CEAZA
Assessing the importance of human activities for the establishment of the invasive Poa annua in Antarctica.
Molina-Montenegro, M., Carrasco-Urra, F., Acuña-Rodríguez, I., Oses, R., Torres-Díaz, C., & Chwedorzewska, K.
Because of its harsh environmental conditions and remoteness, Antarctica is often considered to be at low risk of plant invasion. However, an increasing number of reports have shown the presence and spread of non-native plants in Antarctica; it is therefore important to study which factors control the invasion process in this ecosystem. Here, we assessed the role of different human activities on the presence and abundance of the invasive Poa annua. In addition, we performed a reciprocal transplant experiment in the field, and a manipulative experiment of germination with P. annua and the natives Colobanthus quitensis and Deschampsia antarctica, in order to unravel the effects of physical soil disturbance on the establishment and survival of P. annua. We found a positive correlation between abundance of P. annua and level of soil disturbance, and that survival of P. annua was 33% higher in sites with disturbed soil than non-disturbed. Finally, we found that disturbance conditions increased germination for P. annua, whereas for native species germination in experimentally disturbed soil was either unchanged or reduced compared to undisturbed soil. Our results indicate that human activities that modify abiotic soil characteristics could play an important role in the abundance of this invasive species. If the current patterns of human activities are maintained in Antarctica, the establishment success and spread of P. annua could increase, negatively affecting native flora.
Año: 2014
Palabras claves: Alien species; Colobanthus quitensis; Deschampsia antarctica; human disturbance; Poa annua; tourists.
Referencia APA: Molina-Montenegro, M., Carrasco-Urra, F., Acuña-Rodríguez, I., Oses, R., Torres-Díaz, C., & Chwedorzewska, K. (2014). Assessing the importance of human activities for the establishment of the invasive Poa annua in Antarctica. Polar Research, 33(0).
Differential susceptibility to the Withering Syndrome agent and renal coccidia in juvenile Haliotis rufescens, Haliotis discus hannai and the interspecific hybrid.
González, R., Lohrmann, K., Pizarro, J., & Brokordt, K.
Withering Syndrome (WS) is a pathogenic chronic disease caused by the intracellular rickettsial-like bacterium “Candidatus Xenohaliotis californiensis” (WS-RLOs), which affects many abalone species. The renal coccidium (Margolisiella haliotis) has often been observed concurrent with WS infection. The red abalone Haliotis rufescens is a very susceptible species to WS and is also infected by the coccidium M. haliotis. In contrast, the Japanese abalone Haliotis discus hannai is not infected by these parasites. Interspecific hybridization is a method for improving important traits in animal husbandry. The objective of this study was to determine susceptibility to WS-RLO and M. haliotis infection in the hybrid generated from a cross between red and Japanese abalones. Juveniles from both species and the interspecific hybrid were challenged by exposure to effluent from red abalone adults infected with both parasites. The animals were analyzed by histology at 130 days post-challenge. A 33% prevalence WS-RLOs was observed in the red abalone H. rufescens, whereas a 20% prevalence was observed in the hybrid. Infections were graded on a scale of 0–3. Of these red abalones infected, 53% presented grade 1 infection intensity, 10% had grade 2 infections, and 50% had grade 3 infections. However, the hybrids only presented intensities at the extremes of the scale; of those infected 33% showed grade 1 infections and 66% had grade 3 infections. The coccidium prevalence was 7% in red abalone individuals and 13% in the hybrid abalone. In contrast, the Japanese abalone did not present infections with either parasite. As with the prevalence, the infection intensities for the coccidium were higher in the hybrid abalone; of those infected 25% had grade 2 infections, and 75% had grade 3 infections, but the red abalone presented only grade 2 infection intensities. Therefore, the hybrid did not inherited non-susceptibility or resistance characteristics of the parental H. discus hannai and possessed biological conditions that could foster development of both parasites. Development of a culture based on this hybrid abalone should consider its susceptibility to infection by coccidian, WS-RLOs and the potential for developing the WS disease.
Año: 2014
Palabras claves: Withering Syndrome; Candidatus Xenohaliotis californiensis; Coccidium Margolisiella haliotis; Haliotis rufescens; Haliotis discus hannai; Abalone hybrid.
Referencia APA: González, R., Lohrmann, K., Pizarro, J., & Brokordt, K. (2014). Differential susceptibility to the Withering Syndrome agent and renal coccidia in juvenile Haliotis rufescens, Haliotis discus hannai and the interspecific hybrid. Journal Of Invertebrate Pathology, 116, 13-17
Albedo over rough snow and ice surfaces.
