Chemistry And Plant Ecology Of Zinc-rich Wastes Dominated By Blue-green Algae

Abstract

An account is given of the chemistry and vegetation of wet areas below the Elvins tailings pile in the Old Lead Belt of Missouri. Zinc in particular is present at highly elevated levels in the water (5.9-21.0 mg l-1) and most sediments. The two most widespread plants are a blue-green alga, Plectonema gracillimum, and a moss, Dicranella sp. In wetter areas the latter exists predominantly as protonema. Plectonema and the protonema typically grow in very close association, although situations do occur where only one or the other is present. For instance, algal flocs in two permanent ponds consisted largely of Plectonema and unicellular blue-green algae, with a few eukaryotic algae, but no protonema. Other dominants in the area are Eleocharis sp., Scirpus americanus and Typha latifolia. One seepage was studied in more detail; it showed marked changes in both chemistry and vegetation on passing from source to a site 15 m downstream. Aqueous Zn dropped from 21 to 8 mg l-1. The Plectonema-Dicranella protonema community predominated in the upper part, developing a laminated structure up to 3 cm thick (justifying recognition as a stromatolite). Further downstream a white crust including much hydrozincite and with a very high overall zinc content (c. 370 mg g-1 Zn) was deposited over the green layer, making it endolithic in position, though probably not in origin. Still further downstream the green layer disappeared, leaving only a hard white crust. A discussion is included of the extent to which observed variations in the zinc content of water and sediments below the tailings pile are influenced by living and dead plants. An apparent diel cycle in aqueous zinc at some sites is of particular interest, as it was not matched by changes in Ca or Cd. © 1981 Dr W. Junk Publishers.

Department(s)

Biological Sciences

Second Department

Civil, Architectural and Environmental Engineering

Keywords and Phrases

blue-green algae (cyanobacteria); diel change; protonema; sediments; stromatolite; tailings; water; zinc

International Standard Serial Number (ISSN)

1573-5117; 0018-8158

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2023 Springer, All rights reserved.

Publication Date

01 Jan 1981

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