The effect of environmental conditions in the duration of daily grazing itineraties of small ruminants in Northeast Portugal

The production of small ruminants (sheep and goats) in Northeast Portugal is an extensive activity, mainly based on exploitation of spontaneous resources. The shepherds direct their flocks on daily grazing itineraries over different types of resources. These itineraries vary throughout the year, in both duration and locations visited. The aim of this study is to analyse the variation of the grazing circuits in relation to the environmental conditions. The time spent by flocks on each itinerary varied from 381 to 746 minutes for goat flocks, and from 300 to 921 minutes for sheep flocks, depending on the duration of daylight. Nevertheless, other environmental conditions have an important role on the pattern of grazing circuits, such as mid-day temperature and abundance of resources

L’utilisation du territoire par les petits ruminants dans la région de montagne de Trás-os-Montes, au Portugal

Dans la région de Trás-os-Montes et Alto Douro, au Nord du Portugal, l’élevage des petits ruminants est une activité profondément extensive basée sur “le pâturage de parcours”. Ce système s’appuie sur un ensemble d’itinéraires, variables en fonction de l’année, comme résultat de la distribution dans le temps et dans l’espace des différentes ressources fourragères. Dans ce travail, les parcours des troupeaux de brebis et de chèvres au cours de l’année sont analysés et comparés. Deux troupeaux ovins et deux troupeaux de chèvres ont été suivis entre mai 1999 et mai 2000. Ces troupeaux ont été suivis chaque mois, pendant toute la journée, avec un GPS (“global position system”). Le passage du troupeau par les différents types de milieux est noté (type de surface, strate de végétation, composition du faciès, etc.), en même temps que l’appareil enregistre, chaque minute, la localisation du troupeau au cours de la journée. Cette information permet de déterminer la longueur et le rythme du déplacement, les périodes de pâturage au cours de la journée et le temps de séjour sur chaque type de ressource – communauté pâturée – au cours de la journée. Les ovins et les caprins présentent des stratégies différentes d’utilisation du territoire, les premiers étant tout à fait attachés à l’activité agricole et les derniers étant profondément liés à l’espace à vocation forestière. De plus, la fonctionnalité de chaque type de ressource change en fonction du type de troupeau utilisateur des ressources, ce qui est en accord avec l’hypothèse de l’existence de stratégies différentes entre les ovins et les caprins en ce qui concerne l’utilisation du territoire. Utilisation of the land by small ruminants in the mountainous region of Trás-os-Montes in Portugal”. The production system of small ruminants (sheep and goats) in Northeast Portugal is an extensive activity, based on daily grazing itineraries. In this work, we analyse the seasonality of grazing itineraries of herds of sheep and goats, in the natural region “Terra Fria”. Between May 1999 and May 2000, every month, two herds of goats and two flocks of sheep were monitored along the grazing circuit using a hand rover GPS (global position system). Along the whole grazing circuit, vegetation types crossed by herds were noted, while GPS registered time and geographical position. The main land cover types, the vegetation structure and the composition were noted. Each grazing itinerary was determined for length, progression rhythms, foraging periods throughout the day and forage utilization of each land cover type. Our results indicated a clear and differentiated strategy of rural land use between sheep and goat herds; sheep flocks’ behaviour are markedly influenced by agricultural use of land over the year, and goat herds’ options depend on forest use of rangelands. The functionality of each land cover is different over the year, feed location, rest place or transitory situation, according to season and animal

Effect of livestock grazing on combustibles decreasing in Quercus pyrenaica woodlands

Avaliou-se a biomassa herbácea em bosques de Quercus pyrenaica em dois períodos do ano (Primavera e Outono) durante três anos consecutivos (1999, 2000 e 2001), em áreas pastoreadas e não pastoreadas. Para o efeito utilizou-se o método de corte e pesagem em quadrados de 0,25m de lado em ambos os tratamentos (10 e 9 quadrados, com e sem pastoreio, respectivamente). Este procedimento repetiu-se em quatro carvalhais (Freixedelo, Sortes, Rebordaínhos e Zido) localizados em ambientes diferentes e com estrutura distinta. Os resultados mostram diferenças de biomassa acumulada entre locais, entre períodos do ano e anos, e entre os tratamentos pastoreado e não pastoreado. Comprova-se a interacção positiva entre as componentes lenhosa e animal, condição necessária para a abordagem silvopastoril na gestão destes sistemas. The herbaceous biomass was evaluated in Quercus pyrenaica woodlands in two seasons (Spring and Autumn) for three consecutive years (1999, 2000 and 2001), both in grazed and non-grazed areas. For this, we used the method of clipping and weighing, in 0.25 m side plots in both areas (10 and 9 quadrates of grazed and non-grazed land, respectively). This procedure was repeated in four black oak woodlands (Freixedelo, Sortes, Rebordainhos and Zido), all located in different environments and with different structures. The results show differences in the accumulated biomass among the various locations, seasons, years, and among the grazed and non-grazed plots. Evidence shows the positive interaction between the wood and animal components, an essential condition for the silvopastoral approach in the management of these system

