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Abstract Background Tree regeneration is a key component of resilience because it promotes post-disturbance recovery of forests. Northwestern Patagonia from Argentina is occupied by Nothofagus alpina (Na), N. obliqua (No), and N. dombeyi (Nd) forests that grow along an intense precipitation gradient, managed throughout shelterwood silvicultural system by technicians of the Lanin Natural Reserve. The objective of this study was to evaluate the influence of seeding cuttings over the dynamics of Nothofagus mixed forests across landscape (precipitation gradient) based mainly on the composition and abundance of tree regeneration, permanent sampling plots and generalized linear mixed models. In particular, we analysed: (i) the structure of sexual and asexual regeneration during 20 years after harvest (the dynamics of managed forests), and (ii) the structure of sexual regeneration in primary and managed forests after > 20 years of harvest (the effect of silviculture). Results Nd was the most abundant species in the regeneration of managed forests during all periods in both sites despite its lower contribution to the adult cohort. During the 10–20 years period after harvest, the humid site exhibited higher regeneration density than the mesic site (120,000 and 6000 ind ha−1, respectively), and it decreased afterwards. The number of established regeneration (> 2 m height) was lower for Na in the mesic site and for No in the humid site (0 and 57 ind ha−1, respectively). However, in comparison to No, Na showed a higher number of sprouted stumps and sprouts per stump, and a higher sprout height in the mesic site. No exhibited higher sprout mortality in the humid site. Finally, the regeneration of primary forests showed lower density and height, and a more balanced composition than that of managed forests. Conclusions The silvicultural effects on the mixed forest regeneration dynamics was strongly influenced by the condition of sites. Therefore, management prescriptions should be adjusted in order to consider the environmental variation occurring through the entire landscape. An adaptive management that considers the pattern and process of sexual and asexual regeneration and disturbance will contribute to promote a greater resilience of mixed forest ecosystems.

Background: Tree regeneration is a key component of resilience because it promotes post-disturbance recovery of forests. Northwestern Patagonia from Argentina is occupied by Nothofagus alpina (Na), N. obliqua (No), and N. dombeyi (Nd) forests that grow along an intense precipitation gradient, managed throughout shelterwood silvicultural system by technicians of the Lanin Natural Reserve. The objective of this study was to evaluate the influence of seeding cuttings over the dynamics of Nothofagus mixed forests across landscape (precipitation gradient) based mainly on the composition and abundance of tree regeneration, permanent sampling plots and generalized linear mixed models. In particular, we analysed: (i) the structure of sexual and asexual regeneration during < 10, 10–20 and > 20 years after harvest (the dynamics of managed forests), and (ii) the structure of sexual regeneration in primary and managed forests after > 20 years of harvest (the effect of silviculture). Results: Nd was the most abundant species in the regeneration of managed forests during all periods in both sites despite its lower contribution to the adult cohort. During the 10–20 years period after harvest, the humid site exhibited higher regeneration density than the mesic site (120,000 and 6000 ind ha−1, respectively), and it decreased afterwards. The number of established regeneration (> 2 m height) was lower for Na in the mesic site and for No in the humid site (0 and 57 ind ha−1, respectively). However, in comparison to No, Na showed a higher number of sprouted stumps and sprouts per stump, and a higher sprout height in the mesic site. No exhibited higher sprout mortality in the humid site. Finally, the regeneration of primary forests showed lower density and height, and a more balanced composition than that of managed forests. Conclusions: The silvicultural effects on the mixed forest regeneration dynamics was strongly influenced by the condition of sites. Therefore, management prescriptions should be adjusted in order to consider the environmental variation occurring through the entire landscape. An adaptive management that considers the pattern and process of sexual and asexual regeneration and disturbance will contribute to promote a greater resilience of mixed forest ecosystems. [ABSTRACT FROM AUTHOR]

We present the first network of tree-ring chronologies for co-occurring Nothofagus nervosa and Nothofagus obliqua in Argentina. Using standard dendrochronological techniques, we developed seven tree-ring width chronologies for each species, encompassing their E-W distribution along a precipitation gradient. Chronology statistics indicated thatN. nervosa andN. obliqua are strong candidates for research in dendrochronology. The chronologies were used to study and compare the temporal and spatial growth patterns of each species. Correlation and principal components analysis of the tree-ring chronologies serve as evidence of a strong common signal, indicating shared regional growth patterns across the gradient with some exceptions between sites and species. These results indicate the high potential of N. nervosa and N. obliqua for their use in dendroclimatology. [ABSTRACT FROM AUTHOR]

