Phenotyping tomato root developmental plasticity in response to salinity in soil rhizotrons

Plants have developed multiple strategies to respond to salt stress. In order to identify new traits related to salt tolerance, with potential breeding application, the research focus has recently been shifted to include root system architecture (RSA) and root plasticity. Using a simple but effective root phenotyping system containing soil (rhizotrons), RSA of several tomato cultivars and their response to salinity was investigated. We observed a high level of root plasticity of tomato seedlings under salt stress. The general root architecture was substantially modified in response to salt, especially with respect to position of the lateral roots in the soil. At the soil surface, where salt accumulates, lateral root emergence was most strongly inhibited. Within the set of tomato cultivars, H1015 was the most tolerant to salinity in both developmental stages studied. A significant correlation between several root traits and aboveground growth parameters was observed, highlighting a possible role for regulation of both ion content and root architecture in salt stress resilience

Evaluation of the potential index model to predict habitat suitability of forest species: the potential distribution of mountain pine (Pinus uncinata) in the Iberian peninsula

Characterization of the suitability or potentiality of a territory for forest tree species is an important source of information for forest planning and managing. In this study, we compared a relatively simple methodology to generate potential habitat distribution areas that has been traditionally used in Spain (the potential index model) with a statistical modelling approach (generalized linear model). We modelled the potential distribution of mountain pine (Pinus uncinata) in the Iberian peninsula as a working example. The potential index model generated a map of habitat suitability according to the values of an index of potentiality, whose distribution has usually divided into four categories based on quartiles (from optimum to low suitability). Considering all values of the index of potentiality as presences of mountain pine resulted in a low to moderate degree of agreement between the potential index model and the generalized linear model according to the kappa coefficient. Using the cut-off value of the index of potentiality that maximized the degree of agreement between both modelling approaches resulted in a substantial similarity between the maps of the predicted distribution of mountain pine. This cut-off value did lie in the upper-third quartile of the potential index distribution (high suitability category), and roughly coincided with the upper 30th percentile. The use of statistical techniques, which have proved to be powerful and versatile for species distribution modelling, is recommended. However, the potential index model, together with the adjustments proposed here, could be a reasonably simple methodology to predict the potential distribution of forest tree species that forest managers should take into account when evaluating forestation and afforestation projects

Implicaciones térmicas de la topografía: ensayo de un parámetro termotopográfico

In a previous paper (Gandullo, 1974), a sunshine parameter, evaluating light intensity from hill slope and terrain aspect, was developed. This paper presents a new sunshine parameter development trying to assess sunny and shady aspects from the thermic point of view, considering that the maximum daily temperatures occur between two and three hours in the afternoonEn un trabajo anterior quedó definido un parámetro "insolación" que evaluaba la luminosidad en función de la pendiente y de la orientación del terreno. Se presenta, ahora, un nuevo parámetro que pretende evaluar los mismos conceptos de solana y de umbría, pero desde un punto de vista térmico, teniendo en cuenta que las temperaturas máximas no se dan a media, sino a las dos o tres horas solares de la tarde

Análisis ecológico comparativo de los castañares de Extremadura y de la región Cántabro-Astur (España)

The chestnut (Castanea sativa Miller) forests from Extremadura and Astur-Cantabrian regions have been studied and compared in ecological terms. Parameters which discriminate significantly chestnut forests from both areas have been researched too. The study has been carried out using different multivariate techniques (PCA, DA).A partir de los datos ecológicos de los territorios ocupados por Castanea sativa Miller en las Comunidades Autónomas españolas de Extremadura, Cantabria y en el Principado de Asturias se efectúa un estudio conjunto de sus caracteres generales. Además, se buscan los parámetros que son significativamente distintos en las regiones extremeña y cántabro-astur. Mediante análisis de componentes principales y discriminantes se pone de manifiesto en qué radica, esencialmente, la diversidad de comportamiento de ambas poblaciones

Temporal and spatial variations of patches, corridors and matrix in humed soil (mallin) in the mid-west of the province of Neuquen

Los procesos naturales, como las actividades humanas, cambian los paisajes. Esta realidad no es ajena a los humedales (mallines) en Patagonia. Los mallines son importantes ecosistemas naturales que sirven como recurso forrajero para la ganadería extensiva. Los mismos representan el 4 de la superficie patagónica. Los períodos húmedos y secos modifican la dinámica hidrológica del mallín. Esto repercute en la evolución de los parches, corredores y matriz, que se agrava con la actividad antrópica. En una secuencia temporal se puede apreciar la fragmentación del hábitat: en la variación y tamaño del número de parches, su forma, conectividad y aislamiento, que entre otros factores inciden sobre numerosos procesos ecológicos. El conocimiento de la dinámica temporal y espacial de los parches, corredores y matriz entre un período húmedo y uno seco en un humedal permite la planificación del uso del recurso vegetación, ya que los patrones espaciales controlan fuertemente sus movimientos, flujos y cambios.Natural processes, like human activities, change the landscape. This re-ality is somehow related to humid soils (mallines) in Patagonia. The mallinesare important natural ecosystems that provide forage to extensive animal husbandry. They represent 4% of the Patagonic surface. The wet and dry pe-riods modify the hydrologic dynamics of the mallín, producing an effect on the evolution of patches, corridors and matrix, which worsens with the anthropic activity. In a temporal sequence, the habitat fragmentation can be observed, i.e. in the variation and size of the number of patches, their shape, connectivity and isolation, which together with other factors affect the numerous ecological processes. Knowledge of the temporal and spatial dynamics of the patches, corridors and matrix between wet and dry periods in humid soils allows for the planning of the use of the vegetation resources, since the spatial standards strongly control their movements, lows and changes.Fil: Gandullo, Ricardo J.. Universidad Nacional del Comahue; ArgentinaFil: Peña, Oscar. Universidad Nacional del Comahue; ArgentinaFil: Campo, Alicia María. Universidad Nacional del Sur. Departamento de Geografía y Turismo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentin

Behaviour of Argentinian wetland vegetation between wet and dry periods using hydrological and spectrum analysis

En este estudio se analiza el comportamiento hidrológico y espectral de un humedal (mallín) localizado en la cuenca media del río Catan Lil, en la provincia de Neuquén (Argentina), en una serie de nueve años que abarcan períodos hidrológicos secos-medios y húmedos. Los mallines son importantes ecosistemas naturales que históricamente se han utilizado como recurso forrajero para la ganadería extensiva en la Patagonia argentina. Para evaluar el comportamiento hidrológico, se caracterizaron los años teniendo en cuenta la lluvia y la nieve caída, considerando valores totales mensuales, desde 1996 hasta 2005. El análisis espectral se realizó a través de imágenes satelitales de la serie Landsat tm (path 232 row 087) de las series de años mencionadas. Del análisis resulta que existe una relación directa entre años secos o con adelantamiento de la fusión nival y la disminución de la actividad fotosintética de la vegetación respecto a períodos medios o húmedos. Esto queda reflejado en los índices obtenidos mediante el proceso digital de las imágenes.The present work analyses the hydrologic and spectrum behavior of a “Mallín” (wetland) located in the middle basin of river Catan Lil, in the province of Neuquén, Argentina, during a nine years series that include middle-dry and humid periods. “Mallines” (wetlands) are important natural ecosystems that in Patagonia Argentina have been historically used as foraging resource for extensive cattle. To evaluate hydric behavior, years were characterized taking into account fallen rain and snow level, considering monthly total rates, since 1996 until 2005. Spectrum analysis was made by Landsat Tm (path 232 row 087) satellite images of the mentioned series of years. From the analysis arouses that there is a direct relationship between years dry or with advanced nival fusion and the decrease of the photosynthesis activity of the vegetation regarding middle or wet periods. This fact is reflected on the indexes got by images digital processes.Fil: Peña, Oscar. Universidad Nacional del Comahue. Facultad de Humanidades. Departamento de Geografía; ArgentinaFil: Ostertag, Griselda. Universidad Nacional del Comahue. Facultad de Humanidades. Departamento de Geografía; ArgentinaFil: Gandullo, Ricardo J.. Universidad Nacional del Sur. Departamento de Geografía y Turismo; ArgentinaFil: Campo, Alicia María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Geografía y Turismo; Argentin

Going unnoticed for 40 years: about the presence of the exotic Suaeda paradoxa (Chenopodiaceae, Suaedoideae) in Argentina

Como parte de estudios ecológicos realizados en humedales de la Patagonia, Argentina y en el marco de estudios taxonómicos en Chenopodiaceae para América del Sur, recolectamos especímenes de Suaeda que no coincidían con las características de ninguna de las especies conocidas actualmente para la Flora Argentina. El objetivo de esta contribución es reportar por primera vez la presencia de Suaeda paradoxa para Argentina, mediante el estudio de plantas vivas y material de herbario, descripciones originales y material tipo, complementando con un mapa de distribución, fotografías, una clave y una tabla comparativa de las especies herbáceas de Suaeda en Argentina. Se discuten aspectos ecológicos y de distribución. Éste es el primer registro de S. paradoxa fuera de su rango nativo de distribución.As a part of ecologic studies conducted in wetlands of Patagonia, Argentina, and in the frame of taxonomic studies within Chenopodiaceae for South America, we collected specimens of Suaeda that did not match the features to any of the species currently known to the Flora of Argentina. The aim of this contribution is to report for the first time the presence of Suaeda paradoxa in Argentina, by the means of the study of living plants and herbarium material, original descriptions, type material, and complementing with a distribution map, photos, a diagnostic key, and a comparative table to the herbaceous species of Suaeda in Argentina. Also, some comments regarding ecological and distributional features are discussed. This is the first record of S. paradoxa outside its native distribution range.Fil: Jocou, Adriel Ian. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias. Departamento de Biología Aplicada; ArgentinaFil: Minué, Carlos Rogelio. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias. Departamento de Biología Aplicada; ArgentinaFil: Brignone, Nicolás Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Gandullo, Ricardo J.. Universidad Nacional del Comahue. Facultad de Ciencias Agrarias. Departamento de Biología Aplicada; Argentin