Production of Ruppia cirrhosa (Petagna) Grande in mixed beds in Ringkøbing Fjord (Denmark)
In: Aquatic Botany. Elsevier Science: Tokyo; Oxford; New York; London; Amsterdam. ISSN 0304-3770; e-ISSN 1879-1522, more |  |
| Keywords | Biological production > Primary production
Population characteristics > Biomass
Ruppia cirrhosa (Petagna) Grande, 1918 [WoRMS]
Brackish water |
| Abstract | Maximum biomasses of R. cirrhosa of 10 and 17 g dry wt/m-2 were reached in late June, followed by a distinct decline, in two mixed beds with a massive development of epiphytes. In a third mixed bed, which lacked noticeable epiphytes, a maximum biomass of 28 g dry wt /m-2 was reached by early September. Maximum biomasses of macrophytes other than R. cirrhosa were 104, 84 and 57 g dry wt /m-2 , respectively. Loss of leaves during the growing season was quantified. At the epiphyte-free station loss of leaves was considerably less than at the other two stations. Annual net production was estimated as 57 g dry wt/m-2 at the epiphyte-free station, and at the two other stations as 12 and 27 g dry wt/m-2 , respectively. Ratios of annual net production to maximum biomass (P /B) were found to vary between 1.2 and 2.0, with the higher value for the epiphyte-free population. Differences in phenology and turnover rates between stations are apparently due to the inhibitory effects of epiphytes. |
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