Phytoplankton Community Patterns and Environmental Influencing Factors in Integrated Rice-Crayfish Symbiosis Framing System
In order to explore the community structure of phytoplankton in the integrated rice-crayfish symbiosis farming(IRCSF)system,three surveys were conducted on phytoplankton in the national integrated crayfish-rice co-culture areas of Feixi and Quanjiao in Anhui Province and their relationship with environmental factors was analyzed.The results showed that 55 species belonged to 6 phylum and 61 species belonged to 7 phylum were observed in Feixi and Quanjiao.The average densities of phytoplankton in Feixi and Quanjiao were 3.50×106 ind./L and 7.90×106 ind./L,respectively;and the average biomass was 1.49 mg/L and 2.55 mg/L,respectively.The results of Margalef richness index(D),Shannon Wiener diversity index(H')and Pielou evenness index(J)showed that there was no significant difference(P＞0.05)among the D index of the three cultivation periods of Feixi,but there was significant difference(P＜0.05)among H'index and J index;and there was no significant difference(P＞0.05)among the H',D and J indexes of the three cultivation periods of Quanjiao.CCA analysis showed that phytoplankton community of Feixi was affected by dissolved oxygen,pH,water temperature,chlorophyll a.RDA analysis showed that the key environmental factors affecting the distribution of phytoplankton of Quanjiao were total phosphorus,permanganate index,pH,and ammonia nitrogen.According to the phytoplankton density,the water quality of Feixi and Quanjiao rice fields in the early stage were in the mesotrophic status,and the middle and later stages were in the eutrophic status.
万方数据
维普
