Papers by Piero Guilizzoni
Quaternary Science Reviews
Quaternary International, 2002
Three cores from two crater lakes in central Italy (Albano and Nemi) spanning the last ca. 11 kyr... more Three cores from two crater lakes in central Italy (Albano and Nemi) spanning the last ca. 11 kyr BP are discussed here. They were analysed for organic matter, dry density, algal and photosynthetic bacteria pigments, diatoms and Cladocera. These palaeolimnological records show great internal consistency in their response to distinct, but interrelated , aspects of the lakecatchment system, and reflect major changes in these systems particularly in lake productivity. The early Holocene was characterised by very high productivity at both sites. Trends in productivity are similar for many proxies in the Holocene records of Lake Albano and Lake Nemi. Trophic levels throughout much of the period of human activity (ca. 4000 yr BP onward) are lower but have remained relatively high and stable at both lakes. It is only in the last few decades that inferred productivity levels have exceeded those of the early Holocene. Statistical analysis (CONstrained Incremental Sum of Square cluster analysis, CONISS) showed five distinct periods during the Holocene characterised by major variations in the abundance and community structure of biological remains and geochemistry. A comparison of results from the different taxonomic groups has enabled the reconstruction of phases of increased productivity and the recognition of signals of anthropogenic impact on the lakes and their catchments. From published pollen diagrams, nine major deforestation events are recognised during the Holocene. These events, in particular the one which occurred in both lakes at 1800 yr BP and identifies the Roman Period, plus another at 3000-3500 yr BP related to agricultural activity during the Bronze Age, produced profound changes in the pelagic community structure of diatoms and Cladocera, which in some cases were even more marked than the accelerated eutrophication seen in recent times. The mid-Holocene climatic transition is also clearly evident and is characterised by a strong decrease in the concentrations of the biological proxies. Most of the observed lacustrine environmental changes are almost synchronous in the two lakes indicating the importance of regional rather than local changes.
Journal of Paleolimnology, 2001
A combined bulk and detailed geochemical study of the sedimentary organic matter in Lake Albano, ... more A combined bulk and detailed geochemical study of the sedimentary organic matter in Lake Albano, central Italy, provides critical data to track the response of this aquatic system to the environmental changes of variable amplitude that occurred during the Holocene. Rock-Eval pyrolysis of this predominantly laminated, organic carbon-rich sedimentary sequence shows changes in hydrogen and oxygen indices that are related
Journal of Paleolimnology, 1999
Four cores (ranging between ca. 9 and ca. 14 m in length) from Lago di Albano in Central Italy we... more Four cores (ranging between ca. 9 and ca. 14 m in length) from Lago di Albano in Central Italy were studied for their ostracod content, as well as algal and bacterial pigments, CaCO3 and concentration of organic matter. Cores PALB 94 1E and PALB 94 1C from Site 1, located at the bottom of a steep slope at 70 m
A limnological study was performed during 1991 and 1992 on Lakes Paione Superiore (LPS) and Paion... more A limnological study was performed during 1991 and 1992 on Lakes Paione Superiore (LPS) and Paione Inferiore (LPI), located in the Ossola Valley, Central Alps, Italy. The 2 lakes are characterized by very low alkalinity values, notwithstanding the relatively low ...
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Papers by Piero Guilizzoni