Considering Herbivory, Reproduction, and Gender When Monitoring Plants: A Case Study of Jack-in-the-Pulpit (Arisaema tripyllum [L.] Schott)
Handel SN and Ruhren S. 2000. Considering Herbivory, Reproduction, and Gender When Monitoring Plants: A Case Study of Jack-in-the-Pulpit (Arisaema tripyllum [L.] Schott). Natural Areas Journal. 20(3):261-266
Arisaema triphyllum (L.) Schott, Jack-in-the-pulpit, a sequential hermaphrodite, can switch between male and female sex expression through time. Older, larger individuals are more likely to become female, but damage to leaves or storage tissue may prevent future sexual reproduction. Therefore repeated herbivory could indirectly alter sex ratios within populations. In a field study in hardwood forests in New Jersey, we observed lower than expected flower and fruit production by A. triphyllum in a large sample. The energy reserves of the corms within the study populations may have been depleted by chronic herbivory from white-tailed deer (Odocoileus virginianus Zimmerman), decreasing the likelihood of flower and fruit production. We found that 27.2% of the 3331 monitored A. triphyllum individuals were eaten by white-tailed deer in 1996. Although herbivory by deer declined in 1997 and 1998, long-term effects of repeated overgrazing by deer may result in irreversible losses of plants that fail to reproduce. Therefore, monitoring based only on counting stems may lead to misleading estimates for population-persistence of gender-modifying plants. Similarly, a count of flowers in a predominantly male-biased population is a misleading indicator of reproductive potential.
- Type
- Journal Article
- Authors
- Handel, Steven; Ruhren, Scott
- Units
- MORR
- Keywords
- Herbivory, jack-in-the-pulpit (Arisaema triphyllum), Monitoring, Plant Studies, Reproduction, Research Report, Survey