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The conditions faced by edge populations of a tree species may affect the architecture of individual trees. The latitudinally broad range of Salix humboldtiana Willd. encompasses tropical to cold-temperate climatic regions, with its southernmost population in central Patagonia. We expected S. humboldtiana trees from the southern-edge population to develop smaller shoots and a lower level of axis differentiation than trees of this species from a more northern population, and we expected edge trees to outperform non-edge trees when growing in a common garden at an intermediate latitude. For juvenile individuals of S. humboldtiana from edge and non-edge natural populations, the trunk diameter, height, branching angle, as well as the length, number of nodes, diameter, leaf area, and specific leaf area of the main branch and the trunk annual shoots were measured. The size and extension rates of shoots developed by trees of both origins in a common garden were also evaluated. In natural populations, the shoot leaf area and the specific leaf area were higher for the edge population than for the non-edge population. In a common garden, the shoot extension period and the length were higher for non-edge plants than for edge plants. The growth-period differences between populations in a common garden may support the hypothesis of stress adaptation in the southernmost S. humboldtiana trees.

International audience; Hard and strong transparent glass-ceramics (TGCs) can be used as cooktop plates, telescope mirrors, armor materials, and screens for smartphones and tablets. In this work, transparent glass-ceramics from the MgO-Al2O3-SiO2 (MAS) system were obtained after a refined heat-treatment protocol. The evolution in fracture toughness, KIC (Single Edge Precracked Beam), and Vickers hardness (H-V) were characterized as a function of the crystallization progress. The K-IC of the parent glass was 0.6 MPa m(1/2), whereas the TGC samples present values around 1.1 MPa m(1/2). The average glass hardness was 8.5 and PLUSMN; 0.8 GPa for loads of 0.6-5 N, whereas the H-V of the TGC samples varied from 9 to 10 GPa, for indentation loads ranging from 4.9 to 9.8 N. These results are discussed in light of our previous findings on the evolution of elastic modulus in the same glass-ceramics.

espanolEl objetivo principal de este estudio, es analizar la respuesta estructural de una embarcacion en el evento del Slamming utilizando el Metodo de Elementos Finitos en una Embarcacion tipo Small Water Area Twin Hull (SWATH). En la mencionada condicion de carga se deben cumplir con los criterios de aceptacion establecidos por una sociedad clasificadora, teniendo en cuenta las areas donde este evento incide en la estructura como lo es la cubierta de union, los pontones y demas miembros estructurales establecidos por la norma, todo esto generado por las altas cargas de presion en la estructura del buque en muy corto espacio de tiempo siendo un elemento de estudio en este tipo de embarcaciones, siempre y cuando esten dentro del rango de embarcaciones de alta velocidad. Dentro de los principales resultados de este estudio se obtuvieron las deformaciones y esfuerzos en la estructura bajo los parametros de referencia de la sociedad clasificadora. EnglishThe main objective of this study is to analyze the structural response of a boat during a slamming event using the Finite Element Method in a Small Water Area Twin Hull (SWATH) type boat. In the mentioned load condition, the acceptance criteria established by a classification society must be fulfilled, taking into account the areas where this event affects the structure such as the junction deck, the pontoons and other structural members established by the standard, all this generated by the high pressure loads in the ship's structure in a very short period of time being an element of study in this type of vessels, as long as they are within the range of high speed vessels. Among the main results of this study were the deformations and stresses in the structure obtained under the reference parameters of the classification society.

Understanding the impact of management on the dispersal potential of forest tree species is pivotal in the context of global change, given the implications of gene flow on species evolution. We aimed to determine the effect of logging on gene flow distances in two Nothofagus species from temperate Patagonian forests having high ecological relevance and wood quality. Therefore, a total of 778 individuals (mature trees and saplings) of Nothofagus alpina and N. obliqua, from a single plot managed 20 years ago (2.85 hectares), were mapped and genotyped at polymorphic nuclear microsatellite loci. Historical estimates of gene dispersal distance (based on fine-scale spatial genetic structure) and contemporary estimates of seed and pollen dispersal (based on spatially explicit mating models) were obtained. The results indicated restricted gene flow (gene distance ≤ 45 m, both pollen and seed), no selfing and significant seed and pollen immigration from trees located outside the studied plot but in the close surrounding area. The size of trees (diameter at breast height and height) was significantly associated with female and/or male fertility. The significant fine-scale spatial genetic structure was consistent with the restricted seed and pollen dispersal. Moreover, both estimates of gene dispersal (historical and contemporary) gave congruent results. This suggests that the recent history of logging within the study area has not significantly influenced on patterns of gene flow, which can be explained by the silviculture applied to the stand. The residual tree density maintained species composition, and the homogeneous spatial distribution of trees allowed the maintenance of gene dispersal. The short dispersal distance estimated for these two species has several implications both for understanding the evolution of the species and for defining management, conservation and restoration actions. Future replication of this study in other Nothofagus Patagonian forests would be helpful to validate our conclusions.

Canopy openings due to harvesting practices constitute a disturbance that changes the environmental conditions of microsites. Its impact on the relative performance of the regeneration of different tree species could also be affected by site conditions and forest structure. The objective of this study was to determine how regeneration establishment of Nothofagus mixed forests is influenced by shelterwood silvicultural system. We focused on Lanin National Reserve (Neuquen, Argentina) where this silvicultural system has been applied since the late 1980s. The microsite scale analysis (one managed forest) showed that canopy cover was a key factor conditioning Nothofagus regeneration establishment, with older and larger individuals growing in less exposed microsites. Low understory dominance and leaf litter thickness were also associated with microsites with regeneration, while successful establishment (saplings taller than 2 m) showed positive correlation with soil moisture. Variations of these patterns were observed among species reflecting their specific eco-physiological requirements. On a stand scale (two managed forests along Lacar watershed) regeneration of N. dombeyi and N. alpina showed significant correlation with site and specific basal area, while N. obliqua was correlated with total basal area. Regeneration taller than 2 m was mainly correlated with site and altitude. At both, microsite and stand scale, the relative abundance of species changed between mature trees and regeneration. In particular, for N. alpina, an abundance decrease was observed on regeneration. Our results suggest that forest management systems should diversify silvicultural practices throughout the forest landscape, to provide at each site the micro-environmental conditions required by each species in order to maintain biodiversity and forest functions.

The military ballistic protection market has reached approximately US$ 10 billion/year, and the civil market is also very significant and is steadily increasing, which drives research for new ballistic protection alternatives. Materials currently used and under development as transparent ballistic protection devices include glasses, glass–ceramics, single and polycrystalline ceramics, and polymer-composites. Glass–ceramics are a less expensive, versatile alternative to currently used transparent ceramics. Glass–ceramics are generally harder, stiffer, tougher, and stronger than glasses, and can be made transparent or opaque, according to the needs of the protective system. They can be easily shaped in simple or complex forms, are much less expensive than carbides and nitrades, and are less dense than transparent alumina or spinel. This positive combination of properties makes glass–ceramics suitable for a wide range of applications. However, for an effective development of new transparent glass–ceramics (TGC), it is vital to understand which key properties must be optimized. In this review, we compile information on the role of each material in multi-layer ballistic systems, give a brief description of ballistic impact, and the properties related to it, and discuss the development of TGC to be used as ballistic protection. Our aim is to describe the most important ballistic protection materials and to indicate the pathways that research on TGC for ballistic protection have taken. We finish by concluding that there are still several opportunities that warrant further research on this particular application of glass–ceramics. Keywords: Transparent glass–ceramic, Ballistic protection, Add-on armor

Achieving multi-million-hectare commitments from countries around the world to restore degraded lands in resilient and sustainable ways requires, among other things, huge volumes of tree planting material. Seed systems encompassing all forest reproductive material (e.g., seeds, cuttings, stakes, and wildings), are key to ensuring that sufficient planting material with a diverse range of suitable species, adapted to local conditions and capable of persisting under a changing climate, is available for restoration projects. The ideal structure of a seed system integrates five components: seed selection and innovation, seed harvesting and production, market access, supply and demand, quality control, and an enabling environment. We propose 15 indicators to evaluate these key components and trial them by assessing national seed systems in 7 Latin American countries. We conclude that the indicators enable a straightforward assessment of the strengths and weaknesses of national seed systems, thus assisting governments to identify key areas for improvement and opportunities for horizontal learning., Diversity, 13 (8), ISSN:1424-2818

