HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Titus, J. E. Articles by Gary Sullivan, P. Search for Related Content PubMed Articles by Titus, J. E. Articles by Gary Sullivan, P. Agricola Articles by Titus, J. E. Articles by Gary Sullivan, P.

Heterophylly in the yellow waterlily, Nuphar variegata (Nymphaeaceae): effects of [CO₂], natural sediment type, and water depth¹

Department of Biological Sciences, Binghamton University, Binghamton, New York 13902 USA

We transplanted Nuphar variegata with submersed leaves only into natural lake sediments in pH-, [CO₂]-, depth-, and temperature-controlled greenhouse tanks to test the hypotheses that more fertile sediment, lower free [CO₂], and shallower depth would all stimulate the development of floating leaves. Sediment higher in porewater [NH₄⁺] favored floating leaf development. Low CO₂-grown plants initiated floating leaf development significantly earlier than high CO₂-grown plants, which produced significantly more submersed leaves and fewer floating leaves. Mean floating leaf biomass was significantly greater than mean submersed leaf biomass but was not influenced by CO₂ enrichment, whereas mean submersed leaf biomass increased 88% at high [CO₂]. At the shallower depth (35 cm), floating leaves required 50% less biomass investment per leaf than at 70 cm, and a significantly greater proportion of plants had floating leaves (70 vs. 23–43% at 35 vs. 70 cm, respectively) for the last three of the eight leaf censuses. Sediment type, water depth, and especially free [CO₂] all can influence leaf morphogenesis in Nuphar variegata, and the development of more and larger submersed leaves with CO₂ enrichment favors the exploitation of high [CO₂] when it is present in the water column.

Key Words: amphibious plants • aquatic plants • floating leaves • heterophylly • Nuphar • Nymphaeaceae • plasticity • submersed leaves