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Abstract. Effects of agricultural intensification (AI) on biodiversity are often assessed on the plot scale, although processes determining diversity also operate on larger spatial scales. Here, we analyzed the diversity of vascular plants, carabid beetles, and birds in agricultural landscapes in cereal crop fields at the field (n ¼ 1350), farm (n ¼ 270), and European-region (n ¼ 9) scale. We partitioned diversity into its additive components a, b, and c, and assessed the relative contribution of b diversity to total species richness at each spatial scale. AI was determined using pesticide and fertilizer inputs, as well as tillage operations and categorized into low, medium, and high levels. As AI was not significantly related to landscape complexity, we could disentangle potential AI effects on local vs. landscape community homogenization. AI negatively affected the species richness of plants and birds, but not carabid beetles, at all spatial scales. Hence, local AI was closely correlated to b diversity on larger scales up to the farm and region level, and thereby was an indicator of farm-and region-wide biodiversity losses. At the scale of farms (12.83-20.52%) and regions (68.34-80.18%), b diversity accounted for the major part of the total species richness for all three taxa, indicating great dissimilarity in environmental conditions on larger spatial scales. For plants, relative importance of a diversity decreased with AI, while relative importance of b diversity on the farm scale increased with AI for carabids and birds. Hence, and in contrast to our expectations, AI does not necessarily homogenize local communities, presumably due to the heterogeneity of farming practices. In conclusion, a more detailed understanding of AI effects on diversity patterns of various taxa and at multiple spatial scales would contribute to more efficient agrienvironmental schemes in agroecosystems.

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The traffic load near large cities may show dramatic cyclical changes induced by weekend tourism, and this could induce cyclical changes in the activity patterns of wildlife. We studied a 19-km-long section of a road that crossed a high-use raptor area near a large city in Spain. We observed 18 raptor species along this segment of the road, including some threatened species, such as the Spanish Imperial Eagle (Aquila adalberti). The number of cars increased dramatically on Saturdays and Sundays, so we assessed the effect of varying traffic loads on raptor behavior by recording all birds of prey as close or distant to the road during working days and weekend days. On weekends, the occurrence of Spanish Imperial Eagles and vultures decreased near the road. The occurrence of other species did not change between working days and weekend days. The activity decrease on weekends by Imperial Eagles and other large raptors suggests that there are weekly cycles in raptor activity. Weekly cycles in wildlife caused by human activity are a source of concern in conservation biology. Efecto del Tráfico de Fin de Semana sobre el Uso de Espacio por Rapaces Resumen: El tráfico en carreteras cercanas a las grandes urbes muestra incrementos cíclicos debidos al turismo de fin de semana, lo que podría inducir ciclos semanales en los patrones de actividad de las aves de presa. Cerca de una gran ciudad estudiamos una sección de 19 Km en una carretera que cruza una de las mejoresáreas para las rapaces de toda España. Observamos 18 especies de rapaces en elárea de estudio, incluyendo varias en peligro de extinción, como eláguila imperial ibérica (Aquila adalberti), una de las rapaces en mayor peligro de extinción del mundo. Registramos los movimientos de todas las rapaces observadas en una malla de cuadrículas UTM clasificadas como cercanas o lejanas a la carretera para estudiar si las observaciones de rapaces eran diferentes en días de semana y en fines de semana, dado que hubo un incremento muy marcado en la intensidad de tráfico los fines de semana. Comprobamos que eláguila imperial y los buitres utilizaban con menor frecuencia las inmediaciones de la carretera durante los fines de semana, restringiendo su actividad a lasáreas remotas y poco transitadas. Los cambios cíclicos en actividad humana durante los fines de semana podrían por tanto inducir también cambios cíclicos en los patrones de actividad † †Current address: Instituto de Agrobiotecnología y Recursos Naturales, Consejo Superior de Investigaciones Cientificas, Carretera Disturbance of Raptors by Road Traffic 727de especies amenazadas como eláguila imperial. Los ciclos semanales de actividad en la fauna tienen mucho interés para la biología de la conservación, ya que son consecuencia de la actividad humana.