This chapter deals with two emblematic species of the Argentine forests: Araucaria araucana, a conifer with a restricted distribution area and considered a living fossil, and Salix humboldtiana, a willow with a continental distribution but the only native to this country and particularly threatened in Patagonia. Each species is presented in a separate subchapter (7.1 and 7.2). For each species the main characteristics as well as natural distribution, ecology and reproductive biology are fully described. State of knowledge of the molecular genetic diversity at landscape level together with genetic variation at adaptive traits provide a general picture of the genetic structure of each species. Both are at risk of extinction due to past overexploitation, and different anthropogenic pressures currently menace their conservation. Araucaria araucana is protected under the red list of CITES, so its logging is forbidden. However, climate change, increase of habitat fragmentation and livestock pressure are threatening its persistence. Social and cultural aspects are also discussed, with particular reference to the traditional use of these species; the sacred nature of Pewen for the Mapuche Nation is highlighted. Regarding the native willow, a genetic swamping process caused by the invasion of exotic willows along the Patagonian rivers is described. They have the ability to hybridize spontaneously. Restoration, conservation and breeding strategies are related both with timber and non-timber forest products. The particular case of conservation through use in A. araucana is shown.

Nothofagus obliqua forests in Argentina extend over a wide latitudinal gradient but highly fragmented and locally restricted. The relevance of this species relies in its high wood quality and tolerance to warmer niches, as those predicted under climate change. In this chapter, we describe the species characteristics and natural distribution range as well as the natural hybridisation process that occurs frequently with other Nothofagus species. Genetic variation patterns based on neutral genetic markers (isozymes, cpDNA and microsatellites) allowed inferring past demographic changes during the Pleistocene glaciations. In addition, the level of genetic diversity was used as an indicator for conservation and for the definition of genetic zones as seed sources for breeding and restoration. Quantitative genetic variation and phenotypic plasticity measured at seeds, seedling and juvenile states on nursery and field trials gave insights about adaptation. The first steps towards breeding of roble pellin in Argentina are fully described: provenance and progeny tests and seed producing areas, both natural and cultivated ones. Intra- and interspecific-controlled crossings of N. obliqua represent a fundamental step towards the breeding of this species, and the first achievements are described.

The genus Cedrela comprises endangered and highly valuable species in the forestry sector. Based on molecular genetics, we describe the natural distribution areas, ecological niches, and current state of four Cedrela species distributed in Argentina, in order to apply proper conservation strategies, guide germplasm collection, and design suitable seed orchards. Genetic variability patterns of C. angustifolia populations are associated with the latitudinal and altitudinal gradients of distribution, as well as with its selective logging history in the Yungas Rainforest; instead, genetic patterns of C. balansae were related to the short geographic distance among their populations and the high levels of historical gene flow between them. Molecular evidence of hybrid zones between C. balansae and C. saltensis in the Yungas Rainforest is presented together with their genetic patterns of variation and geographical delimitation of their altitudinal ranges. In addition, the molecular identification was used for the specific purification of clonal seed orchards of C. balansae. In the Alto Parana Rainforest, genetic variability of C. fissilis populations was evaluated. Strategies for use and conservation of Cedrela genetic resources are discussed.

Nothofagus pumilio and N. antarctica are main components of the Andean Patagonian Temperate forests that occur along all the environmental gradients that characterize the Patagonian region. In this chapter, their main botanical features and natural ranges are presented, as well as the state of the art in genetic studies. Phylogeographic patterns based on chloroplast DNA help inferring Pleistocene refugia location and colonization pathways. Both species share haplotypes, and interspecific hybridization occurs naturally. A genetic structure analysis through genomic microsatellites shows latitudinal trends, species admixture, and contact zones. Selective logging evidences an effect on patterns of genetic diversity in N. pumilio. The definition of genetic zones contributes to the conservation and management of the genetic resources of both species. In addition, quantitative genetic variation and phenotypic plasticity are analyzed under nursery and field conditions, in juvenile morphological, phenological, physiological, and growth rhythms traits. Ecotypic variation was detected along longitudinal and altitudinal gradients of N. pumilio. Finally, the domestication and development of low intensity breeding strategies are presented, including a provenance trial network and seed production areas of N. pumilio, and progeny seed orchards of N. antarctica.

Rauli is an iconic species of the temperate sub-Antarctic forests due to its hardwood quality of pinkish tones. Because of its ecological and economic relevance, it is under conservation within national parks and being domesticated for plantation purposes. In this chapter, we present the state of the art of the species in Argentina. General features as distribution, biology and uses are firstly presented. Patterns of genetic variation at neutral markers allowed studying the legacy of the glacial ages as well as recent processes shaping the genetic structure. In addition, variation among populations at quantitative traits (phenological, physiological, morphological, architectural and growth rhythm traits) reflect the action of natural selection. Mycorrhizas and other soil fungi have strong relevance for conservation and domestication programmes, and their diversity is described. The domestication programme is dependent on seed productivity restrictions in natural stands, and the regulation of germination was studied through threshold models. The breeding strategy of rauli includes provenance and progeny tests, definition of genetic zones and seed collection areas based on genetic markers and installation of progeny seed orchards. Conservation and management of N. alpina forests in Argentina is finally discussed in the context of its over-exploitation in the past decades, conservation actions and management guidelines.

The Andean-Patagonian forests are the southernmost temperate forests in the world spreading over a thin strip at both sides of the Andes Mountains. This chapter introduces to a section of the book devoted to different species of these forests. Generalities and particularities of the Andean-Patagonian forests such as disturbs, endemisms, and drastic environmental gradients are described. The distribution patterns of forest tree species are determined by latitudinal, longitudinal, and altitudinal gradients, creating ideal models for studying processes of adaptation. Social aspects cannot be neglected; the value of conserving forest genetic resources of a highly touristic region, the overexploitation in the past, and the pressure of real estate speculation for the change of forestland use are issues that oppose each other. In addition, the claim of rights of “pueblos originarios” over natural forests gave origin to the co-management in the Lanin National Park. General concepts about the main tree species of the Andean-Patagonian forests of Argentina are presented: shared patterns in the distribution of the genetic variation, modeling of the genetic patterns by glaciations, volcanism, and wind, general state of knowledge about their genetic diversity at neutral markers, and adaptive traits. We concluded with describing the species chosen for breeding and postfire restauration initiatives.

Pewen, Araucaria araucana (Molina) K. Koch (also known as monkey puzzle tree), is a dioecious large-seeded emergent conifer endemic to the northern region of the temperate forests of Argentina and Chile. The species integrates the Araucariaceae family, with an ancient origin in the Triassic (ca. 250 My BP), being the only one among the 19 species of the taxa which lives in temperate climate Araucaria araucana is currently at risk of extinction (Farjon and Page 1999), included in the Appendix I of CITES (http://www.cites.org/eng/app/appendices. shtml) and listed in the 2012 IUCN Red List of Threatened Species (http://www. iucnredlist.org) as an endangered species. Although currently protected in both countries, the species was overexploited for its timber of extraordinary value. Its high morphic coeffcient (> 0.80) and the basic density of its wood (0.50-0.60) (CONAF 2013), appropriate for the industry, were the two main reasons for its exploitation. However, the threat is increased given its restricted distribution, slow growth and limited dispersal ability and mainly because of its poor regeneration and continued decline due to diverse anthropogenic causes, such as fres, seed harvest, overgrazing and exotic wild mammal invasions (Gallo et al. 2004a; Sanguinetti 2008; Premoli et al. 2013; Mundo et al. 2013; Tella et al. 2016). In addition, the species is recently going through a general decay expressed as foliar damage in branches and crowns, causing sometimes the death of the tree (Saavedra and Willhite 2017; Vélez et al. 2018). Pewen trees can reach a height of 50 m, a diameter of 2 m and ages of up to 1000 years (Aguilera-Betti et al. 2017). Young trees develop a pyramidal form, while matures often lose lower branches, giving the tree an umbrella-like shape with the distal part of the branches upwards oriented ("Pewen" in the Mapuche language means "the one who looks at the sky") (Fig. 7.1). It is a dioecious tree; male cones are 8-12 cm long and female cones 15-20 cm in diameter containing 120-180 seeds of 4-5 cm long (Fig. 7.1) (Gut 2008). Pewen has exceptional cultural and economic relevance (Aagesen 1998) and is considered sacred by the Mapuche Pewenche people (Herrmann 2006). The edible seed is a pine nut (locally called piñón) and has long been a major element of the diet of the Mapuche Pewenche communities living in and around its natural distribution range (Aagesen 1998). Seeds are also used to feed livestock and constitute a family income when selling and/or exchanging them for food (Herrmann 2006), also as processed products (Cortés et al. 2019). The management of seed collection performed by the Mapuche people involves sociocultural ancestral knowledge, but the economic market pressure for this non-timber forest product and the new assemblage of wild non-native seed feeders creates a novel and more complex socioeconomic and environmental scenario for conservation.

