Positive Changes in Regional Vegetation Cover in Patagonia Shown by MARAS Monitoring System

MARAS (Environmental monitoring of arid and semiarid lands) is a vegetation and soil monitoring system in Patagonia, a 700.000 km2 area in southern South America. Installed between 2008-2015 within INTA-Argentina and INIA-Chile national agricultural research institutes, it includes photographs, 500-point intercepts, 50-m canfield lines to detect patches, 10 land function observations and 0-10 cm soil samples in 458 ground sites. Data is centralized and freely accessible https://maras.inta.gob.ar. We analysed changes based in the first 255 reassessments made at 5-year intervals. At a regional scale significant changes (P \u3c 0.05 paired T test) were detected for: perennial vegetation cover, that was originally 42% and increased +3.1%. Plant species richness of 13.7 species/monitor increased +0.7, bare soil of 35% decreased -7.9%. Length of bare soil interpatches was 157 cm and decreased -42 cm. Land function indexes of Stability 46.2%, Infiltration 45.1% and Recycling 31.0% showed small non-significant changes (-1.3, +0.7 and +1.42 respectively). Significant changes in soils under vegetated patches were: conductivity 0.59 dS/m increased +0.49, and pH 7.3 +0.33. Organic matter was 2.0% and increased 0.35%, and sand was 73% and increased 3%. Finer soil particles decreased non-significantly. Bare soil interpatches had 1.4% organic matter and also increased 0.33%, and clay, that initially was 9.3% reduced -2.3%. The long-term ground sites provide a means to monitor slow changes in these rangelands in relation to global climatic change and regional grazing patterns. Patagonia has currently the lowest domestic stocking rates of the last century and vegetation seems to be slowly growing in perennial cover, with significant reductions in exposed bare soil, increase in biodiversity and soil organic carbon