Lhermitte, S., Abermann, J., & Kinnard, C.
Both satellite and ground-based broadband albedo measurements over rough and complex terrain show several limitations concerning feasibility and representativeness. To assess these limitations and understand the effect of surface roughness on albedo, firstly, an intrasurface radiative transfer (ISRT) model is combined with albedo measurements over different penitente surfaces on Glaciar Tapado in the semi-arid Andes of northern Chile. Results of the ISRT model show effective albedo reductions over the penitentes up to 0.4 when comparing the rough surface albedo relative to the albedo of the flat surface. The magnitude of these reductions primarily depends on the opening angles of the penitentes, but the shape of the penitentes and spatial variability of the material albedo also play a major role.
Secondly, the ISRT model is used to reveal the effect of using albedo measurements at a specific location (i.e., apparent albedo) to infer the true albedo of a penitente field (i.e., effective albedo). This effect is especially strong for narrow penitentes, resulting in sampling biases of up to ±0.05. The sampling biases are more pronounced when the sensor is low above the surface, but remain relatively constant throughout the day. Consequently, it is important to use a large number of samples at various places and/or to locate the sensor sufficiently high in order to avoid this sampling bias of surface albedo over rough surfaces. Thirdly, the temporal evolution of broadband albedo over a penitente-covered surface is analyzed to place the experiments and their uncertainty into a longer temporal context. Time series of albedo measurements at an automated weather station over two ablation seasons reveal that albedo decreases early in the ablation season. These decreases stabilize from February onwards with variations being caused by fresh snowfall events. The 2009/2010 and 2011/2012 seasons differ notably, where the latter shows lower albedo values caused by larger penitentes. Finally, a comparison of the ground-based albedo observations with Landsat and MODIS (Moderate Resolution Imaging Spectroradiometer)-derived albedo showed that both satellite albedo products capture the albedo evolution with root mean square errors of 0.08 and 0.15, respectively, but also illustrate their shortcomings related to temporal resolution and spatial heterogeneity over small mountain glaciers.
Año: 2014
Palabras claves:
Referencia APA: Lhermitte, S., Abermann, J., & Kinnard, C. (2014). Albedo over rough snow and ice surfaces. The Cryosphere, 8(3), 1069-1086.
Antarctic Ecology One Century after the Conquest of the South Pole: How Much Have We Advanced?.
Acuna-Rodriguez, I., Gianoli, E., Carrasco-Urra, F., Stotz, G., Salgado-Luarte, C., Rios, R., & Molina-Montenegro, M.
The knowledge derived from Antarctic ecology may be fundamental for facing the complex environmental future of the world. As an early-warning system, a deep understanding of Antarctic ecosystems is therefore needed, but Antarctic ecology as a field is still very young and currently under consolidation. Around the world, 55 nations are involved in this task through their research programs, and, considering the importance of this joint effort, we evaluate some basic trends of their publications through a wide bibliographical review of Antarctic ecology. All ecology-related Antarctic papers published for 106 years (1904–2010) were reviewed. A lack of population and ecosystem research was observed, even in Animalia, the most studied kingdom. The publications originated mainly in developed countries; however, emerging countries have increased their participation in recent years. The current trends of Antarctic ecology as a field show a constant but low representation in both Antarctic science and ecology.
Año: 2014
Palabras claves: Antarctic ecology, scientific publications, Antarctic research, international territorial administration, Web of Science
Referencia APA: Acuna-Rodriguez, I., Gianoli, E., Carrasco-Urra, F., Stotz, G., Salgado-Luarte, C., Rios, R., & Molina-Montenegro, M. (2014). Antarctic Ecology One Century after the Conquest of the South Pole: How Much Have We Advanced?. Bioscience, 64(7), 593-600.
Quinoa biodiversity and sustainability for food security under climate change.
Ruiz, K., Biondi, S., Oses, R., Acuña-Rodríguez, I., Antognoni, F., & Martinez-Mosqueira, E. et al.
