How Eutrophication Promotes Exotic Aquatic Plant Invasion in the Lake Littoral Zone?

Abstract

Eutrophication and exotic species invasion are key drivers of the global loss of biodiversity and ecosystem functions in lakes. We selected two exotic plants (Alternanthera philoxeroides and Myriophyllum aquaticum) and two native plants (Myriophyllum spicatum and Vallisneria spinulosa) to elucidate the effect of eutrophication on exotic plant invasiveness. We found that (1) elevated nutrient favored invasion of exotic species and inhibited growth of native plants. Species combinations and plant densities of native plants had limited effects on the resistance to invasion of the exotics. (2) A. philoxeroides featured the tightest connectivity among traits, which is consistent with its high competitive ability. Although eutrophication caused physiological stress to A. philoxeroides, it could effectively regulate enzyme activity and alleviate the stress. (3) M. aquaticum possessed strong tolerance to habitat disturbance and was highly disruptive to the surrounding plants. Eutrophication will exacerbate the adverse effects of M. aquaticum on the littoral ecosystem. (4) Nutrient enrichment reduced the biomass and relative growth rates of V. spinulosa and lowered phenolics and starch contents of M. spicatum, thereby making them more susceptible to habitat fluctuations. Overall, our study highlights how eutrophication alters the invasiveness of exotic plants and the resistance of native plants in the littoral zone, which is of relevance in a world with intensified human activities.

Can “Risk-Sharing” Mechanisms Help Clonal Aquatic Plants Mitigate the Stress of Nanoplastics?

“…NPs have been shown to be taken up by the functional organs of plants and to have a significant impact on the growth of individual plants, and further pose a greater risk to ecosystems . Aquatic plants play an important role in ecological balance, nutrient cycling, and reducing pollution in the aquatic environment. − However, due to increasing plastic production and the mismanagement of plastic waste, the discard of plastics into the natural environment has sparked growing global concern. , Plastics can be decomposed in freshwater ecosystems into submicrometer plastics via photodegradation, physical abrasion, hydrolysis, and biodegradation . It is estimated that large amounts of microplastics (17–89 items/L) gradually accumulate in surface water systems .…”