Abstract: This study analyzed the chemical components of leaf waterextracts of typical submerged macrophytes (native species: Hydrilla verticillata and Myriophyllum spicatum; exotic species: Elodea nuttallii and Cabomba caroliniana) from lakes in the middle and lower reaches of Yangtze River. The selected chemical components were 2Naphthalenamine,N-phenyl (produced by all of the four submerged macrophytes), 1-Propanone,1-phenyl (only produced by E. nuttallii), and Benzobfuran,2,3-dihydro (only produced by C. caroliniana). Then we used relative growth rate, algal cell concentration and chlorophyll content as algae growth indicators to explore the influences of different dosages of the three chemical components on the growth of epiphytic algae (Chlorella vulgaris, Scenedesmus obliqnus and S. quadricanda). Our results showed that the three chemical components significantly reduced algal cell concentration and chlorophyll content of S. obliqnus and C. vulgaris, however, their inhibitory effects on S. quadricanda were weaker. There were significant differences in the responses of these three epiphytic algae to different dosages and processing time. The lower dose of chemical components could promote the growth of epiphytic algae, while the higher dose showed inhibition effects, and the algae showed obvious and steady growth with the extension of processing time. Overall, 1-Propanone,1-phenyl-showed the strongest inhibiting effect, followed by Benzobfuran,2,3-dihydro, and the weakest was 2-Naphthalenamine,N-phenyl, suggesting that the chemical components from the exotic submerged macrophytes (E. nuttallii and C. caroliniana) have stronger inhibiting effects on epiphytic algae.

Key words: spatial heterogeneity, geo-satistics, GIS technique, soil phosphorus, Choerospondias axillaris deciduous broadleaved forest