Se estudió la diferenciación altitudinal de seis poblaciones naturales argentinas de lenga (Nothofagus pumilio) del Centro Oeste de laProvincia de Chubut (42° 50´ S) distribuidas en un rango altitudinal de 500 m (1.000 a 1.500 m s.n.m.) a través de ensayos de ambientecomún en invernadero. Se ajustaron curvas individuales de crecimiento en plantines de un año utilizando la ecuación de Boltzmann(regresión no-lineal). Por medio de ANDEVA se analizó la variación inter-poblacional en diversos parámetros de las curvas ajustadas,indicadores del aumento y la fenología del proceso de crecimiento. Se probaron diferencias significativas entre las poblaciones delpiso altitudinal superior y las de los pisos altitudinales intermedio y bajo para la iniciación y la duración del periodo de crecimiento,evidenciando un tipo de variación ecotípica. Los resultados prueban la necesidad de considerar la altitud del origen de las semillas enprogramas de restauración ecológica o plantación comercial con la especie. The genetic differentiation of six natural Argentine populations of lenga (Nothofagus pumilio) from the Center West of the Province of Chubut (42 ° 50 'S) distributed in an altitudinal range of 500 m (between 1,000 and 1,500 m a.s.l.) was studied by means of common garden greenhouse trials. Individual growth curves were fitted in one-year-old seedlings using the Boltzmann equation (non-linear regression). Inter-population variation was analyzed with ANOVA in several parameters of the fitted curves, indicative of the increase and the phenology of the growth process. Significant differences were shown between the upper populations and those of the intermediate and lower altitudinal level for the initiation and duration of the growth period, evidencing an ecotypic variation. Our results point out the relevance of considering the altitude of the seed origin in programs of ecological restoration or commercial plantation with lenga. Fil: Mondino, Victor Alejandro. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Sur. Estación Experimental Agropecuaria Esquel; Argentina Fil: Pastorino, Mario Juan. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentina Fil: Gallo, Leonardo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentina

Lagunas de Epulauquen forests (36°49'S; 71°04'W) have been considered the northernmost population of Nothofagus obliqua in Argentina. Recently, however, its taxonomic status has been questioned due to its morphological, architectural and genetic distinctiveness. The convergence of migratory routes and hybridization with Nothofagus alpina are the two main hypotheses proposed to explain the distinctiveness of this population. Despite its unique characteristics, no evaluation of its putative origin has been carried out. In order to test the hypothesis of hybridization we analyzed nuclear Adh and ITS fragment sequences together with 12 nuclear microsatellites. These nuclear regions were selected based on their previously reported divergence between N. obliqua and N. alpina. The survey was conducted in 12 individuals from Lagunas de Epulauquen, and individuals from N. obliqua (8), N. alpina (1), N. macrocarpa (2), N. glauca (4) and N. leonii (2). By combining a phylogenetic analysis with a principal coordinate analysis of microsatellite data, we showed that Lagunas de Epulauquen individuals were closely related to other N. obliqua individuals, while hybridization with N. alpina was not detected. Our results indicate that hybridization processes could be discarded as the origin of the Lagunas de Epulauquen distinctiveness. The hypothesis of the convergence of two N. obliqua migratory routes at this latitude was reinforced based on detected patterns of genetic diversity. Notwithstanding, its high geographical isolation seems to be also a key evolutionary factor to explain the distinctiveness of this population. Lagunas de Epulauquen population could be therefore included within Argentinean N. obliqua domestication and conservation programs., Los bosques en Lagunas de Epulauquen (36°49'S; 71°04'O) han sido considerados como la población más septentrional de Nothofagus obliqua en Argentina. En años recientes se ha cuestionado su verdadero estatus. La convergencia de rutas migratorias y la hibridación histórica con Nothofagus alpina fueron las hipótesis planteadas como posible origen de esta distinción. A pesar de sus características particulares, no fue realizado hasta el presente un estudio sobre su origen putativo. Con el objetivo de profundizar en la hipótesis de hibridación se analizó la secuencia del gen Adh y la región ITS, junto a 12 microsatélites nucleares que habían mostrado divergencia entre N. obliqua y N. alpina en estudios anteriores. Se analizaron 12 individuos de Lagunas de Epulauquen, junto a individuos de N. obliqua (8), N. alpina (1), N. macrocarpa (2), N. glauca (4) y N. leonii (2). La combinación de estudios filogenéticos y el análisis de coordenadas principales de microsatélites mostró que los individuos de Lagunas de Epulauquen se ubican cercanos a individuos de N. obliqua de otros orígenes, sin detectarse procesos de hibridación con N. alpina. Nuestros resultados sugieren descartar los procesos de hibridación como origen de esta distinción. Se refuerza la hipótesis previa de convergencia de dos rutas migratorias con base en los patrones de diversidad genética detectados, aunque no se debe descartar el efecto de procesos actuales de aislamiento geográfico como un factor evolutivo clave. Lagunas de Epulauquen debería incluirse en los programas de domesticación y conservación de N. obliqua en Argentina.

Within-tree variation in fruit and seed production is little understood for anemophilous trees. This study contributes to identifying this variation for Nothofagus obliqua and N. nervosa by assessing the relative fruit production of reproductive shoots and patterns of filled fruit production in relation to flower position in the tree crown and along flowering shoots. Trees from a natural population (Lanin National Park, Argentina) and a cultivated orchard (Rio Azul Nature Reserve, El Bolson, Argentina) were included in the study. Flowering shoots of high branches (6 m from the ground) and low branches (2.5 m) were sampled, and shoot morphometric attributes (cupule production relative to basal stem diameter and number of leaves) and fruit filling were then evaluated. The proportion of filled fruits arising from different nodes along flowering shoots and for branches at contrasting heights in the crown were quantified. Morphometric attributes were similar for flowering shoots from low and high branches. In N. obliqua, fruit filling was greater in low than high branches, and did not vary with flower position along the flowering shoot. In N. nervosa, fruit filling was unaffected by branch height and tended to decrease as cupule position approached the distal end of the flowering shoot. Pollen limitation could be the main factor affecting fruit filling in N. obliqua, since the lack of relationship between shoot morphological traits and fruit filling does not suggest resource limitations. In N. nervosa, the decline of fruit filling from proximal to distal cupules within the flowering shoots could reflect resource pre-emption by proximal cupules and/or better conditions for pollination in this position. The greater distance between staminate and pistillate flowers along flowering shoots in N. nervosa than in N. obliqua is probably a major factor in explaining the between-species differences found in this study.

