Revealing the last 13,500 years of environmental history from the multiproxy record of a mountain lake (Lago Enol, northern Iberian Peninsula)

This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s10933-009-9387-7.We present the Holocene sequence from Lago Enol (43°16′N, 4°59′W, 1,070 m a.s.l.), Cantabrian Mountains, northern Spain. A multiproxy analysis provided comprehensive information about regional humidity and temperature changes. The analysis included sedimentological descriptions, physical properties, organic carbon and carbonate content, mineralogy and geochemical composition together with biological proxies including diatom and ostracod assemblages. A detailed pollen study enabled reconstruction of variations in vegetation cover, which were interpreted in the context of climate changes and human impact. Four distinct stages were recognized for the last 13,500 years: (1) a cold and dry episode that includes the Younger Dryas event (13,500–11,600 cal. year BP); (2) a humid and warmer period characterizing the onset of the Holocene (11,600–8,700 cal. year BP); (3) a tendency toward a drier climate during the middle Holocene (8,700–4,650 cal. year BP); and (4) a return to humid conditions following landscape modification by human activity (pastoral activities, deforestation) in the late Holocene (4,650–2,200 cal. year BP). Superimposed on relatively stable landscape conditions (e.g. maintenance of well established forests), the typical environmental variability of the southern European region is observed at this site.The Spanish Inter-Ministry Commission of Science and Technology (CICYT), the Spanish National Parks agency, the European Commission, the Spanish Ministry of Science, and the European Social Fund

Revealing the last 13,500 years of environmental history from the multiproxy record of a mountain lake (Lago Enol, northern Iberian Peninsula)

This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s10933-009-9387-7.We present the Holocene sequence from Lago Enol (43°16′N, 4°59′W, 1,070 m a.s.l.), Cantabrian Mountains, northern Spain. A multiproxy analysis provided comprehensive information about regional humidity and temperature changes. The analysis included sedimentological descriptions, physical properties, organic carbon and carbonate content, mineralogy and geochemical composition together with biological proxies including diatom and ostracod assemblages. A detailed pollen study enabled reconstruction of variations in vegetation cover, which were interpreted in the context of climate changes and human impact. Four distinct stages were recognized for the last 13,500 years: (1) a cold and dry episode that includes the Younger Dryas event (13,500–11,600 cal. year BP); (2) a humid and warmer period characterizing the onset of the Holocene (11,600–8,700 cal. year BP); (3) a tendency toward a drier climate during the middle Holocene (8,700–4,650 cal. year BP); and (4) a return to humid conditions following landscape modification by human activity (pastoral activities, deforestation) in the late Holocene (4,650–2,200 cal. year BP). Superimposed on relatively stable landscape conditions (e.g. maintenance of well established forests), the typical environmental variability of the southern European region is observed at this site.The Spanish Inter-Ministry Commission of Science and Technology (CICYT), the Spanish National Parks agency, the European Commission, the Spanish Ministry of Science, and the European Social Fund

Climate-driven regime shifts in the biological communities of arctic lakes

Fifty-five paleolimnological records from lakes in the circumpolar Arctic reveal widespread species changes and ecological reorganizations in algae and invertebrate communities since approximately anno Domini 1850. The remoteness of these sites, coupled with the ecological characteristics of taxa involved, indicate that changes are primarily driven by climate warming through lengthening of the summer growing season and related limnological changes. The widespread distribution and similar character of these changes indicate that the opportunity to study arctic ecosystems unaffected by human influences may have disappeared. © 2005 by The National Academy of Sciences of the USA

School matters: Drinking dimensions and their effects on alcohol related problems among Ontario Secondary School Students

Aims: To test the hypotheses that average volume of alcohol consumption and patterns of drinking, each influence alcohol-related problems and that both act at individual and aggregate levels. Methods: The 2003 cycle of the Ontario Student Drug Use Survey obtained self-administered questionnaires from a representative classroom-based survey of 2455 Ontario secondary school students (grades 9–12) from 74 schools, with a student completion rate of 72%. Average volume of alcohol consumption was assessed using a quantity-frequency measure. Heavy drinking occasions were operationalized by four dummy variables indicating less than monthly, monthly, weekly and daily consumption of five or more drinks per occasion, with never having a heavy drinking occasion serving as the reference group. Alcohol-related problems were measured by using seven items of the Alcohol Use Disorders Identification Test. Results: As hypothesized, both the average volume of alcohol consumption and patterns of drinking influenced alcohol-related problems at the student level, independently of each other. At the school level, both determinants significantly influenced the problems, but not when simultaneously entered into the equation. Conclusions: Future prevention of alcohol-related problems in adolescents should consider both the average volume and patterns of drinking. Both prevention and research should also try to include environmental determination of alcohol-related problems

Volume et profil de consommation d'alcool des élèves et des camarades scolaires comme prédicteurs de l'agression et de la victimisation: une analyse multiniveaux auprès d'adolescents suisses

OBJECTIVE: To test the effects of the volume of alcohol consumption and drinking patterns on alcohol-related aggression and victimization, both at the individual and class levels. METHODS: Representative sample drawn from the European School Survey Project on Alcohol and Other Drugs (ESPAD) of 6496 Swiss adolescents (13 to 16 years). Hierarchical multi-level models were used to simultaneously estimate individual and environmental influences. In addition to indicators of consumption of alcohol and other substances, age, sex, socioeconomic indicators and satisfaction with the relationship to parents were used as covariates. RESULTS: After controlling for confounding, both volume of alcohol consumption and the frequency of binge drinking occasions were associated independently with alcohol-related problems (aggression/victimization) on the individual level. On the aggregate level, there was colinearity between volume of drinking and frequency of heavy drinking occasions. When entered in the same model, however, only the effect of volume effect stayed in the same direction. CONCLUSIONS: Not only individual volume of drinking, but also the way alcohol is consumed influences individual problem levels. This includes individual patterns of drinking as well as environmental influences at school. These results open up important considerations for theory, research and prevention