Vegetation Response to Grazing Pressure in the Puna Flat, NW Argentina

Puna grasslands are located at a high‐altitude flat plateau in the Northwest of Argentina. It is an arid territory (100 to 300 mm rainfall/year) at 3,000 to 4,000 m a.s.l. The vegetation is scarce, where Andean pastoralist communities produce meat and wool, specialized in llama (Lama glama) and sheep‐breeding, although they do breed multi‐species herds that may also include goats and cattle. There are erosion processes in the Puna, where shepherds and their animals could be synergetic factors with natural very hard climatic conditions. In this work we assess the effect of ovine and lama grazing on the plant communities in the Puna grasslands. Considering that stockyards are used in a very complex way along the year, having differences between those used in winter or in summer, or used for many months or only one month, etc. we built up a Grazing Pressure Index taking in account all these factors in each sampling point. We sampled 28 paired transects (14 in sites with high grazing pressure, and 14 in sites with low grazing pressure) in 2 different ecological sites (grassy grassland and shrubby steppe). Focusing our work on the community functionality, we analysed Plant Functional Types (PTF) measuring their cover, richness and diversity. Our results do not show significant differences on PFT cover, richness or diversity between sites at different grazing pressures. It could be the result of a low grazing pressure or a long grazing pressure history that had configured the TFP associations

Modelación del Transporte Reactivo en el Salar del Pipanaco, Catamarca : Evaluación de hipotéticos escenarios de contaminación minera

El Salar del Pipanaco es una cuenca endorreica dentro de las Sierras Pampeanas de la Provincia de Catamarca. Sus recursos hídricos subterráneos están fuertemente comprometidos por importantes actividades agropecuarias dentro de la cuenca como mineras en cuencas vecinas que alimentan sus aguas subterráneas. La presencia de diques de colas mineras, y antecedentes de fugas, producto de años de explotación sobre las áreas de recarga de las aguas subterráneas, hace imperioso evaluar el alcance del impacto de hipotéticos vertidos mineros. La modelación del transporte reactivo ha sido utilizada para evaluar la migración de metales pesados (p.ej., Zn, Pb, etc.), y determinar aquellos parámetros fisicoquímicos que controlarían su movilidad y la capacidad de las aguas subterráneas para neutralizar estos vertidos ácidos. La alta alcalinidad de las mismas conjuntamente con la presencia de carbonatos jugarían un papel clave para controlar el pH, y por extensión la migración de los metales, al incrementar su retardo.Salar del Pipanaco is an endorheic sedimentary basin emplaced within the Sierras Pampeanas of the Catamarca Province. Its groundwater resources are strongly committed by important economic activities developed into the basin (e.g., the olive on the Pomán Valley along the Western flank of Sierras de Ambato), as well as other economic activities developed on the watersheds that recharge its groundwater system (mining). However, the presence of mining tailings and evidences of tailings leakage on the recharge areas make it important to evaluate both the heavy metals transport through the shallow aquifer (e.g., Zn, Pb), and those parameters that may control their mobility and the capacity of the groundwater to neutralize acid sources. The high alkalinity of the groundwater together with the mineral carbonate contents in the aquifer may play an important role to control the pH and so the metals migration downward.Universidad Nacional de La Plat

Efecto del raleo sobre el rendimiento de dos variedades de okra (Abelmoschus esculentus (L.) Moench), en el Valle de Lerma, Salta, Argentina

The purpose of this paper was to determine the effect of thethinning on fruit yield components in two okra (Abelmoschusesculentus (L) Moench) varieties. On October 20, 2008, followinga completely random design with factorial arrangement(varieties and thin) a total of 40 seeds (two per hill) of everyvariety were sown in the experimental unit. Thirty-eight dayslater they were thined, leaving a plant per hill, in each plot. Thefruits were harvested immature from December, 2008 untilMarch, 2009. The measured variables were: total weight offruits per plot during the reproductive period, fruit weight perplot per harvest, weight per fruit, total number of fruits duringreproductive period and number of fruits per harvest. Therewas a trend (P = 0,054) that the total weight and the weight perharvest were highest in the plots without thinning for bothvarieties. The thinning diminished significantly the number oftotal fruits and the number of fruits per harvest in both varieties,because the thinned plots were presenting half of the numberof plants. Finally, there was no significant effect of the thinningon the average weight of the fruit in any of the studiedvarieties.--------------------------------------------------------------------------------------------------El objetivo del presente trabajo fue determinar el efecto del raleo sobre los componentes del rendimiento en dos variedades de okra (Abelmoschus esculentus). El 20 de octubre de 2008, siguiendo un diseño completamente aleatorio con arreglo factorial (variedades y raleo) se sembró en cada unidad experimental un total de 40 semillas (dos por golpe de siembra) de la variedad correspondiente. A los 38 días, se raleó, dejando una planta por golpe de siembra, en las parcelas indicadas. Los frutos fueron cosechados inmaduros desde diciembre de 2008 hasta marzo de 2009. Las variables analizadas fueron: peso total de frutos por parcela durante todo el ciclo de producción, peso por parcela por cosecha, peso por fruto, número total de frutos durante todo el ciclo de producción y número de frutos por cosecha. Hubo una tendencia (P = 0,054) a que el peso total y el peso por cosecha sean superiores en las parcelas sin raleo para ambas variedades. El raleo disminuyó significativamente el número de frutos totales y el número de frutos por cosecha en ambas variedades, debido a que las parcelas raleadas presentaban la mitad del número de plantas. Por último, no hubo un efecto significativo del raleo sobre el peso promedio del fruto en ninguna de las variedades estudiadas

