The effects of dissolved organic matter from a native and an invasive plant species on juvenile Daphnia survival and growth

Abstract

Abstract Shifts in the composition of terrestrial plant communities could have significant effects on freshwater zooplankton due to changes in the quality of inputs of terrestrially derived dissolved organic matter (DOM). Leachate from native red maple (RM) and invasive Amur honeysuckle (AH) were used to explore the effects of DOM source on survival and growth of juvenile Daphnia ambigua. Prior research with both terrestrial and aquatic organisms indicates that AH-derived DOM has negative effects. Comparing bioassays in the presence and absence of algae with no additional DOM, RM- or AH-derived DOM, RM had stronger negative effects on both Daphnia survival and growth while AH only decreased growth. The negative effects seen in the presence and absence of algae provided evidence for both indirect and direct effects due to phytotoxicity and plant secondary compounds, respectively. DOM source may play a key role in regulating consumers in aquatic ecosystems.