The Patagonian region is characterized by a complex biogeographic history, with evidence of deep phylogeographic breaks shared among species. Of particular interest to conservation is the nature of colonization and settlement patterns after the last glacial period, including the detection of secondary contact between different lineages and/or hybridization among related species around phylogeographic breaks. Here we studied population demography and past hybridization of two widespread tree species endemic to South America, Nothofagus pumilio and N. antarctica.Using 8 nuclear microsatellites we genotyped 41 populations of both species. Genetic variation and structure across the geographic region were evaluated within and among species and the past demographic history of hybridization between the two species was inferred using Approximate Bayesian Computation (ABC).Northern and southern lineages were identified in each species, and Bayesian clustering revealed their convergence at mid latitudes (42°S). Spatial genetic structure (SGS) also indicated the existence of a genetic discontinuity at these latitudes, which is in agreement with previous data from maternal DNA markers. Several populations around 42-44°S presented high levels of genetic diversity with a decrease toward southern populations. Even though the species are clearly differentiated (G'ST=0.335), admixed gene pools were observed in both species. Two independent runs of ABC suggested that inter species admixture-like patterns occurred within the timescale of the Last Glacial Maximum (around 20,000 BP). We also provide evidences of recent and bi-directional hybridization/introgression between the two Nothofagus species and describe features of the populations demography in the past. The settlement of a secondary contact zone in Nothofagus species around 42-44°S coincides with the phylogeographic breaks and hotspots of genetic diversity found in other plant and animal species in Patagonia, highlighting its importance as reservoir of diversity. The characterization of the population history of native species can contribute substantially to long-term conservation and management policies. Fil: Soliani, Carolina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina Fil: Tsuda, Yoshiaki. Uppsala University; Suecia Fil: Bagnoli, Francesca. Consiglio Nazionale delle Ricerche; Italia Fil: Gallo, Leonardo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: Vendramin, Giovanni G.. Consiglio Nazionale delle Ricerche; Italia Fil: Marchelli, Paula. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

The crystal nucleation ( I ) and growth ( U ) rates of Na 2 O·2CaO·3SiO 2 glasses with increasing additions of Li 2 O were measured for the primary crystalline phase over wide and overlapping temperature intervals. A partial section of the phase diagram Na 2 O·2CaO·3SiO 2 –Li 2 O was constructed via DSC analysis and shows a narrow range of solid solution formation that is close to that of Na 2 O·2CaO·3SiO 2 . In the four-component system (Na 2 O–Li 2 O–CaO–SiO 2 ), a pseudo-binary eutectic system of Na 2 O·2CaO·3SiO 2 –Li 2 O·SiO 2 exists. The role of Li 2 O in the formation of the crystalline phases was investigated using DSC and X-ray analyses. The addition of Li 2 O results in decreases in the glass transition ( T g ) and liquidus ( T L ) temperatures. With increasing Li 2 O content, both the reduced glass transition temperature T gr ( T gr = T g / T L ) and the fragility index, m , pass through a minimum. These findings extend and confirm the known inverse correlation between T gr and I max (lower values of T gr correspond to higher values of I max ) and provide evidence for a similar correlation between m and I max . When using the low temperature data for the crystal growth rate ( U ) the viscosity (η) and diffusivity ( D ) were decoupled at T T g . Next, a parameter ( U ·η at T g ) that characterized the decoupling phenomenon was proposed.

O substrato de nanofios (MnM) é uma nova tecnologia de interposers visando aplicações em ondas-mm que vêm recebendo atenção devido à facilidade de se fabricar vias de interconexão e estruturas de onda lenta de alto desempenho com resultados no estado-da-arte. Entretanto, embora as estruturas de interconexão, como vias e linhas de transmissão, já estejam bem definidas, ainda não se verificou a viabilidade de se usar essa tecnologia como base para antenas planares, uma parte vital de qualquer aplicação de transmissão de dados sem fio. Esse trabalho visa preencher essa lacuna, apresentando métodos para se realizar a caracterização elétrica do substrato através da extração de sua constante dielétrica relativa e tangente de perdas, e para se projetar antenas de uso frequente em aplicações de ondas-mm através de softwares de simulação eletromagnética. Esse trabalho apresenta também as etapas de fabricação da tecnologia numa visão geral e aplicada às estruturas desenvolvidas, seguida da caracterização das estruturas até 110 GHz. Os resultados mostraram um substrato com constante dielétrica relativa de 7 ± 0,2 e com tangente de perdas de 0,03 ± 0,005. Simulações das antenas projetadas mostraram que o substrato MnM é um candidato viável para antenas do tipo end-fire, cuja irradiação acontece paralela ao plano do substrato, devido ao fato dos parâmetros do substrato não interferirem demasiadamente na eficiência de irradiação desse tipo de antena. Entretanto, as simulações também mostraram que esse substrato é um candidato ruim para antenas tipo back-fire, com irradiação perpendicular ao plano do substrato, devido às baixas figuras de eficiência de irradiação e ganho. The nanowire substrate (MnM) is a novel interposer technology for mm-waves applications that has been receiving more and more attention thanks to the ease of fabricating high performance interconnection vias and slow-wave structures, whose results are in the state-of-the-art. However, even though the interconnection structures, such as transmission lines and vias, are already well-defined, no one has analyzed the potential of the MnM substrate as a planar antenna substrate, a core component of any wireless communications application. This work aims to fill this gap by presenting substrate characterization methods, that involves determining its dielectric constant and loss tangent, and by presenting planar antenna design methods using electromagnetic simulation softwares. This work presents also a general overview of the manufacturing processes being developed, followed by structure measurement up until 110 GHz. The results showed a substrate with a dielectric constant of 7 ± 0.2 and with a loss tangent of 0.03 ± 0.005. Simulations of the designed antennas indicated that this substrate is a viable choice for end-fire antennas, whose radiation is parallel to the plane of the substrate, because the substrate parameters doesn\'t seem to degrade the radiation efficiency of this kind of antenna. However, simulations also showed that the MnM substrate is a poor candidate for back-fire antennas, whose radiation is perpendicular to the plane of the substrate, given the low figures of radiation efficiency and gain.

We investigated the impact of past changes in habitat suitability on the current patterns of genetic diversity of two southern beeches (Nothofagus nervosa and Nothofagus obliqua) in their eastern fragmented range in Patagonian Argentina, and model likely future threats to their population genetic structure. Our goal was to develop a spatially-explicit strategy for guiding conservation and management interventions in light of climate change. We combined suitability modelling under current, past (Last Glacial Maximum ~ 21,000 bp), and future (2050s) climatic conditions with genetic characterization data based on chloroplast DNA, isozymes, and microsatellites. We show the complementary usefulness of the distribution of chloroplast haplotypes and locally common allelic richness calculated from microsatellite data for identifying the locations of putative glacial refugia. Our findings suggest that contemporary hotspots of genetic diversity correspond to convergence zones of different expansion routes, most likely as a consequence of admixture processes. Future suitability predictions suggest that climate change might differentially affect both species. All genetically most diverse populations of N. nervosa and several of N. obliqua are located in areas that may be most severely impacted by climate change, calling for forward-looking conservation interventions. We propose a practical spatially- explicit strategy to target conservation interventions distinguishing priority populations for (1) in situ conservation (hotspots of genetic diversity likely to remain suitable under climate change), (2) ex situ conservation in areas where high genetic diversity overlaps with high likelihood of drastic climate change, (3) vulnerable populations (areas expected to be negatively affected by climate change), and (4) potential expansion areas under climate change. Fil: Marchelli, Paula. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Thomas, E.. Bioversity International; Perú Fil: Azpilicueta, María Marta. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: Zonneveld, M. van. Bioversity International; Costa Rica Fil: Gallo, L.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina

International audience; Glass-ceramics (GC) generally possess enhanced mechanical properties compared to their parent glasses. The knowledge of how crystallization evolves and affects the mechanical properties with increasing temperature is essential to optimize the design of the crystallization cycle. In this study, we crystallized a glass of the MgO-Al2O3-SiO2 system with nucleating agents TiO2 and ZrO2. The crystallization cycle comprised a 48 hour nucleation treatment at the glass-transition temperature followed by a 10 hour growth step at a higher temperature. During this cycle, the evolution of crystalline phases was followed by high-temperature X-ray diffraction (HTXRD), which revealed the presence of karooite (MgO2TiO(2)), spinel (MgOAl2O3), rutile (TiO2), sillimanite (Al2O3SiO2), and sapphirine (4MgO5Al(2)O(3)2SiO(2)). The same heat treatment was applied for in situ measurement of elastic properties: elastic modulus, E, shear modulus, G, and Poisson's ratio, . The evolution of these parameters during the heating path from room temperature to the final crystallization temperature and during the nucleation and the crystallization plateaus is discussed. E and G evolve significantly in the first two hours of the growth step. At the end of the crystallization process, the elastic and shear moduli of the GC were approximately 20% larger than those of the parent glass.

