plants are long-lived and may fl ower profusely, particularly after burning, fruit yield is sparse and seedlings are rare. We investigated potential causes of seedling rarity in scrub plum by studying its fl oral sex and breeding systems, fruit development, and germination ecology. We also developed a fl ow chart based on two time-since-fi re scenarios to illustrate the cumulative impact of these factors on seedling recruitment. Breeding system experiments suggested partial gametophytic self-incompatibility in this functionally andromonoecious species, with inbreeding depression in self-compatible individuals. Predispersal seed predation, the major constraint on seedling recruitment, was lower in the fi rst postburn season. In two fi eld experiments, seed germination was < 11% irrespective of treatment. These results indicate that seedling recruitment in scrub plum may be limited by multiple factors, including sexual reproductive failure, high predispersal seed predation, and low seed germination. The chance of a bisexual fl ower producing a seedling ranges from 5 in 1000 to 5 in 100 000, depending on the time since fi re. Restoration of scrub plum ’ s historical fi re regime may mitigate some of these factors.
Databáze: OpenAIRE
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