Growth, leaf traits and litter decomposition of roadside hybrid aspen (Populus tremula L.× P. tremuloides Michx.) clones.

Road traffic contributes considerably to ground-level air pollution and is therefore likely to affect roadside ecosystems. Differences in growth and leaf traits among 13 hybrid aspen (Populus tremula × P. tremuloides) clones were studied in relation to distance from a motorway. The trees sampled were growing 15 and 30 m from a motorway and at a background rural site in southern Finland. Litter decomposition was also measured at both the roadside and rural sites. Height and diameter growth rate and specific leaf area were lowest, and epicuticular wax amount highest in trees growing 15m from the motorway. Although no significant distance × clone interactions were detected, clone-based analyses indicated differences in genotypic responses to motorway proximity. Leaf N concentration did not differ with distance from the motorway for any of the clones. Leaf litter decomposition was only temporarily retarded in the roadside environment, suggesting minor effects on nutrient cycling.

Urbanization-related changes in European aspen (Populus tremula L.): leaf traits and litter decomposition.

We investigated foliar and litter responses of European aspen (Populus tremula L.) to urbanization, including factors such as increased temperature, moisture stress and nitrogen (N) deposition. Leaf samples were collected in 2006-2008 from three urban and three rural forest stands in the Helsinki Metropolitan Area, southern Finland, and reciprocal litter transplantations were established between urban and rural sites. Urban leaves exhibited a higher amount of epicuticular waxes and N concentration, and a lower C:N ratio than rural ones, but there was no difference in specific leaf area. Urban litter had a slightly higher N concentration, lower concentrations of lignin and total phenolics, and was more palatable to a macrofaunal decomposer. Moreover, litter decay was faster at the urban site and for urban litter. Urbanization thus resulted in foliar acclimatization in terms of increased amount of epicuticular waxes, as well as in accelerated decomposition of the N-richer leaf litter.

Influences of elevated ozone and carbon dioxide in growth responses of lowland hay meadow mesocosms.

We studied the effects of relatively low levels of O(3) (40-50 ppb) and CO(2)-enrichment (+100 ppm) on a northern European lowland hay meadow during the summers 2002-2004 using open-top chambers (OTCs) and ground-planted mesocosms. Ozone reduced the aboveground biomass of the community (up to 40%), and four out of seven species (Campanula rotundifolia, Fragaria vesca, Trifolium medium, Vicia cracca) showed either significant growth reduction and/or visible injuries under elevated O(3). However, the reductions in aboveground biomass were not reflected as changes in the dominance of different functional groups or in the total community root biomass. Elevated CO(2) did not amend the detrimental effects of O(3) on aboveground biomass. Elevated CO(2) alone had only minor effects. An O(3)-induced reduction in the aboveground biomass and N pool of the community are likely to have important consequences in the nutrient cycling of the ecosystem.

Predictors of mortality: an international comparison of socio-demographic and health characteristics from six longitudinal studies on aging: the CLESA project.

PURPOSE: Multiple factors contribute to mortality in the elderly, but the extent to which traditional factors contribute independently to mortality in different countries is not known. Our objective is to determine the differential impact of socio-demographic variables, selected diseases, health habits and disability on all-cause mortality, among older people living in five European countries and Israel. METHODS: From six longitudinal studies on aging (TamELSA-Tampere (Finland), CALAS-Israel, ILSA-Italy, LASA-Netherlands, AL-Leganés (Spain), SATSA-Sweden), a harmonized common database was created in the context of the CLESA Project (Cross-national determinants of quality of life and health services for the elderly). A common five-year follow-up was used. RESULTS: The highest mortality rate was found in Tampere among females (98.7%) and in Israel among males (108.3%), whereas the lowest was observed in Leganés for males (72.3%) and in The Netherlands for females (44.6%). In multivariate models, some predictors were homogeneously, significantly distributed across the six countries, including older age (HR = 1.57) and male sex (HR = 1.60) among the socio-demographic variables; smoking status (HR = 1.15) and alcohol consumption (HR = 0.81) among the health habits variables; presence of heart disease (HR = 1.34), diabetes (HR = 1.46), cancer (HR = 1.93), respiratory disease (HR = 1.19), and disability (HR = 2.92) among the health status variables. Marital status, education, and drug use did not have homogeneous effects in the six countries. DISCUSSION: This large international study shows that multiple factors contribute to increased risk of all cause mortality among older people and that most risk factors are similar across countries. Disability, age greater than 80 years, cancer and male sex were identified as the strongest common risk factors of mortality.

Cross-national determinants of quality of life from six longitudinal studies on aging: the CLESA project.

BACKGROUND AND AIMS: The Comparison of Longitudinal European Studies on Aging (CLESA) Project, here presented for the first time, is a collaborative study involving five European and one Israeli longitudinal study on aging. The aim of this paper is to describe the methodology developed for the harmonization of data and the creation of a Common Data Base (CDB), and to investigate the distribution of some selected common variables among the six countries. The design of each study is briefly introduced and the methodology leading to the harmonization of the common variables is described. METHODS: The study base includes data from five European countries (Finland, Italy, the Netherlands, Spain, Sweden) and Israel, for older people aged 65-89 living both in the community and in institutions (total, 11557 subjects). For two age classes (65-74 and 75-84), the prevalence ratios or the mean values of the following selected variables are provided: a) sociodemographic variables; b) health habits; c) health status; d) physical functioning; e) social networks and support; and f) health and social services utilization. RESULTS: Statistically significant differences were found between most of the investigated characteristics across the CLESA countries, with very few exceptions. While some of the differences found may be due to cultural variations, others require further investigation and should be encompassed in the main framework of the Project, which is to identify predictors of hospitalization, mortality, institutionalization and functional decline. CONCLUSIONS: A common data base is available for the study of the aging process in five European and one Israeli population. These data provide a unique opportunity to identify common risk factors for mortality and functional decline and increase our understanding of country-specific exposures and vulnerability.

Are IADLs comparable across countries? Sociodemographic associates of harmonized IADL measures.

BACKGROUND AND AIMS: Independence in Instrumental Activities of Daily Living (IADLs) is determined not only by physical ability but also by the environmental and cultural surroundings of the individual. The present study describes the harmonization of data on IADL functioning of the Comparison of Longitudinal European Studies on Aging (CLESA) Project. The focus of this report is to examine the comparability of IADLs across countries and to study the association of IADLs with age, gender and socioeconomic status, and the scalability of the measure. METHODS: The study base includes data from five European countries (Finland, Italy, The Netherlands, Spain, Sweden) and Israel, for older people aged 65-89 living both in the community and in institutions, for a total of 11,557 subjects. In this report, only community-dwelling respondents were included (N=8420). The common IADL items in all six countries were: preparing meals, shopping, and doing housework. The analyses include how these items are distributed by age group and gender, and the associations between independence in these items and socioeconomic status (SES) with logistic regression modeling. The scale properties of these three items are also examined. RESULTS: Independence in IADLs decreases steadily with age in all countries. Associations with gender and SES follow largely similar patterns across countries. The reliability of the 3-item scale is satisfactory in most countries, and Cronbach's alpha-coefficient for the complete CLESA sample was 0.75. CONCLUSIONS: The associations between sociodemographic variables and independence in preparing meals, shopping, and doing housework are similar across countries. Results suggest that the predictors of IADLs in different countries are comparable.