Habitat fragmentation might significantly affect mating and pollen dispersal patterns in plant populations, contributing to the decline of remnant populations. However, wind-pollinated species are able to disperse pollen at longer distances after opening of the canopy. Our objectives were to characterize the mating system parameters and to estimate the average distance of effective pollen dispersal in the wind- pollinated conifer Austrocedrus chilensis. We sampled 19 "mother trees," 200 progeny, and 81 additional adults (both male and female), in a fragmented population at the Argentinean Patagonian steppe. We registered the spatial po- sitions of individuals and genotyped all samples with five microsatellite markers. We found a high genetic diversity, a moderated rate of biparental inbreeding (tmts=0.105), and a complete absence of correlated paternity (rp=−0.015). The effective number of pollen donors contributing to a single mother (Nep) was 13.9. Applying TWOGENER,weestimated a low but significant differentiation among the inferred pollen pools (ΦFT=0.036,p=0.001) and a very large average pollen dispersal distance (d=1,032.3 m). The leptokurtic distribution (b=0.18) presumes a potential for even larger dispersal dis- tances. The high genetic diversity, the mating patterns, and the extensive pollen dispersal presume that habitat fragmentation did not have a negative impact on pollen movement in this population of A. chilensis. Genetic connectivity among fragmented populations scattered in the Patagonian region is possible, and we stress the need of management policies at the landscape level.

International audience; Using next-generation sequencing, we developed the first whole-genome resources for two hybridizing Nothofagus species of the Patagonian forests that crucially lack genomic data, despite their ecological and industrial value. A de novo assembly strategy combining base quality control and optimization of the putative chloroplast gene map yielded ~32 000 contigs from 43% of the reads produced. With 12.5% of assembled reads, we covered ~96% of the chloroplast genome and ~70% of the mitochondrial gene content, providing functional and structural annotations for 112 and 52 genes, respectively. Functional annotation was possible on 15% of the contigs, with ~1750 potentially novel nuclear genes identified for Nothofagus species. We estimated that the new resources (13.41 Mb in total) included ~4000 gene regions representing ~6.5% of the expected genic partition of the genome, the remaining contigs potentially being nongenic DNA. A high-quality single nucleotide polymorphisms resource was developed by comparing various filtering methods, and preliminary results indicate a strong conservation of cpDNA genomes in contrast to numerous exclusive nuclear polymorphisms in both species. Finally, we characterized 2274 potential simple sequence repeat (SSR) loci, designed primers for 769 of them and validated nine of 29 loci in 42 individuals per species. Nothofagus obliqua had more alleles (4.89) on average than N. nervosa (2.89), 8 SSRs were efficient to discriminate species, and three were successfully transferred in three other Nothofagus species. These resources will greatly help for future inferences of demographic, adaptive and hybridizing events in Nothofagus species, and for conserving and managing natural populations.

Development of appropriate forest conservation and management measures for a given tree species includes the identification of distinct genetically homogeneous units across its overall distribution range, which depends on the availability of knowledge on genetic, morphological and adaptive variation. This has important implications for germplasm transfer within and between areas, for example in reforestation or restoration activities. Genetic zones are defined as genetically more or less homogeneous regions within which propagation material can be transferred with relative certainty not to cause changes at the genetic structure level. The main goal of this study was to define genetic zones for Nothofagus nervosa and Nothofagus obliqua within their Argentinean natural distribution range. A total of 823 individuals belonging to 24 populations (14 of N. nervosa and 10 of N. obliqua, μ= 34 ± 5) were genotyped by means of seven nuclear microsatellite markers. The geographic clustering encountered through the application of a Bayesian approach was analysed in combination with additional information on diversity parameters, chloroplast DNA and isozymes. For assembling the maps showing the distribution of clusters, we averaged cluster membership values of trees in each grid cell. This allowed us to distinguish five genetic zones for N. nervosa and three for N. nervosa. The identified genetic zones were consistent with the management history of the species, and display a certain level of geographic congruence. To visualize geographical patterns in nSRR richness and the distribution of different clusters of both species, we carried out grid-based spatial analyses using 30 seconds grid cells (~1 km at the equator) as the unit of analyses. We observed higher allelic richness values in the surroundings of areas identified as potential glacial refuges, which suggest that the distribution pattern of allelic richness is closely associated with the glacial history of the species within the region. We expect this information to constitute a valuable tool for the identification of seed transfer zones, and to guide recruitment and plantation activities in the context of domestication programs of both species in Argentina. For migration assisted programs under progressive climate change the identification of these zones together with knowledge concerning hotspots at genetic diversity level should constitute an input for planning the activities. Fil: Azpilicueta, María Marta. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: Gallo, L. A.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: van Zonneveld, M.. Bioversity International. Regional Office for the Americas; Colombia Fil: Thomas, E.. Bioversity International. Regional Office for the Americas; Colombia Fil: Moreno, Angela Carolina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Marchelli, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina

Our study aims to determine the dynamic that led to the spread of exotic Salicaceae on the Limay River floodplain and its implications in shaping the current neoecosystem. We used images obtained by the HRG sensor on board the SPOT-5 satellite. We selected two images dates allowed a comparison of the floodplain under different flooding regimes programmed by the Interjuridiccional Basin Authority, at a rate of 1290 m3/s in Spring and a flow rate of less than 400 m3/s in Summer. To characterize the vegetation cover, the Normalized Difference Vegetation Index (NDVI) was used to compare images of September and December, also the Normalized Difference Water Index (NDWI) was applied to delineate the riverbed and floodplain in September. To evaluate the influence of flooding regime on the detected patches a Principal Component Analysis (PCA), was performed; and biotic and abiotic factors on the composition of the dominant tree species in each patch by Multiple Factor Analysis (MFA) were analized. A 58.4 % coverage of forest patches had developed on the Limay River floodplain. Patches of older trees grew on surfaces at 1.5 m above the water level. However, the surfaces not reached by floods >1.5 m have a very low rocky coverage (1 %). The analysis of the age of the trees downstream of the dam system showed that the vegetation, often exposed to high floods before the dams were built (1971), was composed of the native willow (Salix humboldtiana) and the exotic Salix alba. As the river regime was attenuated and extraordinary floods disappeared with the operation of the dam Arroyito in 1980, the first patches of Populus nigra spread. Fil: Datri, Leonardo Ariel. Universidad Nacional del Comahue. Facultad de Cs.del Ambiente y la Salud; Argentina Fil: Faggi, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentina. Universidad de Flores; Argentina Fil: Gallo, Leonardo Ariel. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: Carmona, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires; Argentina

Knowledge of the impact of forest management practices is crucial to allow the use of natural resources while ensuring the sustainability of genetic variation, which is essential for the potential adaptive capacity of forests. The main objective of this work was to study the effects of a seed cut on the genetic diversity of a mixed Nothofagus forest in northwestern Andean Patagonia. Silviculture based on the shelterwood system was carried out in stands composed of Nothofagus dombeyi , Nothofagus nervosa and Nothofagus obliqua , located in Lanin Natural Reserve (Neuquen province, Argentina). Through intensive sampling of pre (mature trees) and post (regeneration) harvest populations of all three species from a 3-ha plot established after 20 years of the silvicultural intervention, in combination with microsatellite genotyping (more than 2000 individuals with 15 markers), we determined that modification of relative abundance of species in the post-harvest population that followed the implemented management had altered the global genetic diversity of the mixed forest; however, no impact was detected at species level in the entire plot or in two subplots with different species proportions. Pollen and seed dispersal from the surrounding areas may have contributed significantly to maintaining both genetic diversity in the post-harvest natural regeneration and the low differentiation between this and the pre-harvest gene pool in all species. The use of species-specific markers allowed us to determine that the level of introgressive hybridization was not changed by management; however, further studies are required to evaluate whether this practice influences the directionality of introgression.