Cooperação com empresas de base tecnológica: pesquisa-ação no setor elétrico Cooperation network between technology-based enterprises: action-research in the electro-electronic sector

A pressão por inovação em empresas de base tecnológica, em ciclos cada vez mais curtos e demandando competências complexas, tem levado as empresas à busca de uma estruturação sob a forma de redes de cooperação empresarial, a fim de mitigar riscos e reduzir custos enquanto acelera o time to market. Entretanto, apesar de todas as vantagens e oportunidades reais, há grandes barreiras a serem transpostas. O objetivo dessa pesquisa é compreender o processo de estruturação de uma rede de cooperação no contexto de empresas de base tecnológica. A abordagem metodológica utilizada foi a pesquisa-ação desenvolvida em 30 empresas do setor eletroeletrônico. Os resultados apontam o temor ao comportamento oportunista como o item mais crítico à formação da rede de cooperação empresarial.<br>The pressure for short-cycle innovation in technology-based enterprises and the demand for complex competencies have led companies to focus on developing enterprise network cooperation in order to reduce risks and costs, while speeding up time to market. Despite all real advantages and chances, there are great barriers to overcome. The objective of this research is to understand the process of development of a cooperation network between technology-based enterprises. The methodology used was the action-research, which was carried out in 30 companies in the electro-electronic sector. The results indicate that fear of opportunistic behavior is the most critical factor to the development of enterprise network cooperation

People and jaguars: New insights into the role of social factors in an old conflict

Throughout its range in Latin America, the jaguar Panthera onca is threatened by habitat loss and fragmentation, and by conflict as a result of coexistence with people. This Near Threatened species is a top predator, and is often illegally hunted. Understanding people's attitudes and perceptions and the factors that could influence them is crucial for the conservation of this species. In this study we assess how knowledge, attitudes and perceptions among people in northern Argentina regarding jaguars vary depending on their level of education, age and occupation. We interviewed 810 people living in and around 10 protected areas in northern Argentina. Positive perceptions and attitudes towards the jaguar were associated with economic benefits that people may receive from the species' presence, such as income from tourism. Unexpectedly, higher levels of formal education were not associated with more positive attitudes and perceptions. Negative attitudes and perceptions towards the species were determined by fear; people see jaguars as a threat to their lives. This study shows that the socio-economic factors that affect the level of tolerance towards jaguars are not related only to economic losses. Our findings provide information for the design, implementation and evaluation of jaguar conservation projects in Argentina

Post-fire soil erosion control: using “fajinas” in a dry mountain forest (Salta, Argentina)

Los incendios forestales en bosques montañosos pueden modificar las tasas de infiltración y de escorrentía, lo cual aumenta el arrastre de sedimentos ladera abajo. Por lo tanto, es urgente diseñar e implementar técnicas de control de sedimentos en laderas incendiadas. Una metodología sencilla y económica es la construcción de fajinas (i.e., una empalizada de forma cilíndrica construida con ramas trenzadas). Nuestro objetivo fue evaluar la efectividad de colocar distintos números de fajinas (0, 2 y 3) en distintas posiciones de la laderapara controlar el arrastre de sedimentos en una ladera quemada (Serranía de Tres Cerritos, Salta-Argentina). Encontramos que a mayor número de fajinas, y ubicándolas en las partes bajas e intermedias de la ladera, el perfil de cenizas fue más profundo, lo que evidencia un mejor control del arrastre de sedimentos. Si bien el costo logístico de construir un sistema con hileras de 3 fajinas es un 50% más altoqueotro con 2 hileras de fajinas, la ganancia en el control de sedimentos al trabajar con 3 fajinas fue superior enun 64%. Recomendamos implementar un sistema con 3 (o más) fajinas para controlar el arrastre de sedimentos y la erosión del suelo en laderas quemadas en próximos eventos de incendios en bosques secos de montaña.Wildfires in mountain forests can trigger changes in rates of infiltration and runoff, increasing sediment flow downhill. Therefore, it is urgent to design and implement soil erosion control techniques on burned slopes. A simple and economic method is the construction of “fajinas” (cylindrical palisade built with braided branches). Our objective was to evaluate the effectiveness of the “fajinas” method in controlling sediment trawling on a burned slope located in the Serranía de Tres Cerritos (Salta, Argentina). We experimentally evaluated the effect of placing different numbers of “fajinas” (0, 2 and 3) and in three different positions on a burned slope (high, medium and low) on the amount of ash retained (measuring ash profile height). We found that the greater the number of “fajinas”, the deeper the ash profile was, showing a better control of sediment trawling. In addition, “fajinas” located in the lower or middle position of the slope controlled more effectively the sediment drag. Both factors acted independently. Although the cost/work of the construction of a control system with rows of 3 “fajinas” is greater (by 50%) compared to a system with only 2 rows of “fajinas”, the gain observed in the control of sediments exceeded 64% when working with 3 “fajinas”. This justifies the recommendation of implementing systems with 3 “fajinas” as to control sediment trawling and soil erosion on slopes burned in future wildfire events in dry mountain forests.Fil: Tálamo, Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Arévalo, Eliana Vanesa. Universidad Nacional de Salta. Facultad de Ciencias Naturales; ArgentinaFil: Martínez Gálvez, María Fernanda. Universidad Nacional de Salta. Facultad de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Garibaldi, Lucas Alejandro. Universidad Nacional de Rio Negro. Sede Andina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Harmann, Salomé C.. Universidad Nacional de Salta. Facultad de Ciencias Naturales; ArgentinaFil: Díaz Leguizamón, Marina A.. Universidad Nacional de Salta. Facultad de Ciencias Naturales; ArgentinaFil: Croce, Johanna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentin