The river network waters of the Xijiang and Beijiang Delta are the essential route for the two main streams of the Pearl River, Xijiang and Beijiang, to flow into the South Sea, China.To explore the relation-ship between phytoplankton chlorophyll a(Chla) particle size and environmental factors, the research team in-vestigated the water environment and phytoplankton Chla particle size characteristics in this water during the dry(February and December) and wet(May and August) periods in 2021, which can provide a scientific basis for the later environmental management and restoration work.Origin visualized the spatial and temporal charac-teristics of environment factors and size-fractioned Chla.The relationship between environmental factors and size-fractioned Chla were analyzed by RDA analysis.The results showed that the significant temporal differ-ences characterized WT,pH, TN and silicate concentration.Variations of DO and transparency showed signifi-cant spatial differences.The total Chla concentration showed significant seasonal differences,with the highest val-ue occurring in August, the second highest in December, and the lowest in May, mainly related to the magni-tude of runoff, water pH, and ORP changes.The spatial characteristics of the total Chla concentration showed that the Chla concentration was significantly higher at the stations around Guangzhou city,which was mainly re-lated to the spatial distribution pattern of nutrients and the exchange capacity of the water bodies.The results of particle size characteristics showed that micro and nano phytoplankton were the main contributors to Chla in the water column of the PRD river network,showing alternating dominance.Seasonal characteristics showed that nano Chla was dominant in February and May,and micro Chla was dominant in August and December, mainly related to the magnitude of runoff, water pH and light.The spatial characteristics of the phytoplankton particle size structure showed that the phytoplankton particle size structure primarily consisted of micro and nano Chla,both of which showed alternating dominance.The highest values of micro Chla tended to occur at stations in the middle of the river network during August and December.The highest values of nano Chla dominance tended to occur at stations far from Guangzhou city,mainly related to the highest values of nano Chla tended to occur at stations far from Guangzhou, related primarily for DO and nitrate content.RDA analysis showed that pH,transparency, light, resistivity, ORP, TP, TN and silicate were the main factors affecting phytoplank-ton Chla concentration and pH, DO, light, TP and nitrate content were the main factors affecting the particle size distribution of phytoplankton.In summary,physical factors, including the magnitude of runoff volume and the variation of water pH affect the seasonal variation of Chla particle size characteristics.In contrast,chemical factors such as nutrient content are the key factors determining the spatial distribution of Chla particle size char-acteristics.
deltaic river networkphytoplanktonchlorophyll a particle size characteristicsspatial and temporal characteristics
维普
万方数据