Extensive knowledge of the ecological and genetic consequences of implementing management practices (i.e. logging) in natural ecosystems is of fundamental importance to conservation action. Accordingly, characterization of forest genetic resources in managed vs non-managed stands may inform management decisions to ensure the long-term persistence of genetic diversity. The main objective of this study was to evaluate the impact of management practices on the genetic diversity and spatial genetic structure of contrasting forests, through an age-class sampling design and the use of microsatellite markers. We evaluated the impact of logging in three populations of Nothofagus pumilio, a dominant tree species in Patagonian temperate forests, by comparing managed and non-managed stands in each population. Selective extraction of best-featured individuals, i.e. those with forestry aptitude, such as higher trees with straight trunks and good sanitary conditions, was performed between 1990 and 2004. One of the studied sites was located in a state-protected area while the others were on private land affected by grazing. At each managed stand over-mature trees (MF-O), adult remnant trees (MF-A) and seedlings representing forest regeneration (MF-R) after silvicultural management were sampled. In non-managed stands age classes were restricted to adults (CF-A) and seedlings (CF-R). A minimum of 30 individuals per age class were collected, totalling 454 samples which were genotyped at six microsatellite loci. Non-significant differences in genetic diversity were found between managed and natural woods in all populations. A trend towards decreasing frequencies or even allele loss among remnant adults of logged stands can however be interpreted as a sign of impact, probably a consequence of genetic drift. Each site showed particular, different outcomes with respect to genetic structure. While in Pop 1 (Huemules, 42°S) significant genetic differentiation was found between management treatments, admixture of genetic clusters (Bayesian clustering and DAPC analysis) occurred in Pop 2 (Guacho Lake, 43°S) and no genetic structure was found in Pop 3 (Engaño Lake, 43°S). Post-harvest genetic contact between contrasting stands is likely. A Landscape Interpolation Analysis showed clusters of individuals (shared genotypes) spatially restricted for managed stands (significant in Pop 3), whereas a random spatial distribution characterized control forests. Therefore, it is possible that management affected and disrupted the genetic structure. The different genetic patterns revealed for each population call for site-by-site interpretation. Differential intensity and frequency of management practices, presence/absence of livestock in the forest, and evolutionary history may all have had combined effect on current genetic diversity. Fil: Soliani, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: Vendramin, Giovanni G.. Institute of Biosciences and Bioresources; Italia Fil: Gallo, Leonardo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: Marchelli, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina

Cedrela lilloi C. DC. (cedro coya, Meliaceae), an important south American timber species, has been historically overexploited through selective logging in Argentine Yungas Rainforest. Management and conservation programs of the species require knowledge of its genetic variation patterns; however, no information is available. Molecular genetic variability of the species was characterized to identify high-priority populations for conservation and domestication purposes. Fourteen native populations (160 individuals) along a latitudinal gradient and with different logging's intensities were assessed by 293 polymorphic AFLP (amplified fragment length polymorphism) markers. Genetic diversity was low (Ht = 0.135), according to marginal location of the species in Argentina. Most of the diversity was distributed within populations (87%). Northern populations showed significant higher genetic diversity (R(2)= 0.69) that agreed with latitudinal pattern of distribution of taxonomic diversity in the Yungas. Three clusters were identified by Bayesian analysis in correspondence with northern, central, and southern Yungas. An analysis of molecular variance (AMOVA) revealed significant genetic differences among latitudinal clusters even when logging (Φ(RT) = 0.07) and unlogging populations (Φ(PT) = 0.10) were separately analyzed. Loss of genetic diversity with increasing logging intensity was observed between neighboring populations with different disturbance (Φ(PT) = 0.03-0.10). Bottlenecks in disturbed populations are suggested as the main cause. Our results emphasize both: the necessity of maintaining the genetic diversity in protected areas that appear as possible long-term refuges of the species; and to rescue for the national system of protected areas some high genetic diversity populations that are on private fields.

The mating system (outcrossing, selfing, and biparental inbreeding) and the extent of pollen flow are two of the most important genetic features that determine the genetic structure of plant populations, and both are crucial for the design of conservation strategies. The objectives here were to estimate mating system parameters and to fit the pollen dispersal kernel for the southern beech, Nothofagus nervosa. We sampled 25 mothers and 372 progeny from two stands in the Tromen Lake region of Argentina. We registered spatial positions of the maternal trees, and genotyped mothers and offspring for five simple sequence repeat markers.

The rear edges of tree species have begun to be perceived as highly valuable for genetic resources conservation and management. In view of expected climatic changes, the responses of trees at their xeric limits may largely be determined by their capacity to cope with augmented environmental variance.We assess the heritability of early survival of Patagonian cypress in two common-garden field tests with contrasting summer water deficits, comprising 140 and 163 open-pollinated families from 10 marginal xeric populations. The first experiment underwent less rigorous conditions than the average mesic, Mediterranean climatic conditions, which were sufficient to reveal additive genetic effects of summer drought on seedling survival. The second trial suffered strong summer water-deficit stress and a winter extreme cold event. In this harsher environment, the heritabilities of survival under summer water-deficit stress were high in all the populations (h200.84 on average), while the heritabilities of seasonal, extreme cold survival were moderate or even nil (h200.28 on average). We did not find evidence of genetic differentiation among populations in their capabilities to survive droughts and cold extremes. Our results indicate that even when climatic changes were strong enough to cause the extinction of the most threatened populations, heritable variation for traits underlying drought and cold tolerances may allow the marginal xeric edge of cypress to persist under augmented environmental variance, without losing overall genetic diversity. Estación Experimental Agropecuaria Bariloche Fil: Aparicio, Alejandro Gabriel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área de Recursos Forestales. Grupo de Genética Ecológica y Mejoramiento Forestal; Argentina Fil: Zuki, Sebastián Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Pastorino, Mario Juan. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina Fil: Martinez Meier, Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área de Recursos Forestales. Grupo de Ecología Forestal; Argentina Fil: Gallo, Leonardo Ariel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área de Recursos Forestales. Grupo de Genética Ecológica y Mejoramiento Forestal; Argentina

In phylogenetically related plant species, hybridization can influence their current genetic structure. Long-lasting hybridization may be related to persistence in shared glacial refugia, where the differential abilities of each species to survive could have provided adaptations to changing environmental conditions. In temperate South American forests at the Patagonia region, the pattern of Quaternary glaciations offered several opportunities for refuge. At mid-latitudes (42° to 44° S), particular topographic characteristics determined different glaciation patterns, defining the existence of a transitional zone. We studied two widespread Nothofagus species (Nothofagus pumilio, Nothofagus antarctica) characterized by contrasting plasticity. We screened 40 coupled populations with three cpDNA markers and found 14 different haplotypes. Both species presented significant phylogeographic structure (N ST ≥ G ST, p > 0.001), with two geographically segregated lineages (north–south). A latitudinal cline in the distribution of genetic diversity was determined, with most variable populations in the north (35°–41° S). Population diversity diminished to southern latitudes, but a particular situation occurs between 42°S and 44°S. The transition zone, a putative refuge area, presented unique haplotypes. The more plastic species, N. antarctica, probably persisted in more refuge areas, which could be reflected in its higher levels of diversity. In these species, sympatric distribution explains introgression (IG > IG e), but the differential levels of haplotype sharing between N. pumilio and N. antarctica at population level are relevant to the understanding of phylogeographic patterns. Hybridization may have facilitated recruitment in the onset of postglacial colonization by middle to long-distance pollen dispersal. In the current scenario of climate change, the presence of hybrids with different plastic responses is of remarkable importance.

The study of the genetic variation of early height growth traits in seedlings helps to predict the possible outcomes of tree populations in the face of climate change. Second-year height growth of 10 geographically marginal populations of Patagonian cypress (Austrocedrus chilensis (D. Don) Pic. Ser. et Bizzarri) (Cupressaceae) was characterized under greenhouse conditions. Variation among and within an average of 15 open-pollinated families (comprising 21 seedlings per family) for each population was analysed for six size and timing traits obtained from fitted Boltzmann growth curves. The among-family and among-population variances were 4.03% and 2.74% of the total phenotypic variation, while the residual variance was 84.57% on average. Genetic differentiation among populations was low, except for the maximum growth rate (QST = 0.35) and for growth initiation (QST = 1). For most traits, genetic variation and heritability were variable across populations, except for growth initiation, which showed in general null intra-population levels of genetic variance. Although no direct associations were found between the additive genetic variation and latitude or altitude, the north range of the distribution was more variable for the pool of the analysed traits. Although most extreme-marginal populations of A. chilensis would be very limited in their ability to evolve if climate in north-west Patagonia turns drier and warmer, their long-term persistence could largely rely on a phenotypic diversification strategy.

