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Summary 1.A 4-year study was conducted in a Mediterranean herbaceous community in north-eastern Israel to investigate the eects of cattle grazing management on the structure and composition of the community. Understanding the eects of grazing on the dynamics of Mediterranean herbaceous communities is important in formulating rational management plans for both conservation and sustainable animal production. 2. The relationships among plant functional groups were studied in the context of inter-annual variation in rainfall. Treatments included manipulations of stocking rates (moderate, heavy and very heavy) and grazing regimes (continuous vs. seasonal), in a factorial design. 3. The herbaceous community was rich in species, with 166 species recorded at the site, of which 74% were annuals. Plant cover was dominated by 10 species that accounted for 75% of the total cover. 4. Inter-seasonal rainfall variation was a dominant factor in the expression of different grazing treatments on the structure of the plant community. Grazing eects were stronger in wet years than in dry years. 5. Paddocks under continuous grazing were higher in number of species compared with paddocks subjected to seasonal grazing, independently of grazing intensity. 6. Functional group analyses showed that reduction in cover of tall grasses was correlated with an increase in cover of prostrate annual legumes and less palatable groups such as annual and perennial thistles, crucifers and forbs. 7. Cover of functional groups composed of hemicryptophytic species was less variable (lower coecient of variation) in response to grazing treatments and interannual variation in climatic conditions compared with functional groups with annual species. 8. The persistence of the dominant species and the relatively small amplitude of change in plant cover of the functional groups suggest that the community was rather stable in spite of wide variation in grazing regimes and climatic conditions. East-Mediterranean grasslands appear to be adapted to grazing due to their long history of human association.

Global positioning systems (GPSs) enable continuous and automatic tracking of an animal's position. The value of such spatialtemporal information can be improved if the corresponding activity of the animal is known. We evaluated the potential of Lotek GPS collars to predict activity of beef cattle on extensive rangeland in 2 contrasting foraging environments. Collars were configured to record animal location at intervals of 20 minutes (United States) or 5 minutes (Israel), together with counts from 2 motion sensors. Synchronized field observations of collared cows were conducted in 1999 (United States) and in 2002 and 2003 (Israel). Grazing, traveling (without grazing), and resting activities were recorded as minutes out of 20 for each category (United States), or as a single category (Israel). For the US data, stepwise regression models of grazing, traveling, and resting time accounted for 74%-84% of the variation, on the basis of the motion sensor counts for the left-right axis and the distances between GPS fixes. Regression tree analysis of grazing time yielded a simple model (4 splits) that accounted for 85% of the variation. For the Israeli data, the misclassification rates obtained by discriminant analysis and classification tree analysis of animal activity were 14% and 12%, respectively. In both analyses, almost all grazing observations were correctly classified, but other activities were sometimes misclassified as grazing. Distance alone is a poor indicator of animal activity, but grazing, traveling, and resting activities of free-ranging cattle can be inferred with reasonable accuracy from data provided by Lotek GPS collars. Resumen Los sistemas de posicionamiento global (GPS) permiten el rastreo continuo y automá tico de la posició n de un animal. El valor de tal informació n espacial-temporal pueden ser mejorado si la actividad correspondiente del animal es conocida. Evaluamos el potencial de los collares de GPS Lotek para predecir la actividad del ganado para carne en un pastizal extensivo en dos ambientes de forrajeo contrastantes. Los collares fueron configurados para registrar la ubicació n del animal a intervalos de 20 min (US) o 5 min (Israel), junto con conteos de dos sensores de movimiento. En 1999 (US), 2001 y 2002 (Israel) se condujeron observaciones de campo sincronizadas de las vacas con collar. Se registraron actividades de apacentamiento, viaje (sin apacentamiento) y descanso en términos de minutos dedicados a cada actividad dentro del período de 20 minutos (US) o como una sola categoría (Israel). Para los datos de US, los modelos de regresió n a pasos para apacentamiento, viaje y tiempo de descanso explicaron de 74-84% de la variació n, basados en los conteos del sensor de movimiento para los ejes derecho-izquierdo y las distancias entre las determinaciones del GPS. El aná lisis de regresió n de á rbol del tiempo de apacentamiento produjo un modelo simple (cuatro divisiones) que explicaron el 85% de la variació n. Para los datos de Israel, las tasas de clasificació n erró nea obtenidas p...

Abstract. The relationship between intensity and timing of cattle grazing on changes in the size and composition of the soil seed bank were investigated in a 3‐yr study in a Mediterranean grassland in northeastern Israel. Treatments included manipulations of stocking rates and of grazing regimes, in a factorial design. The retrieved soil seed bank community was rich in species, with 133 species accounting for 80% of the 166 species recorded at the site. Within the seed bank, 89% of the species were annuals. Seed bank dynamics was analysed in terms of plant functional groups and germination strategies. In terms of total seed bank density and including all functional groups, 42% of the seeds present in the soil did not germinate under watering conditions. The dormancy level differed greatly among functional groups. The seed bank of annual legumes, crucifers, annual thistles and annual forbs had a large fraction of non‐germinated seeds and characterized areas grazed early in the growing season under high and very high grazing intensity. These functional groups were considered to have a higher potential for persistent seed banks production. In contrast, short and tall annual grasses and tall perennial grasses, that were dominant in ungrazed or moderately grazed paddocks, generally had seed banks with a very small fraction of non‐germinated seeds. Seed bank densities varied widely between grazing treatments and years. Under continuous grazing, heavy grazing pressure reduced seed bank densities of grasses and crucifers in comparison to moderate grazing. The greatest reduction on the seed bank densities resulted from heavy grazing concentrated during the seed‐set stages.

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