Changes on the climatic edge: adaptation of and challenges to pastoralism in montesinho (Northern Portugal)

Mountain areas are sensitive to changes in precipitation and temperature, which significantly impact traditional pastoralist communities, their economy, and their lifestyle. Alarming climate change scenarios justify the investigation of the ecological and socioeconomic vulnerabilities that characterize Portugal’s mountain regions. This work explores how the traditional production systems of small ruminants—sheep and goats—could adapt in the Montesinho mountain range as it changes over the next 2 decades. Land use–land cover maps from 1995 and 2018 show how the pastoral landscape has changed and indicate trends for a future scenario. Documented landscape grazing patterns are used to determine sheep and goat landscape preferences under different climatic conditions. Finally, we identify the near-future constraints on traditional sheep and goat systems, contrasting landscape changes with sheep and goat preferences. Over coming decades, the balance between rangelands and cultivated lands will persist in the Montesinho mountain landscape, despite some trade-offs between both. Woodlands could emerge from scrublands colonizing rangelands, and permanent crops could significantly replace arable lands in agricultural areas. Therefore, it is likely that the agricultural areas preferred for sheep, and rangelands preferred for goats, may not be affected by the forecast landscape changes, but rather be favored by the expansion of permanent crops. However, pasture areas must expand, as they are key to pastoral landscape function in a warming climate scenario. Landscape decision makers and managers should implement a landscape-monitoring system to inform policies and strategies aimed at protecting and safeguarding mountain pastoralism and its vital ecosystem services.The authors would like to thank Am^andio Carloto for his help with data collection, as well as 2 anonymous reviewers for their helpful and constructive comments and suggestions on the manuscript. This research was partially funded from Portuguese national funds, through the Foundation for Science and Technology (FCT), under the projects MTS/CAC/0028/2020: PASTOPRAXIS and UIDB/00690/2020 (FCT/MCTES to CIMO).info:eu-repo/semantics/publishedVersio

A cluster model with random anisotropy for hysteresis jumps in CeNi1−x_{1-x}Cux_{x} alloys

Some Cerium compounds exhibit hysteresis cycles with sharp macroscopic jumps in the magnetization at very low temperatures. This effect is attributed to the formation of clusters in which the anisotropy competes with the applied magnetic field. Here, we present a simple model where a lattice of ferromagnetically coupled spins is separated in clusters of random sizes and with random anisotropy. Within this model, we obtain hysteresis cycles presenting jumps that behave in a similar way that the experimental ones, and that disappear when increasing the temperature. The results are in good agreement with the hysteresis cycles measured at very low temperatures in CeNi$_{1-x}$Cu$_{x}$ and the comparison with these experimental results allows to discriminate the relative importance of the mechanisms driving the thermal evolution of the cycles.Comment: Accepted in PR

Sostenibilidad ecológica : espacios y oportunidades para un reto inaplazable

Como parte del conjunto de artículos que constituyen el tema central del presente número de Quorum, mi contribución incide sobre la sostenibilidad desde una perspectiva ecológica. Después de una primera parte de presentación de los contenidos de los artículos que siguen, se presenta un modelo para valoración multidimensional del desarrollo. El modelo consiste en un conjunto de ejes valorativos conceptualmente independientes, aunque ligados por compromisos funcionales y relaciones jerárquicas, con los que se construyen escenarios que sirven de referencia para la discusión y valoración de los procesos de desarrollo. El papel básico que reconoce para la calidad del medio natural, lo hace muy adecuado para un continente, América Latina, que destaca por su contribución a la biodiversidad del planeta. Se exponen a continuación algunas ideas sobre el concepto de integridad ecológica que inciden sobre el umbral admisible para la explotación de los recursos y algunas referencias para su estimación. Por último proponemos recomendaciones para tener en cuenta en los sobre procesos de sostenibilidad, basados en nuestra experiencia en planificación ecológica y en la cooperación universitaria en Centroamérica.As a part of the whole of papers forming the main topic of Quorums present number, my contribution deals on sustainability from an ecological perspective. Following the presentation of the main issues discussed in the papers that come afterwards, a model for development multidimensional evaluation is explained. The model consists in a conceptually independent group of evaluative axes, but related by functional trade-offs and hierarchical relationships. Scenarios useful w discuss and assess development processes can be built widí those axis. The basic role that the model recognizes for the ecosystem quality -ecological integrity-, make it as very suitable for a Continent, Latin America, that stands out for his contribution to the earth biodiversity. Following, some ideas about the ecological integrity concept and the way that it contributes to define an admissible resource exploitation threshold, are proposed. In this approach, references for the natural valué assessment are provided. Finally we suggest recommendations to bear in mind in sustainability processes. They are based both on our experience in ecological planning and the Alcalá University cooperation in Central America

