CEAZA
A 700-year record of climate and environmental change from a high Andean lake: Laguna del Maule, central Chile (36 S).
Carrevedo, M., Frugone, M., Latorre, C., Maldonado, A., Bernardez, P., & Prego, R. et al.
Central Chile is heavily exploited for mineral and water resources, with agriculture and large urban populations all creating intensive landscape use. Few records of past environmental and climate change are available that afford a broader context. To aid in this assessment, we present a 700-year reconstruction from Laguna del Maule (LdM) in the high Andes of central Chile based on sedimentological, geochemical, diatom and pollen analyses. The age model is based on 210Pb/137Cs and 14C dating tied into known volcanic eruptions. Sedimentology consists of organic-rich sediments and diatom oozes with several interspersed volcanic-rich facies and two tephra deposits. Sediment geochemistry exhibits increased productivity (high Br/Ti, biosilica) and more dominant oxic conditions (high Fe/Mn) from AD 1300 to 1400 and from AD 1650 to 1850, likely during periods of relatively lower lake levels and better development of littoral environments. However, during this later period, high elevation vegetation was dominant, indicative of regional cooler/wetter conditions. In contrast, sediments deposited from AD 1850 to 1930 evidence decreased productivity and increased anoxic lake bottom conditions. The ‘Little Ice Age’ (LIA) in LdM is characterized by significant variations in lake dynamics and hydrology with cooler/wetter conditions (AD 1570–1700), major environmental changes in the 18th century and ending at ca. AD 1850. LdM record documents the impact of the LIA in the southern hemisphere and stresses the global nature of this climate period. Large changes in lake dynamics and diatoms assemblages during the 20th century could be related to anthropogenic impacts, but recent changes in climate patterns cannot be excluded.
Año: 2015
Palabras claves: Chile, diatoms, geochemistry, Late Holocene, Little Ice Age, pollen.
Referencia APA: Carrevedo, M., Frugone, M., Latorre, C., Maldonado, A., Bernardez, P., & Prego, R. et al. (2015). A 700-year record of climate and environmental change from a high Andean lake: Laguna del Maule, central Chile (36 S). The Holocene, 25(6), 956-972.
Isolation and Characterization of 12 Microsatellite Loci in Soapbark, Quillaja saponaria (Quillajaceae).
Letelier, L., Harvey, N., Valderrama, A., Stoll, A., & González-Rodríguez, A.
Premise of the study: Microsatellite primers were developed for the endemic Chilean tree Quillaja saponaria (Quillajaceae), a common member of the sclerophyllous Mediterranean forest, to investigate intraspecific patterns of genetic diversity and structure.
Methods and Results: Using an enriched library, 12 polymorphic microsatellite loci were developed in Q. saponaria. All loci consisted of dinucleotide repeats. The average number of alleles per locus was 5.3 (2–13), with a total of 64 alleles recorded in 39 individuals from three populations.
Conclusions: The microsatellite markers described here are the first characterized for Q. saponaria. The polymorphic loci will be useful in studies of genetic diversity and genetic population differentiation in natural populations of this species.
Año: 2015
Palabras claves: Chile, microsatellites, Quillaja saponaria, Quillajaceae, soapbark.
Referencia APA: Letelier, L., Harvey, N., Valderrama, A., Stoll, A., & González-Rodríguez, A. (2015). Isolation and Characterization of 12 Microsatellite Loci in Soapbark, Quillaja saponaria (Quillajaceae). Applications In Plant Sciences, 3(5), 1500024.
Effects of wind-driven spatial structure and environmental heterogeneity on high-altitude wetland macroinvertebrate assemblages with contrasting dispersal modes.
Bertin, A., Alvarez, E., Gouin, N., Gianoli, E., Montecinos, S., & Lek, S. et al.
Dispersal is a major determinant of connectivity between communities that may modulate the importance of environmental and spatial processes on taxonomic composition. While wind is likely to influence transport distance, rate and direction for numerous species, its effects on community composition remain poorly understood.
Using eigenvector-based spatial analyses, we investigated the influence of wind flows, estimated by mesoscale models, on the spatial structure of benthic macroinvertebrate assemblages with contrasting flying abilities in high Andean wetlands (26–32°S). We further quantified the relative importance of local and regional processes through a variation partitioning approach.
The influence of environmental heterogeneity was prevalent and of relatively similar amplitude in both flying and non-flying assemblages. Significant spatial structure more strongly driven by wind flows than by Euclidean schemes was detected for both assemblages. As expected, the highest levels of spatial structure were observed for the flying macroinvertebrate assemblage and they occurred at a much larger spatial scale in this group, suggesting a greater dispersal aptitude of the flying taxa.
Our results show that environmental effects are predominant in shaping the spatial structure of macroinvertebrate communities in high Andean wetlands, as generally found in other systems. They also demonstrate the significance of wind flows in regulating high-altitude wetland macroinvertebrate communities and illustrate the importance of considering adequate spatial models and biological characteristics of species to advance our understanding of community patterns.
Año: 2015
Palabras claves: Benthic macroinvertebrates; dispersal; eigenvector maps; wetlands; wind.
