CEAZA
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.
Ecophysiological plasticity and local differentiation help explain the invasion success of Taraxacum officinale (dandelion) in South America.
Molina-Montenegro, M., Palma-Rojas, C., Alcayaga-Olivares, Y., Oses, R., Corcuera, L., Cavieres, L., & Gianoli, E.
Plasticity and local adaptation have been suggested as two main mechanisms that alien species use to successfully tolerate and invade broad geographic areas. In the present study, we try answer the question if the mechanism for the broad distributional range of T. officinale is for phenotypic plasticity, ecotypic adaptation or both. For this, we used individuals of T. officinale originated from seeds collected in five localities along its latitudinal distribution range in the southern-hemisphere. Seedlings were acclimated at 5 and 25°C for one month. After the acclimation period we evaluated ecophysiological and cytogenetic traits. Additionally, we assessed the fitness at each temperature by recording the seed output of individuals from different localities. Finally, we performed a manipulative experiment in order to assess the tolerance to herbivory and competitive ability between T. officinale from all origins and Hypochaeris scorzonerae a co-occurring native species. Overall, individuals of T. officinale showed high plasticity and ecotypic adaptation for all traits assessed in this study. Changes both in physiology and morphology observed in T. officinale from different origins were mostly correlated, enhancing their ecophysiological performance in temperatures similar to those of their origin. Additionally, all localities showed the same chromosome number and ploidy level. On the other hand, all individuals showed an increase the seed output at 25°C, but those from northern localities increased more. T. officinale from all origins was not significantly affected by herbivory while native showed a negative effect. On the other hand, T. officinale exerted a strong negative effect on the native species, but this former not effected significantly to the invasive T. officinale. High plasticity and local adaptation in all ecophysiological traits, seed-set and the low cytogenetic variability in T. officinale suggests that both strategies are present in this invasive plant species and are not mutually exclusive. Finally, higher tolerance to herbivory and competitive ability suggests that T. officinale could perform successfully in environments with different climatic conditions, and thus colonize and invade South-America.
Año: 2013
Palabras claves:
Referencia APA: Molina-Montenegro, M., Palma-Rojas, C., Alcayaga-Olivares, Y., Oses, R., Corcuera, L., Cavieres, L., & Gianoli, E. (2013). Ecophysiological plasticity and local differentiation help explain the invasion success of Taraxacum officinale (dandelion) in South America. Ecography, 36(6), 718-730.
Is Physiological Performance a Good Predictor for Fitness? Insights from an Invasive Plant Species.
Molina-Montenegro, M., Salgado-Luarte, C., Oses, R., & Torres-Díaz, C.
Is physiological performance a suitable proxy of fitness in plants? Although, several studies have been conducted to measure some fitness-related traits and physiological performance, direct assessments are seldom found in the literature. Here, we assessed the physiology-fitness relationship using second-generation individuals of the invasive plant species Taraxacum officinale from 17 localities distributed in five continents. Specifically, we tested if i) the maximum quantum yield is a good predictor for seed-output ii) whether this physiology-fitness relationship can be modified by environmental heterogeneity, and iii) if this relationship has an adaptive consequence for T. officinale individuals from different localities. Overall, we found a significant positive relationship between the maximum quantum yield and fitness for all localities evaluated, but this relationship decreased in T. officinale individuals from localities with greater environmental heterogeneity. Finally, we found that those individuals from localities where environmental conditions are highly seasonal performed better under heterogeneous environmental conditions. Contrarily, under homogeneous controlled conditions, those individuals from localities with low environmental seasonality performed much better. In conclusion, our results suggest that the maximum quantum yield seem to be good predictors for plant fitness. We suggest that rapid measurements, such as those obtained from the maximum quantum yield, could provide a straightforward proxy of individual’s fitness in changing environments.
Año: 2013
Palabras claves: Plant physiology, Photosynthesis, Seeds, Physiological adaptation, Chlorophyll, Rain, Invasive species, Ecophysiology.
Referencia APA: Molina-Montenegro, M., Salgado-Luarte, C., Oses, R., & Torres-Díaz, C. (2013). Is Physiological Performance a Good Predictor for Fitness? Insights from an Invasive Plant Species. Plos ONE, 8(10), e76432. http://dx.doi.org/10.1371/journal.pone.0076432
Internal structure and composition of a rock glacier in the Andes (upper Choapa valley, Chile) using borehole information and ground-penetrating radar.
Monnier, S. & Kinnard, C.
