The influence of plant-associated filter feeders on phytoplankton biomass: a mesocosm study |
| |
Authors: | M Vanderstukken S A J Declerck A Pals L De Meester K Muylaert |
| |
Institution: | (1) Laboratory of Aquatic Biology, Katholieke Universiteit Leuven, Campus Kortrijk, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium;(2) Laboratory of Aquatic Ecology and Evolutionary Biology, Katholieke Universiteit Leuven, Ch. De Beriotstraat 32, 3000 Leuven, Belgium;(3) Laboratory of Plant Ecology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 31, 3001 Heverlee, Belgium |
| |
Abstract: | Low phytoplankton biomass usually occurs in the presence of submerged macrophytes, possibly because submerged macrophytes
enhance top-down control of phytoplankton by offering a refuge for efficient grazers like Daphnia against fish predation. However, other field studies also suggest that submerged macrophytes suppress phytoplankton in the
absence of Daphnia. In order to investigate these mechanisms further, we conducted an outdoor mesocosm experiment to study the effect of submerged
macrophytes (Elodea nuttallii) on phytoplankton and zooplankton biomass. The experiment combined four nutrient addition levels (0, 10, 100, and 1000 μg P l−1; N/P ratio: 16) with three macrophyte levels (no macrophytes, artificial macrophytes, and real macrophytes). We inoculated
the tanks with species-rich inocula of phytoplankton and zooplankton but excluded fish or macro-invertebrates. Probably due
to the lack of predators in the mesocosms, potential grazing rates of pelagic zooplankton (estimated from zooplankton biomass)
did not differ between the macrophyte treatment combinations. Compared to the treatment combinations without macrophytes,
lower phytoplankton biomass occurred in the treatment combinations with real macrophytes at all the nutrient addition levels
and in those with artificial macrophytes at all the nutrient levels except the highest. Significantly, higher abundances of
plant-associated filter feeders (Simocephalus vetulus and Ceriodaphnia spp.) occurred in the treatment combinations with real and artificial macrophytes. The estimated potential grazing rate of
these plant-associated filter feeders indicated that these filter feeders could be responsible for the lower phytoplankton
biomass in the presence of real and artificial macrophytes. Our results suggest that the plant-associated filter feeders may
be significant grazers in vegetated shallow lakes. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|