Oenological and Quality Characteristic on Young White Wines (Sauvignon Blanc): Effects of High Hydrostatic Pressure Processing
Briones-Labarca, V., Perez-Wom, M., Habib, G., Giovagnoli-Vicuña, C., Cañas-Sarazua, R., Tabilo-Munizaga, G., & Salazar, F. N.
High hydrostatic pressure (HHP) has shown to have an effect of enhancing some properties without detrimental effects on important quality characteristics, such as colour, pH, and turbidity. This suggests that this technique can be used as an alternative to the existing methods used in wine industry processing. The aim of this study was to investigate the effects of HHP on aroma compounds and also sensory and quality properties of young white wine. HHP treatment did not influence physicochemical parameters, total phenols, and flavonoid contents of white wine; however, the results from analysis of wine indicate that there was a great variation in the concentration of free and total sulphur dioxide (SO2) values and antioxidant capacity of white wine after HHP application. The sensory attributes, such as taste, odour, and overall quality, were not affected by HHP processing at 300 MPa. The chromatic characteristics changed slightly after applying HHP, but these changes could not be visually perceived because they were less than 5%. The use of this technique has the potential to decrease the amount of SO2 added to raw grapes thus maintaining the same properties found in untreated wine. This study provided valuable insights into the biochemical and sensory composition of commercial white wine and how this might change during HHP processing.
Referencia APA: Briones-Labarca, V., Perez-Wom, M., Habib, G., Giovagnoli-Vicuña, C., Cañas-Sarazua, R., Tabilo-Munizaga, G., & Salazar, F. N. (2017). Oenological and Quality Characteristic on Young White Wines (Sauvignon Blanc): Effects of High Hydrostatic Pressure Processing. Journal of Food Quality, 2017. https://doi.org/10.1155/2017/8524073
Comparative population genetics of two dominant plant species of high Andean wetlands reveals complex evolutionary histories and conservation perspectives in Chile’s Norte Chico
Troncoso, A. J., Bertin, A., Osorio, R., Arancio, G., & Gouin, N.
High Andean wetlands are naturally fragmented ecosystems that are impacted by anthropogenic activities. Although they constitute important reservoirs of biodiversity and ecosystem service providers, many aspects of their ecology are still unknown. In this study, we investigated the population genetic structure of two dominant and highly interactive plant species of high altitude wetlands, Patosia clandestina (Juncaceae) and Carex gayana (Cyperaceae), in 21 high Andean wetlands of Chile’s Norte Chico. Using rbcL gene sequences and AFLP markers, we found that both species displayed low levels of within-wetland genetic diversity, high inter-population genetic differentiation, and spatially-dependent genetic variation arising from isolation-by-distance. The distance at which populations become genetically independent was of the same order of magnitude in both species (125–175 km). Despite these similarities, idiosyncratic spatial patterns were detected. C. gayana in the three most northeastern wetlands demonstrated marked differences relative to the rest of the populations, with the latter group following a latitudinal stepping-stone pattern. In P. clandestina, a genetic barrier was found to divide the northern and southern populations into two balanced groups, and spatial genetic variation was consistent with a hierarchical island model. The data indicate that each of the two species likely responded to different geological and ecological events, resulting in the definition of unique evolutionarily significant units in both. These results suggest that the implementation of global conservation programs at regional scales would likely result in the loss of important components of biodiversity in these ecosystems, and underscore the need for caution in designing effective conservation strategies.
Palabras claves: AFLP, Carex gayana, Genetic diversity, Patosia clandestina, Population differentiation, Evolutionarily significant units
Referencia APA: Troncoso, A. J., Bertin, A., Osorio, R., Arancio, G., & Gouin, N. (2017). Comparative population genetics of two dominant plant species of high Andean wetlands reveals complex evolutionary histories and conservation perspectives in Chile’s Norte Chico. Conservation Genetics, 18(5), 1047-1060. https://doi.org/10.1007/s10592-017-0957-3
On the indiscriminate use of imported emission factors in environmental impact assessment: A case study in Chile
Bernal, M. F., Oyarzún, J., & Oyarzún, R.
