We surveyed the trophic status and its limiting factors of the Three-Gorges Reservoir (TGR) in China, including 153 sites in the mainstream of Yangtze River and 17 tributary bays quarterly for one year after the first full-capacity impoundment (175 m above sea level.) in 2010. Carlson-type trophic state indexes (TSI), including the trophic index of total phosphorus (TSITP), total nitrogen (TSITN), chlorophyll a (TSICHL,), and Secchi depth (TSISD), were used to assess trophic status of TGR. Based on TSICHL, trophic status of the mainstream was oligotrophic in the four seasons; however most of tributary bays were in eutrophic status in spring and summer and oligotrophic states in autumn and winter. Judging from TSISD, the mainstream and tributary bays were in the status of mesotrophication in winter, but hypertrophication or eutrophication in the other seasons, TSITP showed that the mainstream was in the eutrophic or hypertrophic status; the tributary bays were in the eutrophic status in spring and summer, but in the mesotrophic status in autumn and winter. TSITN revealed that mainstream and tributary bays were characterized as eutrophic status in the four seasons. Using Carlson's two-dimensional graphical approach, the deviations of TSISD, TSITP and TSITN from TSICHL, indicated that algal growth in the mainstream of TGR was limited by light other than nutrient in all year. For the tributary bays of TGR, light might be the factor limiting algal growth in autumn and winter. However, in spring and slimmer, nutrient and grazing became the limiting factors in some tributary bays. In addition, Basin characteristic had a significant influence on the trophic status and limiting factors in TGR. Our research provided fundamental information trophic status of the whole TGR water body and is helpfulness for water quality management of the reservoir.
英文摘要:
We surveyed the trophic status and its limiting factors of the Three-Gorges Reservoir (TGR) in China, including 153 sites in the mainstream of Yangtze River and 17 tributary bays quarterly for one year after the first full-capacity impoundment (175 m above sea level.) in 2010. Carlson-type trophic state indexes (TSI), including the trophic index of total phosphorus (TSITP), total nitrogen (TSITN), chlorophyll a (TSICHL,), and Secchi depth (TSISD), were used to assess trophic status of TGR. Based on TSICHL, trophic status of the mainstream was oligotrophic in the four seasons; however most of tributary bays were in eutrophic status in spring and summer and oligotrophic states in autumn and winter. Judging from TSISD, the mainstream and tributary bays were in the status of mesotrophication in winter, but hypertrophication or eutrophication in the other seasons, TSITP showed that the mainstream was in the eutrophic or hypertrophic status; the tributary bays were in the eutrophic status in spring and summer, but in the mesotrophic status in autumn and winter. TSITN revealed that mainstream and tributary bays were characterized as eutrophic status in the four seasons. Using Carlson's two-dimensional graphical approach, the deviations of TSISD, TSITP and TSITN from TSICHL, indicated that algal growth in the mainstream of TGR was limited by light other than nutrient in all year. For the tributary bays of TGR, light might be the factor limiting algal growth in autumn and winter. However, in spring and slimmer, nutrient and grazing became the limiting factors in some tributary bays. In addition, Basin characteristic had a significant influence on the trophic status and limiting factors in TGR. Our research provided fundamental information trophic status of the whole TGR water body and is helpfulness for water quality management of the reservoir.
关键词[WOS]:
3 GORGES RESERVOIR
; LAKES LAKE TAIHU
; XIANGXI BAY
; MACROINVERTEBRATE COMMUNITY
; NUTRIENT LIMITATION
; SHALLOW LAKES
; EUTROPHICATION
; PHOSPHORUS
; WATER
; MANAGEMENT
TROPHIC STATUS OF TRIBUTARY BAY AGGREGATE AND THEIR RELATIONSHIPS WITH BASIN CHARACTERISTICS IN A LARGE, SUBTROPICAL DENDRITIC RESERVOIR, CHINA.pdf（673KB）
1.Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