This study uses boreholes, ground temperature monitoring and ground-penetrating radar (GPR) in order to understand the internal structure and composition of a rock glacier in the upper Choapa valley, northern Chile. The rock glacier is a small valley-side feature, 200 m long and ranging between 3710 and 3780 m a.s.l. Two boreholes were drilled down to depths of 20 and 25 m, respectively, using the diamond drillhole technique. An ice–rock mixture was encountered in the boreholes, with heterogeneous ice content averaging 15–30%. Data from common-midpoint (CMP) and constant-offset (CO) GPR surveys acquired, respectively, near the boreholes and across the whole rock glacier were processed to highlight the internal stratigraphy and variations in the radar-wave velocity. The GPR profiles depict a rock glacier constituted of stacked and generally concordant layers, with a thickness ranging from 10 m in its upper part to ∼30 m towards its terminus. The CMP analysis highlights radar-wave velocities of 0.13–0.16 m ns–1 in the first 20 m of the structure. Larger vertical and lateral velocity variations are highlighted from CO data, reflecting the heterogeneous composition of the rock glacier and the likely presence of unfrozen water in the structure. Given the average air temperature registered at the site (+0.5°C), the near-melting-point temperature registered in the boreholes over more than a year and the presence of locally high water content inferred from GPR data, it is thought that the permafrost in the rock glacier is currently degrading.
Año: 2013
Palabras claves:
Referencia APA: Monnier, S. & Kinnard, C. (2013). Internal structure and composition of a rock glacier in the Andes (upper Choapa valley, Chile) using borehole information and ground-penetrating radar. Annals Of Glaciology, 54(64), 61-72.
Zoning of the Mejillones Peninsula marine protected coastal area of multiple uses, northern Chile.
Ulloa, R., Vargas, A., Hudson, C., & Rivadeneira, M.
Marine protected areas of multiple uses (MPA-MU), are an important management tool to protect biodiversity and regulate the use of coastal marine resources. However, robust conservation plans require an explicit consideration of not only biological but also social components, balancing the protection of biodiversity with a sustainable exploitation of marine resources. Here we applied the decision-making algorithm MARXAN to provide a zoning analysis at the Mejillones Peninsula MPA-MU in northern Chile, one of largest MPA's of the Humboldt Current Marine Ecosystem. We set conservation goals for coarse and fine-filter conservation targets that were crossed out against different threats and pressure factors from human activities across the area. We identified a portfolio of sites for conservation, within the Mejillones Peninsula MPA-MU, representing different ecological systems with different levels of human impacts and vulnerability. These results may serve as a foundational guideline for the future administration of the MPA-MU.
Año: 2013
Palabras claves: MPA-MU, MARXAN, conservation plans, marine coastal ecosystems, northern Chile.
Referencia APA: Ulloa, R., Vargas, A., Hudson, C., & Rivadeneira, M. (2013). Zoning of the Mejillones Peninsula marine protected coastal area of multiple uses, northern Chile. Lat. Am. J. Aquat. Res. vol.41 no.3 Valparaíso jul.
Naturalised grapevines collected from arid regions in Northern Chile exhibit a high level of genetic diversity.
Milla-Tapia, A., Gómez, S., Moncada, X., León, P., Ibacache, A., & Rosas, M. et al.
Over 150 grapevine accessions were collected and characterised using 11 Simple Sequence Repeats (SSR) markers, to determine the genetic diversity and to propose a population structuring. SSR diversity was high, with observed heterozygosity (Ho = 0.87) greater than expected heterozygosity (He = 0.70). Three discrete genetic groups were identified, which did not show any association with geographical distribution. Groups 1 (G1) and G3 had a higher level of genetic diversity and also an important level of heterozygosity.
Año: 2013
Palabras claves: Arid regions; genetic structure; germplasm; naturalised grapevines; Vitis.
Referencia APA: Milla-Tapia, A., Gómez, S., Moncada, X., León, P., Ibacache, A., & Rosas, M. et al. (2013). Naturalised grapevines collected from arid regions in Northern Chile exhibit a high level of genetic diversity. Australian Journal Of Grape And Wine Research, 19(2), 299-310.
Evidencing a large body of ice in a rock glacier, Vanoise Massif, Northern French Alps.
Monnier, S., Camerlynck, C., Rejiba, F., Kinnard, C., & Galibert, P.
