Izvorni znanstveni članak

Effect of current velocity on diatom colonization on glass slides in unpolluted headwater creek

ANĐELKA PLENKOVIĆ-MORAJ ; Department of Botany, Division of Biology, Faculty of Science, Univesity of Zagreb, Rooseveltov trg 6, 10000 Zagreb, Croatia
KORALJKA KRALJ ; Department of Botany, Division of Biology, Faculty of Science, Univesity of Zagreb, Rooseveltov trg 6, 10000 Zagreb, Croatia
MARIJA GLIGORA ; Department of Botany, Division of Biology, Faculty of Science, Univesity of Zagreb, Rooseveltov trg 6, 10000 Zagreb, Croatia

Sažetak

Abstract

Background and Purpose: The goal of this study was to determine the
effect of current velocity on diatom colonization rate during the first 30 days of artificial substrate (glass slides) exposure.

Materials and Methods: From autumn 1990 to summer 1993 artificial
substrates were submerged in an unpolluted mountain stream. The parallel oriented glass slides (against the surface) were placed 10 cm beneath thewater surface (protected from debris) and exposed to different current velocities (10–30 cm s–1, 40–60 cm s–1 and 80–100 cm s–1). The samples were collected seasonally. To define diatom colonization, a nonlinear regressive analysis of empirical data was performed.

Results: A total of 71 diatom species were found. Species Cocconeis
placentula, Surirella ovata, Gomphonema olivaceum, and Navicula
gracilis were the most abundant, depending on different current velocity.

Conclusions: The time needed for reaching the equilibrium progressively increased with the current velocity (F= 16.7; P< 0.01). In the summer and autumn, the time needed for the stabilization of diatom flora was longer than in spring and winter. Concerning species abundance, Cocconeis placentula, and Navicula gracilis were independent of the current velocity, while Surirella ovata was abundant at lower (≤30 cm s–1) and Gomphonema olivaceum at higher (≤60 cm s–1) current velocities.

Ključne riječi

current velocity; periphyton; diatoms; nonlinear regressive analysis

Hrčak ID:

32606

URI

https://hrcak.srce.hr/32606

Datum izdavanja:

31.10.2008.

Posjeta: 1.606 *