Climate change is rapidly degrading the conditions of crop production. For instance, increasing salinization and aridity is forecasted to increase in most parts of the world. As a consequence, new stress-tolerant species and genotypes must be identified and used for future agriculture. Stress-tolerant species exist but are actually underutilized and neglected. Many stress-tolerant species are indeed traditional crops that are only cultivated by farmers at a local scale. Those species have a high biodiversity value. Besides, the human population will probably reach nine billion within coming decades. To keep pace with population growth, food production must increase dramatically despite the limited availability of cultivable land and water. Here, we review the benefits of quinoa, Chenopodium quinoa Willd., a seed crop that has endured the harsh bioclimatic conditions of the Andes since ancient times. Although the crop is still mainly produced in Bolivia and Peru, agronomic trials and cultivation are spreading to many other countries. Quinoa maintains productivity on rather poor soils and under conditions of water shortage and high salinity. Moreover, quinoa seeds are an exceptionally nutritious food source, owing to their high protein content with all essential amino acids, lack of gluten, and high content of several minerals, e.g., Ca, Mg, Fe, and health-promoting compounds such as flavonoids. Quinoa has a vast genetic diversity resulting from its fragmented and localized production over the centuries in the Andean region, from Ecuador to southern Chile, and from sea level to the altiplano. Quinoa can be adapted to diverse agroecological conditions worldwide. Year 2013 has therefore been declared the International Year of Quinoa by the United Nations Food and Agriculture Organization. Here, we review the main characteristics of quinoa, its origin and genetic diversity, its exceptional tolerance to drought and salinity, its nutritional properties, the reasons why this crop can offer several ecosystem services, and the role of Andean farmers in preserving its agrobiodiversity. Finally, we propose a schematic model integrating the fundamental factors that should determine the future utilization of quinoa, in terms of food security, biodiversity conservation, and cultural identity.
Año: 2014
Palabras claves: Agrobiodiversity, Quinoa, Food security, Food quality, Stress tolerance, Andean farmers, Sustainability.
Referencia APA: Ruiz, K., Biondi, S., Oses, R., Acuña-Rodríguez, I., Antognoni, F., & Martinez-Mosqueira, E. et al. (2014). Quinoa biodiversity and sustainability for food security under climate change. A review. Agronomy For Sustainable Development, 34(2), 349-359.
Water Quality Assessment of the Mining-Impacted Elqui River Basin, Chile.
Ribeiro, L., Kretschmer, N., Nascimento, J., Buxo, A., Rötting, T., & Soto, G., Soto, M., Oyarzún, J., Maturana, H., Oyarzún, R.
Multivariate data analysis techniques were used to identify the interrelationships between the physical–chemical analyses of 22 parameters sampled monthly from 1991 to 2007 at 16 monitoring stations along the Elqui river and its tributaries to characterize the scale of the geogenic and anthropogenic impacts on the river’s water quality. Principal component analysis was used to identify the differences and similarities between variables in the watershed. Factorial indices, computed to highlight the sections of the river and tributaries more influenced by hydrothermal, mining or agricultural activities, made it possible to synthesize groups of parameters with similar characteristics into a single value.
Año: 2014
Palabras claves: Acid drainage, Arid zones, Elqui river, Mining pollution, PCA.
Referencia APA: Ribeiro, L., Kretschmer, N., Nascimento, J., Buxo, A., Rötting, T., & Soto, G., Soto, M., Oyarzún, J., Maturana, H., Oyarzún, R. (2014). Water Quality Assessment of the Mining-Impacted Elqui River Basin, Chile. Mine Water And The Environment, 33(2), 165-176.
EltonTraits 1.0: Species-level foraging attributes of the world’s birds and mammals.
Wilman, H., Belmaker, J., Simpson, J., de la Rosa, C., Rivadeneira, M., & Jetz, W.
Species are characterized by physiological, behavioral, and ecological attributes that are all subject to varying evolutionary and ecological constraints and jointly determine species' role and function in ecosystems. Attributes such as diet, foraging strata, foraging time, and body size, in particular, characterize a large portion of the “Eltonian” niches of species. Here we present a global species-level compilation of these key attributes for all 9993 and 5400 extant bird and mammal species derived from key literature sources. Global handbooks and monographs allowed the consistent sourcing of attributes for most species. For diet and foraging stratum we followed a defined protocol to translate the verbal descriptions into standardized, semiquantitative information about relative importance of different categories. Together with body size (continuous) and activity time (categorical) this enables a much finer distinction of species' foraging ecology than typical categorical guild assignments allow. Attributes lacking information for specific species are flagged, and interpolated values based on taxonomy are provided instead. The presented data set is limited by, among others, these select cases missing observed data, by errors and uncertainty in the expert assessment as presented in the literature, and by the lack of intraspecific information. However, the standardized and transparent nature and complete global coverage of the data set should support an array of potential studies in biogeography, community ecology, macroevolution, global change biology, and conservation. Potential uses include comparative work involving these traits as focal or secondary variables, ecological research on the trait or trophic structure of communities, or conservation science concerned with the loss of function among species or in ecosystems in a changing world. We hope that this publication will spur the sharing, collaborative curation, and extension of data to the benefit of a more integrative, rigorous, and global biodiversity science.
