Allelochemical autotoxicity in the emergent wetland macrophyte Juncus effusus (Juncaceae)

摘要: Bioassays for allelochemical toxicity of aboveground Juncus effusus tissues were conducted with seeds and seedlings Eleocharis obtusa Scirpus cyperinus, two emergent sedge species (Cyperaceae) found sympatric J. effusus, itself to evaluate potential autotoxicity. performed under controlled, axenic conditions aqueous shoot extract treatments simulating in situ dissolved organic carbon concentrations. With respect the species, neither development nor seedling biomass accrual was significantly suppressed by lyophilized whole extracts from effusus. Although induced no significant reduction growth E. or S. biomass-specific chlorophyll a concentration reduced seedlings. In contrast, exhibited reductions concentrations, retarded response leachate exposure. Results present study suggest that possess autotoxic sensitivity dead, adult plants. Competitive effects on plant community structure can occur via indirect, exploitative competition resources direct interference among competing individuals, latter usually taking form interac