Ectomycorrhizas (EcM) constitute a crucial component of soil biota in forest ecosystems, where they perform functions of great ecological significance. Although there is available information about the individual effects of various factors shaping EcM fungal communities, it is still challenging to understand the intricate interaction among different environmental factors and forest management on these communities. Our aim was to evaluate the potential modulation of silvicultural management impacts by site conditions on different facets of EcM fungal biodiversity in mixed Nothofagus forests in northern Patagonia. We compared managed and unmanaged plots located in mesic and humid sites, and assessed root colonization by EcM, taxonomic α- and β- EcM fungal diversity, as well as relative abundance of functional EcM groups defined by fungal soil nutrient foraging strategies (exploration types). We found that the effect of silvicultural management on root colonization was not modulated by site conditions, being colonization percentages higher in the mesic site and in unmanaged plots. Conversely, the effect of silvicultural management on taxonomic α- and β-diversity of EcM fungi, as well as on the relative abundance of exploration types, was modulated by site conditions. We found that in the mesic site silvicultural management tended to increase the α-diversity of EcM fungal communities and changed the relative abundance of different EcM fungal taxa and EcM functional groups. In the humid site, silvicultural management did not generate changes in α-diversity, but a shift in the relative abundance of certain EcM fungal taxa and of different EcM functional groups was detected. These changes in taxonomic and functional EcM groups could be related to the intrinsic traits of the EcM fungal species present in each site (e.g., stress tolerance, water, and nutrient acquisition strategies) and how they interact with environmental disturbances, such as silvicultural management. Overall, the composition of EcM fungi in all groups was affected by the interaction of both factors, although the detected changes were mostly explained by modifications in the relative abundance of EcM fungi within each group rather than species replacement terms. Our study highlights the complexity of ectomycorrhizas dynamics in ecosystems and emphasizes the importance of considering belowground communities when analyzing the impacts of silvicultural management. Furthermore, our results also reveal that silvicultural management assessment and implementation should consider the environmental variation of the forest landscape. • Forest management system and site conditions affect biodiversity of ectomycorrhizas. • Under management, richness and evenness increased in the mesic site. • Fifteen taxa explain more than 70% of community structure dissimilarity. • Dissimilarity of community structure was associated to functional exploratory types. • Medium-distance exploration type decreased under management at the mesic site. [ABSTRACT FROM AUTHOR]

Las actividades humanas alteraron la frecuencia y la intensidad de los incendios, lo cual puede tener consecuencias severas sobre los ecosistemas terrestres. Se sugiere que aplicar enmiendas y trasplantar especies nativas serían alternativas exitosas para recuperar zonas incendiadas. En la región andina de la Patagonia Argentina se produce compost de biosólidos que se podría usar a tal fin. Sin embargo, se conoce poco sobre el efecto de estas enmiendas orgánicas en el crecimiento de las plantas nativas. El objetivo del trabajo fue evaluar la respuesta al agregado de compost y la fertilización nitrogenada de dos especies nativas: ciprés (Austrocedrus chilensis) y roble (Nothofagus obliqua), cultivadas en un sustrato volcánico forestal afectado por un incendio. Después de 4 años se observó que el efecto de los tratamientos (en la planta y en el suelo) dependió de la especie. El efecto principal del compost fue un aumento marcado en la disponibilidad de fósforo en los suelos. El roble incrementó su biomasa y modificó parámetros arquitecturales en respuesta a la fertilización nitrogenada, pero no presentó cambios ante la adición de compost. El ciprés, por el contrario, no respondió a la fertilización nitrogenada, pero sí incrementó su biomasa en el tratamiento con compost y fertilización. Es posible que agregar nitrógeno haya favorecido la absorción de nutrientes que aporta el compost, como fósforo, calcio y magnesio.

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ecologia Austral is the property of Asociacion Argentina de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Non-systemic logging, cattle browsing and grazing with the site natural vegetation can modify tree covers in native forests and alter the quantity and quality of organic matter entering the soil and hence its overall quality. The objective of this study was to evaluate the effect of modifying tree covers by uncontrolled logging and grazing processes on soil quality, in a mature and unmanaged roble (Nothofagus obliqua (Mirb.) Blume) forest. Soil quality was evaluated under partly-closed (PC), partly-open (PO), and open (OP) forest covers, and two soil depths. The indicators used were soil organic C (SOC), potential net N mineralization (N-min), and nitrification (N-NO3), soil microbial respiration (SMR), microbial biomass C (MBC), soil aggregates, and light fraction (LF). At 0-5 cm soil depth SMR and MBC in PC cover was approximately 12% higher than in PO and OP covers. For the same soil depth N-min in PC cover was 68% and 95% higher than in PO and OP covers, respectively; and for N-NO3 PC cover was 45% higher than PO cover. OP tree cover presented a negative N-NO3 (immobilization). Dry weight for LF fraction in OP cover (labile OM) was 90% and 67% lower respect PC and PO covers, respectively (P < 0.05). The soil quality and the activity of its microbial processes were affected by alteration of tree cover, as well by the anthropic action of logging and extensive grazing, the soil in OP cover was the most affected. [ABSTRACT FROM AUTHOR]