Environmental Impact Assessment (EIA) aims to determine if the environmental effect of an activity or project complies with standards and regulations. A primary component of the environment to evaluate is air and the effect that various activities can have on its quality. To this end, emission factors (EFs), which are empirical coefficients or mathematical relationships, are normally used. The present research critically analyzes the implications and consequences of using imported EFs in environmental impact studies (EISs), taking as case of study the situation in Chile. Among the main results, the widespread use of EFs in EISs in the country and the lack of assessments of their actual applicability stand out. In addition, the official guidelines related to emissions estimation that are used for EIA in the country mostly include EFs derived elsewhere, without considering the recommendations or restrictions that the original sources indicate for their use. Finally, the broad use of default values defined for the Metropolitan Region in Central Chile, is highly questionable for a country that extends north-south along more than 35° of latitude, with wide variability in climate, traffic conditions, population, soil types, etc. Finally, it is very likely that situations similar to those observed in the present work occurs in other countries with young environmental impact assessment systems, and therefore, that the results herein presented should be of general interest and relevance.
Palabras claves: Empirical models, Law 20417, Air quality, Environmental management
Referencia APA: Bernal, M. F., Oyarzún, J., & Oyarzún, R. (2017). On the indiscriminate use of imported emission factors in environmental impact assessment: A case study in Chile. Environmental Impact Assessment Review, 64, 123-130. https://doi.org/10.1016/j.eiar.2017.03.006
A simple approach for the analysis of the structural-geologic control of groundwater in an arid rural, mid-mountain, granitic and volcanic-sedimentary terrain: The case of the Coquimbo Region, North-Central Chile
Oyarzún, R., Oyarzún, J., Fairley, J. P., Núñez, J., Gómez, N., Arumí, J. L., & Maturana, H.
A practical approach for the assessment of surface water and groundwater resources in rain-fed mid-mountain domains of arid to semi-arid zones is much needed, especially in rural areas for which groundwater is the only reliable and permanent water supply source. This is the case in the Coquimbo region (29°15′- 32°10′ S latitude) of north-central Chile, where groundwater is needed for human consumption but also for agricultural and mining activities at a small to medium scale. This paper examines the usefulness of community knowledge, as encoded in the historical record, for identifying water resources. The existing record of wells and springs in the Coquimbo region is used as a guide to the identification and characterization of structural patterns that may influence the distribution of water resources. The proposed approach combines simple graphical, statistical and geostatistical methods to identify patterns, likely related to local and regional structural controls that influence the distribution of groundwater resources. In the Coquimbo area, these influences tend to align in NW and NE orientations that approximately coincide with regional geological trends. The methodology presented has the potential to form a first step in the search for additional water resources in the Coquimbo region, and may be useful for targeting detailed field studies on the basis of community and historical knowledge in many arid and semi-arid rural areas.
Palabras claves: Wells, Springs, Rain-fed area, Drylands, Geohydrology
Referencia APA: Oyarzún, R., Oyarzún, J., Fairley, J. P., Núñez, J., Gómez, N., Arumí, J. L., & Maturana, H. (2017). A simple approach for the analysis of the structural-geologic control of groundwater in an arid rural, mid-mountain, granitic and volcanic-sedimentary terrain: The case of the Coquimbo Region, North-Central Chile. Journal of Arid Environments, 142, 31-35. https://doi.org/10.1016/j.jaridenv.2017.03.003
Landscape connectivity among remnant populations of guanaco (Lama guanicoe Müller, 1776) in an arid region of Chile impacted by global change
Espinoza, M. I., Gouin, N., Porcile, F. A. S., Aspe, D. L., & Bertin, A.
