Experimental evidence for enhanced top-down control of freshwater macrophytes with nutrient enrichment.

ABSTRACT: The abundance of primary producers is controlled by bottom-up and top-down forces. Despite the fact that there is consensus that the abundance of freshwater macrophytes is strongly influenced by the availability of resources for plant growth, the importance of top-down control by vertebrate consumers is debated, because field studies yield contrasting results. We hypothesized that these bottom-up and top-down forces may interact, and that consumer impact on macrophyte abundance depends on the nutrient status of the water body. To test this hypothesis, experimental ponds with submerged vegetation containing a mixture of species were subjected to a fertilization treatment and we introduced consumers (mallard ducks, for 8 days) on half of the ponds in a full factorial design. Over the whole 6

SUBMITTER: Bakker ES 

PROVIDER: S-EPMC4207960 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature