Effects of Brachythecium plumosum and Plagiomnium venustum on seed germination and seedling growth of invasive plants

Abstract

Invasive plants can inhibit the survival and reproduction of native species through alle-lopathy. It is not clear whether the native plants, especially the mosses in the ground layer, inf-luence the invasive plants. In this study, we examined the effects of two native moss species, Brachythecium plumosum and Plagiomnium venustum, on two malignant invasive plants, Echinochloa crusgalli and Daucus carota. The effects of mosses on seed germination and seedling growth of both invasive species were determined based on the clump structure and allelopathy of the mosses. The germination rate, germination potential and germination index of the two invasive species were significantly inhibited when seeds fallen on or into the moss clump, with an order of inhibition effect: above moss clump>below moss clump>no moss. Radicle length and radicle/plumule of D. Carota were significantly affected when seeds fallen into the moss clump. Moss water extracts significantly reduced germination rate, germination potential, and germination index of the two invasive plants, with these effects being concentration-dependent. To some extent, moss water extracts increased the plumule length, radicle length and radicle/plumule of D. Carota seedlings, but without effect on E. crusgalli. Both mosses showed inhibitory effects on seed germination and seedling growth of two invasive plants, with higher sensitivity of E. crusgalli than D. Carota. Along with the increases in concentration of water extract, stronger inhibitory effects were found. Therefore, mosses could partially inhibit seed germination and seedling growth of invasive plants.