Sexual Reproduction of Wild Celery (Vallisneria americana): Why it’s Worth the Effort
by Jessie J. Campbell and Ken A. Moore
Virginia Institute of Marine Science
College of William and Mary
presented at the
Annual Meeting of the Estuarine Research Federation
October 19, 2005
Vallisneria americana is a submersed macrophyte found in freshwater systems across North America. Despite considerable annual seed production, the role of seeds in the ecology of this and other SAV species are not well known although recent research has highlighted the importance of seeds in long distance dispersal and restoration. Our objective was to address this gap by quantifying environmental conditions for V. americana seed germination to explain both population dynamics and improve our restoration efforts. We investigated the effects of sediment organic content (1-8%), seed burial depth (2-100 mm), light (present/absent), dissolved oxygen (DO <2 or >4 mg l-1), temperature (13-31°C), and salinity (0-15 psu) on total percent germination under controlled conditions and relate these to field dynamics. Seeds were found to germinate under a wide variety of conditions indicative of a species with a wide habitat range. Germination percentages increased significantly when oxygen was present, temperatures were >19°C, salinities were <5psu, sediment organic content was <3%, and seed burial depths were <15mm. The presence/ absence of light had no significant effect on germination. These results represent an important step in understanding the seed ecology of V. americana and its role in SAV population dynamics.