Connectivity between populations plays a key role in the long-term persistence of species in fragmented habitats. This is of particular concern for biodiversity preservation in drylands, since water limited landscapes are typically characterized by little suitable habitat cover, high habitat fragmentation, harsh matrices, and are being rapidly degraded at a global scale. In this study, we modelled landscape connectivity between 11 guanaco Lama guanicoe populations in Chile’s arid Norte Chico, a region that supports the last remnant coastal populations of this emblematic herbivore indigenous to South America. We produced a habitat suitability model to derive a regional surface resistance map, and used circuit theory to map functional connectivity, investigate the relative isolation between populations, and identify those that contribute most to the patch connectivity network. Predicted suitable habitat for L. guanicoe represented about 25% of the study region (i.e., 29,173 km2) and was heterogeneously distributed along a continuous stretch along the Andes, and discontinuous patches along the coast. As a result, we found that high connectivity current flows in the mid and high Andes formed a wide, continuous connectivity corridor, enabling connectivity between all high Andean populations. Coastal populations, in contrast, were more isolated. These groups demonstrate no inter-population connectivity between themselves, only with higher altitude populations, and for two of them, animal movement was linked to the effectiveness of wildlife crossings along the Pan-American highway. Our results indicate that functional connectivity is an issue of concern for L. guanicoe in Chile’s Norte Chico, implying that future conservation and management plans should emphasize strategies aimed at conserving functional connectivity between coastal and Andean populations, as well as the protection of habitat patches likely to act as stepping stones within the connectivity network.
Referencia APA: Espinoza, M. I., Gouin, N., Porcile, F. A. S., Aspe, D. L., & Bertin, A. (2017). Landscape connectivity among remnant populations of guanaco (Lama guanicoe Müller, 1776) in an arid region of Chile impacted by global change. PeerJ PrePrints. https://doi.org/10.7717/peerj.4429
Population variation in drought-resistance strategies in a desert shrub along an aridity gradient: Interplay between phenotypic plasticity and ecotypic differentiation
Carvajal, D. E., Loayza, A. P., Rios, R. S., Gianoli, E., & Squeo, F. A.
Adaptations to drought of deciduous and evergreen species in arid environments are associated with resource-acquisitive (drought avoidance) and resource-conservative (drought tolerance) strategies of water use, respectively. Few studies have addressed whether a single species can exhibit both drought avoidance and drought tolerance strategies along an aridity gradient, and none have evaluated the role of ecotypic differentiation and phenotypic plasticity in shaping such strategies. In the desert shrub Encelia canescens, distributed along an aridity gradient in the Atacama Desert, we hypothesized that populations located in sites with lower and more variable rainfall (northern populations) would exhibit patterns of trait means and plasticity reflecting a water-conservative strategy, while populations in less arid and less variable environments (southern populations) would exhibit a water-acquisitive strategy. We also tested the hypothesis that functional variation in trait means and plasticity are not alternative mechanisms of adaptation to the environment. In a common garden experiment using plants from seeds collected from six populations spanning the species distribution range we found that plants from the northern populations were smaller, had fewer leaves, lower photosynthetic rates and had higher plasticity for root:shoot ratios and lower plasticity for leaf shedding, suggesting a resource-conservative strategy compared to plants from the southern populations, which showed a resource-acquisitive strategy. We found no association between variation in trait means and plasticity, which indicates that these are not alternative mechanisms of plant adaptation to environmental variation. Results suggest that E. canescens populations have evolved different strategies to cope with drought stress depending on their location along the Atacama Desert’s aridity gradient. This gives us a better understanding of the ecological and evolutionary processes that drive phenotypic variation among populations.
Palabras claves: Atacama desert, Arid environments, Drought resistance, Intraspecific variation, Phenotypic plasticity, Encelia canescens
Referencia APA: Carvajal, D. E., Loayza, A. P., Rios, R. S., Gianoli, E., & Squeo, F. A. (2017). Population variation in drought-resistance strategies in a desert shrub along an aridity gradient: Interplay between phenotypic plasticity and ecotypic differentiation. Perspectives in Plant Ecology, Evolution and Systematics, 29, 12-19. https://doi.org/10.1016/j.ppees.2017.10.001
Conspecific plants are better ‘nurses’ than rocks: consistent results revealing intraspecific facilitation as a process that promotes establishment in a hyper-arid environment
Loayza, A. P., Herrera-Madariaga, M. A., Carvajal, D. E., García-Guzmán, P., & Squeo, F. A.
