Influence of aquatic macrophytes on the stable carbon isotopic signatures of sedimentary organic matter in lakes on the Tibetan Plateau

Understanding terrestrial organic carbon export : a time-series approach

“…n-Alcohol relative contribution displays a statistically significant increase during Cuvette Congolaise dominated periods, balanced by an equal decrease in n-alkanoic acids (Figure 4.10). These results agree with literature measurements of individual plants, as macrophytes display considerably higher n-alcohol production rates than do other PFTs (Ficken et al, 1998(Ficken et al, , 2000Bugalho et al, 2004;Ali et al, 2005a,b;Aichner et al, 2010;Gao et al, 2011;Diefendorf et al, 2011;Wang and Liu, 2012;Gao et al, 2014).…”

Biogeochemical evidence for freshwater periods during the Last Glacial Maximum recorded in lake sediments from Nam Co, south-central Tibetan Plateau

“…This aeolian transport is assumed to have been stronger in glacial times than during warm and humid periods. In contrast, mid-chain-length, oddnumbered n-alkanes n-C 21-25 are mainly produced by submerged and floating aquatic plants (Ficken et al 2000;Aichner et al 2010a), which is also confirmed by analyses of aquatic plants from Nam Co (ESM Fig. 2).…”

“…A distinction between the signal of woody and herbaceous plants is not possible because of mixing of different organic matter sources within the lake sediment (Rao et al 2011). On the other hand, n-C 29 was also found in higher proportions in emergent macrophyte species Hippuris and lower abundances in submerged plants (Potamogeton, Batrachium), with more affinity to shallow lakes that experience dryer conditions (Ficken et al 2000;Aichner et al 2010a).…”

δ13Corg and n-alkane evidence for changing wetland conditions during a stable mid-late Holocene climate in the central Tibetan Plateau

“…Details of their species, habitats and altitude information, organic carbon isotope (δ 13 C org ) values and n-alkane indices are listed in Table 1, along with results of submerged macrophyte samples from the study area provided by Aichner et al (2010). The data are arranged by species and grouped into tree, shrubs, C4 herbs, C3 herbs and submerged macrophytes for interpretation and discussion.…”

“…Previous researchers suggest that n-alkane distributions of aquatic algae and bacteria generally maximize at n-C17 and distinctly differ from vascular plants which mainly contain n-alkanes of mid to long chains in n-C21-C31 (Cranwell, 1987;Rieley, 1991;Ficken, 2000). Within the group of vascular plants, submerged and floating macrophytes are believed to contain large proportions of n-C21, n-C23 and n-C25 alkanes (Aichner et al, 2010), whilst terrestrial plants have abundant n-C27, n-C29 and n-C31 alkanes (Cranwell, 1984;Ficken, 2000). In other words, n-alkanes can be an ideal addition to the δ…”