Second growth forests of Nothofagus obliqua (roble), N. alpina (raulí), and N. dombeyi (coihue), known locally as RORACO, are among the most important native mixed forests in Chile. To improve the sustainable management of these forests, managers need adequate information and models regarding not only existing forest conditions, but their future states with varying alternative silvicultural activities. In this study, an individual-tree diameter growth model was developed for the full geographical distribution of the RORACO forest type. This was achieved by fitting a complete model by comparing two variable selection procedures: cross-validation (CV), and least absolute shrinkage and selection operator (LASSO) regression. A small set of predictors successfully explained a large portion of the annual increment in diameter at breast height (DBH) growth, particularly variables associated with competition at both the tree- and stand-level. Goodness-of-fit statistics for this final model showed an empirical coefficient of correlation (R²emp) of 0.56, relative root mean square error of 44.49% and relative bias of 1.96% for annual DBH growth predictions, and R2emp of 0.98 and 0.97 for DBH projection at 6 and 12 years, respectively. This model constitutes a simple and useful tool to support management plans for these forest ecosystems. [ABSTRACT FROM AUTHOR]

Previous studies of afforestation in Patagonia indicate that 30-50 % tree cover produces positive effects on the pasture. This coverage level is achieved by applying pruning and strong thinning to reduce the volume of timber production per area unit. From an economic standpoint, in order to not reduce the income level of the system, it is necessary to find tree species that could replace ponderosa pine ( Pinus ponderosa) and maximize income per volume unit of wood. We evaluated the feasibility of implementation of five broadleaved tree species (native and exotic) with higher intrinsic wood quality than ponderosa pine. We tested the influence of tree cover generated by a framework of silvopastoral plantation on the increase in survival, regrowth and absolute increase in height, and compared ecophysiological variables (net photosynthetic activity, stomatal conductance, intrinsic water use efficiency) of different species to the status of a traditional plantation without tree cover. Additionally values of air temperature and relative humidity were registered under both cover conditions. Preliminary results support the conclusion that three of these five species could be considered as alternatives to ponderosa pine species for establishing silvopastoral systems with higher timber value. Our Based on the results, the use of tree cover generated under the current plantations of P. ponderosa could increase the success of the establishment of these species. [ABSTRACT FROM AUTHOR]

Discriminant molecular markers are required for research on population genetics, as well as evolutionary studies involving identification of hybrids and parental species, or detection of the genome regions under selection. We provide a set of 27 transcriptomic microsatellite markers (SSRs) for South AmericanNothofagusspecies, derived from 73Nothofagus alpina (=N. nervosa)annotated unigenes. Rates of cross-amplification ranged from 22% to 37%. Genetic characterisation of 22 transcriptomic SSRs forN. alpinaandN. obliquareveals low genetic variability, due to the general occurrence of one major allele at each locus, and high specificity, with few alleles shared between species (14%). At inter-species level 95% of loci were discriminant, with a total G''st over loci of 0.9, indicating that alleles were mostly fixed for all loci in both species. At intra-species level the number of markers with significant differentiation was 2.5 times higher forN. obliquathan forN. alpinapopulations. Moreover, transcriptomic SSRs showed higher performance compared with published anonymous microsatellites isolated from genome sequences without annotation. This set of transcriptomic microsatellites will be useful to the scientific community working on conservation and evolutionary aspects ofNothofagusspecies. [ABSTRACT FROM PUBLISHER]

The objective of this research was to determine emission factors (EF) for particulate matter (PM 2.5 ), combustion gases and particle size distribution generated by the combustion of Eucalyptus globulus (EG), Nothofagus obliqua (NO), both hardwoods, and Pinus radiata (PR), softwood, using a controlled combustion chamber (3CE). Additionally, the contribution of the different emissions stages associated with the combustion of these wood samples was also determined. Combustion experiments were performed using shaving size dried wood (0% humidity). The emission samples were collected with a tedlar bag and sampling cartridges containing quartz fiber filters. High reproducibility was achieved between experiment repetitions (CV < 10%, n = 3). The EF for PM 2.5 was 1.06 g kg − 1 for EG, 1.33 g kg − 1 for NO, and 0.84 g kg − 1 for PR. Using a laser aerosol spectrometer (0.25–34 μm), the contribution of particle emissions (PM 2.5 ) in each stage of emission process (SEP) was sampled in real time. Particle size of 0.265 μm were predominant during all stages, and the percentages emitted were PR (33%), EG (29%), and NO (21%). The distributions of EF for PM 2.5 in pre-ignition, flame and smoldering stage varied from predominance of the flame stage for PR (77%) to predominance of the smoldering stage for NO (60%). These results prove that flame phase is not the only stage contributing to emissions and on the contrary, pre-ignition and in especial post-combustion smoldering have also very significant contributions. This demonstrates that particle concentrations measured only in stationary state during flame stage may cause underestimation of emissions. [ABSTRACT FROM AUTHOR]

Se describe el huevo, larva, pupa e imago de Microdulia mirabilis (Rotschild), insecto nativo defoliador de Nothofagus obliqua Mirb. (Oerst). M. mirabilis se distribuye entre los 35° y 47° S en Chile y en Neuquén, Argentina. Se entregan aspectos del ciclo de vida relacionados con períodos de duración de sus diferentes estados de desarrollo. Se ilustran los distintos estados inmaduros, los imagos y las estructuras de las armaduras genitales.The egg, larvae, pupae, and imago oí Microdulia mirabilis (Rothschild), an insect that defoliates native Nothofagus obliqua Mirb. (Oerst.), are described. M. mirabilis distributes between 35° and 47°S in Chile and Neuquén, Argentina. Aspects of the life cycle associated with the duration of different stages of development are given. Immature stages, the imago, and the genitalia are illustrated.

