Philip Sheridan1,2 and William Scholl1
Seed banks are known to maintain reservoirs of genetic variation for populations through times of environmental stress. Propagules lie dormant in a seed bank and germinate under conditions favorable for that species survival and persistence. Similarly the phenomenon of growing season dormancy has also been documented in orchid species. Various authors have proposed that Sarracenia are released from growing season dormancy when competition is removed. In the winter of 1986 we discovered a site in northern Dinwiddie County, Virginia which contained both Sarracenia flava L. (n = 50)and S. purpurea L. (n = 26) in a fire suppressed pond pine flatwoods. Due to the possibility of encroaching development we removed all visible plants of both species in January 1989. In 1990 the area was clear cut and the site monitored for the next four years. No plants of S. purpurea appeared after the removal and timber cut and only one specimen of S. flava appeared which was most likely a resprouted, broken rhizome or a missed plant. These results indicate that after decades of fire suppression in Virginia bogs no Sarracenia seed bank remains and that Sarracenia do not exhibit a growing season dormancy. Careful investigation of heavily shaded bogs will disclose meager growth on pitcher plants. These stressed plants are easily missed by investigators. As a consequence, when a site is released from competition there is suddenly the appearance of more pitcher plants than was initially observed resulting in the erroneous conclusion of a growing season dormancy. Since most Virginia pitcher plant bogs are fire suppressed, with low numbers of pitcher plants in poor condition, the reintroduction of fire must be carefully handled to avoid destroying these rare plants.1. Meadowview Biol. Research Station and
2. Dept. of Biological Sciences, ODU.