Biología de poblaciones de Festuca gracillima

Festuca gracillima es una gramínea dominante de los "coironales" del sur de Patagonia y Tierra del Fuego. Estas comunidades desaparecen por pastoreo, a pesar de que el coirón no es preferido por los ovinos, y dán lugar por un proceso irreversible a estepas subarbustivas de baja productividad y diversidad, con suelos erosionados. Existen actualmente metodologías para evaluar disponibilidades forrajeras de gramíneas cortas y hierbas, y ajustar cargas animales. Se ignora sin embargo, si el manejo del pastoreo con estas herramientas asegura la subsistencia a largo plazo del coirón, que tiene probablemente una dinámica y tolerancia al pastoreo muy distinta. La hipótesis central fue que el pastoreo a altas cargas interfiere en la regeneración de los coironales, y de que existe un nivel de pastoreo intermedio que les permite subsistir. Se estudió la evolución de la cobertura y composición florística de las comunidades y los procesos de natalidad y mortalidad de la especie dominante a escala de poblaciones y bajo dos intensidades de pastoreo y en clausura desde 1989 hasta 1994. Se instalaron monitores fijos de tendencia para evaluar composición florística y parcelas permanentes fotográficas para evaluar mortalidad y reclutamiento de plantas. Se sembraron semillas y se registró la supervivencia de plántulas. Se analizó el banco de semiilas del suelo. Hubo una tendencia general al aumento de la cobertura vegetal en la comunidad, probablemente generado por un proceso a escala de paisaje. Las especies dominantes no se comportaron como se esperaba a partir de la teoría sucesinal, ya que con altas cargas animales el pastizal se mantuvo en un estado estable, y no se registraron las tendencias esperadas de arbustización y desaparición de coirones a esta escala. La fecundidad osciló entre 1 y 700 propágulos/m2, y fue controlada por las lluvias de octubre y noviembre. La germinación fue masiva, en el otoño, eliminando todo el banco de semillas viables en el suelo. La predación causó importantes pérdidas en esta etapa. La primera primavera es crítica en la vida de las plántulas, y la supervivencia a largo plazo osciló entre el 0 y el 5%. El crecimiento de las plántulas es muy lento, probablemente por competencia radicular, y al quinto año ninguna de ellas había florecido. A pesar de que el pastoreo no interfirió directamente en la reproducción sexual, éste parece ser un proceso lento e improbable en este ambiente. Ninguna planta se incorporó a las parcelas permanentes en forma natural por semilla en los cinco años del estudio. El número de plantas en el coironal fue controlado por activos procesos de crecimiento vegetativo y subdivisión. La mortalidad fue escasa, y no puede ser atribuida al agotamiento de recursos por pastoreo directo y repetido. Las plantas de los tratamientos pastoreados fueron más numerosas y pequeñas, y mostraron una mayor productividad y fecundidad en años favorables. Como contrapartida, sufrieron mayores tasas de mortalidad en años secos. Los coirones grandes serían reservas de meristemas, que suplantan a las semillas en la función de mantenerse en latencia en los períodos favorables. Se construyó un modelo matricial demográfico de las poblaciones. La proyección indica que la población desaparecería en el mediano plazo bajo alta carga, pero se mantendría en condiciones de carga moderada y en clausura. Bajo cargas animales moderadas la estructura poblacional sería equilibrada, con una combinación de plantas de distintos tamaños que permitirían responder a períodos favorables y subsistir en épocas de sequía. Las condiciones ambientales en primavera son críticas para la subsistencia, y las proyecciones para escenarios con diferencias de unos pocos mm de precipitación varían entre la extinción y el aumento vigoroso de los números poblacionales. El pastoreo a cargas moderadas parece ser sustentable en estos pastizales, aún en ausencia total de la reproducción sexual, pero se requieren nuevas técnicas que permitan monitorear los procesos a escala poblacional y de paisaje para hacer interpretables los cambios en la comunidad.Festuca gracillima is a tussock- forming grass in the patagonian grasslands or "coironales" in southern Santa Cruz and Tierra del Fuego. These grasses do not withstand grazing. They give way to shrub-dominated communities, with low productivity and diversity. Soil erosion is involved in this one way process. Range evaluation thechniques have been devised recently to adjust stocking rates to the forage availability, but they are based mainly in the palatable, short grasses and herbs that show different tolerances to grazing. We could not assure that F.gracillima populations managed with these methods will persist. Our main hypothesis was that grazing at high stocking rates hinders the regeneration of F. gracillima, but that a moderate grazing pressure that will allow its populations to persist. We monitored floristic composition and species cover of these communities, and birth and death rates of the populations of the dominant species under two different stocking rates, and in exclosures from 1989 to 1994. We modelled population dynamics with demographic matrix models. Point line methods were used to measure species cover. Permanent plots were photographed yearly, and survival, birth and mortality events were recorded. Seedling establishment and survival were estimated with experimental seedings. Soil samples were examined to follow soil seed bank dynamics. The grassland showed a general tendency to build up vegetation cover, driven probably by a landscape level process. Dominant species did not respond to grazing in the expected, way. Stable states were observed at high stocking rates and we did not record shrub increase tendencies. Seed production ranged between 1 and 700 seeds/m2, depending on the late spring (October -november) rainfalls. All viable seeds germinated in autumn, leaving no long term soil seed banks. Seed predation in the soil was high. Most seedlings died in the first spring. Long term survival ranged from 0 to 5%. Seedlin growth was extremely slow, probably due to root competition. Five year seedlings had not yet flowered at the end of the expecience. Even though direct effects of grazing were unimportant on the seedling survival, sexual reproduction seems to be an extremely slow and ulikely process in this grasslands. Adult plant numbers ware regulated by the vegetative growth and division of tussocks. Mortality rates were low. The tussocks did not die as a consequence of repeated defoliations. Populations of the high grazing treatment were dominated by small tussocks. These plants were extremely productive in favourable years, but showed high mortality rates in dry periods. Big tussocks are probably meristem reserves that take the place of seeds in maintaining dormancy in unfavourable periods. Matrix model projections show that the populations under high stocking rates will eventually become extinct, but those under moderate grazing and in exclosure persist. The most adequate size class distribution is attained under moderate grazing pressures, and this population structure allows the populations to take advantage of favourable years, and yet maintain big tussocks to buffer the population against changes. Spring rainfalls are critical for these grass populations. Scenarios that differ in 14 milimeters of rainfalls in this period show matrix projections that range from total extinction to a strong buildup of population numbers. Sustainable use of these grasslands seems to be possible, even though sexual reproduction is completely absent. To achieve this, new monitoring techniques of population and landscape scale processes should be incorporated to standard evaluation techniques.Fil:Oliva, Gabriel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Orla doce : a relação Imbé - Tramandaí

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Mercado de derivativos : operações estruturadas com opções de ações