Las ramas principales y secundarias se diferencian en mayor o menor medida según las especies, lo cual puede observarse en base al crecimiento primario de los brotes que las originan. En ejemplares de vivero juveniles-adultos de Nothofagus obliqua, N. nervosa e híbridos entre ambas especies, se compararon la dinámica de alargamiento, el tamaño y la morfología de dos brotes distales de ramas principales: uno que continúa el alargamiento de la rama principal y el otro que inicia una rama secundaria. En N. alpina y en híbridos, los dos brotes más distales se diferencian más que en N. obliqua. A pesar de la homogeneidad ambiental en el vivero y el origen geográfico común para los ejemplares de N. nervosa y los híbridos, hubieron diferencias fenológicas y morfológicas entre estas entidades. La duración y tasa de alargamiento y la longitud final de los brotes fueron altamente variables en cada entidad. Las variaciones entre entidades en la diferenciación de ejes podrían indicar diferencias en sus capacidades de uso del espacio circundante. La diferenciación entre ramas principales y secundarias se iniciaría en el estado de yema. La variación intra-específica fenológica y morfológica es útil para programas de selección artificial de individuos.Main and secondary branches are more or less differentiated according to the species and this could be observed during the primary growth of the shoots that produce them. In young-adult trees of Nothofagus obliqua, N. nervosa and hybrids between them growing in a common garden, growth dynamics, size and morphology were compared between two distal shoots produced by main branches: one of these shoots continued the extension of the main branch whereas the other initiated a secondary branch. The two distal shoots differed from each other more notably in N. nervosa and in the hybrids than in N. obliqua. Despite the environmental homogeneities at the nursery and the common geographic origin of the individuals of N. nervosa and the hybrids, there were phenological and morphological differences of these entities. Growth duration and rate and final shoot length were largely variable within each entity. The variation between entities regarding axis differentiation could indicate differences in their capacities to use the surrounding space. The differentiation between main and secondary branches would start at the bud stage. Intra-specific phenological and morphological variation could be useful in artificial selection programs.

Land cover changes have a great impact on nitrogen (N) and phosphorous (P) fluxes catchments. In this study, we wanted to compare different land covers: deciduous (D), evergreen (E) (both native forests), and exotic Eucalyptus globulus plantation (EP), affected precipitation, and stream discharge on N and P species concentrations and fluxes, under a low deposition climate in south-central Chile. For this, we collected bulk precipitation, throughfall, and stream water samples after 41 rainfall events in E and EP, during the period June 2009-March 2011, and 31 rainfall events in D, during the period October 2009-March 2011. The highest canopy enrichment of N and P species for throughfall was observed in deciduous forest, while E. globulus showed the minimum enrichment. Total nitrogen (total-N) discharge in EP was about 8.6 times higher than that of E and D catchments. Total-N annual retention was positive only in E and D catchments. However, EP catchment showed a net loss (−4.79 kg N ha/year). The biggest difference was observed in nitrate stream concentrations, which showed low values for E (3.4 ± 1.3 μg/L), while EP and D showed higher nitrate concentrations (84.9 ± 16.7 and 134.7 ± 36.7 μg/L, for EP and D, respectively). Total phosphorous (total-P) discharge flux was low in EP (0.4 kg P ha/year), and negligible in E and D forests (<0.1 kg P ha/year). Total-P annual retention was near to 1.0 kg N ha/year (on E and D), while a net loss (−1.5 kg N ha/year) was observed for EP. We attribute the observed differences in nutrient throughfall enrichment due to high multi-stratified canopies in the native forests. Both deciduous and evergreen native forest-covered catchments showed the highest retention of total-N and total-P, in contrast to Eucalyptus-covered plantation. [ABSTRACT FROM AUTHOR]

High inter-annual variations in flower and seed production have been frequently reported for wind-pollinated tree species. Such variations have been generally studied from a population perspective. The present study focuses on the meristematic cost of flower production in main branches of Nothofagus obliqua and N. nervosa through a retrospective analysis of flower production over 4-5 consecutive years. In both species, the percentage of flowering nodes in one year varied between 0 and 55 %. In N. obliqua, total flower production was bimodally distributed: years of high and low production were more common than years of intermediate production. Bimodality was not significant either for total flower production in N. nervosa or for each flower type separately in both species. Flower production affected branching negatively, which meant a meristematic cost. Periodicity in flower production was uneven among co-specific trees; more than two consecutive years of high flower production were rare in all trees. Inter-annual variations in the production of staminate and pistillate flowers were synchronized. In N. nervosa, the production of pistillate flowers tended to be more variable among years than the production of staminate flowers. The applied technique helps in the assessment of individual variations of flower production and contributes to understanding factors promoting seed-production variations in tree species at population scale. [ABSTRACT FROM AUTHOR]

