Transformation and fate of allochthonous nutrients in the Sarracenia microecosystem

Data

• hf098-01: food web

Overview

• Lead: Aaron Ellison, Nicholas Gotelli
• Investigators: Jessica Butler
• Contact: Aaron Ellison
• Start date: 2005-06-01
• End date: 2007-09-15
• Location: Harvard Forest Greenhouse
• Latitude: +42.53
• Longitude: -72.19
• Elevation: 330 meters
• Taxa: Sarracenia purpurea (northern pitcher plant), Sarracenia flava (yellow pitcher plant), Sarracenia alata (pale pitcher plant)
• Research topic: community
• Study type: short-term measurement
• LTER core area: inorganic nutrients
• Keywords: 15N, carnivorous plants, detritus-based food web, nitrogen cycling, pitcher plants, producer-based food web, Sarracenia, stable isotopes
• Release date: 2008
• EML version: knb-lter-hfr.98.8
• Revisions:
• Related links:
• Effects of Prey Availability on Sarracenia Physiology
• Nitrogen Cycling Dynamics in Sarracenia Purpurea
• Abstract:

  Linkages between detritus-based ("brown") food webs and producer-based ("green") food webs are critical components of ecosystem functionality, but these linkages are difficult to study because soil is opaque and brown food webs are poorly characterized. We used the well-defined detritus-based food web that forms in water-filled leaves of the pitcher plant Sarracenia purpurea to directly study how food web structure affects nitrogen (N) transformation and N-uptake by the plant itself. We used isotopically-enriched prey (detritus) and soluble inorganic N to test three predictions of the hypotheses that N uptake efficiency (UE) by S. purpurea is enhanced by the presence of a complete food web in its pitchers: (1) presence of top trophic levels increases UE of prey-derived, but not inorganic, N; (2) UE is contingent on availability of different forms of N; and (3) congeneric Sarracenia species that do not host food webs differ from S. purpurea in UE of prey-derived N. Surprisingly, none of these predictions were borne out in a 3-month greenhouse experiment. We conclude that the higher trophic-level members of this brown food web actively process detritus, but it is the activity of the microbial component of this web that ultimately influences N-availability in S. purpurea.

• Methods:

• Use:

  This dataset is released to the public and may be freely downloaded. 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. For more information on LTER Network data access and use policies, please see: http://www.lternet.edu/data/netpolicy.html.

• Citation:

  Ellison A, Gotelli N. 2008. Transformation and fate of allochthonous nutrients in the Sarracenia microecosystem. Harvard Forest Data Archive: HF098.

Detailed Metadata

hf098-01: food web

1. Treat: treatment applied to each plant
   • 15IN: 15N added as NH4NO3
   • 15prey: 15N added as Drosophila prey
   • 15prey with IN: 15N added as Drosophila prey with natural abundance NH4NO3
   • prey with 15IN: natural abundance Drosophila prey with 15N-NH4NO3
2. Species: species of plant
   • SP: Sarracenia purpurea without food webs
   • SPfw: S. purpurea with food webs
   • SA: S. alata
   • SF: S. flava
3. 15NaddedNH4NO3: amount (mg of N) of 15N-NH4NO3 tracer fed to pitchers during three months (milligram )
4. 15NaddedPrey: amount of 15N-Drosophila (mg of N) fed to pitchers during three months (milligram )
5. Nplant: mg of nitrogen (N) within entire plant (milligram )
6. 15Nplant: mg of 15N tracer within entire plant (milligram )
7. Npitcher: concentration (%) of N within living pitchers (dimensionless )
8. 15Npitcher: mg of 15N tracer within all pitchers produced during the three months (milligram )
9. 15NRandR: mg of 15N tracer within roots and rhizomes (milligram )
10. AT15Nff: Atom% 15N of Fletcherimyia fletcheri larvae (dimensionless )