Responses of morphological and physiological traits to herbivory by snails of three invasive and native submerged plants

Abstract

Aims The submerged plant species Carolina fanwort (Cabomba caroliniana) has become a dominant invasive aquatic plant in the Lake Taihu Basin (LTB) in China. Introduced species may escape their original specialist enemies and encounter fewer enemies in their new environment. They were assumed to have suffered less herbivory than native species as they are relatively unpalatable (the enemy release hypothesis (ERH)). The objective of this study was to compare the responses of C. caroliniana with those of co-occurring native species to herbivory from native herbivores. Methods We conducted a mesocosm experiment to record the responses of C. caroliniana and two commonly co-occurring native submerged plant counterparts, water thyme (Hydrilla verticillata) and Eurasian watermilfoil (Myriophyllum spicatum), to herbivory by two native generalist gastropod snails, Radix swinhoei and Sinotaia quadrata. Plant morphological traits (total biomass, shoot/root (S/R) biomass ratio and relative growth rate (RGR)) and physiological traits (leaf total nonstructural carbohydrate (TNC), lignin, and cellulose) were recorded. Important Findings The snail S. quadrata rarely influenced the plant traits of the three submerged plants. With the increasing numbers of R. swinhoei treatments, most of the plant traits of H. verticillata and M. spicatum changed, while those of C. caroliniana showed a relatively stable fluctuation. This result indicates that C. caroliniana is more resistant to herbivory by the snail R. swinhoei, which is consistent with the ERH hypothesis. This finding indicates that herbivorous snail species contributes to the invasion of C. caroliniana, which potentially alters the species composition of submerged plants in the plant community.

Underwater light attenuation inhibits native submerged plants and facilitates the invasive co‐occurring plant Cabomba caroliniana

“…However, the performance of C. caroliniana was better and more stable than those of M. spicatum or H. verticillata in response to the low underwater PAR (for instance, 50%, 25% and 5% underwater PAR) treatments. According to a previous study, C. caroliniana does not have a better competitive ability than native co‐occurring submerged plants (Huang et al, 2021), but it is relatively resistant to herbivory by grass‐feeding snails (Huang et al, 2022). In this study, we provide new insights into the possible invasion mechanism of C. caroliniana under low underwater PAR levels, which may improve the ability to predict its invasion.…”

Effect of natural enemies on the invasion of the exotic plant buffalobur (Solanum rostratum Dunal.) in the arid oasis of Urumqi

“…Natural enemies (such as parasitic plants and phytophagous animals) are one of the key factors affecting plant life history (Duncan and Williams, 2020;Huang et al, 2021). In the process of plant growth, natural enemies obtain nutrients and water by directly parasitizing or feeding on the stems, leaves, flowers, fruits, and other organs of the plant, subsequently impacting the photosynthetic rate of the host plant, thereby affecting the growth and development of the host plant, among other life history characteristics (Zhong et al, 2021;Min-Yao et al, 2022;Velasco Cuervo et al, 2022).…”