CEAZA
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.
Alimentos, Tecnologías Vegetales Y Paleoambiente En Las Aldeas Formativas De La Pampa Del Tamarugal, Tarapacá (ca. 900 AC-BOO DC).
García, M., Vidal, A., Mandakovic, V., Maldonado, A., Peña, M., & Belmonte, E.
Este trabajo pretende introducir a los usos e imaginarios relacionados con las plantas en las aldeas formativas de la Pampa del Tamarugal, Tarapacá (Chile). Se estudiaron los restos vegetales recuperados de las excavaciones de los sitios Pircas y Caserones, en la quebrada de Tarapacá, así como de Guatacondo 1 y Ramaditas, en la de Guatacondo. Estas aldeas poseen contextos domésticos, ceremoniales, mortuorios y de almacenaje, asociados a alimentos silvestres y cultivados, así como un amplio universo artefactual, principalmente en madera, que incluye materias primas, instrumentos y desechos de talla. Se concluye que, si bien las cuatro aldeas comparten aspectos significativos como su orientación agrícola y forestal, las ocupaciones de ambas cuencas expresan situaciones disímiles que permiten cuestionar la noción evolucionista que se ha tenido del período Formativo como una sucesión unilineal de etapas de progreso.
Año: 2014
Palabras claves: Aldeas - Prosopis - alimentos - tecnologías vegetales -período Formativo - Tarapacá.
Referencia APA: García, M., Vidal, A., Mandakovic, V., Maldonado, A., Peña, M., & Belmonte, E. (2014). Alimentos, Tecnologías Vegetales Y Paleoambiente En Las Aldeas Formativas De La Pampa Del Tamarugal, Tarapacá (ca. 900 AC-BOO DC). Estud. Atacam., (47), 33-58.
Surface ocean response to synoptic-scale variability in wind stress and heat fluxes off south-central Chile.
Aguirre, C., Garreaud, R., & Rutllant, J.
The effect of the high frequency (synoptic) variability of wind and heat fluxes upon the surface ocean off south-central Chile (west coast of South America) is investigated using a regional ocean model. We focus our analysis in austral summer, when the regional wind experiences significant day-to-day variability superimposed on a mean, upwelling favorable flow. To evaluate the nature and magnitude of these effects, we performed three identical simulations except for the surface forcing: the climatological run, with long-term monthly mean wind-stresses and heat fluxes; the wind-synoptic run, with daily wind stresses and climatological heat fluxes; and the full-synoptic run, with daily wind-stresses and daily fluxes. The mean currents and surface geostrophic EKE fields show no major differences between simulations, and agree well with those observed in this ocean area. Nevertheless, substantially more ageostrophic EKE is found in the simulations which include synoptic variability of wind-stresses, impacting the total surface EKE and diffusivities, particularly south of Punta Lavapie (37° S), where the lack of major currents implies low levels of geostrophic EKE. Summer mean SSTs are similar in all simulations and agree with observations, but SST variability along the coast is larger in the runs including wind-stress synoptic variability, suggesting a rather linear response of the ocean to cycles of southerly wind strengthening and relaxation. We found that coastal SST variability does not change significantly in the first tenths of kilometers from the shore when including daily heat fluxes, highlighting the prominent role of wind-driven upwelling cycles. In contrast, in the offshore region situated beyond the 50 km coastal strip, it is necessary to include synoptic variability in the heat fluxes to account for a realistic SST variability.
Año: 2014
Palabras claves: Atmospheric forcing; Air–sea interaction; Surface currents; Surface temperature; Synoptic variability, Chile.
Referencia APA: Aguirre, C., Garreaud, R., & Rutllant, J. (2014). Surface ocean response to synoptic-scale variability in wind stress and heat fluxes off south-central Chile. Dynamics Of Atmospheres And Oceans, 65, 64-85
Twelve Years of Change in Coastal Upwelling along the Central-Northern Coast of Chile: Spatially Heterogeneous Responses to Climatic Variability.
Aravena, G., Broitman, B., & Stenseth, N.
We use time-series analyses to characterize the effects of recent climate variability upon the local physical conditions at 11 study sites along the northern-central coast of Chile (29–34°S). Environmental indices show that the 1° Bakun upwelling index in this coastal region has fluctuated in time, starting from a stable period around the 1980's, peaking during the mid 90s, decreasing during the next ten years and increasing at a steep rate since 2010. Upwelling intensity decreased with increasing latitude, showing also a negative correlation with climate patterns (El Niño3 sea surface temperature-SST anomalies and the Multivariate El Niño Index). We hypothesize that the impacts of climate variability on upwelling events seem to be spatially heterogeneous along the region. Non-sheltered locations and, particularly, sites on prominent headlands show an immediate (lag = 0) and negative correlation between local SST, upwelling events and wind stress. We suggest that near-shore thermal conditions are closely coupled to large-scale forcing of upwelling variability and that this influence is modulated through local topographic factors.
Año: 2014
Palabras claves: Chile (country), Surface temperature, Oceanography, El Niño-Southern Oscillation, Summer, Latitude, Seasons, Ocean temperature.
Referencia APA: Aravena, G., Broitman, B., & Stenseth, N. (2014). Twelve Years of Change in Coastal Upwelling along the Central-Northern Coast of Chile: Spatially Heterogeneous Responses to Climatic Variability. Plos ONE, 9(2), e90276.
Hongos endófitos antárticos como herramienta para la reintroducción de especies nativas en zonas áridas.
Fardella, C., Oses, R., Torres-Díaz, C., & Molina-Montenegro, M.
Ecological restoration is the deliberate action that speeds recovery from a degraded system by direct or indirect human intervention. Xerophytic formations are among the most degraded ecosystems where low water availability makes reintroduction plans unsuccessful and extremely expensive. Roots inoculation with endophytic fungi has been reported as a successful strategy to maintain or improve the ecophysiological performance and survival in different species of shrubs and trees. In harsh environments, endophytes have been shown to provide benefits in terms of survival and growth for their associated vegetation. In this study, we showed that inoculation with endophytes isolated from plants growing in Antarctica improve survival and water use efficiency for irrigation on native species of xerophytic formations: Flourensia thurifera, Senna cumingii and Puya berteroniana. Overall, the presence of endophytes improved survival of all native species. Furthermore, the presence of endophytes improved water use efficiency for irrigation, reaching higher percentages of survival in plants with a reduction in the added water. The application of Antarctic endophytes could be considered a successful strategy for future projects and reintroduction programs in arid and semi-arid zones of Chile.
Año: 2014
Palabras claves: Endophytes, water use efficiency, xerophytic formations, restoration.
Referencia APA: Fardella, C., Oses, R., Torres-Díaz, C., & Molina-Montenegro, M. (2014). Hongos endófitos antárticos como herramienta para la reintroducción de especies nativas en zonas áridas. Bosque (Valdivia), 35(2), 235-239. http://dx.doi.org/10.4067/s0717-92002014000200011
Identifying appropriate spatial scales for marine conservation and management using a larval dispersal model: The case of Concholepas concholepas (loco) in Chile.
Garavelli, L., Kaplan, D., Colas, F., Stotz, W., Yannicelli, B., & Lett, C.
Along the coast of Chile, fisheries targeting the marine gastropod Concholepas concholepas, commonly named “loco”, were highly valuable until the end of the 80s when catches declined significantly. Since the late 90s, a management plan based on territorial-user-rights areas has been implemented, with limited effect on stock recovery. More effective loco conservation and management is impeded by lack of information regarding connectivity via larval dispersal between these individually-managed areas. To develop a regional view of loco connectivity, we integrate loco life history information into a biophysical, individual-based larval dispersal model. This model is used to evaluate scales of loco connectivity and seasonality in connectivity patterns, as well as to partition the coast into largely disconnected subpopulations using a recently developed connectivity-matrix clustering algorithm. We find mean dispersal distances ranging from 170 to 220 km depending on release depth of larvae and planktonic larval duration. Settlement success levels depend quantitatively on the physical and biological processes included in the model, but connectivity patterns remain qualitatively similar. Model estimates of settlement success peak for larval release dates in late austral autumn, consistent with field results and with favorable conditions for larval coastal retention due to weak upwelling during austral autumn. Despite the relatively homogeneous Chilean coastline, distinct subpopulations with minimal connectivity between them are readily identifiable. Barriers to connectivity that are robust to changes in model configuration exist at 23°S and 29°S latitudes. These zones are all associated with important headlands and embayments of the Chilean coast.
Año: 2014
Palabras claves:
Referencia APA: Garavelli, L., Kaplan, D., Colas, F., Stotz, W., Yannicelli, B., & Lett, C. (2014). Identifying appropriate spatial scales for marine conservation and management using a larval dispersal model: The case of Concholepas concholepas (loco) in Chile. Progress In Oceanography, 124, 42-53.
Antarctic macrolichen modifies microclimate and facilitates vascular plants in the maritime Antarctica – a reply to Casanova-Katny et al.
Molina-Montenegro, M., Torres-Díaz, C., & Gianoli, E.
In a current article in the Journal of Vegetation Science, Casanova-Katny et al. addressed a comment about an article by Molina-Montenegro et al., which demonstrated the climate modification induced by the macrolichen Usnea antarctica and its role as facilitator. They provided useful corrections concerning species identification and pointed out several issues that, in their view, weakened our study. They indicated that the role of U. antarctica as a facilitative species in the maritime Antarctica is merely philosophical and has no ecological relevance. In this commentary, we argue why these critiques are unsubstantial, and provide evidence that the macrolichen can modify the microclimate, ameliorating the harsh conditions prevailing in Antarctica, establishing positive interactions and eventually facilitating vascular species. Thus, the macrolichen U. antarctica would act as a ‘nurse species’, playing a key role in structuring the maritime Antarctic plant community.
Año: 2014
Palabras claves: Antarctica; Deschampsia Antarctica; Facilitation; Nurse effect; Positive interactions.
Referencia APA: Molina-Montenegro, M., Torres-Díaz, C., & Gianoli, E. (2014). Antarctic macrolichen modifies microclimate and facilitates vascular plants in the maritime Antarctica - a reply to Casanova-Katny et al. (2014). J Veg Sci, 25(2), 606-608.
Spatial variability in community composition on a granite breakwater versus natural rocky shores: Lack of microhabitats suppresses intertidal biodiversity.
Aguilera, M., Broitman, B., & Thiel, M.
Strong differences have been observed between the assemblages on artificial reefs and on natural hard-bottom habitats worldwide, but little is known about the mechanisms that cause contrasting biodiversity patterns. We examined the influence of spatial attributes in relation to both biogenic and topographic microhabitats, in the distribution and composition of intertidal species on both artificial and natural reefs. We found higher small-scale spatial heterogeneity on the natural reef compared with the study breakwater. Species richness and diversity were associated with a higher availability of crevices, rock pools and mussels in natural habitats. Spatial distribution of certain grazers corresponded well with the spatial structure of microhabitats. In contrast, the lack of microhabitats on the breakwater resulted in the absence of several grazers reflected in lower species richness. Biogenic and topographic microhabitats can have interactive effects providing niche opportunities for multiple species, explaining differences in species diversity between artificial versus natural reefs.
Año: 2014
Palabras claves: Artificial reefs; Biodiversity; Breakwater; Grazers; Spatial heterogeneity; Microhabitats.
Referencia APA: Aguilera, M., Broitman, B., & Thiel, M. (2014). Spatial variability in community composition on a granite breakwater versus natural rocky shores: Lack of microhabitats suppresses intertidal biodiversity. Marine Pollution Bulletin, 87(1-2), 257-268.