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European Sites (european + site)
Selected AbstractsDo changes in climate patterns in wintering areas affect the timing of the spring arrival of trans-Saharan migrant birds?GLOBAL CHANGE BIOLOGY, Issue 1 2005Oscar Gordo Abstract The life cycles of plants and animals are changing around the world in line with the predictions originated from hypotheses concerning the impact of global warming and climate change on biological systems. Commonly, the search for ecological mechanisms behind the observed changes in bird phenology has focused on the analysis of climatic patterns from the species breeding grounds. However, the ecology of bird migration suggests that the spring arrival of long-distance migrants (such as trans-Saharan birds) is more likely to be influenced by climate conditions in wintering areas given their direct impact on the onset of migration and its progression. We tested this hypothesis by analysing the first arrival dates (FADs) of six trans-Saharan migrants (cuckoo Cuculus canorus, swift Apus apus, hoopoe Upupa epops, swallow Hirundo rustica, house martin Delichon urbica and nightingale Luscinia megarhynchos), in a western Mediterranean area since from 1952 to 2003. By means of multiple regression analyses, FADs were analysed in relation to the monthly temperature and precipitation patterns of five African climatic regions south of the Sahara where species are thought to overwinter and from the European site from where FADs were collected. We obtained significant models for five species explaining 9,41% of the variation in FADs. The interpretation of the models suggests that: (1) The climate in wintering quarters, especially the precipitation, has a stronger influence on FADs than that in the species' potential European breeding grounds. (2) The accumulative effects of climate patterns prior to migration onset may be of considerable importance since those climate variables that served to summarize climate patterns 12 months prior to the onset of migration were selected by final models. (3) Temperature and precipitation in African regions are likely to affect departure decision in the species studied through their indirect effects on food availability and the build-up of reserves for migration. Our results concerning the factors that affect the arrival times of trans-Saharan migrants indicate that the effects of climate change are more complex than previously suggested, and that these effects might have an interacting impact on species ecology, for example by reversing ecological pressures during species' life cycles. [source] Predicting the effect of disturbance on coastal birdsIBIS, Issue 2007RICHARD A. STILLMAN Assessments of whether disturbance is having a deleterious effect on populations have often measured behavioural responses to disturbance and assumed that populations with a larger behavioural response are more susceptible to disturbance. However, there is no guarantee that the behavioural response to disturbance is related to the population consequence, measured in terms of decreased reproduction or increased mortality. Individual-based models, consisting of fitness-maximizing individuals, are one means of linking the behavioural responses to disturbance to population consequences. This paper reviews how individual-based models have been used to predict the effect of disturbance on populations of shorebirds and wildfowl at several European sites, and shows how these models could be improved in the future by incorporating a range of alternative responses to disturbance. [source] Sensitivity of different taxonomic levels of soil Gamasina to land use and anthropogenic disturbancesAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2010José Camilo Bedano 1The effect of taxonomic level on the sensitivity of bioindicators has been widely investigated in aquatic ecosystems and, to a lesser extent, in terrestrial ecosystems. However, no studies have been conducted on the sensitivity of the different taxonomic levels of soil mites, especially Gamasina, to human activities. 2The present study aimed to assess the sensitivity of different taxonomic levels of soil Gamasina mites to anthropogenic disturbances in Europe and Argentina. We arranged the data from previous projects in a hierarchical system and conducted a study to identify the critical taxonomical levels that had the highest discriminative potential between sites (Europe and Argentina) or management types (forests, grasslands, fallows, succession, recultivation and agricultural sites). 3For the Gamasina community, geographical location was by far more important than the influence of any land use type. The analysis including only the European sites demonstrated that communities belonging to sites subjected to different land uses were also significantly different. 