Para os investidores de todo o mundo, de um modo geral, é importante investir e poupar dinheiro, pois, é de conhecimento público, ser esse fator essencial para se alcançar estabilidade financeira e consecutiva segurança no futuro. Para proteger os investidores nesses mercados imprevisíveis, foi criado o mercado de derivativos e posteriormente o mercado de opções. Entretanto, os novos investidores têm pouco conhecimento destes mercados. Sendo assim, este trabalho se propôs a apresentar as principais operações estruturadas com opções e realizar uma simulação de uma operação estruturada de venda coberta de ações da Petrobras S/A. Para alcançar estes objetivos, a pesquisa quanto a natureza foi aplicada, os objetivos foram abordados de forma descritiva e o problema abordado de forma qualitativa e quantitativa. Este trabalho, devido aos riscos inerentes ao mercado de derivativos, em especial o mercado de opções, caracteriza-se como um manual sobre o mercado de derivativo com foco no mercado de opções.For investors around the world, in general, it is important to invest and save money, as it is public knowledge that this is an essential factor in achieving financial stability and, consequently, security in the future. To protect investors in these unpredictable markets, the derivatives market and later the options market were created. However, new investors have little knowledge of these markets. Therefore, this structuring of the sale operation presents the main operations and performs a simulation of a Petrobras operation. For the objectives to be studied regarding the applied form, the objectives were achieved to seek the form selectively and to seek the problem in a selective and accessible way. This work, due to the risks inherent to the derivatives market, especially the options market, is characterized as a manual on the derivatives market with a focus on the options market

Design and Experimental Evaluation of a Route Optimisation Solution for NEMO

An important requirement for Internet protocol (IP) networks to achieve the aim of ubiquitous connectivity is network mobility (NEMO). With NEMO support we can provide Internet access from mobile platforms, such as public transportation vehicles, to normal nodes that do not need to implement any special mobility protocol. The NEMO basic support protocol has been proposed in the IETF as a first solution to this problem, but this solution has severe performance limitations. This paper presents MIRON: Mobile IPv6 route optimization for NEMO, an approach to the problem of NEMO support that overcomes the limitations of the basic solution by combining two different modes of operation: a Proxy-MR and an address delegation with built-in routing mechanisms. This paper describes the design and rationale of the solution, with an experimental validation and performance evaluation based on an implementation.Publicad

Monitoring Patagonian Rangelands: The MARAS System

Rangelands in Patagonia have been managed with a lack of regulation since the introduction of sheep in the late 1880’s. Most rangelands are under private freehold in ‘estancias’ and the rest are public and managed by small subsistence-type farmers. Natural resources of rangelands are property of the provincial states according to the Constitution, but they have no mandate or resources to monitor their condition and public support funds have not been tied to proper management. Government agencies designed in the 1990’s two range evaluation systems hat have been applied extensively but they focus on short time - scale processes to allocate forage resources at the “estancia” scale. The need of a regional monitoring system to evaluate rangeland condition and trend is slowly being recognized by governments and farmers, and scientists of Patagonia have been discussing a possible unified methodology. The system has been named MARAS and is based on Australia’s WARMS (Holm 1998) and other similar methods. Lines of point interception and frequency samplers are used to evaluate herbaceous vegetation, Camfield lines to evaluate shrubs and patches, surface sampling, and estimates of soil condition. Ground observation points would be set one per cadastral unit (about 20.000 ha) and evaluated at five-year intervals. State funding has been obtained in 2004 to put in place the first monitors, and to design a web data base that would give selective access to the information to federal, provincial, or non-governmental institutions. The main challenge of the system is to assure funding through decades in order to assess long time-scale processes. We expect that ecocertification market requirements will induce farmers to support it, and that the new trend of public funding included in a new sheep promotion law will allow the system to continue.EEA Santa CruzFil: Oliva, Gabriel Esteban. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Oliva, Gabriel Esteban. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; Argentina.Fil: Escobar, Juan Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; Argentina.Fil: Siffredi, Guillermo Lorenzo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina.Fil: Salomone, Jorge Manuel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; Argentina.Fil: Buono, Gustavo Gabriel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; Argentina

Adaptación de la escala de calidad de vida de Olson y Barnes en mujeres víctimas de violencia conyugal

En la presente investigación, se realizó la adaptación de la Escala de Calidad de Vida de Olson y Barnes, para ser utilizada en una población de mujeres víctimas de violencia conyugal con edades que fluctúan entre los 18 a 50 años del AAHH “Virgen del Buen Paso” perteneciente al distrito de San Juan de Miraflores (S.J.M) y el AAHH “Virgen de Lourdes” en el distrito de Villa María del Triunfo de Lima (V.M.T). La muestra fue no probabilística, está conformada por 151 mujeres víctimas de violencia conyugal. La escala alcanza niveles aceptables de confiabilidad y validez expresada en un Alfa de Cronbach de 0.888 para el análisis factorial se hallaron 8 factores, sin embargo se realizó una rotación para que quedara en 7 factores. Respecto al nivel total de la calidad de vida se halló que el 46.4 % de mujeres, se ubican en nivel de calidad de vida promedio hacia abajo y con respecto a las dimensiones de la Calidad de Vida, la dimensión que obtuvo puntaje más alto fue la dimensión de la religión y la dimensión que obtuvo el puntaje más bajo, fue la dimensión medios de comunicación