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Predation is an important ecological process that can significantly impact the maintenance of ecosystem services. In arctic environments, the relative ecological importance of predation is thought to be increasing due to climate change, partly because of increased productivity with rising temperatures. Therefore, understanding predator–prey interactions in arctic ecosystems is vital for the sustainable management of these northern regions. Network theory provides a framework for quantifying the structures of ecological interactions. In this study, we use dietary observations on mammalian and avian predators in a high arctic region, including isolated peninsulas on Ellesmere Island and north Greenland, to construct bipartite trophic networks. We quantify the complexity, specialization, and nested as well as modular structures of these networks and also determine if these properties varied among the peninsulas. Mammal prey remains were the dominant diet item for all predators, but there was spatial variation in diet composition among peninsulas. The predator–prey networks were less complex, had more specialized interactions, and were more nested and more modular than random expectations. However, the networks displayed only moderate levels of modularity. Predator species had less specialized interactions with prey than prey had with predators. All network properties differed among the peninsulas, which highlights that ecosystems often show complex responses to environmental characteristics. We suggest that gaining knowledge about spatial variation in the characteristics of predator–prey interactions can enhance our ability to manage ecosystems exposed to environmental perturbations, particularly in high arctic environments subject to rapid environmental change., Predation is an important ecological process that can significantly impact the maintenance of ecosystem services. In arctic environments, the relative ecological importance of predation is thought to be increasing due to climate change, partly because of increased productivity with rising temperatures. Therefore, understanding predator–prey interactions in arctic ecosystems is vital for the sustainable management of these northern regions. Network theory provides a framework for quantifying the structures of ecological interactions. In this study, we use dietary observations on mammalian and avian predators in a high arctic region, including isolated peninsulas on Ellesmere Island and north Greenland, to construct bipartite trophic networks. We quantify the complexity, specialization, and nested as well as modular structures of these networks and also determine if these properties varied among the peninsulas. Mammal prey remains were the dominant diet item for all predators, but there was spatial variation in diet composition among peninsulas. The predator–prey networks were less complex, had more specialized interactions, and were more nested and more modular than random expectations. However, the networks displayed only moderate levels of modularity. Predator species had less specialized interactions with prey than prey had with predators. All network properties differed among the peninsulas, which highlights that ecosystems often show complex responses to environmental characteristics. We suggest that gaining knowledge about spatial variation in the characteristics of predator–prey interactions can enhance our ability to manage ecosystems exposed to environmental perturbations, particularly in high arctic environments subject to rapid environmental change.

Las Islas Baleares poseen gran tradición ganadera, pero la intensificación de las producciones y la competencia del turismo por el territorio han hecho que los sistemas tradicionales basados en el pastoreo estén en riesgo de desaparecer, con las consecuencias ambientales negativas que conlleva. Para su conservación, una buena opción sería mejorar la comercialización de los productos derivados del pastoreo a través de una marca de calidad. En Mallorca existe una raza autóctona ovina “Mallorquina” cuyo manejo está basado en el aprovechamiento de los pastos. Se seleccionaron 10 explotaciones ovinas con diferentes sistemas de alimentación. Se diferenciaron 5 grupos de corderos en función del sistema de alimentación y del peso de venta: lechales-leche, recentales medianos-leche, recentales medianos-pasto, recentales medianos-concentrado y recentales grandes-concentrado. Se analizó el perfil de ácidos grasos de la grasa intramuscular del Longissimus dorsi de 10 corderos de cada grupo. No se encontraron diferencias significativas al comparar el perfil lipídico en animales de diferente peso con el mismo sistema de alimentación. Sí se encontraron diferencias significativas entre corderos del mismo peso alimentados con diferentes sistemas. El perfil más favorable para la salud se halló en los corderos alimentados en sistemas pastorales sin concentrado, The Balearic Islands have a long livestock tradition, but because of production intensification and tourism competition for territory, traditional systems based on grazing are at risk of disappearing, with negative environmental consequences. In order to preserve them, one option would be to improve the commercialization of products derived from grazing through a quality mark. In Majorca, there is an autochthonous sheep breed raised on rangeland systems. Management data from 10 farms were collected. Five groups of lambs were differentiated according to feed management and weight: suckling lambs-milk, light lambs-milk, light lambs-pasture, light lambs-concentrate and heavy lambs-concentrate. Fatty acid composition of Longissimus dorsi intramuscular fat was analyzed from 10 lambs of each group. No differences were found comparing animals with the same feed management and different weights. Significant differences were found comparing animals with similar weight and different feed management. The best lipidic profile for human health was observed in grazing lambs fed without concentrate.

En la región Mediterránea la dispersión endozoócora de semillas es una alternativa potencial para recuperar pastizales y matorrales degradados o abandonados. Los objetivos de este estudio fueron determinar si el paso a través del sistema digestivo de cabras afectó la recuperación de semillas, la germinación y emergencia de plántulas de tres leguminosas herbáceas comunes del área Mediterránea (Ornithopus compressus L., Medicago polymorpha L. y Melilotus officinalis L. Pall.). El porcentaje total de recuperación de semillas osciló entre 0,31% y 6,80%. En todas las especies las semillas recuperadas tras la ingestión presentaron una germinación significativa menor que las semillas control, con porcentajes de germinación de 26,7% a 50,0%. La emergencia de plántulas fue menor en las heces intactas que en las disgregadas. No se encontró emergencia de plántulas de las semillas de O. compressus para ninguno de los tratamientos ni tiempos de muestreo. Aunque los porcentajes de recuperación de semillas, la germinación y emergencia de plántulas fueron bajos en términos absolutos, se concluye que las semillas de M. polymorpha y M. officinalis podrían establecerse desde el estiércol y representar una alternativa potencial para recuperar áreas de pastoreo degradadas o abandonadas.

Aquest document conté originàriament altre material i/o programari només consultable a la Biblioteca de Ciència i Tecnologia., En el estudio se ha valorado la preferencia del ganado bobino, caprino y ovino además del venado cola blanca (Odocoileus Virginianus) con cuatro especies de árboles forrajeros comunes en trópico centroamericano: carbón (Acacia pennatula), guácimo (Guazuma ulmifolia), madero negro (Gliricidia sepium) y guanacaste (Enterolobium cyclocarpum). Para ello, se realizó un test de cafetería con un diseño experimental de medidas repetidas con cuatro vacas mestizas Pardo-Suizo x Brahman, con seis cabras domésticas, seis ovejas pelibuey y nueve Odocoileus virginianus en cautividad. El periodo experimental fue de siete días consecutivos con cada especie animal durante los meses de enero, febrero y marzo de 2016. En las tres espcies de ganado, la especie preferida fue la Acacia pennaturla, y en el caso del Odocileus virginianus la especie preferida fue Guazuma ulmifolia. Dados los resultados del test y sus características, Acacia pennatula parece ser la más apta para usos silvopastoriles en los pastos y fincas de la zona de Estelí, Nicaragua. Por otra parte, se recogieron datos de las comunidades y de académicos para acercarnos al estado de las poblaciones de Odocoileus virginianus en León y Estelí, Nicaragua. También se trabajó en los test de cafetería para conocer sus preferencias alimenticias y su posible competencia con el ganado de libre pastura. Los datos obtenidos muestran preferencias distintas en cuanto al ganado, y debido a la distribución de las fincas concluimos que no hay posible competencia con el ganado., The study has assessed the preference of bovine, goats and ovine cattle, and also whitetail deer (Odocoileus virginianus) livestock with four species of common fodder trees in Central American tropics: carbón (Acacia pennatula), guácimo (Guazuma ulmifolia), madero negro (Gliricidia sepium) and guanacaste (Enterolobium cyclocarpum). For this, a cafeteria test was conducted with an experimental design of repeated measures with four crossbred cows Pardo-Swiss x Brahman, with six domestic goats, six pelibuey sheeps and nine Odocoileus virginianus captives. The experimental period was of seven consecutive days with each animal species during the months of January, February and Marc 2016. Among the three species of cattle, the preferred species was Acacia pennatula, while in the case of Odocoileus virginianus the preferred species was Pithcellobiun. Given the test results and its characteristics, pennatula Acacia appears to be the most suitable for use in silvopastoral pastures and farms in the area of Esteli, Nicaragua. Additionally, community and academic data were collected to have an approach of the population status of Odocoileus virginianus in Leon and Esteli, Nicaragua. Cafeteria tests were conducted to learn about their food preferences and possible competition with free pasture livestock. The data obtained shows that this species has different feed preferences to cattle, and given the distribution of the land estates we can conclude that there is no competence issues with the livestock.