Grazing and over-exploitation can severely degrade soil in native forests. Considering that productivity in ecosystems is related to soil organic matter (SOM) content and quality, the objectives of this study were to: (1) determine the influence of degraded (DEF), partly-degraded (PDF), and undisturbed (UNF) Nothofagus forests on the stocks of carbon (C) in tree biomass and SOM; (2) evaluate fractions of SOM as indicators of sustainable management; and (3) use the Century model to determine the potential gains of soil organic C (SOC). The forests are located in the Andes and Coastal mountains of southern Chile. The SOM was fractionated to separate the light fraction (LF), macroaggregates (>212 µm), mesoaggregates (212-53 µm), and microaggregates (<53 µm). In two measurement periods, the SOC stocks at 0-20 cm and 20-40 cm depths in macroaggregates were on average 100% higher in the Andean UNF, and SOC was over twice as much at 20-40 cm depth in Andean DEF. Century simulations showed that improved silvopastoral management would gradually increase total SOC in degraded soils of both sites, especially the Ultisol with a 15% increase between 2016 and 2216 (vs. 7% in the Andisol). Greater SOC in macroaggregates (p < 0.05) of UNF indicate a condition of higher sustainability and better management over the years. [ABSTRACT FROM AUTHOR]

Evaluamos los patrones de infestación por insectos xilófagos en renovales de Nothofagus obliqua y Nothofagus dombeyi en las provincias de Valdivia, Osorno y Llanquihue (Chile). Realizamos los análisis a dos escalas: en primer lugar se consideraron las variables diámetro a la altura del pecho (DAP) y clase de copa del árbol hospedante (CC) como predictores de daño por xilófagos a nivel del árbol. En segundo lugar se consideraron las variables densidad arbórea total, densidad de hospedante, número y cobertura de especies (estas últimas agrupadas en los estratos arbóreo, arbustivo, de herbáceas y de epífitas), y su asociación con el porcentaje de infestación a nivel de rodal. El área de estudio presentó una infestación promedio de 9,35 % en N. obliqua y 15,89 % en N. dombeyi. A nivel individual tanto el DAP como la CC se relacionan positivamente con la presencia de daño, sin embargo el DAP resultó mejor predictor tanto para N. obliqua como para N. dombeyi, aumentando la probabilidad de encontrar un árbol dañado con el aumento del DAP. A nivel de rodal se encontró que las variables estudiadas no se relacionan con la infestación en N. obliqua, mientras que en N. dombeyi renovales con mayor número de especies en el estrato arbustivo y/o con mayor densidad de rodal y hospedante presentaron menores niveles de infestaciónInfestation patterns of xylophagous insects were evaluated in second growth stands of Nothofagus obliqua and Nothofagus dombeyi in Valdivia, Osorno and Llanquihue provinces of Chile. The analysis addressed two scales. First, at the individual level, diameter at breast height (DBH) and canopy class (CC) of the host tree were used as predictor traits of xylophagous damage. Second, at the stand level, variables such as total tree density, host density, species richness and cover (arboreal, shrubby, herbaceous and epiphytic strata) and their asociation with infestation average were considered. The infestation mean was 9.35 % for N. obliqua and 15.89 % for N. dombeyi. At individual level both DBH and CC were positively associated with damage presence. However, the best predictor of tree infestation was DBH in both N. dombeyi and N. obliqua, greater DBH increasing the probability to find an infested tree. At the stand level, no relationship was found between insect infestation and evaluated traits in N. obliqua, whereas N. dombeyi stands with high species richness in the shrubby stratum and/or with higher total tree density and host density showed the lowest infestation levels