Año: 2014
Palabras claves: Bird; body size; diet; eco-informatics; foraging; function; mammal; mass; niche; stratum; traits; vertebrate.
Referencia APA: Wilman, H., Belmaker, J., Simpson, J., de la Rosa, C., Rivadeneira, M., & Jetz, W. (2014). EltonTraits 1.0: Species-level foraging attributes of the world's birds and mammals. Ecology, 95(7), 2027-2027.
Nutritional status affects the capacity of the snail Concholepas concholepas to synthesize Hsp70 when exposed to stressors associated with tidal regimes in the intertidal zone.
Jeno, K. & Brokordt, K.
Synthesis of the heat shock protein Hsp70 is one of the most important physiological mechanisms that intertidal organisms possess to counteract damage to macromolecules caused by stressors associated with the tidal cycle. However, the synthesis and activity of Hsp70 involves an elevated energetic cost. We evaluated the effect of the nutritional status (fed vs. starved for 2 weeks) of juvenile Concholepas concholepas mollusc on their capacity to synthesize Hsp70 during emersion (i.e. low tide) and immersion (i.e. high tide) at high temperatures (24 °C, e.g. summer conditions) and at low temperatures (7 °C, e.g. winter conditions). In addition, we evaluated whether Hsp70 is induced directly upon exposure to stress (emersion) or during recovery (re-immersion). Starvation decreased the content of stored energy substrates of juveniles as well as their ability to synthesize Hsp70 during emersion under thermal stress, especially at high temperatures. Additionally, analysis of environmental factors associated with laboratory simulation of tidal regimes indicated that juveniles in starvation, in contrast to fed juveniles, did not significantly increase their levels of Hsp70 during cold emersion (7 °C) or warm emersion (24 °C) or upon re-immersion. Induction of Hsp70 occurred during exposure to stress (low-tide conditions) and not when juveniles returned to “normal” conditions (high-tide conditions). Thus, the synthesis of Hsp70 for the juveniles of this intertidal snail species was coordinated and adapted to the tidal cycle, and the species responds in a similar way to hot and cold emersion conditions. The observed levels of Hsp70 reflect the ability of the individual to synthesize these proteins, which is dependent on the nutritional status of the individual.
Año: 2014
Palabras claves:
Referencia APA: Jeno, K. & Brokordt, K. (2014). Nutritional status affects the capacity of the snail Concholepas concholepas to synthesize Hsp70 when exposed to stressors associated with tidal regimes in the intertidal zone. Marine Biology, 161(5), 1039-1049.
Glacier meltwater flow paths and storage in a geomorphologically complex glacial foreland: The case of the Tapado glacier, dry Andes of Chile (30°S).
Pourrier, J., Jourde, H., Kinnard, C., Gascoin, S., & Monnier, S.
The Tapado catchment is located in the upper Elqui river basin (4000–5550 m) in northern Chile. It comprises the Tapado glacial complex, which is an assemblage of the Tapado glacier and the glacial foreland (debris-covered glacier, rock glacier, and moraines). Although the hydrological functioning of this catchment is poorly known, it is assumed to actively supply water to the lower semi-arid areas of the Elqui river basin. To improve our knowledge of the interactions and water transfers between the cryospheric compartment (glacier, debris-covered glacier, and rock glacier) and the hydrological compartment (aquifers, streams), the results of monitoring of meteorological conditions, as well as discharge, conductivity and temperature of streams and springs located in the Tapado catchment were analyzed. The hydrological results are compared to results inferred from a ground penetrating radar (GPR) survey of the underground structure of the glacial foreland. Water production from the Tapado glacier was shown to be highly correlated with daily and monthly weather conditions, particularly solar radiation and temperature. The resulting daily and monthly streamflow cycles were buffered by the glacial foreland, where underground transfers took place through complex flow paths. However, the development of a thermokarst drainage network in a portion of the glacial foreland enabled rapid concentrated water transfers that reduced the buffer effect. The glacial foreland was shown to act as a reservoir, storing water during high melt periods and supplying water to downstream compartments during low melt periods. GPR observations revealed the heterogeneity of the internal structure of the glacial foreland, which is composed of a mixture of ice and rock debris mixture, with variable spatial ice content, including massive ice lenses. This heterogeneity may explain the abovementioned hydrological behaviors. Finally, calculation of a partial hydrological budget confirmed the importance of the Tapado catchment in supplying water to lower areas of the Elqui river basin. Water production from, and transfer through, cryospheric compartments, and its subsequent interactions with hydrological compartments are key processes driving the summer water supply from the Tapado catchment.