Estructura ecológica de los pastos de monte turolenses : análisis de las relaciones entre los factores del medio y la vegetación en un territorio de vocación ganadera

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Biológicas, leída en 1982.Fac. de Ciencias BiológicasTRUEProQuestpu

Sostenibilidad ecológica : espacios y oportunidades para un reto inaplazable

Como parte del conjunto de artículos que constituyen el tema central del presente número de Quorum, mi contribución incide sobre la sostenibilidad desde una perspectiva ecológica. Después de una primera parte de presentación de los contenidos de los artículos que siguen, se presenta un modelo para valoración multidimensional del desarrollo. El modelo consiste en un conjunto de ejes valorativos conceptualmente independientes, aunque ligados por compromisos funcionales y relaciones jerárquicas, con los que se construyen escenarios que sirven de referencia para la discusión y valoración de los procesos de desarrollo. El papel básico que reconoce para la calidad del medio natural, lo hace muy adecuado para un continente, América Latina, que destaca por su contribución a la biodiversidad del planeta. Se exponen a continuación algunas ideas sobre el concepto de integridad ecológica que inciden sobre el umbral admisible para la explotación de los recursos y algunas referencias para su estimación. Por último proponemos recomendaciones para tener en cuenta en los sobre procesos de sostenibilidad, basados en nuestra experiencia en planificación ecológica y en la cooperación universitaria en Centroamérica.As a part of the whole of papers forming the main topic of Quorums present number, my contribution deals on sustainability from an ecological perspective. Following the presentation of the main issues discussed in the papers that come afterwards, a model for development multidimensional evaluation is explained. The model consists in a conceptually independent group of evaluative axes, but related by functional trade-offs and hierarchical relationships. Scenarios useful w discuss and assess development processes can be built widí those axis. The basic role that the model recognizes for the ecosystem quality -ecological integrity-, make it as very suitable for a Continent, Latin America, that stands out for his contribution to the earth biodiversity. Following, some ideas about the ecological integrity concept and the way that it contributes to define an admissible resource exploitation threshold, are proposed. In this approach, references for the natural valué assessment are provided. Finally we suggest recommendations to bear in mind in sustainability processes. They are based both on our experience in ecological planning and the Alcalá University cooperation in Central America

Monopentamethylcyclopentadienyl isocyanide, amine and imido tantalum(V) complexes. X-ray crystal structure of [TaCp*Cl4(CN-2,6-Me2C6H3)]

[TaCp★Cl4](Cp★ = η5-C5Me5) reacts with isocyanides and amines to give the pseudo-octahedral adducts [TaCp★Cl4L] (L = 2,6-Me2C6H3NC, 1; 2,4,6-Me3C6H2NC, 2; tBuNC, 3; or C6H5NH2, 4). Reduction of 1, or alternatively of [TaCp★Cl4] in the presence of stoichiometric amounts of isocyanide, with two equivalents of Na/Hg gives the diamagnetic pseudo-octahedral tantalum(III) complex, [TaCp★Cl2(CN-2,6-Me2C6H3)35. Reaction of 4 with two equivalents of LiNEt2 affords the pseudo-octahedral imido complex [TaCp★Cl2(NC6H5). 6. All the complexes were characterized by usual IR and NMR spectroscopic methods and the molecular structure of I was confirmed by X-ray diffraction methods

Doniach diagram for ordered, disordered and underscreened Kondo lattices

The Doniach's diagram has been originally proposed to describe the competition between the local Kondo effect and the intersite RKKY interactions in cerium compounds. Here we discuss the extension of this diagram to different variations of Kondo lattice model. We consider a) ordered cerium compounds where the competition between magnetic order and Kondo effect plays an important role, as $CeRh_2Si_2$, b) disordered cerium systems with competing spin glass phase, magnetic ordered phases and a Kondo phase, as the heavy fermion cerium alloy $CeCu_xNi_{1-x}$ and, c) uranium compounds where a coexistence between Kondo effect and ferromagnetic order has been observed, as UTe. We show that all these cases can be described by a generalized Doniach phase diagram.Comment: Presented in the Latin American Workshop on Magnetism and Magnetic Materials (LAW3M) Rio de Janeiro, Brazil, August 12-16, 2007. Proceedings to be published in JMM