El estudio de la ecología de la regeneración natural del bosque constituye una parte esencial de la silvicultura. El cerro Tren Tren (40°12' S, 71°26' O, 1.367 m, Reserva Mapuche Curruhuinca, Argentina) está ocupado por un bosque cerrado compuesto por Nothofagus dombeyi, N. nervosa y N. obliqua. En 1994 se estimó la densidad de renovales (diámetro en la base del tallo < 10 cm) en 90 ind ha-1. Posteriormente, se implementaron cortas de selección en bosquetes y los 10 claros artificiales resultantes de entre 1.587 y 4.322 m² se clausuraron al ganado. En 2002 las estructuras de tamaño y edad de los renovales se estimaron a través de muestreos sistemáticos y aleatorios. Las tres especies de Nothofagus se establecieron en forma simultánea en los claros artificiales. Sin embargo, la especie más tolerante a la sombra N. nervosa exhibió una edad media ligeramente mayor debido a su persistencia como "regeneración avanzada" antes de las cortas. La densidad de renovales se estimó en 97.006 ind ha-1 (68 % N. dombeyi, 20 % N. obliqua y 12 % N. nervosa). Los renovales mostraron una abundancia y composición independiente de la forma y tamaño de los claros, y de la abundancia relativa de árboles adultos que conformaban el rodal y el límite de los claros. En la zona clausurada los renovales ramoneados representaron el 15 % mientras que en la zona no clausurada el 33 %, una diferencia atribuible al efecto protector de la clausura. El 86 % de los renovales se localizaron en las áreas con niveles bajos e intermedios de altura y cobertura del sotobosque. El plan de manejo se considera adecuado si se compara el proceso de regeneración del bosque antes y después de su implementación, y se abren perspectivas alentadoras para la conservación de la comunidad dominada por Nothofagus bajo este sistema silviculturalUnderstanding forest regeneration is essential to develop sound, ecologically-based silvicultural practices. Mount Tren Tren (40°12' S, 71°26' W, 1,367 m, Reservation Mapuche Curruhuinca, Argentina) is occupied by a closed stand of Nothofagus dombeyi, N. obliqua, and N. nervosa. In 1994, tree regeneration (root collar diameter < 10 cm) was estimated to be 90 ind ha-1. After that, a group selection silvicultural system was implemented and the resulting 10 artificial gaps of between 1,587 and 4,322 m² were enclosed to prevent grazing by domestic livestock. Size and age structure of regeneration were analysed based on systematic and random samplings. All tree species became established simultaneously within the artificial gaps. However, the less light demanding N. nervosa exhibited a mean age slightly larger given its differential persistence as "advanced regeneration" previous to cutting treatment. Tree regeneration was estimated in 97,006 ind ha-1 (68 % of N. dombeyi, 20 % of N. obliqua, and 12 % of N. nervosa). Regeneration abundance and composition were unrelated to shape and size of regeneration gaps, nor to abundance of adult trees within the stand and along the gap boundaries. A significant positive effect of the enclosure on plant was observed. The 86 % of juvenile Nothofagus were present when understory height and cover were low to intermediate. The management plan is considered adequate if the abundance of regeneration is compared before and after its implementation, and encourages the use and conservation of this forest type under the current silvicultural system

RESUMEN Se caracterizó la diversidad de artrópodos del suelo asociados a N. obliqua (Mirb.) Oersted en el "Fundo Universidad de Concepción". Para esto se realizaron muestreos de hojarasca en un área con predominio de roble chileno, durante las temporadas de invierno y primavera (junio a noviembre de 1997). Se determinó la riqueza específica y abundancias relativas de cada uno de los grupos que conforman esta comunidad. Los resultados muestran que tanto los ácaros Oribatida y Gamasida, como los Collembola fueron siempre los grupos que presentaron las mayores abundancias relativas. Por otro lado, la diversidad y la equidad disminuyeron paulatinamente desde el primer mes de muestreo (H'= 0.597 y J'= 0.574) hacia el final del estudio, en temporada estival (H'= 0.404 y J'= 0.353). Esta tendencia se debió al notable aumento de los grupos dominantes en los últimos meses. El incremento de las abundancias de estos grupos se encuentra altamente correlacionado con el incremento mensual en las acumulaciones de hojarasca (r=0.935; p < 0.005)ABSTRACT The diversity of arthropods of soil, associated to N. obliqua was characterized in the "Fundo Universidad de Concepción". For this they were carried out dead leaves samplings in an area with prevalence of N. obliqua, during the winter and spring seasons (June to November of 1997). The wealth was determined the specific richness and relative abundance of each one of the groups that conformed this community. The results show that the Oribatida and Gamasida mites, as the Collembola, were the groups that presented the major relative abundances. On the other hand, the diversity and the eveness diminished gradually from the first month of sampling (H' = 0.597 and J' = 0.574) toward the end of the study, in the spring season (H' = 0.404 and J' = 0.353). This tendency was due to the notable increase of the dominant groups in the last months. The increment of the abundances of these groups is highly correlated with the monthly increment in the dead leaves accumulations (r = 0.935; p < 0.005)

Since 2009 extensive dieback and mortality of Nothofagus obliqua, associated with bleeding cankers on stems and branches, has been observed in the UK. The causal agent was identified as Phytophthora pseudosyringae, based on morphological and analysis of the internal transcribed spacer (ITS) sequences. Between 2011 and 2013, a survey assessed the frequency and nature of these P. pseudosyringae infections. Mature trees of Nothofagus with stem lesions caused by P. pseudosyringae were found across England, Scotland and Wales. Additional symptoms such as twig blight and leaf necrosis indicated that aerial infection was occurring. Besides N. obliqua, other hosts regularly encountered included Nothofagus alpina, Fagus sylvatica and Vaccinium myrtillus. In pathogenicity tests involving inoculation of logs, P. pseudosyringae was shown to be an aggressive bark pathogen of N. obliqua and F. sylvatica, but significantly less aggressive on N. alpina. Foliage susceptibility and sporulation tests showed marked differences between the six host species tested. Leaves of N. obliqua and V. myrtillus were highly susceptible. Leaves of N. alpina were moderately susceptible, those of Rhododendron ponticum slightly susceptible and those of F. sylvatica not susceptible at all. High levels of sporulation were observed only on inoculated N. obliqua and V. myrtillus leaves. This suggests that P. pseudosyringae may sporulate heavily on N. obliqua foliage in the field and that this inoculum initiates the aerial lesions observed on the shoots, branches and stems. The results also suggest that P. pseudosyringae has the potential to pose a serious threat to N. obliqua and other Nothofagus species in their Southern Hemisphere native ranges. [ABSTRACT FROM AUTHOR]