Harsh environmental conditions in arid ecosystems limit seedling recruitment to microhabitats under nurse structures, such as shrubs or rocks. These structures, however, do not necessarily afford the same benefits to plants because nurse rocks provide only physical nurse effects, whereas nurse plants can provide both physical and biological nurse effects. Nevertheless, if the nurse plant is a conspecific, the benefits it provides may be outweighed by higher mortality due to negative density-dependent processes; consequently, negative density-dependence is expected to limit plants from acting as nurses to their own seedlings. The degree to which an abiotic nurse may be more beneficial than a conspecific one remains largely unexplored. Here, we examine the role and elucidate the mechanisms by which conspecific plants and rocks promote plant establishment in a hyper-arid desert. For 4 years, we examined establishment patterns of Myrcianthes coquimbensis (Myrtaceae), a threatened desert shrub that recruits solely in rock cavities and under conspecific shrubs. Specifically, we characterized these microhabitats, as well as open interspaces for comparison, and conducted germination, seed removal and seedling survival experiments. Our results revealed that conspecific shrubs and nurse rocks modified environmental conditions in similar ways; soil and air temperatures were lower, and water availability was higher than in open interspaces. We found no evidence on negative density-dependent recruitment: seed removal was lowest and seedling emergence highest under conspecific plants, moreover seedling survival probabilities were similar in rock cavities and under conspecific plants. We conclude that the probability of establishment was highest under conspecific plants than in other microhabitats, contrasting what is expected under the Janzen–Connell recruitment model. We suggest that for species living in stressful environments, population regulation may be a function of positive density-dependence and intraspecific facilitation may be a process that promotes the persistence of some plant species within a community.
Referencia APA: Loayza, A. P., Herrera-Madariaga, M. A., Carvajal, D. E., García-Guzmán, P., & Squeo, F. A. (2017). Conspecific plants are better ‘nurses’ than rocks: consistent results revealing intraspecific facilitation as a process that promotes establishment in a hyper-arid environment. AoB Plants, 9(6), plx056. https://doi.org/10.1093/aobpla/plx056
Uso del Test de Rendimiento Continuo de Conners para diferenciar niños normales y con TDAH en Chile.
Salas-Bravo, S., Gonzalez-Arias, M., Araya-Piñones, A., Valencia-Jimenez, M., & Oyarce-Cortes, S.
El trastorno de déficit atencional con hiperactividad (TDAH) constituye uno de los cuadros de mayor prevalencia durante la niñez. El presente trabajo se focalizó en evaluar si el Test de Rendimiento Continuo de Conners era capaz de discriminar entre niños con y sin TDAH diagnosticados por el docente. Se conformó una muestra no probabilística de 30 niños escolares (15 clínicos y 15 normales) a través de la aplicación del cuestionario de atención. Todos los niños completaron la aplicación del test computarizado de Conners. Se observaron diferencias significativas entre la muestra normal y clínica. Todos los niños seleccionados como normales no encajaron el perfil clínico. Solo el 50% de los casos considerados con TDAH encajaron el perfil clínico. Se analizan las implicancias del sobre/diagnóstico del trastorno.
Palabras claves: TDAH, Test de rendimiento continuo, Diagnóstico, Escalas diagnósticas
Referencia APA: Salas-Bravo, S., Gonzalez-Arias, M., Araya-Piñones, A., Valencia-Jimenez, M., & Oyarce-Cortes, S. (2017). Uso del Test de Rendimiento Continuo de Conners para diferenciar niños normales y con TDAH en Chile. Terapia Psicológica, 35(3), 283-291. https://scielo.conicyt.cl/pdf/terpsicol/v35n3/0716-6184-terpsicol-35-03-0283.pdf
Surface water quality in a sulfide mineral‐rich arid zone in North‐Central Chile: Learning from a complex past, addressing an uncertain future
Flores, M., Núñez, J., Oyarzún, J., Freixas, G., Maturana, H., & Oyarzún, R.