The significant mortality of the Austrocedrus chilensis (D. Don) Pic. Serm. et Bizarri forests, locally known as “Mal del Cipres”, has been reported since 1945 for most sites across its distribution in Argentina. However, the cause of this decline is still a topic of discussion. In this study, radial growth patterns from symptomatic and asymptomatic A. chilensis trees were analyzed to determine the influence of drought events on tree growth. Fifty pairs of symptomatic and asymptomatic trees with similar DBH, competition, and microsite conditions were cored at five pure A. chilensis stands near El Bolson, Rio Negro, Argentina. A reference chronology from nonaffected trees was used to cross-date all cores and to determine the relationship between A. chilensis radial growth and climate. The growth of A. chilensis is favored by above average precipitation in late spring–early summer (November and December). A strong relationship was also observed between radial growth patterns and the Palmer drought severity index, a measure of the regional water deficit. Significant differences in growth patterns were recorded between symptomatic and asymptomatic trees. Following extreme drought events, the growth of symptomatic trees is consistently lower than in asymptomatic trees. Based on the larger number of droughts recorded during the past decades and on future climatic predictions suggesting increasing trends in the frequency and intensity of drought events in northern Patagonia, a gradual increase in the number of trees affected by “Mal del Cipres” along the twenty-first century is likely expected., Laboratorio de Investigación de Sistemas Ecológicos y Ambientales, Instituto de Biotecnología y Biología Molecular

Fourteen natural populations of the South-American Beech Nothofagus obliqua at the Eastern naturally fragmented area of its distribution range were subjected to genetic analysis using genetic markers. The genetic characterization of the analysed populations suggested probable distinct glacial origin of populations at North and South of the distribution. Furthermore, based on the allelic richness parameter, relict areas could be postulated within each of the identified latitudinal group. Natural hybridisation processes with the close related and sympatric species Nothofagus nervosa were also identified as one of the shaping forces modelling genetic variation patterns of the species. While ancient hybridisation was postulated for the northern watersheds, current hybridisation processes were suggested within the southern ones. Genetic isolation was identified as the main cause promoting the high genetic differentiation found among populations within watersheds.

The role of the morphology of strontium doped lanthanum manganite (LSM) and LSM/yttria stabilized zirconia (YSZ) composite electrodes was studied by using DC polarization measurement and impedance spectroscopy. Different electrodes were tested: single pure LSM with small porosity layer, porous LSM layer over pure LSM layer and LSM-YSZ composite (50wt% YSZ) with a porous LSM layer. Electrochemical properties of these structures were investigated as a function of temperature. Impedance diagrams show that the electrode reaction of pure LSM electrodes could be related to a high frequency contribution attributed to a charge transfer between LSM and YSZ and a low frequency one semicircle related to an oxygen adsorption step. The impedance response of the electrode based on a LSM-YSZ composite could be related to only the high frequency contribution. No electrochemical activation was evidenced in this case. Maximum current density was around -0.1 A.cm-2 for a cathodic overpotential equal to -0.1 V.

Microdensity profiles of Douglas-fir's clones and weather data were used to study phenotypic plasticity (dendroplasticity). Within-ring microdensity was interpreted as the variation of tree response to drought constraints during selected growing seasons. An original norm of reaction was obtained by pairing evident points of abrupt changes in tree-ring microdensity profiles and in weather indices. The coefficients of the non-linear models adjusted to the reaction norms were analysed as dendroplasticity variables. Dendroplasticity variables were significantly different between geographical locations, years and clones. Heritability of the dendroplasticity variables ranged from low to high and was similar to heritability values of microdensity variables such as mean ring density (MRD). Coefficients of genetic variation of dendroplasticity variables were intermediate between those of wood density and growth variables. Dendroplasticity variables were phenotypically and genetically related to ring microdensity variables, more strongly to latewood variables. Dendroplasticity provides retrospective, synthetic and easy-to-interpret information about tree response to the variation of the balance between water availability and water demand during the growing season. The proposed model of dendroplasticity is described by a number of parameters that are linked to a biological meaning. Our results suggest that there is a potential for adaptation to drought in Douglas-fir, with two mechanisms involved: at individual level, short-term plastic response during the growing season and, at population level, long-term, between-generation, evolution process.

El ciprés de la cordillera, Austrocedrus chilensis (D. Don) Pic Ser. et Bizzarri, es una conífera nativa de gran importancia forestal en la región patagónica. Con el objetivo de analizar variación temprana en caracteres cuantitativos, se estableció un ensayo de ambiente común en invernáculo con regulación automatizada del ambiente y un régimen de ferti-irrigación por micro-aspersión ajustado para la especie, durante dos temporadas de crecimiento

Fragmentation of the habitat due to glaciations, fires and human activities affected the distribution range of Araucaria araucana in southern South America. On the borders of the Argentinean Patagonian steppe, the species is restricted to isolated patches without natural regeneration. Our objective is to test the hypothesis that these populations are relicts of pre-Pleistocene origin. A total of 224 individuals from 16 populations were sampled. Twenty chloroplast microsatellites, 19 non-coding chloroplast DNA regions and eight mitochondrial DNA fragments were screened for polymorphisms. A low transferability rate of universal primers from Pinaceae and also a low variation were detected for this ancient species. Only one non-coding region of the chloroplast DNA showed polymorphism allowing the identification of five haplotypes. A low genetic differentiation (G ST = 0.11; G′ ST = 0.267) and lack of geographic structure was found. Allelic richness was lower and genetic differentiation higher among the eastern isolated populations, suggesting a long lasting persistence. Conservation guidelines are given for these relictual populations, which are located outside the limits of the National Parks.

Climatic oscillations during the Quaternary strongly affected the distribution of warm-temperate tree species, which experienced local restrictions into ice-free areas and posterior expansions. To evaluate the impact of these range movements on the genetic structure of populations, we performed a phylogeographical analysis of the species Nothofagus obliqua with chloroplast DNA markers. A total of 27 populations covering the whole natural distribution range were analyzed using polymerase chain reaction-restriction fragment length polymorphism. Diversity (h T, h S), allelic richness (r g), and differentiation among populations for unordered (G ST) and ordered alleles (N ST) were calculated. The relationships among haplotypes were evaluated by the construction of a minimum spanning network. The spatial distribution of the genetic variation was analyzed through a Mantel test and with a nested analysis of molecular variance to differentiate between geographic regions. The screening of 11 non-coding regions allowed the identification of 14 haplotypes. A high genetic differentiation was detected (N ST = 0.875 and G ST = 0.824) with the existence of phylogeographic structure (p

The management of the genetic resources of any wild species requires the definition of genetically homogeneous units about which practical decisions can be taken. To this end, a structure analysis was performed on the Patagonian cypress Austrocedrus chilensis (D.Don) Pic. Ser. et Bizzarri. A total of 746 seed trees corresponding to 27 natural populations sampled across its entire Argentinean range were genotyped at 12 isozyme gene markers. Genetic structure was analyzed following four successive steps: (1) proposal of different population groupings according to (a) environmental features, (b) cluster and principal coordinate analyses on genetic distances, (c) Bayesian inference utilizing BAPS program and (d) maximally differentiated groups by the software SAMOVA. (2) Evaluation of the proposed groupings with AMOVA, considering that best groupings were those with a proportion of covariance component due to inter-group differences higher than that due to intra-group differences. (3) New grouping proposition after a synthetic analysis. (4) Evaluation and characterization of the final structure proposed. Mean values of diversity parameters revealed a generally low level of allelic diversity ( A / L = 1.52; A e = 1.163; r 18 = 1.436), with moderate expected and observed heterozygosities ( H e = 0.143; H o = 0.135). Differentiation at species level was low ( δ = 0.048 and F ST = 0.060). Grouping according to precipitation regimes and glacial patterns proved not to be significant. Cluster and principal coordinate analyses did not reveal any geographical pattern. A six-group structure was proposed considering AMOVA results with intuitive adjustments based on biological facts. Three out of the six groups include most of the Argentinean range of the species. Since they are latitudinal groups, a latitudinal pattern is the basis of this structure, onto which other effects seem to superimpose. The three remaining groups would be related to the glacial history of the region. One of them is composed of populations outside the glaciated area but close to the ice sheet border, which are probably related to the re-colonization process after last deglaciation. Populations forming the fifth group are extremely isolated patches far beyond the glacial border. It is possible that those populations are the remnants of a pre-glaciation distribution of the species that managed to last to the present without any profound change. The sixth one is a rather atypical single-population group, most likely determined by drift processes. Each group of this structure serves as a preliminary operational genetic management unit (OGMU). The addition of complementary genetic data on adaptive traits is necessary to delineate definitive OGMUs.

