Journal of Chemical Ecology

, Volume 25, Issue 9, pp 2027–2039

Piperidine Alkaloids in Nitrogen Fertilized Pinus ponderosa

  • Elizabeth A. Gerson
  • Rick G. Kelsey

DOI: 10.1023/A:1021080605332

Cite this article as:
Gerson, E.A. & Kelsey, R.G. J Chem Ecol (1999) 25: 2027. doi:10.1023/A:1021080605332


We fertilized individual, pole-size ponderosa pine trees at two low-quality sites and pine saplings at a relatively high-quality site, with ammonium nitrate. Six to 12 months later, we measured total %N and 2,6-disubstituted piperidine alkaloids in the foliage. The N additions raised foliar %N above deficiency levels (i.e., from 1.0–1.1% to 1.4–1.6%) at the low-quality sites, but did not elevate foliar %N in saplings at the higher quality site, where it was already (1.9%) well above critical levels. In control trees with foliar N below a threshold of 1.1%, we detected no more than trace levels of alkaloids, indicating that alkaloid production is highly constrained by N deficiency. The N additions increased mean concentrations of the predominant alkaloid, pinidine, at all three sites. Mean total alkaloid concentrations for fertilized trees at the two low-quality sites were 12 and 155 μg/g dry wt higher than controls (relative increases of 12× and 4.5×, respectively). For saplings at the high-quality site, the mean total increased by 584 μg/g dry wt (1.6×) with the N additions. Allocation of foliar N to alkaloids was highest in fertilized saplings (0.81%) compared to control saplings (0.53%). These findings demonstrate that foliar alkaloid concentrations can be increased by nitrogen fertilization of forest trees growing on both low- and high-quality sites. Fertilizing for the purpose of inhibiting potential herbivores may be more successful at higher quality sites where alkaloid levels are enhanced relative to food quality (foliar %N).

2,6-Disubstituted piperidine alkaloidsPinus ponderosaponderosa pinefertilizationnitrogen availabilityfoliar nitrogenPinaceae

Copyright information

© Plenum Publishing Corporation 1999

Authors and Affiliations

  • Elizabeth A. Gerson
    • 1
  • Rick G. Kelsey
    • 1
  1. 1.USDA Forest Service, PNW Research StationCorvallis