| Title | Is it possible to study paleoenvironmental changes in alpine spring habitats? a few example from the south-eastern Alps (Ne Italy) |
| Abstract | Palaeolimnological techniques were applied to spring habitats in the Trentino Region (NE Italy) as a test in order to reconstruct past environmental changes in these crucial and fragile milieus. Three different sites were selected from a database of more than one hundred on the basis of morphological, geological, and biological factors, including human impact evaluation: Nambrone, Paul and Madonnina Val Lomasona. Sampling was performed by adapting standard lake-sediment coring methods, and the retrieved sediment was described and subsampled following standard "lake" procedures. Field work and sedimentological analyses revealed clear influence from nearby fluvial environment for the Nambrone site, whereas Paul and Madonnina Val Lomasona were selected for further analyses (e.g., dating, diatoms, chironomids). Lead-210 and Caesium-137 dating methods were used to obtain a chronological framework, in addition to historical information on land use and other events in the area. The upper part of the Paul sequence presented organic rich sediment compatible with spring environments, but the lower and essentially detrital part appeared to record alluvial deposition, probably linked to extraordinary flood events (1882, 1966). This interpretation is indirectly confirmed by the records of the fallout nuclides Caesium-137 and Lead-210, that were both unfortunately concentrated in the topmost 1 cm, making it impossible to construct a normal age-depth profile. Madonnina Val Lomasona sedimentological and biological indicators point to a marked charge around ca 5 cm, dividing the sequence in two units, corresponding to different environmental conditions. Although the interpretation of the dating results is not completely straightforward, the assembled data suggest that the upper 5 cm of the record represents ca the last 50 years. During this period we found typical limnocrenic, clear-water spring conditions, while before 1960s the coexistence of lotic and lentic chironomid species including several opportunistic ones and the low richness, emphasized the presence of a disturbance (e.g., highly variable flow and/or trophic conditions), as confirmed also by diatom assemblages and,sedimentological features. The recorded disturbance is probably linked to a water-level change due to the local land use, as also testified by historical data. The results of this study support the idea that carefully selected spring sites might be approached with adapted palaeolimnological techniques to extract valuable palaeoenvironmental information. However, it also highlighted the low percentage of "good sites" (1%) and considerable difficulties in coring and sampling without disturbing the sediment. |
| Source | Journal of limnology (Testo stamp.) 70 (S1), pp. 155–167 |
| Keywords | SpringspalaeolimnologyAlpspalaeoenvironmental changesmethodology |
| Journal | Journal of limnology (Testo stamp.) |
| Editor | Istituto per lo Studio degli Ecosistemi., Verbania Pallanza, Italia |
| Year | 2011 |
| Type | Articolo in rivista |
| DOI | 10.3274/JL11-70-S1-12 |
| Authors | Filippi, ML (Filippi, Maria Letizia) ; Piliposian, G (Piliposian, Gayane) ; Marziali, L (Marziali, Laura); Angeli, N (Angeli, Nicola) ; Lencioni, V (Lencioni, Valeria) ; Cantonati, M (Cantonati, Marco) |
| Text | 42441 2011 10.3274/JL11 70 S1 12 ISI Web of Science WOS 00289588500013 Springs palaeolimnology Alps palaeoenvironmental changes methodology Is it possible to study paleoenvironmental changes in alpine spring habitats a few example from the south eastern Alps Ne Italy Filippi, ML Filippi, Maria Letizia ; Piliposian, G Piliposian, Gayane ; Marziali, L Marziali, Laura ; Angeli, N Angeli, Nicola ; Lencioni, V Lencioni, Valeria ; Cantonati, M Cantonati, Marco Museo Tridentino Sci Nat, I 38122 Trento, Italy ; Univ Liverpool, Dept Math Sci, Liverpool L69 7ZL, Merseyside, England ; CNR IGAG ; CNR IRSA ; CNR ISE Palaeolimnological techniques were applied to spring habitats in the Trentino Region NE Italy as a test in order to reconstruct past environmental changes in these crucial and fragile milieus. Three different sites were selected from a database of more than one hundred on the basis of morphological, geological, and biological factors, including human impact evaluation Nambrone, Paul and Madonnina Val Lomasona. Sampling was performed by adapting standard lake sediment coring methods, and the retrieved sediment was described and subsampled following standard lake procedures. Field work and sedimentological analyses revealed clear influence from nearby fluvial environment for the Nambrone site, whereas Paul and Madonnina Val Lomasona were selected for further analyses e.g., dating, diatoms, chironomids . Lead 210 and Caesium 137 dating methods were used to obtain a chronological framework, in addition to historical information on land use and other events in the area. The upper part of the Paul sequence presented organic rich sediment compatible with spring environments, but the lower and essentially detrital part appeared to record alluvial deposition, probably linked to extraordinary flood events 1882, 1966 . This interpretation is indirectly confirmed by the records of the fallout nuclides Caesium 137 and Lead 210, that were both unfortunately concentrated in the topmost 1 cm, making it impossible to construct a normal age depth profile. Madonnina Val Lomasona sedimentological and biological indicators point to a marked charge around ca 5 cm, dividing the sequence in two units, corresponding to different environmental conditions. Although the interpretation of the dating results is not completely straightforward, the assembled data suggest that the upper 5 cm of the record represents ca the last 50 years. During this period we found typical limnocrenic, clear water spring conditions, while before 1960s the coexistence of lotic and lentic chironomid species including several opportunistic ones and the low richness, emphasized the presence of a disturbance e.g., highly variable flow and/or trophic conditions , as confirmed also by diatom assemblages and,sedimentological features. The recorded disturbance is probably linked to a water level change due to the local land use, as also testified by historical data. The results of this study support the idea that carefully selected spring sites might be approached with adapted palaeolimnological techniques to extract valuable palaeoenvironmental information. However, it also highlighted the low percentage of good sites 1% and considerable difficulties in coring and sampling without disturbing the sediment. 70 ID_PUMA cnr.ise/2011 A0 024 s it possible to study paleoenvironmental changes in alpine spring habitats Is_it_possible_to_study_palaeoenvironmental_changes_in_Alpine_spring_habitats.pdf Articolo in rivista Istituto per lo Studio degli Ecosistemi. 1129 5767 Journal of limnology Testo stamp. Journal of limnology Testo stamp. J. limnol. Testo stamp. Journal of limnology. Testo stamp. CANTONATI MARCO FILIPPI MARIA LETIZIA laura.marziali MARZIALI LAURA TA.P04.016.004 Ecologia teorica e applicata degli ecosistemi acquatici INT.P03.001.003 Sistemi di monitoraggio per suoli e acque |