Año: 2014
Palabras claves: Cryosphere hydrology; Debris-covered glacier; Rock glacier; Thermokarst; Water transfers; Semiarid Andes.
Referencia APA: Pourrier, J., Jourde, H., Kinnard, C., Gascoin, S., & Monnier, S. (2014). Glacier meltwater flow paths and storage in a geomorphologically complex glacial foreland: The case of the Tapado glacier, dry Andes of Chile (30°S). Journal Of Hydrology, 519, 1068-1083.
Rise and fall in diversity of Neogene marine vertebrates on the temperate Pacific coast of South America.
Villafaña, J. & Rivadeneira, M.
Año: 2014
Palabras claves:
Referencia APA: Villafaña, J. & Rivadeneira, M. (2014). Rise and fall in diversity of Neogene marine vertebrates on the temperate Pacific coast of South America. Paleobiology, 40(04), 659-674. http://dx.doi.org/10.1666/13069
Diversity of Quinoa in a Biogeographical Island: a Review of Constraints and Potential from Arid to Temperate Regions of Chile.
Bazile, D., Martínez, E., & Fuentes, F.
Chile, isolated by a hyper-arid desert in the north, the Andes Range to the east and the Pacific and Antarctic waters (west and south), has a highly endemic flora. This hotspot of biodiversity is in danger not only due to increasing desertification, but also because human activities can diminish agrobiodiversity. Quinoa (Chenopodium quinoa Willd.) is an Andean species producing highly nutritious grains, which almost disappeared from Chile during the Spanish colonization. Today less than 300 small-scale and highly isolated farmers still grow it as a rain-fed crop. This review describes the biogeographical-social context of quinoa in Chile, and its high genetic diversity as a product of a long domestication process, resulting in numerous local landraces whose conservation and use for breeding improved varieties is of paramount importance. We suggest the term “lighthouse crop” to emphasize its contribution to small scale ecological and bio diverse agriculture, particularly in stressful environments, to promote a healthier nutrition and more equitable markets in the world. Furthermore this crop and its exceptional nutritional properties were invoked by the United Nations Food and Agriculture Organization (FAO) to promote its use worldwide, and to declare 2013 the International Year of Quinoa.
Año: 2014
Palabras claves: Agrobiodiversity, agroecosystems, Chenopodium quinoa, conservation, cropping systems, lighthouse crop.
Referencia APA: Bazile, D., Martínez, E., & Fuentes, F. (2014). Diversity of Quinoa in a Biogeographical Island: a Review of Constraints and Potential from Arid to Temperate Regions of Chile. Not Bot Hort Agrobot Cluj, 42(2).
Multi-method assessment of connectivity between surface water and shallow groundwater: the case of Limarí River basin, north-central Chile.
Oyarzún, R., Barrera, F., Salazar, P., Maturana, H., Oyarzún, J., & Aguirre, E. et al.
A study that tests the applicability and consistency of independent but complementary approaches in the assessment of interactions between surface water and shallow groundwater within a water-stressed basin is described. The mostly agricultural Limarí basin in arid north-central Chile was chosen as a suitable case study. The analyses involved: (1) a connectivity index method, (2) hydrochemistry, and (3) water isotopic geochemistry. Chemical and isotopic data were obtained from two sampling campaigns conducted in April (fall) and December (summer) of 2011 in 22 sampling locations, which included surface water and groundwater. The results obtained by each of the methodologies were mutually consistent and indicate high connectivity conditions. Additionally, the relative contribution by different sources was assessed through end-member mixing analysis, and for reaches of the river that showed gaining conditions, the contribution of groundwater inflow to stream discharge was estimated. It is suggested that this multi-method approach is useful for the characterization of surface-water–groundwater interactions, since it at least represents a suitable starting point for obtaining basic information on these relationships. Thus, it may become the base for further studies in arid and semi-arid basins facing water management challenges.
Año: 2014
Palabras claves: Stable isotopes, RadonOver-allocated basin, Arid regions, Chile.
Referencia APA: Oyarzún, R., Barrera, F., Salazar, P., Maturana, H., Oyarzún, J., & Aguirre, E. et al. (2014). Multi-method assessment of connectivity between surface water and shallow groundwater: the case of Limarí River basin, north-central Chile. Hydrogeol J, 22(8), 1857-1873.