Campus Units

Botany

Document Type

Article

Publication Version

Published Version

Publication Date

1995

Journal or Book Title

Canadian Journal of Botany

Volume

73

Issue

12

First Page

1966

Last Page

1773

DOI

10.1139/b95-210

Abstract

Vallisneria americana declined in backwaters of the Upper Mississippi River, U.S.A., after a drought in 1988. To determine whether viable seeds of V. americana occurred in the seed bank of navigation pool 7, Lake Onalaska, the upper 5 cm of sediment was collected from 103 sites in May 1990. These sediment samples were kept in pots at a depth of 0.4, 0.8, and 1.2 m in an outdoor pond for 12 weeks. Vallisneria americana seeds germinated from sites throughout the lake, and some seedlings produced overwintering buds by the end of the study. Seeds, spores, or fragments of 12 other species of aquatic plants also germinated. Seed germination trials with fresh and stored seeds in both greenhouse and ponds in which light availability was reduced with shade cloths indicated that seed germination was insensitive to light level. To determine the light requirements for seedling survival and bud production, sediment from Lake Onalaska was incubated in ponds under neutral density shade screens reducing light to 2, 5, 9, and 25% of full sun. Seeds germinated under all shade treatments but survival was significantly higher in the 9 and 25% light treatments, and bud production was restricted to these light levels. Key words: aquatic macrophytes, seeds, germination, light response.

Comments

This article is published as Kimber, Anne, Arnold G. van der Valk, and Carl E. Korschgen. "The distribution of Vallisneria americana seeds and seedling light requirements in the Upper Mississippi River." Canadian Journal of Botany 73, no. 12 (1995): 1966-1973. doi: 10.1139/b95-210.

Rights

Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.

Language

en

File Format

application/pdf

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