El treball que es presenta postula recuperar i utilitzar els ramats en la gestió forestal encaminada a la prevenció d’incendis en hàbitats mediterranis. L’objectiu d’aquest estudi ha estat determinar les variacions estructurals de la vegetació d’una brolla mediterrània sotmesa a pastura de cavalls i cabres, i comparar l’efecte de cada espècie animal sobre la vegetació per a disminuir el risc d’incendi. La càrrega ramadera va ser de 70 UR/ha, elevada i intensa, de quatre dies de durada. Els resultats obtinguts indiquen que tant les cabres com els cavalls són eficients en la disminució del fitovolum combustible. Les espècies més pasturades van ser la foixarda (Globularia alypum) i el bruc d’hivern (Erica multiflora). L’efecte dels cavalls va ser significativament superior sobre la mortalitat de les plantes (21 %) respecte de les cabres (10 %). Les dues espècies animals redueixen significativament l’alçària dels matolls però no es van trobar diferències entre elles. En canvi, la pastura amb cabres va mostrar una reducció més gran de superfície de capçada i del fitovolum (38 % enfront del 36 %).Paraules clau: pasturatge, vegetació arbustiva, risc d’incendi., This paper postulates the recovery and use of livestock in forest management aimed at preventing wildfires in Mediterranean habitats. The purpose of this study was to determine the structural variations of Mediterranean scrub vegetation subjected to grazing horses and goats, and to compare the effect of each animal species on vegetation with respect to the reduction of fire risk. The stocking rate was 70 UR/ha, for four days. The results indicate that both goats and horses are efficient in reducing fire hazard. The species most grazed were Globularia alypum and Erica multiflora. Horses produced a significantly higher mortality of plants (21%) than goats (10%). There were no significant differences in the reduction of plant height. On the other hand, grazing with goats led to a greater reduction of crown surface and phytovolume (38% vs 36%).Keywords: grazing, scrub, fire hazard., El trabajo que se presenta postula la recuperación y utilización de los rebaños en la gestión forestal encaminada a la prevención de incendios en hábitats mediterráneos. El objetivo de este estudio ha sido determinar las variaciones estructurales de la vegetación de un matorral mediterráneo sometido a pastoreo de caballos y cabras, y comparar el efecto de cada especie animal sobre la vegetación para la disminución del riesgo de incendio. La carga ganadera fue de 70 UR/ha, elevada e intensa, de cuatro días de duración. Los resultados obtenidos indican que tanto las cabras como los caballos son eficientes en la disminución del riesgo de incendio. Las especies más pastoreadas fueron la coronilla de fraile (Globularia alypum) y el brezo de invierno (Erica multiflora). El efecto de los caballos fue significativamente superior sobre la mortalidad de las plantas (21 %) respecto a las cabras (10 %). No se encontraron diferencias significativas en la reducción de la altura de las plantas. En cambio, el pastoreo con cabras mostró una mayor reducción de superficie de copa y del fitovolumen (38 % versus 36 %).Palabras clave: pastoreo, vegetación arbustiva, riesgo de incendio.

Land abandonment is pervasive in mountainous Europe. In the present situation of price-cost squeeze on pastoral households and general shift in the role of farming, the development of farming abandonment risk regions is generally associated with adoption of new multifunctional rural development strategies, such as farm tourism, which in the end entail less time being devoted to farming practices. We explored the effects of such developmental scheme on the preservation of semi-natural grasslands, in particular, and on the sustainability of mountain pastoralism, in general. While the effects on the preservation of semi-natural grasslands of full abandonment have been extensively explored, this is not the case of partial abandonment. Results showed that the adoption of simplified and low-cost management regimes, associated with partial abandonment and the increased adoption of part-time farming, immerses semi-natural grasslands in processes of secondary succession that undermine both their conservation and pastoral functions. This points the need for caution when endorsing multifunctional developmental schemes in farming abandonment risk regions, particularly when those imply less labor being devoted to pastoral practices. In conclusion, we stress that in farming abandonment risk regions it is possible to guarantee both viable pastoralism and diversified rural economy. However, it is necessary to implement developmental strategies that are centered on stimulating synergies between pastoralism and other economic activities, rather than promoting activities that depend on additional farmers’ polyvalence.