Experimental determination of effects of water depth on Nymphaea odorata growth, morphology and biomass allocation

Authors

Jennifer H. Richards, Department of Biological Sciences, Florida International UniversityFollow
Tiffany Troxler-Gann, Department of Biological Sciences, Florida International UniversityFollow
David W. Lee, Department of Biological Sciences, Florida International UniversityFollow
Michael S. Zimmerman, National Park Service South Florida Ecosystem OfficeFollow

Abstract

Growth, morphology and biomass allocation in response to water depth was studied in white water lily,Nymphaea odorata Aiton. Plants were grown for 13 months in 30, 60 and 90 cm water in outdoor mesocosms in southern Florida. Water lily plant growth was distinctly seasonal with plants at all water levels producing more and larger leaves and more flowers in the warmer months. Plants in 30 cm water produced more but smaller and shorter-lived leaves than plants at 60 cm and 90 cm water levels. Although plants did not differ significantly in total biomass at harvest, plants in deeper water had significantly greater biomass allocated to leaves and roots, while plants in 30 cm water had significantly greater biomass allocated to rhizomes. Although lamina area and petiole length increased significantly with water level, lamina specific weight did not differ among water levels. Petiole specific weight increased significantly with increasing water level, implying a greater cost to tethering the larger laminae in deeper water. Lamina length and width scaled similarly at different water levels and modeled lamina area (LA) accurately (LA_modeled = 0.98LA_measured + 3.96, R² = 0.99). Lamina area was highly correlated with lamina weight (LW = 8.43LA − 66.78, R² = 0.93), so simple linear measurements can predict water lily lamina area and lamina weight. These relationships were used to calculate monthly lamina surface area in the mesocosms. Plants in 30 cm water had lower total photosynthetic surface area than plants in 60 cm and 90 cm water levels throughout, and in the summer plants in 90 cm water showed a great increase in photosynthetic surface area as compared to plants in shallower water. These results support setting Everglades restoration water depth targets for sloughs at depths ≥45 cm and suggest that in the summer optimal growth for white water lilies occurs at depths ≥75 cm.

Comments

This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements #DBI-0620409 and #DEB-9910514. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Recommended Citation

Richards, J.H., T. Troxler, D. Lee, M.S. Zimmerman. 2011. Experimental determination of effects of water depth on Nymphaea odorata growth, morphology and biomass allocation . Aquatic Botany 95(1): 9-16.