An ex-situ mesocosm study of emergent macrophyte effects on phytoplankton communities

Publication Type:
Journal Article
Fundamental and Applied Limnology, 2019, 192, (3), pp. 225-235
Issue Date:
Full metadata record
© 2019 E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, Germany. Although the ability of submerged macrophytes to inhibit phytoplankton growth has been studied extensively, little has been done for emergent macrophytes. We investigated the effects of four emergent macrophyte species (Brachiaria mutica, Ipomoea aquatica, Ischaemum muticum, Ipomoea pes-caprae) on the phytoplankton community of a eutrophic tropical reservoir with cyanobacterial dominance. A mesocosm experiment was conducted over 28 days by growing macrophytes on a substrate of expanded clay pellets with 18 % surface area coverage in tanks filled with water from a reservoir with phytoplankton dominated by cyanobacteria. Nutrient levels (total nitrogen and total phosphorus concentrations), total phytoplankton biomass and the structure of phytoplankton community were compared over the course of the experiment. All four species of macrophytes did not significantly reduce the total nitrogen, total phosphorus, or phytoplankton biomass. The Ipomoea pes-caprae treatment, however, led to a shift in the phytoplankton community structure with an increased abundance of Aphanocapsa sp., a small-celled colonial cyanobacterium often found dominant in post-restoration phytoplankton communities. This study shows that using the current approach and a planting density reflecting natural conditions, the four macrophyte species tested may not necessarily reduce phytoplankton biomass, but their introduction may lead to phytoplankton community changes.
Please use this identifier to cite or link to this item: