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.
Linking human activity and ecosystem condition to inform marine ecosystem based management.
Menzel, S., Kappel, C., Broitman, B., Micheli, F., & Rosenberg, A.
There is growing consensus that integrated marine management is needed. However, implementation of ecosystem-based management (EBM) faces major operational challenges, including accurately delineating the links between ecosystem components and benefits to humans, and quantifying trade-offs associated with different management decisions.
It is suggested using human activity level as an indicator of the benefit provided by marine ecosystems at a certain location in comparison with other locations and establishing links between human activity levels and ecological conditions.
This approach allows for the determination of what ecological conditions may provide the greatest human benefits and thus may be targets for management action.
This approach is used to investigate the link between scuba diving in the Monterey Bay area, California, USA, and different ecological characteristics of kelp forests. Diving intensity levels correlate with kelp persistence, suggesting that kelp persistence may be used as an indicator of benefits from diving and for evaluating the impact of potentially competing activities through their effects on kelp.
Overall, an operational definition of marine ecosystem services is provided and it is suggested that this method could be extended to a suite of different activities and systems and thus may become useful in considering trade-offs among different activities that depend upon the same ecosystem.
Año: 2013
Palabras claves: Ecosystem services; natural resource management; ecological indicators; Monterey Bay; California; kelp forest ecosystem; scuba diving; ecological production function; human benefits from ecosystems.
Referencia APA: Menzel, S., Kappel, C., Broitman, B., Micheli, F., & Rosenberg, A. (2013). Linking human activity and ecosystem condition to inform marine ecosystem based management. Aquatic Conserv: Mar. Freshw. Ecosyst., 23(4), 506-514.
The response of leaf respiration to water stress in Nothofagus species.
Sanhueza, C., Bascunan-Godoy, L., Corcuera, L., & Turnbull, M.
Nothofagus solandri is regarded as more tolerant to drought than Nothofagus menziesii in the field. However, the physiology of responses to water limitation in these species is not well understood. In this study, the thermal sensitivity of leaf respiration and its underlying metabolism in response to drought were investigated in mature trees and saplings. Respiration (R d) and photosynthesis (A max) were measured during drying and re-wetting cycles. In addition, respiratory pathway changes were evaluated by oxygen isotope fractionation and protein analyses. Under drought treatment in the glasshouse, both species showed similar photosynthetic performance, but under mild water stress N. solandri was able to increase A max. Under moderate water deficit (around −2 MPa), N. solandri increased respiration at a base temperature of 10°C (R 10) but then decreased it to initial values after re-watering. In N. menziesii, R 10 did not respond significantly to water-stress treatment. The temperature sensitivity of R d (Q 10 and E o) was unchanged for both species during the gradual deficit water treatment in the glasshouse. Although respiratory electron flow was mainly via the cytochrome pathway under all conditions, an increase in alternative oxidase/cytochrome oxidase protein content suggests that the alternative pathway is involved in modulating respiratory metabolism during the recovery after drought.
Año: 2013
Palabras claves: Alternative oxidase, cytochrome oxidase, drought, metabolism, New Zealand, trees.
Referencia APA: Sanhueza, C., Bascunan-Godoy, L., Corcuera, L., & Turnbull, M. (2013). The response of leaf respiration to water stress in Nothofagus species. New Zealand Journal Of Botany, 51(2), 88-103.
Analysis of benthic macroinvertebrates and biotic indices to evaluate water quality in rivers impacted by mining activities in northern Chile.
Alvial, I., Tapia, D., Castro, M., Duran, B., & Verdugo, C.
Catchments in the semiarid regions are especially susceptible to environmental perturbation associated with water scarcity, hydrological variations and overuse by anthropogenic activities. Using multivariate analysis to relate environmental and biological data, and diversity and biotic indices (ChBMWP, ChIBF), we analyzed the macroinvertebrate composition of 12 rivers of the semiarid region of northern Chile. A non-metric multidimensional scaling for macroinvertebrate taxa and a principal component analysis for environmental variables strongly separated upstream sites (e.g. Vacas Heladas and Malo Rivers), which presented low pH and high dissolved metal concentrations, from other sites. Effectively, CCA showed that metals and low pH, associated with the altitudinal gradient, determined the distributional patterns of macroinvertebrates in the Elqui catchment. The causes of these particular conditions could be related to geological processes and human impact. The biotic indices applied to the sampling sites corroborated and reflected these characteristics, with La Laguna and Turbio Rivers showing a diverse macroinvertebrate community and moderate to good water quality, and the Claro River showing favorable conditions for the development of aquatic biota, indicating its better quality relative to other stations. To the middle and low part of the basin, a change in the composition of the community was observed, with species that suggest an impact by an increase in organic matter, due to agricultural activities and urban settlements concentrated in this area. Our results suggest that macroinvertebrate taxa in northern Chile may be exceptional species, adapted to unfavorable geochemical conditions, and emphasize the need for protection of the semiarid basins of the region.
Año: 2013
Palabras claves: macro-invertebrates / biotic indices / multivariate analysis / semiarid region
Referencia APA: Alvial, I., Tapia, D., Castro, M., Duran, B., & Verdugo, C. (2013). Analysis of benthic macroinvertebrates and biotic indices to evaluate water quality in rivers impacted by mining activities in northern Chile. Knowledge And Management Of Aquatic Ecosystems, (407), 01.
Meteorological observations on the northern Chilean coast during VOCALS-REx.
Rutllant, J., Muñoz, R., & Garreaud, R.
Surface coastal observations from two automatic weather stations at Paposo (~25° S) and radiosonde observations at Paposo and Iquique (~20° S) were carried out during VOCALS-REx (VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment). Within the coastal marine boundary layer (MBL), sea–land breezes are superimposed on the prevailing southerlies, resulting in light northeasterly winds from midnight to early morning and strong southwesterlies in the afternoon. The prevailing northerlies above the MBL and below the top of the Andes are modulated by the onshore-offshore (zonal) flow forced by the diurnal cycle of surface heating/cooling along the western slope of the Andes. The daytime phase of this diurnal cycle is consistent with an enhanced afternoon coastal subsidence manifested in afternoon warming near the top of the subsidence inversion (~1.8 K at 800 hPa), lowering (~130 m) of its base (top of the MBL), and clearing of coastal Sc (stratocumulus) clouds. Results from a numerical simulation of the atmospheric circulation in a mean zonal cross section over the study area capture the afternoon zonal wind divergence and resulting subsidence of about 2 cm s−1 along a narrow (~10 km) coastal strip maximizing at around 800 hPa. Day-to-day variability in the MBL depth during VOCALS-REx shows sub-synoptic oscillations, aside from two major disruptions in connection with a deep trough and a cutoff low, as described elsewhere. These oscillations are phase-locked to those in sea-level pressure and afternoon alongshore southerlies, as found in connection with coastal lows farther south.
From 24-h forward trajectories issued from significant points at the coast and inland at the extremes of the diurnal cycle, it can be concluded that the strong mean daytime Andean pumping prevents any possibility of continental sulfur sources from reaching the free troposphere above the Sc cloud deck in at least a one-day timescale, under mean conditions. Conversely, coastal sources could contribute with sulfur aerosols preferentially in the morning, provided that the weak daytime inland flow becomes partially blocked by the coastal terrain.
Año: 2013
Palabras claves:
Referencia APA: Rutllant, J., Muñoz, R., & Garreaud, R. (2013). Meteorological observations on the northern Chilean coast during VOCALS-REx. Atmospheric Chemistry And Physics, 13(6), 3409-3422.
Anthropogenic marine debris in the coastal environment: A multi-year comparison between coastal waters and local shores.
Thiel, M., Hinojosa, I., Miranda, L., Pantoja, J., Rivadeneira, M., & Vásquez, N.
Anthropogenic marine debris (AMD) is frequently studied on sandy beaches and occasionally in coastal waters, but links between these two environments have rarely been studied. High densities of AMD were found in coastal waters and on local shores of a large bay system in northern-central Chile. No seasonal pattern in AMD densities was found, but there was a trend of increasing densities over the entire study period. While plastics and Styrofoam were the most common types of AMD both on shores and in coastal waters, AMD composition differed slightly between the two environments. The results suggest that AMD from coastal waters are deposited on local shores, which over time accumulate all types of AMD. The types and the very low percentages of AMD with epibionts point to mostly local sources. Based on these results, it can be concluded that a reduction of AMD will require local solutions.
Año: 2013
Palabras claves: Anthropogenic marine debris; Local shores; Coastal waters; Plastics; SE Pacific.
Referencia APA: Thiel, M., Hinojosa, I., Miranda, L., Pantoja, J., Rivadeneira, M., & Vásquez, N. (2013). Anthropogenic marine debris in the coastal environment: A multi-year comparison between coastal waters and local shores. Marine Pollution Bulletin, 71(1-2), 307-316
Daidzein and Genistein contents in seeds of quinoa (Chenopodium quinoa Willd.) from local ecotypes grown in arid Chile.
Lutz, M., Martínez, A., & Martínez, E.
The contents of bioactive compounds of quinoa (Chenopodium quinoa Willd.) are poorly known. We analyzed two isoflavones (daidzein and genistein) by HPLC in three local ecotypes of quinoa seeds from three different geographical and genetic regions in Chile: (a) Extreme North, with prevailing conditions of high temperature and dryness (local ecotype R49); (b) Center, with milder climate (local ecotype UdeC9); and (c) South, with cold, humid environment (local ecotype BO78). Genetic-driven differences among cultivars were tested by homogenizing the culture conditions of the three seed sources. In addition, seven commercial samples of quinoa purchased at local food markets were analyzed and compared to our experimental harvested seeds. In all samples daidzein content was higher than genistein (P < 0.05). The northern ecotype R49 exhibited higher content of isoflavones compared with the other two (UdeC9 and BO78), all grown under the same experimental conditions. Daidzein ranged from 1.15 (R49) to 0.70 (BO78) mg/100 g, while genistein varied from 0.25 (R49) to 0.05 (UdeC9) mg/100 g. Ecotype R49 had 1.6 and 1.7 fold higher daidzein contents than UdeC9 and BO78, respectively (P < 0.05). In the commercial samples, the daidzein/genistein ratio ranged from 25.2 to 3.9, daidzein ranged from 2.05 to 0.78 mg/100 g, and genistein ranged from 0.41 to 0.04 mg/100 g. To the best of our knowledge, this is the first report on the contents of daidzein and genistein in quinoa seeds. The study demonstrates that, besides its well-recognized nutritional value, quinoa possesses an excellent potential as a source of these health-promoting bioactive compounds.
Año: 2013
Palabras claves: Quinoa; Daidzein; Genistein; Isoflavones; Ecotypes.
Referencia APA: Lutz, M., Martínez, A., & Martínez, E. (2013). Daidzein and Genistein contents in seeds of quinoa (Chenopodium quinoa Willd.) from local ecotypes grown in arid Chile. Industrial Crops And Products, 49, 117-121.
Importance of geochemical factors in determining distribution patterns of aquatic invertebrates in mountain streams south of the Atacama Desert, Chile.
Alvial, I., Orth, K., Durán, B., Álvarez, E., & Squeo, F.
The ecology of macroinvertebrate communities in arid regions is still poorly understood. Here we examined how the community structure varied at spatial and temporal scales in streams and tributaries of the Huasco River in semi-arid region of Northern Chile. We expected that macroinvertebrate distribution may be responding to natural processes of mineralization described for Chilean semiarid basins. The relationships among biotic and abiotic variables were assessed through multivariate techniques (principal component analysis, non-metric multidimensional scaling, canonical correspondence analysis), and a two-way analysis of similarity was used to evaluate differences between basins and years (2007, 2008, and 2009). Significant differences in community structure and physical–chemical variables between basins (Del Carmen and Del Tránsito) were found, but not between years. Altitude, Mn, Al, Ca, Na, HCO3, and dissolved oxygen were the variables that best accounted for the communities distribution. In particular, high metals concentration in El Transito basin should determine low density and diversity of macroinvertebrates. Chironomidae, Ephydridae, and Glossiphoniidae were associated to waters with high metals content and acidic pH, whereas Baetidae, Hydroptilidae, and Blephariceridae were associated to sites with more favorable physical–chemical conditions. These results contribute to understand the ecological patterns of macroinvertebrates in arid regions and should lead to conservation and monitoring plans for this remote place.
Año: 2013
Palabras claves: Huasco basin, Desert climate, Macroinvertebrates, Biomonitoring, Habitat variables, Handling editor: Koen Martens
Referencia APA: Alvial, I., Orth, K., Durán, B., Álvarez, E., & Squeo, F. (2013). Importance of geochemical factors in determining distribution patterns of aquatic invertebrates in mountain streams south of the Atacama Desert, Chile. Hydrobiologia, 709(1), 11-25.