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Harvard Forest Data Archive

HF109

Effects of Prey Availability on Sarracenia Physiology at Harvard Forest 2005

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Data

Overview

  • Lead: Aaron Ellison, Elizabeth Farnsworth
  • Investigators: Cheryl Hester
  • Contact: Aaron Ellison
  • Start date: 2005
  • End date: 2005
  • Status: completed
  • Location: Harvard Forest Greenhouse
  • Latitude: +42.53
  • Longitude: -72.19
  • Elevation: 330 meter
  • Taxa: Sarracenia alabamensis, Sarracenia alata, Sarracenia flava, Sarracenia jonesii, Sarracenia leucophylla, Sarracenia minor, Sarracenia psittacina, Sarracenia purpurea, Sarracenia rosea, Sarracenia rubra
  • Release date: 2005
  • Revisions:
  • EML file: knb-lter-hfr.109.17
  • DOI: digital object identifier
  • Related links:
  • Study type: short-term measurement
  • Research topic: physiological ecology, population dynamics and species interactions
  • LTER core area: populations
  • Keywords: carnivorous plants, food webs, nitrogen, phosphorus, photosynthesis, plant physiology
  • Abstract:

    Allometric relationships exist between maximal mass-based net photosynthetic rates, leaf mass per unit area, and foliar Nitrogen (N) and Phosphorus (P) content, which hold across a diverse spectrum of over 2500 plant species worldwide. Carnivorous plants depart from this spectrum because they dedicate substantial leaf area to capturing prey, from which they derive N and P under very nutrient-limiting situations. We conducted a manipulative feeding experiment to test whether morphological and physiological allometric relationships of carnivorous plants when nutrients are not limiting are more similar to allometric relationships of non-carnivorous plants.

    We examined the effects of prey availability on photosynthetic rate (Amass), chlorophyll fluorescence, growth, architecture, and foliar nutrient and chlorophyll content of ten pitcher plant (Sarracenia) species. We tested the hypothesis that increased prey availability would stimulate Amass of one or more leaves, increase photosynthetic N- and P-use efficiencies (PNUEN, PNUEP), increase relative biomass allocation to photosynthetically efficient, non-predatory phyllodes rather than pitchers, increase overall plant biomass, and reduce stress-related chlorophyll fluorescence. This is the first multi-species, controlled feeding experiment using realistic prey treatments, measuring these physiological parameters directly, and elucidating mechanisms of nutrient stoichiometry and allometry in carnivorous plants.

    Increased prey availability increased chlorophyll content, Amass and photosystem efficiency (the Fv/Fm ratio) across the 10 Sarracenia species. These increases were most evident in younger leaves, as older leaves rapidly translocated nutrients to newer, growing tissues. Better-fed plants produced a significantly higher proportion of phyllodes than controls. Higher prey availability was associated with lower N:P ratios, and a shift from P- to N-limitation. PNUEP was significantly enhanced by supplementary feeding, whilst PNUEN was not. Overall biomass and root:shoot ratios were unaffected by feedings.

    Feeding shifted allometric relationships of P relative to Amass, N, and LMA from outside the third bivariate quartile to within the 50th bivariate percentile of the relationships found for non-carnivorous plants; other allometric relationships were unaffected. Carnivorous plants can plastically shift phosphorus allometry when nutrients are plentiful, but are less flexible in terms of nitrogen and other ecophysiological parameters.

  • Methods:

    Two plants of each Sarracenia species were assigned to one of six feeding levels in a regression design ranging from 0 - 0.25g of finely ground wasps per feeding (for small species), 0 - 0.5g (for species of intermediate sizes), and 0 - 1.0g (for large species); N equals120 plants total. Aboveground size and Amass were measured prior to commencing treatments. Plants were fed once/week for 7 weeks.

  • Use:

    This dataset is released to the public under Creative Commons license CC BY (Attribution). Please keep the designated contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement.

  • Citation:

    Ellison A, Farnsworth E. 2005. Effects of Prey Availability on Sarracenia Physiology at Harvard Forest 2005. Harvard Forest Data Archive: HF109.

