RESUMO
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.
Assuntos
Bryopsida , Plântula , Alelopatia , Germinação , SementesRESUMO
A mixed absorbent had been proposed to enhance the chemical absorption-biological reduction process for NO(x) removal from flue gas. The mole ratio of the absorbent of Fe(II)Cit to Fe(II)EDTA was selected to be 3. After the biofilm was formed adequately, some influential factors, such as the concentration of NO, O(2), SO(2) and EBRT were investigated. During the long-term running, the system could keep on a steady NO removal efficiency (up to 90%) and had a flexibility in the sudden changes of operating conditions when the simulated flue gas contained 100-500 ppm NO, 100-800 ppm SO(2), 1-5% (v/v) O(2), and 15% (v/v) CO(2). However, high NO concentration (>800 ppm) and relative short EBRT (<100s) had significant negative effect on NO removal. The results indicate that the new system by using mixed-absorbent can reduce operating costs in comparison with the single Fe(II)EDTA system and possesses great potential for scale-up to industrial applications.