close
Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2006 Jun 13;103(24):9086-9.
doi: 10.1073/pnas.0602392103. Epub 2006 Jun 5.

Biomass and toxicity responses of poison ivy (Toxicodendron radicans) to elevated atmospheric CO2

Jacqueline E Mohan  1 , Lewis H Ziska, William H Schlesinger, Richard B Thomas, Richard C Sicher, Kate George, James S Clark
Affiliations

Biomass and toxicity responses of poison ivy (Toxicodendron radicans) to elevated atmospheric CO2

Jacqueline E Mohan et al. Proc Natl Acad Sci U S A. .

Abstract

Contact with poison ivy (Toxicodendron radicans) is one of the most widely reported ailments at poison centers in the United States, and this plant has been introduced throughout the world, where it occurs with other allergenic members of the cashew family (Anacardiaceae). Approximately 80% of humans develop dermatitis upon exposure to the carbon-based active compound, urushiol. It is not known how poison ivy might respond to increasing concentrations of atmospheric carbon dioxide (CO(2)), but previous work done in controlled growth chambers shows that other vines exhibit large growth enhancement from elevated CO(2). Rising CO(2) is potentially responsible for the increased vine abundance that is inhibiting forest regeneration and increasing tree mortality around the world. In this 6-year study at the Duke University Free-Air CO(2) Enrichment experiment, we show that elevated atmospheric CO(2) in an intact forest ecosystem increases photosynthesis, water use efficiency, growth, and population biomass of poison ivy. The CO(2) growth stimulation exceeds that of most other woody species. Furthermore, high-CO(2) plants produce a more allergenic form of urushiol. Our results indicate that Toxicodendron taxa will become more abundant and more "toxic" in the future, potentially affecting global forest dynamics and human health.

PubMed Disclaimer

Conflict of interest statement

Conflict of interest statement: No conflicts declared.

Figures

Fig. 1.
Fig. 1.
Mean plant biomass and cumulative proportion surviving from 1999 to 2004. (A) Mean plant aboveground dry biomass calculated from a species- and site-specific allometric equation (see Materials and Methods). Error bars denote ± 1 SE. The rate of increase is greater at elevated CO2 (P = 0.022 in a repeated-measures analysis; n = 3). (B) Mean cumulative proportion of stems surviving aboveground over time. Error bars denote ±1 SE. Kaplan–Meier survivorship analysis indicates no significant effect of CO2.
Fig. 2.
Fig. 2.
Mean population biomass standardized by dividing by the initial plot biomass in 1999 (n = 3). Error bars denote ±1 SE. The rate of increase is greater at elevated CO2 (P = 0.046 in a repeated-measures analysis).
Fig. 3.
Fig. 3.
Relative proportion of known congeners of urushiol in poison ivy sampled from May to September at the Duke FACE site in 2004. Under elevated CO2, the concentration of the unsaturated triene congener of urushiol increased 153% (P < 0.001), whereas the saturated urushiol variant decreased by 61% (P < 0.001), resulting in an increased [unsaturated:saturated] congener ratio (P < 0.01). Bar graph represents the ratio of [unsaturated:saturated] congeners for urushiol extracted from leaves growing at ambient and elevated CO2 concentrations. The higher the ratio of [unsaturated:saturated] variants, the more allergenic urushiol is to humans (29, 30). Error bars denote +1 SE.
See this image and copyright information in PMC

References

    1. Krenzelok K., Provost F. J. J. Nat. Toxins. 1995;4:195–202.
    1. Baldwin R. A., Clegg J. A., Curran A. C., Austin E. B., Khan T., Ma Y., Gunn B., Hudecz F., Byers V. S., Lepoittevin J. P., Price M. R. Arch. Dermatol. Res. 1999;291:652–658. - PubMed
    1. Mabberley D. J. The Plant Book. Cambridge: Cambridge Univ. Press; 1993. p. 27.
    1. Liu D. K., Wannemacher R. W., Snider T. H., Hayes T. L. J. Appl. Toxicol. 1999;19(Suppl. 1):S41–S45. - PubMed
    1. Gillis W. T. Rhodora. 1971;73:72–152. 161–237, 370- 443, 465–540.

Publication types