This study presents an analysis of up to 30 years of hydrological variables and selected waterquality parameters (pH, SO4, Fe, Cu, and As) in the upper area of the Elqui River basin inNorth‐Central Chile. A correlation analysis determined statistically significant positive relation-ship for SO4‐Cu, Fe‐As, and Fe‐Cu. In terms of historical behaviour, no statistically significanttrends were detected for precipitation or temperature. In contrast, for flow, there is an overalldecreasing pattern for the entire area of study, although only in one case this trend was statisti-cally significant. Along with the aforementioned analysis, a characterization of the flow‐waterquality relationships is considered for the time period analyzed. Although erratic behaviours wereconfirmed, a negative (i.e., inverse) flow‐concentration relationship was identified for SO4, a pos-itive (i.e., direct) relationship for Fe, and undefined relationships for As and Cu were obtained.From these analyses and based on previous studies on projections regarding climate change forthe Andean region, and in particular for the upper Elqui zone, an estimation of the possible effectsof the change in water regimes on water quality in the area of study is developed. It is likely that adecrease in surface flow, as a consequence of climate change could translate into improvementsin water quality in terms of Fe and eventually As and Cu, but into an impairment in the case ofSO4. In any case, this is a complex situation that demands special attention in the face of indus-trial activities that could be developed in tributaries like the Claro River, which currently play animportant role in depurating or diluting contaminants in the waters of the Elqui River. Finally, itshould be noted that this study addresses an issue that goes beyond the local interest and couldbe used as a reference to compare other transitional environments containing sulphide ores orareas of hydrothermal alterations, which are considered to be highly vulnerable to climate changeand variability.
Palabras claves: Acid rock drainage, Andean river, arid zone, Coquimbo region
Referencia APA: Flores, M., Núñez, J., Oyarzún, J., Freixas, G., Maturana, H., & Oyarzún, R. (2017). Surface water quality in a sulfide mineral‐rich arid zone in North‐Central Chile: Learning from a complex past, addressing an uncertain future. Hydrological Processes, 31(3), 498-513. http://doi.dx.org/10.1002/hyp.11086
A framework for the classification Chilean terrestrial ecosystems as a tool for achieving global conservation targets
Martínez-Tilleria, K., Núñez-Ávila, M., León, C., Pliscoff, P., Squeo, F., & Armesto, J.
Countries that are signatories of the Convention of Biological Diversity are committed to the goal of protecting 17% of their natural ecosystems by 2020. The lack of an up-to-date, operational classification and cartography of regional ecosystems seriously limits the assessment of progress towards this goal. Here, we present a broad ecosystem framework, which combines land use, functional traits of dominant plant species, and climatic factors for the classification of terrestrial ecosystems and apply this framework to classify Chilean terrestrial ecosystems. This new classification is consistent with the recently proposed IUCN framework to assess ecosystem conservation status. Using this framework, we identified and described 30 Chilean terrestrial ecosystems, including land units of natural and anthropogenic origin. We also provide a cartographic representation of ecosystems for land planning purposes and an overall assessment of their conservation status. We evaluated the representation of the 30 ecosystems in the Chilean National System of Protected Areas (NSPA) and in Private Protected Areas (PPA), identifying 15 ecosystems underrepresented (below the 17% target) in the NSPA, in contrast to only 11 when the area of NSPA+PPA was considered. The proposed classification can be broadly applicable to assess the conservation status of ecosystems elsewhere, using similar conceptual and methodological tools. The development of functional ecosystem classifications for different countries must be encouraged to facilitate monitoring of global conservation targets.
Palabras claves: Ecosystem approach, Biodiversity conservation, Functional traits, Protected areas
Referencia APA: Martínez-Tilleria, K., Núñez-Ávila, M., León, C., Pliscoff, P., Squeo, F., & Armesto, J. (2017). A framework for the classification Chilean terrestrial ecosystems as a tool for achieving global conservation targets. Biodiversity And Conservation, 26(12), 2857-2876. http://dx.doi.org/10.1007/s10531-017-1393-x
The importance of scale-dependent ravine characteristics on breeding-site selection by the Burrowing Parrot, Cyanoliseus patagonus
Ramirez-Herranz, M., Rios, R., Vargas-Rodriguez, R., Novoa-Jerez, J. and Squeo, F.