The Sachette rock glacier is an active rock glacier located between 2660 and 2480 m a.s.l. in the Vanoise Massif, Northern French Alps (45° 29′ N, 6° 52′ E). In order to characterize its status as permafrost feature, shallow ground temperatures were monitored and the surface velocity measured by photogrammetry. The rock glacier exhibits near-surface thermal regimes suggesting permafrost occurrence and also displays significant surface horizontal displacements (0.6–1.3 ± 0.6 m yr–1). In order to investigate its internal structure, a ground-penetrating radar (GPR) survey was performed. Four constant-offset GPR profiles were performed and analyzed to reconstruct the stratigraphy and model the radar wave velocity in two dimensions. Integration of the morphology, the velocity models and the stratigraphy revealed, in the upper half of the rock glacier, the good correspondence between widespread high radar wave velocities (>0.15–0.16 m ns–1) and strongly concave reflector structures. High radar wave velocity (0.165–0.170 m ns–1) is confirmed with the analysis of two punctual common mid-point measurements in areas of exposed shallow pure ice. These evidences point towards the existence of a large buried body of ice in the upper part of the rock glacier. The rock glacier was interpreted to result from the former advance and decay of a glacier onto pre-existing deposits, and from subsequent creep of the whole assemblage. Our study of the Sachette rock glacier thus highlights the rock glacier as a transitional landform involving the incorporation and preservation of glacier ice in permafrost environments with subsequent evolution arising from periglacial processes.
Año: 2013
Palabras claves: Rock glacier; ground-penetrating radar; ice.
Referencia APA: Monnier, S., Camerlynck, C., Rejiba, F., Kinnard, C., & Galibert, P. (2013). Evidencing a large body of ice in a rock glacier, Vanoise Massif, Northern French Alps. Geografiska Annaler: Series A, Physical Geography, 95(2), 109-123.
Late Holocene summer temperatures in the central Andes reconstructed from the sediments of high-elevation Laguna Chepical, Chile (32° S).
de Jong, R., von Gunten, L., Maldonado, A., & Grosjean, M.
High-resolution reconstructions of climate variability that cover the past millennia are necessary to improve the understanding of natural and anthropogenic climate change across the globe. Although numerous records are available for the mid- and high-latitudes of the Northern Hemisphere, global assessments are still compromised by the scarcity of data from the Southern Hemisphere. This is particularly the case for the tropical and subtropical areas. In addition, high elevation sites in the South American Andes may provide insight into the vertical structure of climate change in the mid-troposphere. This study presents a 3000 yr-long austral summer (November to February) temperature reconstruction derived from the 210Pb- and 14C-dated organic sediments of Laguna Chepical (32°16' S, 70°30' W, 3050 m a.s.l.), a high-elevation glacial lake in the subtropical Andes of central Chile. Scanning reflectance spectroscopy in the visible light range provided the spectral index R570/R630, which reflects the clay mineral content in lake sediments. For the calibration period (AD 1901–2006), the R570/R630 data were regressed against monthly meteorological reanalysis data, showing that this proxy was strongly and significantly correlated with mean summer (NDJF) temperatures (R3 yr = −0.63, padj = 0.01). This calibration model was used to make a quantitative temperature reconstruction back to 1000 BC.
The reconstruction (with a model error RMSEPboot of 0.33 °C) shows that the warmest decades of the past 3000 yr occurred during the calibration period. The 19th century (end of the Little Ice Age (LIA)) was cool. The prominent warmth reconstructed for the 18th century, which was also observed in other records from this area, seems systematic for subtropical and southern South America but remains difficult to explain. Except for this warm period, the LIA was generally characterized by cool summers. Back to AD 1400, the results from this study compare remarkably well to low altitude records from the Chilean Central Valley and southern South America. However, the reconstruction from Laguna Chepical does not show a warm Medieval Climate Anomaly during the 12–13th century, which is consistent with records from tropical South America. The Chepical record also indicates substantial cooling prior to 800 BC. This coincides with well-known regional as well as global glacier advances which have been attributed to a grand solar minimum. This study thus provides insight into the climatic drivers and temperature patterns in a region for which currently very few data are available. It also shows that since ca. AD 1400, long-term temperature patterns were generally similar at low and high altitudes in central Chile.
Año: 2013
Palabras claves:
Referencia APA: de Jong, R., von Gunten, L., Maldonado, A., & Grosjean, M. (2013). Late Holocene summer temperatures in the central Andes reconstructed from the sediments of high-elevation Laguna Chepical, Chile (32° S). Climate Of The Past, 9(4), 1921-1932. http://dx.doi.org/10.5194/cp-9-1921-2013