Hylamorpha elegans (Burmeister) is a native Chilean scarab beetle considered to be a relevant agricultural pest to pasture and cereal and small fruit crops. Because of their cryptic habits, control with conventional methods is difficult; therefore, alternative and environmentally friendly control strategies are highly desirable. The study of proteins that participate in the recognition of odorants, such as odorant-binding proteins (OBPs), offers interesting opportunities to identify new compounds with the potential to modify pest behavior and computational screening of compounds, which is commonly used in drug discovery, may help to accelerate the discovery of new semiochemicals. Here, we report the discovery of four OBPs in H. elegans as well as six new volatiles released by its native host Nothofagus obliqua (Mirbel). Molecular docking performed between OBPs and new and previously reported volatiles from N. obliqua revealed the best binding energy values for sesquiterpenic compounds. Despite remarkable divergence at the amino acid level, three of the four OBPs evaluated exhibited the best interaction energy for the same ligands. Molecular dynamics investigation reinforced the importance of sesquiterpenes, showing that hydrophobic residues of the OBPs interacted most frequently with the tested ligands, and binding free energy calculations demonstrated van der Waals and hydrophobic interactions to be the most important. Altogether, the results suggest that sesquiterpenes are interesting candidates for in vitro and in vivo assays to assess their potential application in pest management strategies. [ABSTRACT FROM AUTHOR]

Mortality of Nothofagus trees in the southern-central Chile region has been observed for over 30 years. A field survey conducted in 2013 detected partial defoliation and bleeding cankers on Nothofagus obliqua in a pure stand in the Nahuelbuta coastal ranges of the Biobío region. A Phytophthora sp. was isolated from stem cankers and soil samples around symptomatic N. obliqua trees: All isolates were identified as Phytophthora pseudosyringae. These isolates were pathogenic on 1-year-old N. obliqua and Nothofagus alpina, and on detached twigs of adult N. obliqua and Nothofagus dombeyi trees. This paper is the first to report association and pathogenicity of P. pseudosyringae with N. obliqua, N. alpina and N. dombeyi native to the Biobío region of Chile. The potential of P. pseudosyringae to cause damage in natural Nothofagus stands in Chile must be determined. [ABSTRACT FROM AUTHOR]

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 cp DNA 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. [ABSTRACT FROM AUTHOR]

The effect of glaciation on the levels and patterns of genetic variation has been well studied in the Northern Hemisphere. However, although glaciation has undoubtedly shaped the genetic structure of plants in the Southern Hemisphere, fewer studies have characterized the effect, and almost none of them using microsatellites. Particularly, complex patterns of genetic structure might be expected in areas such as the Andes, where both latitudinal and altitudinal glacial advance and retreat have molded modern plant communities. We therefore studied the population genetics of three closely related, hybridizing species of Nothofagus ( N. obliqua, N. alpina, and N. glauca, all of subgenus Lophozonia; Nothofagaceae) from Chile. To estimate population genetic parameters and infer the influence of the last ice age on the spatial and genetic distribution of these species, we examined and analyzed genetic variability at seven polymorphic microsatellite DNA loci in 640 individuals from 40 populations covering most of the ranges of these species in Chile. Populations showed no significant inbreeding and exhibited relatively high levels of genetic diversity ( HE = 0.502-0.662) and slight, but significant, genetic structure ( RST = 8.7-16.0%). However, in N. obliqua, the small amount of genetic structure was spatially organized into three well-defined latitudinal groups. Our data may also suggest some introgression of N. alpina genes into N. obliqua in the northern populations. These results allowed us to reconstruct the influence of the last ice age on the genetic structure of these species, suggesting several centers of genetic diversity for N. obliqua and N. alpina, in agreement with the multiple refugia hypothesis. [ABSTRACT FROM AUTHOR]