In birds, the environmental variables and intrinsic characteristics of the nest have important fitness consequences through its influence on the selection of nesting sites. However, the extent to which these variables interact with variables that operate at the landscape scale, and whether there is a hierarchy among the different scales that influences nest-site selection, is unknown. This interaction could be crucial in burrowing birds, which depend heavily on the availability of suitable nesting locations. One representative of this group is the burrowing parrot, Cyanoliseus patagonus that breeds on specific ravines and forms large breeding colonies. At a particular site, breeding aggregations require the concentration of adequate environmental elements for cavity nesting, which are provided by within ravine characteristics. Therefore, intrinsic ravine characteristics should be more important in determining nest site selection compared to landscape level characteristics. Here, we assess this hypothesis by comparing the importance of ravine characteristics operating at different scales on nest-site selection and their interrelation with reproductive success. We quantified 12 characteristics of 105 ravines in their reproductive habitat. For each ravine we quantified morphological variables, distance to resources and disturbance as well as nest number and egg production in order to compare selected and non-selected ravines and determine the interrelationship among variables in explaining ravine differences. In addition, the number of nests and egg production for each reproductive ravine was related to ravine characteristics to assess their relation to reproductive success. We found significant differences between non-reproductive and reproductive ravines in both intrinsic and extrinsic characteristics. The multidimensional environmental gradient of variation between ravines, however, shows that differences are mainly related to intrinsic morphological characteristics followed by extrinsic variables associated to human disturbance. Likewise, within reproductive ravines, intrinsic characteristics are more strongly related to the number of nests. The probability of producing eggs, however, was related only to distance to roads and human settlements. Patterns suggest that C. patagonus mainly selects nesting sites based on intrinsic morphological characteristics of ravines. Scale differences in the importance of ravine characteristics could be a consequence of the particular orography of the breeding habitat. The arrangement of resources is associated to the location of the gullies rather than to individual ravines, determining the spatial availability and disposition of resources and disturbances. Thus, nest selection is influenced by intrinsic characteristics that maximize the fitness of individuals. Scaling in nest-selection is discussed under an optimality approach that partitions patch selection based on foraging theory.
Palabras claves: Nesting site, Burrowing bird, Intrinsic morphological characteristic, Foraging, Landscape variables.
Referencia APA: Ramirez-Herranz, M., Rios, R., Vargas-Rodriguez, R., Novoa-Jerez, J. and Squeo, F. (2017). The importance of scale-dependent ravine characteristics on breeding-site selection by the Burrowing Parrot, Cyanoliseus patagonus. PeerJ, 5, p.e3182. https://doi.org/10.7717/peerj.3182
Genetic variation of loci potentially under selection confounds species–genetic diversity correlations in a fragmented habitat
Bertin, A., Gouin, N., Baumel, A., Gianoli, E., Serratosa, J., Osorio, R. and Manel, S.
Positive species–genetic diversity correlations (SGDCs) are often thought to result from the parallel inﬂuence of neutral processes on genetic and species diversity. Yet, con-founding effects of non-neutral mechanisms have not been explored. Here, we investigate the impact of non-neutral genetic diversity on SGDCs in high Andean wetlands.We compare correlations between plant species diversity and genetic diversity (GD)calculated with and without loci potentially under selection (outlier loci). The study system includes 2188 specimens from ﬁve species (three common aquatic macroinvertebrate and two dominant plant species) that were genotyped for 396 ampliﬁed fragment length polymorphism loci. We also appraise the importance of neutral processes onSGDCs by investigating the inﬂuence of habitat fragmentation features. Signiﬁcant positive SGDCs were detected for all ﬁve species (mean SGDC = 0.52 0.05). While only a few outlier loci were detected in each species, they resulted in signiﬁcant decreases in GD and in SGDCs. This supports the hypothesis that neutral processes drive species–genetic diversity relationships in high Andean wetlands. Unexpectedly, the effects on genetic diversity GD of the habitat fragmentation characteristics in this study increased with the presence of outlier loci in two species. Overall, our results reveal pitfalls in using habitat features to infer processes driving SGDCs and show that a few loci potentially under selection are enough to cause a signiﬁcant downward bias in SGDC. Investigating confounding effects of outlier loci thus represents a useful approach to evidence the contribution of neutral processes on species–genetic diversity relationships.
Palabras claves: Community genetics, connectivity, habitat, high Andean wetlands, outlier loci,species–genetic diversity correlations.
Referencia APA: Bertin, A., Gouin, N., Baumel, A., Gianoli, E., Serratosa, J., Osorio, R. and Manel, S. (2017). Genetic variation of loci potentially under selection confounds species-genetic diversity correlations in a fragmented habitat. Molecular Ecology, 26(2), pp.431-443. dx.doi.org/10.1111/mec.13923