1 / 21

The study of spatial and temporal nutrient limitation in Meiliang Bay, Lake Taihu

The study of spatial and temporal nutrient limitation in Meiliang Bay, Lake Taihu. Longyuan Yang 1 , Feizhou Chen 1 , Yunling Zhang 1 , Shixin Wang 2 (1 Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences; 2 Institute of Remote Sensing Applications,

rooney-lucas
Télécharger la présentation

The study of spatial and temporal nutrient limitation in Meiliang Bay, Lake Taihu

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The study of spatial and temporal nutrient limitation in Meiliang Bay, Lake Taihu Longyuan Yang1, Feizhou Chen1, Yunling Zhang1, Shixin Wang2 (1 Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences; 2 Institute of Remote Sensing Applications, Chinese Academy of Sciences )

  2. Purpose • To measure nitrogen and phosphorus concentrations in Meiliang Bay, Lake Taihu, and analyze spatial and temporal variation of water quality parameters; • To analyze the relationship between nutrient concentrations and dominant algae species. • To study nutrient limitation status in Meiliang Bay, Lake Taihu.

  3. Redfield Ratio • If N:P ratio > 16, there is P limitation in the aquatic ecosystem; • If N:P ratio < 16, there is N limitation in the aquatic ecosystem.

  4. Background about limitation factor research in Lake Taihu • Phosphorus is the limitation factor in Lake Taihu (traditional opinion); • There is nitrogen limitation sites in some seasons and in some aquatic area (Martin Dokulil et al. 2000); • There is a limitation factor change phenomenon that from Liangxi river discharge area to the main body of Lake Taihu (McCarthy et al. 2007)

  5. Sampling sites Regular site: 25 (per 3 months) Add specific site: 20 (2 times in 2004) Total sites: 45

  6. Distribution of sampling area

  7. Function of Distribution

  8. Results (Oct-2003 to Aug-2005) For whole research area

  9. Spatial and temporal variation calculate of nutrients • Spatial variation in research area were calculated by average of all sites in one distribution area; • Annual variation were calculated by all sites in same distribution area and separated seasons.

  10. Interval to Average Index (IA Index) I %=(Ci-Cm)*100/Cm Where:I mean the IA index coefficient ; Ci concentration of individual parameter; Cm mean concentration of whole area

  11. The ratio of nitrogen over phosphorus

  12. Annual variation characters summary • In winter and spring seasons the mole ratio of TN:TP are more higher than Readfield ratio (16) ; but in summer and fall seasons the mole ratio of TN:TP are almost equal to Readfield ratio. • So there is dominant P limitation in Winter and Spring seasons (Colder season, water temperature < 20 oC ) and there is dominant N limitation in some areas in Summer and Fall seasons (Warmer season, water temperature > 20 oC ) except the P limitation in shore area of Lake Taihu. • In open and central areas(B4 and B5) the mole ratio of TN:TP reduced serious than in river discharge area(B1) in whole year; so the open and central areas is the hot point for nitrogen limitation or nitrogen and phosphorus co-limitation mainly occur areas.

  13. Dominant algae species in different areas (Oct. 27, 2003)

  14. Conclusion • There is a phenomenon that phosphorus limitation change to nitrogen limitation from Liangxi river discharge area to the main body (open area) of Lake Taihu; • Summer and Fall seasons is the nitrogen Limitation occur season; especially in the area that far away from pollution river discharge area such as in central area of Lake Taihu • The phenomenon that limitation factor changes may occur in all large shallow eutrophication lakes and estuaries in east part of China and other north temperate zones

  15. 谢谢莅临指导! Welcome to Taihu Field Station ! Thank you for presentation Thank you!

More Related