Nothofagus is the main component of southern South American temperate forests. Overexploitation in the past has led to the loss of 40% of the original distribution range. Genetic diversity as well as biological processes shaping the distribution of the genetic variation (e.g. gene flow) constitutes basic knowledge for the implementation of conservation measures and for the definition of Evolutionary Significant Units. Nuclear microsatellites are the marker of choice for gene flow and fine-scale genetic structure studies. We enlarged a previous set of microsatellites (SSRs) for South American Nothofagus species, with special concern to Nothofagus nervosa (Phil.) Dim. et Mil. Five new SSRs are presented with allele numbers up to 12 in a single population. The primers transferred well to five related species (N. obliqua (Mirb.) Oerst, N. glauca (Phil.) Krasser, N. dombeyi (Mirb.) Oerst , N. pumilio (Poepp et Endl.) Krasser and N. antarctica (G. Forster) Oerst, with allele numbers up to 11. The high level of polymorphism promises a sufficient power for gene flow and parentage analyses.

During the Quaternary, southern South American temperate forests were confined to small and isolated refugia. Recolonization could be related not only with location of refugia but also with postglacial phenomena like volcanism, which could have interrupted the expansion of the forests. The aim of this study was to analyze the local effect of volcanism during the postglacial migration of Nothofagus nervosa in a particular region of Argentina were convergence of two migratory routes was suggested. The main question is whether admixture occurred or not and if the current populations are connected by pollen or seed gene flow. Two populations separated by a 3-km-width lava flow were sampled. Buds from 30 individuals of each of the two populations and from a total of 142 juveniles were analyzed. Genetic variation was detected through maternally inherited chloroplast deoxyribonucleic acid (cpDNA; polymerase chain reaction restriction fragment length polymorphisms of two fragments) and nuclear markers like isozymes (six loci) and simple sequence repeats (three loci). Population genetic parameters were estimated and the existence of a genetic structure was tested with an analysis of molecular variance. Historical gene flow was estimated through the indirect method of the genetic differentiation (F ST). Chloroplast DNA revealed a total genetic differentiation between the two populations indicating completely isolation respecting seed gene flow. On the contrary, the degree of genetic differentiation for the nuclear markers was significantly lower, and moderate levels of historical gene flow through pollen were inferred. The results suggest that in this area, volcanism has played an important local role during the expansion of N. nervosa maintaining these two populations separated.

Background: Although the importance of using local provenance planting stock for woodland production, habitat conservation and restoration remains contentious, the concept is easy to understand, attractive and easy to ‘sell’. With limited information about the extent and scale of adaptive variation in native trees, discussion about suitable seed sources often emphasises “local” in a very narrow sense or within political boundaries, rather than being based on sound evidence of the scale over which adaptation occurs. Concerns exist over the actual scale (magnitude and spatial scale) of adaptation in trees and the relative dangers of incorrect seed source or restricted seed collection, leading to the establishment of trees with restricted genetic diversity and limited adaptive potential. Tree provenance and progeny field trials in many parts of the world have shown the existence of genotype by environment interaction in many tree species, but have not necessarily looked at whether this is expressed as a home site advantage (i.e. whether provenance performance is unstable across sites, and there is better performance of a local seed source). Methods/design: This review will examine the evidence for local adaptation and its scale in a number of native tree species from different trial sites across the globe (e.g. tropical, Mediterranean, temperate). These trials have been measured and in some cases results published in a range of formats. The data have, however, usually been presented in the form of which provenances grow best at which sites. The review will examine existing data (published and unpublished) in the context of the scale of local adaptation, with the results being presented in two formats: (a) relating survival, performance of provenances (classified by seed zone/provenance region of origin) to seed zone/provenance region of the planting site; (b) plotting survival, performance provenances against the distance (Euclidean/ecological) between the provenance and the trial site. EEA Bariloche Fil: Boshier, David. University of Oxford. Department of Plant Sciences; Reino Unido Fil: Broadhurst, Linda. CSIRO National Research Collections Australia (NRCA). Centre for Australian National Biodiversity Research (CANBR); Australia Fil: Cornelius, Jonathan. International Center for Research in Agroforestry. World Agroforestry Centre; Perú Fil: Gallo, Leonardo Ariel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina Fil: Koskela, Jarkko. FAO; Italia Fil: Loo, Judy. Bioversity International; Italia Fil: Petrokofsky, Gillian. University of Oxford. Department of Zoology; Reino Unidos Fil: St Clair, Bradley. US Forest Service. Pacific Northwest Research Station; Estados Unidos

Seeds integrate environmental cues that modulate their dormancy and germination. Although many mechanisms have been identified in laboratory experiments, their contribution to germination dynamics in existing communities and their involvement in defining species habitats remain elusive. By coupling mathematical models with ecological data we investigated the contribution of seed temperature responses to the dynamics of germination of three Nothofagus species that are sharply distributed across different altitudes in the Patagonian Andes. Seed responsiveness to temperature of the three Nothofagus species was linked to the thermal characteristics of their preferred ecological niche. In their natural distribution range, there was overlap in the timing of germination of the species, which was restricted to mid-spring. By contrast, outside their species distribution range, germination was temporally uncoupled with altitude. This phenomenon was described mathematically by the interplay between interspecific differences in seed population thermal parameters and the range in soil thermic environments across different altitudes. The observed interspecific variations in seed responsiveness to temperature and its environmental regulation, constitute a major determinant of the dynamics of Nothofagus germination across elevations. This phenomenon likely contributes to the maintenance of patterns of species abundance across altitude by placing germinated seeds in a favorable environment for plant growth. Fil: Arana, María Verónica. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Gonzalez Polo, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche; Argentina Fil: Martinez Meier, Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina Fil: Gallo, Leonardo Ariel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina Fil: Benech-arnold, Roberto Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina Fil: Sanchez, Rodolfo Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas A la Agricultura; Argentina Fil: Batlla, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina

Premise of the study: We present a set of 23 polymorphic nuclear microsatellite loci, 18 of which are identified for the first time within the riparian species Salix humboldtiana (Salicaceae) using next‐generation sequencing. Methods and Results: To characterize the 23 loci, up to 60 individuals were sampled and genotyped at each locus. The number of alleles ranged from two to eight, with an average of 4.43 alleles per locus. The effective number of alleles ranged from 1.15 to 3.09 per locus, and allelic richness ranged from 2.00 to 7.73 alleles per locus. Conclusions: The new marker set will be used for future studies of genetic diversity and differentiation as well as for unraveling spatial genetic structures in S. humboldtiana populations in northern Patagonia, Argentina. EEA Bariloche Fil: Bozzi, Jorge Alfredo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina Fil: Liepelt, Sascha. University of Marburg. Faculty of Biology. Conservation Biology Group; Alemania Fil: Ohneiser, Sebastian. University of Marburg. Faculty of Biology. Conservation Biology Group; Alemania Fil: Gallo, Leonardo Ariel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina Fil: Marchelli, Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Leyer, Ilona. University of Marburg. Faculty of Biology. Conservation Biology Group; Alemania. University of Geisenheim. Institute of Botany, Plant Ecology and Nature Conservation; Alemania Fil: Ziegenhagen, Birgit. University of Marburg. Faculty of Biology. Conservation Biology Group; Alemania Fil: Mengel, Christina. University of Marburg. Faculty of Biology. Conservation Biology Group; Alemania