Beneficios ambientales de la trashumancia: la raza merina (variedad de los Montes Universales) apuesta por el medio ambiente

La trashumancia, entendida como la forma de actividad ganadera más extensiva, en la que el ganado se desplaza a través de las vías pecuarias de forma estacional de unas zonas a otras para el aprovechamiento alternativo de la diversidad de pastos en el momento óptimo de su producción (VVAA, 2013), sigue estando presente en el territorio nacional, aunque de una forma muy residual. Y es que, la cabaña ganadera trashumante se ha reducido enormemente desde el siglo pasado, debido fundamentalmente a causas sociales y económicas. Sin embargo, los movimientos trashumantes conllevan una serie de beneficios tanto de carácter histórico-cultural, por la amplia tradición pastoral existente a lo largo de la historia de España, como de carácter ambiental, a través de los denominados servicios ecosistémicos, en los cuales se ha centrado este estudio. Además, en la mayoría de las ocasiones, dichos movimientos son realizados por rebaños de razas autóctonas, como la Raza Merina (variedad de los Montes Universales), con la rentabilidad económica, social y ambiental que ello conlleva..

Vías pecuarias y recursos pascícolas en rutas trashumantes de ovino de la provincia de Huesca

La trashumancia es un sistema de producción animal que evita periodos críticos de la producción vegetal mediante movimientos estacionales del ganado, que se realizan tradicionalmente desde la zona llana hasta la montaña, al inicio de la época estival, y a la inversa al inicio del otoño. Los objetivos de este artículo fueron: (I) desarrollar una metodología de seguimiento del ganado para analizar las rutas recorridas por cuatro rebaños de ovino trashumantes entre la hoya de Huesca y el Pirineo aragonés; (II) caracterizar los tipos de viales que utilizan los rebaños durante sus desplazamientos; (III) comparar las rutas seguidas con las vías pecuarias registradas por la Administración; (IV) caracterizar los recursos pascícolas disponibles y el tiempo de permanencia del rebaño en cada tipo de pasto. Para ello, se utilizó un sistema creado ad hoc, consistente en la incorporación de un GPS comercial, modificado mediante la adición de una batería, a un collar colocado alrededor del cuello de varios animales del rebaño, y programado para registrar datos de posición cada 30 segundos para su posterior procesado mediante un sistema de información geográfica, el software QGIS. Mediante este programa informático, las rutas descritas por los rebaños se superpusieron con información cartográfica para la identificación de los viales y se intersectaron con la capa de vías pecuarias registradas por la Administración y con el mapa de pastos. Una vez obtenidos y sintetizados los resultados, se analizaron estadísticamente (test de Friedman y test de Kruskal Wallis) mediante el software SPSS. El vial más utilizado durante estas rutas fueron las pistas y las carreteras secundarias, que son las que menos trabas ponen al desplazamiento de los rebaños. Entre las longitudes de avance diarias de cada rebaño no se observaron diferencias significativas. Tres de las rutas estudiadas utilizan vías pecuarias de mayor entidad, puesto que las ovejas recorren fundamentalmente cañadas reales. En cuanto a los recursos pascícolas, el ganado transita por distintos tipos de pastos de monte, fundamentalmente “erizonales prepirenaicos”, “romerales y aliagares prepirenaicos”, “pastos con arbolado de Pinus sylvestris en masas puras y mixtas del Prepirineo” y “pastizales prepirenaicos”, aunque son reseñables también los porcentajes de tiempo sobre los barbechos y rastrojos elegidos en ocasiones para el reposo y las pernoctas del ganado. El valor pastoral (VP) promedio de cada ruta, que indica la calidad forrajera de los recursos pascícolas utilizados, no mostró diferencias significativas entre las cuatro rutas analizadas. La metodología puesta a punto proporcionó información con una alta precisión, adecuándose satisfactoriamente a los objetivos del artículo

Understanding herbivore-plant-soil feedbacks to improve grazing management on Mediterranean mountain grasslands

The surface of many European mountain grasslands is decreasing due to global change and extensive grazing stands out as a key tool for their conservation. Sound knowledge of grassland ecosystem functioning and its feedback processes is required to implement sustainable grazing management. This study aimed to understand the effect of different grazing intensities on herbivore-plant-soil feedbacks in Mediterranean mountain grasslands. We estimated spatial distribution of sheep grazing intensity using GPS technology in order to assess the effect of grazing pressure on vegetation and soil properties measured throughout the study area. Our results showed that grazing intensity ranged from 0.06 to 2.85 livestock units / ha, corresponding to a gradient of pasture utilisation rates varying from 2.38% to 45.60% of annual productivity from pasture. Increasing grazing pressure was associated with smaller relative cover and species richness of non-leguminous forbs, while the opposite trends were observed for graminoids. Forage had a greater concentration of N and smaller C:N ratio in more heavily grazed areas. Increasing grazing intensity was also associated with higher values of total soil N, NO3-, NH4+, soil organic carbon, microbial biomass C and activity of ß-glucosidase. Higher litter quality was the main factor explaining greater content of soil organic matter, which favoured both soil microbes and plant productivity. Grazing induced changes in the plant community triggered positive hervibore-plant-soil feedbacks, as they ultimately improved forage quality and productivity, which significantly influenced the pasture preference of free-ranging domestic grazers. Our work showed that grazing management aiming pasture utilisation rates of around 45% is critical in sustaining positive herbivore-plant-soil feedbacks and preserving or enhancing the whole ecosystem functioning in the Mediterranean mountain grasslands studied. © 2021 The Author

