Seasonal Variation Of C/N and Delta 13C Of Particulate Organic Matters From Three Lakes in Taiwan

Surface waters from three lakes were sampled and measured every one to two months from 2003 to 2004. Shuanglian Pond (470 m in altitude) and Lake of Plum Blossom (50 m) are located at the northern Taiwan, whereas Longluantan (15 m) is situated in the southern part. To compare the differences of organic carbon isotopes and C/N among these lakes, filtered particulate organic matters (POM) were studied. POM delta 13C and C/N showed variations which corresponded to seasonal change during the monitoring period. The values of ƒO13C ranged from -21.11 to -28.65 (concentrated between -22.45 and -26.77), while C/N ranged from 5.1 to 9.34. POM in the three lakes recorded heavier delta 13C in 2003 than in 2004, and showed lighter trend to the end of the year. However, the C/N of POM in these lakes revealed a more variable signal between 2003 and 2004.