4The species data set provided a clearer separation of sites according to both the geographical and the land-use gradients than the genus and family data sets. The genus and, to a lesser extent, the family approach may be sufficient to elucidate the influence of great geographical differences and also of certain land uses (e.g. grasslands from the forests and arable sites). 5Species presence/absence data provided valuable information in our analyses, although the use of quantitative data yielded a clearer separation of sites. [source] A new European testate amoebae transfer function for palaeohydrological reconstruction on ombrotrophic peatlands,JOURNAL OF QUATERNARY SCIENCE, Issue 3 2007Dan J. Charman Abstract Proxy climate data can be obtained from reconstructions of hydrological changes on ombrotrophic (rain-fed) peatlands using biological indicators, such as testate amoebae. Reconstructions are based on transfer functions, relating modern assemblage composition to water table and moisture content, applied to fossil sequences. Existing transfer functions in Europe and elsewhere are limited geographically and there are often problems with missing or poor analogues. This paper presents a new palaeohydrological transfer function based on sampling raised mires from across Europe. Relationships between assemblages and hydrological variables are described using ordination analyses. Transfer functions are developed for depth to water table (n,=,119) and moisture content (n,=,132) with root mean squared errors (RMSEP) of 5.6,cm and 2.7% respectively. Both transfer functions have an r2 of 0.71, based on ,leave one out' cross-validation. Comparisons with an existing transfer function for Britain show that the European transfer function performs well in inferring measured water tables in Britain but that the British data cannot be used to infer water tables for other European sites with confidence. Several of the key missing and poor analogue taxa problems encountered in previous transfer functions are solved. The new transfer function will be an important tool in developing peat-based palaeoclimatic reconstructions for European sites. Copyright © 2006 John Wiley & Sons, Ltd. [source] Variations in bark-stripping by red deer Cervus elaphus across EuropeMAMMAL REVIEW, Issue 3 2006HÉLÈNE VERHEYDEN ABSTRACT 1The literature on bark-stripping by red deer Cervus elaphus in Europe is reviewed to reveal quantitative variation in this behaviour and relate it to deer density and local characteristics such as dominant tree species, occurrence of artificial feeding, altitude, region and size of the study site. We also review the importance of bark in red deer diets over the seasons and discuss the causes of bark-stripping, focusing on the significance of bark as food. 2Over the 36 sites examined, the rate of bark-stripping was highly variable (from 0 to 84% of susceptible trees debarked), with less damage in Scotland than in other European sites for which bark-stripping rates were higher at high red deer density. Altitude, the size of the study site, the number of dominant tree species and the occurrence of artificial feeding do not significantly relate to the rate of bark-stripping. 3Bark sometimes made up a large proportion of red deer diet (> 10%), especially in areas with severe winters (high levels of snow), whereas in study sites with mild winters, bark was practically not eaten at all. 4These results suggest that severe bark-stripping could be related to a reduction in food resource availability. This food availability hypothesis needs to be better documented, dealing particularly with the possible interaction between food availability and red deer density. [source] Closure of ostium secundum atrial septum defect with the Atriasept occluder: Early European experience,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 7 2010Valérie Steiger Stolt MD Abstract Objectives: This multicentre study sought to report the safety and efficacy of the ATRIASEPT septal occluder to repair atrial septal defect (ASD). Background: The ATRIASEPT is a low profile, flexible, double disk occluder with centering system specifically designed for closure of ostium secundum ASD. Method: Patients were enrolled from four participating European sites and followed up for 12 months post procedure. Outcomes were evaluated, including closure success and incidence of adverse events. Results: Seventy-six patients received the ATRIASEPT device. Mean size of the defect was 15 ± 4 mm. Closure success was observed in 69 patients (89%) at the end of the procedure. Sixty-four patients had a six-month follow up with a complete closure by 58 patients (90%). Minor adverse events occurred in two patients. Significant functional improvement was reported by all symptomatic patients. Conclusion: Percutaneous closure of ASD ostium secundum type defects with the ATRIASEPT is safe and effective with high success rate and excellent mid-term outcome. © 2010 Wiley-Liss, Inc. [source] | ||||||||||