Transhumant GPS tracked sheep flocks from lowlands to highlands in Spain: grazing resources use and difficulties of walking/herding

The need for preserving walking/herding transhumance drove roads on the Iberian Peninsula hasbeen widely recognized, as they provide a wide range of ecosystem services. In spite of the decline of walkingtranshumance in Spain, some drove roads are being reactivated due mainly to the high price of lorrytransport and feeds for livestock. The objectives of this work were: (i) develop a method to track the transhumantflocks in order to know the route followed and detail the type of pastures that the sheep use during thetrip; (ii) know the main difficulties of the activity, either technical, economic or social. Collars with GPS wereinstalled around the neck of some animals of five transhumant flocks. The data provided by GPS were analyzedby a GIS and overlapped with pastures/vegetation maps. For each flock, interviews with the farmersprovided data in terms of difficulties for the activity to be continued. The method provided highly accurate dataof the routes. The main types of vegetation used by sheep and main difficulties perceived by the farmers tocontinue the activity are summarized

Estrategias de mitigación de emisiones de gases de efecto invernadero en sistemas ganaderos bovinos extensivos del sur de San Luis, Argentina. Estudio de casos

La ganadería bovina es una de las principales fuentes de emisiones antropogénicas de gases de efecto invernadero (GEI). A nivel internacional, regional y nacional existe una gran diversidad de estudios relacionados con la búsqueda de estrategias de mitigación de esos gases. El objetivo de este trabajo fue analizar el efecto de la aplicación de tecnologías estratégicas sobre las emisiones de GEI en sistemas productivos ganaderos típicos de la región sur de San Luis. Para ello se analizaron 6 casos de estudios en sus características actuales (SPA) y se plantearon y simularon dos propuestas mejoradoras de sus sistemas productivos (SPM1 y SPM2), se estimaron emisiones de CH4 por fermentación entérica y N2O de suelos gestionados. Se caracterizaron las emisiones y se realizó una comparación de emisiones de GEI de los sistemas entre sus tres estados (SPA, SPM1 y SPM2) a través de un ANOVA. Las “emisiones por ternero” fueron significativamente superiores (P<0,001) en el SPA que en los SPM1 y SPM2 emitiendo un 33% y un 36% menos de emisiones que el SPA. En el caso de las “emisiones por kg de peso vivo vendido” las emisiones fueron significativamente superiores en el SPA respecto al SPM2 emitiendo este un 25% menos. La aplicación de nuevas tecnologías no solamente disminuye las emisiones, sino que mejora la producción de esos sistemas. Por lo que, los resultados demuestran que la aplicación de prácticas de mejora en los sistemas de producción (ajuste de carga animal, reordenamiento del rodeo, manejo del pasto, sanidad animal, división de potreros) tienen un considerable potencial para mitigar las emisiones de GEI en estos sistemas. Cattle farming are one of the main sources of anthropogenic emissions of greenhouse gases (GHG). At the international, regional and national levels, there is a great diversity of studies related to the search for mitigation strategies for these gases. The objective of this work was to analyze the effect of the application of strategic technologies on GHG emissions in typical livestock production systems of the southern region of San Luis. To do this, six case studies were analyzed in their current characteristics (SPA) and two proposals were raised to improve their production systems (SPM1 and SPM2), estimating emissions by CH4 through enteric fermentation and N2O of the managed soils. The GHG emissions were characterized and comparison was made of the systems between their three states (SPA, SPM1 and SPM2) was conducted through an ANOVA. The “emissions per calf” were significantly higher (P &lt;0.001) in the SPA than in the SPM1 and SPM2, emitting 33% and 36% less emissions than the SPA. In the case of “emissions per kg of live weight sold”, emissions were significantly higher in the SPA compared to SPM2, emitting 25% less. The application of technologies not only reduce emissions but also improve the production of these systems. Therefore, the results show that the application of management practices in the production systems (animal load adjustment, herd rearrangement, pasture management, animal health, division of paddocks) have considerable potential to mitigate emissions of GHG in these systems

Multiple phosphorus acquisition strategies adopted by fine roots in low-fertility soils in Central Amazonia