Abstract: Tree invasions cause important conservation problems, such as changes in plant community composition, reduced regeneration rates of native species, and alteration in landscape structures. One of the most invasive tree genera in the world is Acacia (Fabaceae). In Chile, Acacia dealbata Link is distributed in the mediterranean zone, mostly associated with roadsides and anthropogenic disturbances. In this paper we address the following questions: How does A. dealbata perform across a gradient of native forest and invasive stands? Will it be capable of establishing itself in non-invaded native forests and regenerating under its own canopy in the absence of disturbances? From a contrasting viewpoint, will native species such as Cryptocarya alba (Molina) Looser and Nothofagus obliqua (Mirb.) Oerst be able to survive in an A. dealbata stand, allowing re-colonization of the invaded area? We conducted survival and growth experiments on A. dealbata seedlings in three sites near Concepción, Chile (36°S–72°W) under three conditions: under Acacia stand, in a close native forest and on an intermediate matrix between these two conditions. We compared this to the performance of two native trees (Cryptocarya alba and Nothofagus obliqua). Results showed that A. dealbata and C. alba have high growth and establishment capacities within the native forest, but on the intermediate matrix only A. dealbata can grow and survive. C. alba survives at significantly higher rates than A. dealbata within Acacia stand. Nothofagus obliqua only survive at a very low rate in the native forest. Without disturbances, A. dealbata would be successful on the intermediate matrix and within native forest, while C. alba seems capable of surviving and establishing itself in invaded areas, thereby contributing to recovery and restoration of natural spaces. The interplay between Acacia dealbata and the native vegetation may show us a larger picture of how invasive species are capable of expanding even into forested ecosystems and, furthermore, how we can restore native vegetation and avoid further invasion. [Copyright &y& Elsevier]

Abstract: This study describes the application of a multilocus sequence typing (MLST) analysis for molecular discrimination at the strain level of Spanish wine yeast strains. The discrimination power of MLST is compared to mitochondrial RFLP analysis. Fragments of the ADP1, ACC1, RPN2, GLN4, and ALA1 genes were amplified by PCR from chromosomal DNA of 18 wine Saccharomyces cerevisiae strains. Ten polymorphic sites were found in the five loci analyzed showing 13 different genotypes, with 11 of them represented by only one strain. RFLP analysis of the same 18 wine yeast strains showed seventeen different mitochondrial patterns. Phylogenetic relationships among the strains analyzed, inferred by MLST data, showed wine isolates of S. cerevisiae as a rather homogeneous group. The discrimination potential of mitochondrial RFLP analysis was superior to the MLST scheme used in this work. However, MLST analysis allowed an easy construction of reliable phylogenetic trees. MLST analysis offers the possibility of typing wine S. cerevisiae strains simultaneously to the study of the genetic relationship among them. [Copyright &y& Elsevier]

Abstract: 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. [Copyright &y& Elsevier]

The field of conflict resolution is in constant evolution. Every day, theories are defined and redefined, and new contributions are made to the field. This continuous process challenges scholars, researchers, and practitioners to develop new conceptual and methodological frameworks for the analysis of conflict. This article highlights the potential of social cartography (participatory mapping) as a tool for the transformation of environmental and social conflicts at the household, community, national, and international levels. The advantages of social cartography as an appraisal, planning, and analytical tool for conflict transformation are illustrated here with a case study of the Afro-Colombian community of Roble's. [ABSTRACT FROM AUTHOR]

Shoot growth and dieback were compared among progenies of nursery-grown seedlings of Nothofagus obliqua belonging to seven progenies of the same provenance (Quila-Quina, Argentina). First-year shoots consisted of one growth unit (GU) and second-year shoots of one or two GUs. The probability of development of two GU was similar for all progenies. Progenies were different in terms of shoot size, terminal bud abscission, the extent of shoot dieback after shoot extension and the node of origin of the relay shoot on the first shoot. Plants with a second-year shoot consisting of two GUs had a thicker stem and more nodes than those with single-GU shoots. The selection of N. obliqua seed trees based on architectural traits suitable for forestry development at specific sites must contemplate variability among progenies and their probabilities of successful development under different conditions. D?veloppement et d?p?rissement des pousses de descendances de Nothofagus obliqua. La croissance et le d?p?rissement des pousses ont ?t? compar?s entre sept descendances de Nothofagus obliqua ?lev?es en p?pini?re et issues d''une m?me provenance (Quila-Quina, Argentine). Les pousses de la premi?re ann?e n''?taient form?es que d''une seule Unit? de Croissance (UC) tandis que les pousses de deuxi?me ann?e ?taient constitu?es d''une ou deux UCs. La probabilit? de d?veloppement d''une deuxi?me UC ?tait constante quelle que soit la descendance. Les descendances ont montr? des diff?rences en termes de taille de pousse, d''abscission du bourgeon terminal, d''?tendue de d?p?rissement des UC en fin d''extension et vis-?-vis du n?ud d''origine de la pousse relais sur la pousse de premi?re ann?e. Les plantes avec une pousse de seconde ann?e comportant deux UC avaient une tige plus ?paisse et avec plus de n?uds que celles avec des pousses ? une seule UC. La s?lection, bas?e sur des traits architecturaux, d''arbres de N. obliqua issus de graines, pour qu''elle soit adapt?e ? la foresterie, doit prendre en compte la variabilit? entre descendances et leurs probabilit?s de r?ussite et de bon d?veloppement sous des conditions diverses. [ABSTRACT FROM AUTHOR]