Nutrient Availability Affects Flowering Rate but has Limited Influence on Morphology of the Hooded Pitcher Plant, Sarracenia minor.
Carnivorous plants perform as both producers and consumers. Botanical carnivory has evolved in sunny, moist, nutrient-poor environments, and the primary nutrient supplied by prey is proposed to be nitrogen. There is a trade-off between carnivorous and photosynthetic structures which corresponds to d...
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Format: | Others |
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UNF Digital Commons
2013
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Online Access: | http://digitalcommons.unf.edu/etd/475 http://digitalcommons.unf.edu/cgi/viewcontent.cgi?article=1493&context=etd |
Summary: | Carnivorous plants perform as both producers and consumers. Botanical carnivory has evolved in sunny, moist, nutrient-poor environments, and the primary nutrient supplied by prey is proposed to be nitrogen. There is a trade-off between carnivorous and photosynthetic structures which corresponds to degree of carnivory expression and available nutrients. This study was conducted on the hooded pitcher plant, Sarracenia minor, which is a facultative wetland plant and Florida-threatened species. Sarracenia minor is considered a specialist myrmecophage and ants characterize the majority of attracted and captured prey. Ants not only provide nutritional benefit, but also protection against herbivory. A natural population of S. minor in northeast Florida was selected to test response to prey and fertilizer nitrogen in a press-experimental design. Introduced fire ants (Solenopsis invicta) and ammonium nitrate (NH4NO3) were used as prey and fertilizer nitrogen sources, respectively. Treatments included: 1) ant addition; 2) fertilizer addition; 3) ant addition/fertilizer addition; 4) no ants/no fertilizer; 5) control. Treatments were administered biweekly and morphological characteristics and herbivory were measured monthly from April-November 2012. Results indicated no significant treatment effects on plant performance and morphological characteristics, except for a significantly greater number of flowers displayed by the nutrient-deprived group (p < .005). Herbivory by Exyra semicrocea also showed a marginally significant negative effect on the tallest pitchers per ramet. Since nitrogen is primarily stored by pitchers and allocated to new growth in the following growing season, the predictive power of this study may be limited. However, increased flowering rate in the nutrient-deprived group suggests that plants were induced to flower from nutrient stress. Also, a burn at the beginning of the study likely influenced nutrient availability and plant response to experimental treatments. In conclusion, stress may have occurred from both fire and nutrients, and S. minor showed resistance and poor response to nitrogen addition. |
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