Detailed Metadata

hf109-01: sarrancenia data

  1. species: species of pitcher plant used (all species epithets are in genus Sarracenia)
  2. feedlevel: grams of ground hymenoptera fed per week (unit: gram / missing value: NA)
  3. plant.num: number assigned to each plant
  4. fv.fm.lf1: Fv/Fm ratio calculated from dark-adapted chlorophyll fluorescence performed on the first leaf produced by all plants (for which these leaves were available in August 2005) (unit: dimensionless / missing value: NA)
  5. fv.fm.lf2: Fv/Fm ratio calculated from dark-adapted chlorophyll fluorescence performed on the second leaf produced by all plants (for which these leaves were available in August 2005) (unit: dimensionless / missing value: NA)
  6. totmass: total above- and below-ground plant biomass (unit: gram / missing value: NA)
  7. rt.sht: Root:Shoot ratio calculated from aboveground and belowground biomass (unit: dimensionless / missing value: NA)
  8. mass.lf: mass of youngest fully-expanded leaf produced by the plant (unit: gram / missing value: NA)
  9. area.lf: area of youngest fully-expanded leaf produced by the plant (unit: squareCentimeters / missing value: NA)
  10. sla: specific Leaf Area (cm2/g) of youngest fully-expanded leaf produced by the plant (unit: centimeterSquaredPerGram / missing value: NA)
  11. chlorophyll: chlorophyll a + b content (mg/g) of youngest fully-expanded leaf produced by the plant (unit: milligramPerGram / missing value: NA)
  12. np.ratio: ratio of Nitrogen content to Phosphorus content of youngest leaf produced by plant (unit: dimensionless / missing value: NA)
  13. nk.ratio: ratio of Nitrogen content to Potassium content of youngest leaf produced by plant (unit: dimensionless / missing value: NA)
  14. kp.ratio: ratio of Potassium content to Phosphorus content of youngest leaf produced by plant (unit: dimensionless / missing value: NA)
  15. n: foliar Nitrogen content (%) of youngest leaf (unit: dimensionless / missing value: NA)
  16. p: foliar Phosphorus content (%) of youngest leaf (unit: dimensionless / missing value: NA)
  17. k: foliar Potassium content (%) of youngest leaf (unit: dimensionless / missing value: NA)
  18. ca: foliar Calcium content (%) of youngest leaf (unit: dimensionless / missing value: NA)
  19. mg: foliar Magnesium content (%) of youngest leaf (unit: dimensionless / missing value: NA)
  20. na: foliar Sodium content (%) of youngest leaf (unit: dimensionless / missing value: NA)
  21. s: foliar Sulfur content (%) of youngest leaf (unit: dimensionless / missing value: NA)
  22. lma: Leaf Mass Area (grams/square meter) of youngest leaf (unit: gramsPerSquareMeter / missing value: NA)
  23. amass: mass-based light-saturated photosynthetic rate of youngest leaf (units: nmol CO2 • g-1 • s-1) (unit: nanomolesPerGramPerSecond / missing value: NA)
  24. pnue.n: Photosynthetic Nitrogen Use Efficiency of youngest leaf (units: mmol CO2 • mol N-1 • s-1) (unit: millimolePerMolePerSecond / missing value: NA)
  25. pnue.p: Photosynthetic Phosphorus Use Efficiency of youngest leaf (units: mmol CO2 • mol P-1 • s-1) (unit: millimolePerMolePerSecond / missing value: NA)
  26. num.lvs: total number of pitchers and phyllodes produced by each plant (unit: number / missing value: NA)
  27. num.phylls: number of phyllodes produced by each plant (unit: number / missing value: NA)
  28. mass.phy: mass of a single, randomly-selected, fully-expanded phyllode (when produced by a plant) (unit: gram / missing value: NA)
  29. area.phy: area of the same, randomly-selected, fully-expanded phyllode (when produced by a plant) (unit: squareCentimeters / missing value: NA)
  30. lma.phy: Leaf Mass Area of the same, randomly-selected, fully-expanded phyllode (when produced by a plant) (unit: gramsPerSquareMeter / missing value: NA)
  31. chloro.phy: Chlorophyll a + b content of the same, randomly-selected, fully-expanded phyllode (when produced by a plant) (unit: milligramPerGram / missing value: NA)
  32. amass.phy: mass-based light-saturated photosynthetic rate (units: nmol CO2 • g-1 • s-1) of the same, randomly-selected, fully-expanded phyllode (when produced by a plant) (unit: nanomolesPerGramPerSecond / missing value: NA)