“…In contrast, short-chain n-alkanes, with chain lengths of 14-20 carbons and no distinct odd-over-even predominance, are predominantly ascribed to the algal and bacterial contribution [Han and Calvin, 1969;Giger et al, 1980;Pearson et al, 2007]. Submerged/floating aquatic macrophytes sampled from lakes, such as Myriophyllum, Potamogeton, Chara and many lake sediments are mainly characterized by medium-chain n-alkanes (n-C 23 and n-C 25 ) [Aichner et al, 2010;Ficken et al, 2000;Gao et al, 2011;Herzschuh et al, 2005;Lin et al, 2009;Mügler et al, 2008;Pearson et al, 2007], although the growing evidence also indicates that some palustrine Sphagnum species also have higher abundance of medium-chain n-alkanes [Bingham et al, 2010;Nichols et al, 2006]. We consequently ascribe the short-chain, long-chain, and medium chain n-alkanes to origins from bacteria and algae, terrestrial higher plants, and typical macrophytes or palustrine plants, respectively.…”