| Title | Use of sedimentary pigments to infer past phosphorus concentration in lakes |
| Abstract | We propose a palaeolimnological method for inferring past total phosphorus (TP) concentrations in lake water from spectrophotometrically-measured sedimentary pigments, particularly total carotenoids (TC). Our approach is based on a highly significant statistical correlation (P < 0.0001) between pigment concentrations (total carotenoids) in the surface sediment of 28 Italian lakes (subalpine, large, deep, shallow, volcanic) and TP concentrations measured in these lakes at overturn when the core was collected. A transfer function was developed from this "training" set, and used to estimate past TP concentrations from pigment concentrations in sediment cores. The results generally agreed with TP values as measured by long-term water quality monitoring programs. Contrasting results were obtained by a comparison with diatom-inferred TP. While the diatom model showed a tendency to overestimate TP values higher than 100 mu g l(-1), the pigment model correctly estimated TP in lakes when TP was < 100 mu g l(-1), but not when lakes were rich in macrophytes. In fact, lakes with extensive populations of aquatic submersed macrophytes and epiphytes are outliers in terms of the TC versus TP relationship. The root mean square error of prediction of the pigment model is lower than those derived from certain diatom-based inference models. The predicted and residual values are not related to the estimated values and their average is not statistically different from zero. Errors were estimated via a 'leave-one-out' re-sampling technique. The proposed method permits rapid and relatively inexpensive determination of reference trophic conditions. |
| Source | Journal of paleolimnology 45 (4), pp. 433–445 |
| Keywords | Fossil pigmentsSedimentsTrophic stateReference conditionsDiatoms |
| Journal | Journal of paleolimnology |
| Editor | Kluwer Academic, Boston, Paesi Bassi |
| Year | 2011 |
| Type | Articolo in rivista |
| DOI | 10.1007/s10933-010-9421-9 |
| Authors | Guilizzoni, P (Guilizzoni, Piero)[ 1 ] ; Marchetto, A (Marchetto, Aldo)[ 1 ] ; Lami, A (Lami, Andrea)[ 1 ] ; Gerli, S (Gerli, Stefano)[ 1 ] ; Musazzi, S (Musazzi, Simona)[ 1 ] |
| Text | 203785 2011 10.1007/s10933 010 9421 9 ISI Web of Science WOS 000290043900004 Fossil pigments Sediments Trophic state Reference conditions Diatoms Use of sedimentary pigments to infer past phosphorus concentration in lakes Guilizzoni, P Guilizzoni, Piero 1 ; Marchetto, A Marchetto, Aldo 1 ; Lami, A Lami, Andrea 1 ; Gerli, S Gerli, Stefano 1 ; Musazzi, S Musazzi, Simona 1 1 CNR, Ist Studio Ecosistemi, I 28922 Verbania, Italy We propose a palaeolimnological method for inferring past total phosphorus TP concentrations in lake water from spectrophotometrically measured sedimentary pigments, particularly total carotenoids TC . Our approach is based on a highly significant statistical correlation P < 0.0001 between pigment concentrations total carotenoids in the surface sediment of 28 Italian lakes subalpine, large, deep, shallow, volcanic and TP concentrations measured in these lakes at overturn when the core was collected. A transfer function was developed from this training set, and used to estimate past TP concentrations from pigment concentrations in sediment cores. The results generally agreed with TP values as measured by long term water quality monitoring programs. Contrasting results were obtained by a comparison with diatom inferred TP. While the diatom model showed a tendency to overestimate TP values higher than 100 mu g l 1 , the pigment model correctly estimated TP in lakes when TP was < 100 mu g l 1 , but not when lakes were rich in macrophytes. In fact, lakes with extensive populations of aquatic submersed macrophytes and epiphytes are outliers in terms of the TC versus TP relationship. The root mean square error of prediction of the pigment model is lower than those derived from certain diatom based inference models. The predicted and residual values are not related to the estimated values and their average is not statistically different from zero. Errors were estimated via a leave one out re sampling technique. The proposed method permits rapid and relatively inexpensive determination of reference trophic conditions. 45 ID_PUMA cnr.ise/2011 A0 030 Use of sedimentary pigments to infer past phosphorus concentration in lakes Use_of_sedimentary_pigments_to_infer_past_phosphorus_concentration_in_lakes.pdf Articolo in rivista Kluwer Academic 0921 2728 Journal of paleolimnology Journal of paleolimnology J. paleolimnol. simona.musazzi MUSAZZI SIMONA GERLI STEFANO aldo.marchetto MARCHETTO ALDO piero.guilizzoni GUILIZZONI PIERO andrea.lami LAMI ANDREA |