This is the final version. Available from Springer Verlag via the DOI in this record.Background and aims Ancient Amazon soils are characterised by low concentrations of soil phosphorus (P). Therefore, it is hypothesised that plants may invest a substantial proportion of their resources belowground to adjust their P-uptake strategies, including root morphological, physiological (phosphatase enzyme activities) and biotic (arbuscular mycorrhizal (AM) associations) adaptations. Since these strategies are energy demanding, we hypothesise that trade-offs between morphological traits and root phosphatase exudation and symbiotic associations would occur. Specifically, we expected that plants which invest in finer roots, and therefore have greater ability to explore large soil volumes, would have a high investment in physiological adaptations such as enhanced phosphatase production. In contrast, we expected that plants with predominantly thicker roots would invest more in symbiotic associations, in which carbon is traded for P acquired from AM fungal communities. Methods We collected absorptive roots (<2 mm diameter) from a lowland Central Amazon forest near Manaus, Brazil. We measured fine root diameter, specific root length (SRL), specific root area (SRA), root tissue density (RTD), root phosphatase activity (APase) and arbuscular mycorrhizal (AM) fungi colonisation. Results Root morphological traits were related to APase activity, with higher APase activity in roots with higher SRL and SRA but lower RTD. However, the degree of AM colonisation was not related to any measured root morphological trait. Conclusions Fine absorptive roots likely benefit from having low RTD, high SRL, SRA and APase exudation to acquire P efficiently. However, because AM colonisation was not related to root morphology, we suggest that investment in multiple P-uptake strategies is required for maintaining productivity in Central Amazon forests.Natural Environment Research Council (NERC)Brazilian National Council for Scientific and Technological Development (CNPq)Australian Research Counci

Extracellular enzyme activities in tropical soils are driven by seasonal litter input

Background It is relatively unknown if and how seasonal fluctuations of tropical microbial activity affect soil nutrient availability. In tropical forests, nutrient economics are often considered to be centered around phosphorus, which might be a limiting factor to sustain crucial ecosystem processes, such as primary production and decomposition of organic material, thus in turn affecting microbial processes and associated nutrient dynamics of the forest ecosystem. Aims We investigate seasonal fluctuations in extracellular hydrolytic soil enzyme activities and soil nutrients and its relationship with precipitation and litterfall input, in a lowland tropical forest in the Central Amazon region. Methods We analyzed data obtained from monitoring microbial enzyme activity and nutrient dynamics in litter and soil and use stoichiometric enzyme theory and proportional vectors for assessing relative nutrient limitation throughout a year. Results Our results show that precipitation seasonality was driving leaf litterfall, which was subsequently synchronized with extracellular enzyme activities in soil, such that both litterfall and enzyme activities peaked during the dry season. Conclusions Our study indicates that soil extractable nutrient concentrations were positively related to microbial enzyme activities, which thus highlights the importance of soil microbial processes for nutrient cycling in this phosphorus limited ecosystem. Our results suggest that projected shifts in climate seasonality that result in longer and more pronounced dry seasons, might desynchronize seasonal patterns of aboveground nutrient input and belowground microbial activity, and thus leading to a decoupling of nutrient cycling in tropical forest ecosystems

Seasonal fluctuations of extracellular enzyme activities are related to the biogeochemical cycling of C, N and P in a tropical terra-firme forest

Extracellular enzymes (EE) play a vital role in soil nutrient cycling and thus affect terrestrial ecosystem functioning. Yet the drivers that regulate microbial activity, and therefore EE activity, remain under debate. In this study we investigate the temporal variation of soil EE in a tropical terra-firme forest. We found that EE activity peaked during the drier season in association with increased leaf litterfall, which was also reflected in negative relationships between EE activities and precipitation. Soil nutrients were weakly related to EE activities, although extractable N was related to EE activities in the top 5 cm of the soil. These results suggest that soil EE activity is synchronized with precipitation-driven substrate inputs and depends on the availability of N. Our results further indicate high investments in P acquisition, with a higher microbial N demand in the month before the onset of the drier season, shifting to higher P demand towards the end of the drier season. These seasonal fluctuations in the potential acquisition of essential resources imply dynamic shifts in microbial activity in coordination with climate seasonality and resource limitation of central-eastern Amazon forests

Relationship among research collaboration, number of documents and number of citations. A case study in Spanish computer science production in 2000-2009.

This paper analyzes the relationship among research collaboration, number of documents and number of citations of computer science research activity. It analyzes the number of documents and citations and how they vary by number of authors. They are also analyzed (according to author set cardinality) under different circumstances, that is, when documents are written in different types of collaboration, when documents are published in different document types, when documents are published in different computer science subdisciplines, and, finally, when documents are published by journals with different impact factor quartiles. To investigate the above relationships, this paper analyzes the publications listed in the Web of Science and produced by active Spanish university professors between 2000 and 2009, working in the computer science field. Analyzing all documents, we show that the highest percentage of documents are published by three authors, whereas single-authored documents account for the lowest percentage. By number of citations, there is no positive association between the author cardinality and citation impact. Statistical tests show that documents written by two authors receive more citations per document and year than documents published by more authors. In contrast, results do not show statistically significant differences between documents published by two authors and one author. The research findings suggest that international collaboration results on average in publications with higher citation rates than national and institutional collaborations. We also find differences regarding citation rates between journals and conferences, across different computer science subdisciplines and journal quartiles as expected. Finally, our impression is that the collaborative level (number of authors per document) will increase in the coming years, and documents published by three or four authors will be the trend in computer science literature