Referencia APA: Bertin, A., Alvarez, E., Gouin, N., Gianoli, E., Montecinos, S., & Lek, S. et al. (2015). Effects of wind-driven spatial structure and environmental heterogeneity on high-altitude wetland macroinvertebrate assemblages with contrasting dispersal modes. Freshwater Biology, 60(2), 297-310.
Updated site compilation of the Latin American Pollen Database
Flantua, S., Hooghiemstra, H., Grimm, E., Behling, H., Bush, M., & González-Arango, C., Gosling, W.D., Ledru, M.P., Lozano-García, S., Maldonado, A., Prieto, A.R., Rull, V., Van Boxel, J.H.
The updated inventory of the Latin American Pollen Database (LAPD) offers a wide range of new insights. This paper presents a systematic compilation of palynological research in Latin America. A comprehensive inventory of publications in peer-reviewed and grey literature shows a major expansion of studies over the last decades. The inventory includes 1379 cores and sections with paleoecological data and more than 4800 modern samples from throughout the continent. Through the years, pollen datasets extend over increasing spans of time and show improved taxonomic and temporal resolution. Currently, these datasets are from 12 modern biomes and 30 countries, covering an altitudinal range of 0 to 6300 m asl. The most densely sampled regions are the Colombian Andes, the southeast coast of Brazil, and Patagonia. Underrepresented biomes are the warm temperate mixed forest (3%), dry forests (3%), and warm temperate rainforest (1%); whereas steppe, tropical rainforest, and cool grass shrublands, such as the páramos, are generally well represented (all > 17%). There are 126 records that span the late Pleistocene to the Last Glacial Maximum transition (21,000 cal yr BP), and > 20% of the records cover the Younger Dryas interval and the Pleistocene/Holocene transition. Reanalysis of numerous sites using multiproxy tools emphasize the informative value of this approach in paleoenvironmental reconstruction. We make suggestions for several pollen sites and regions to be visited again; similarly we identify some key research questions that have yet to be answered. The updated LAPD now provides the platform to support an exciting new phase of global palynological research in which multi-site data are being integrated to address current cutting-edge research questions. The LAPD compilation of sites and the literature database will be available through the Neotoma Paleoecology Database website and a new LAPD website by the end of 2015.
Año: 2015
Palabras claves: Pollen analysis; Latin America; Site distribution patterns; Age control density; Publication history; LAPD.
Referencia APA: Flantua, S., Hooghiemstra, H., Grimm, E., Behling, H., Bush, M., & González-Arango, C., Gosling, W.D., Ledru, M.P., Lozano-García, S., Maldonado, A., Prieto, A.R., Rull, V., Van Boxel, J.H. (2015). Updated site compilation of the Latin American Pollen Database. Review Of Palaeobotany And Palynology, 223, 104-115.
Comparison of DNA extraction methods for polymerase chain reaction amplification of guanaco (Lama guanicoe) fecal DNA samples.
Espinosa, M., Bertin, A., Squeo, F., Cortés, A., & Gouin, N.
Feces-based population genetic studies have become increasingly popular. However, polymerase chain reaction (PCR) amplification rates from fecal material vary depending on the species, populations, loci, and extraction protocols. Here, we assessed the PCR amplification success of three microsatellite markers and a segment of the mitochondrial control region of DNA extracted from field-collected feces of guanaco (Lama guanicoe) using two protocols - Qiagen DNA Stool Kit and 2 cetyltrimethylammonium bromide/phenol:chloroform:isoamyl alcohol (2CTAB/PCI) method. Chelex resin treatment to remove inhibitors was also tested. Our results show that the mitochondrial locus was the most difficult to amplify. PCR success rates
improved for all markers after Chelex treatment of extracted DNA, and 2CTAB/PCI method (95.83%) appeared to perform slightly better than stool kit (91.67%) for the nuclear markers. Amplification success was significantly influenced by the extraction method, Chelex treatment, and locus (P < 0.001) but not by the freshness of the feces (fresh vs old, P = 0.17). The repeatability levels were high without Chelex treatment (> 0.89), but they decreased slightly after treatment for amplification of nuclear markers and markedly after treatment for amplification of the mitochondrial control region. Thus, we showed that Chelex treatment gives high PCR success, especially for nuclear markers, and adequate DNA extraction rates can be achieved from L. guanicoe feces even from non-fresh fecal material. Although not significant, 2CTAB/PCI method tended to provide higher successful amplification rates on a whole set of samples, suggesting that the method could be particularly useful when using small sample sizes.
Año: 2015
Palabras claves: Non-invasive genetics; Mitochondrial control region;Microsatellites; Polymerase chain reaction inhibitors;Chelex treatment; Lama guanicoe.
Referencia APA: Espinosa, M., Bertin, A., Squeo, F., Cortés, A., & Gouin, N. (2015). Comparison of DNA extraction methods for polymerase chain reaction amplification of guanaco (Lama guanicoe) fecal DNA samples. Genetics And Molecular Research, 14(1), 400-406.
Changes of heritability and genetic correlations in production traits over time in red abalone ( Haliotis rufescens ) under culture.
Brokordt, K., Winkler, F., Farías, W., González, R., Castaño, F., Fullsack, P., & Herbinger, C.
Red abalone Haliotis rufescens is one of the most valuable mollusks in the international market, but it has a low growth rate. A breeding program is being developed to increase its growth rate in Chile. We estimated the changes in direct heritability (h2), maternal/common environments heritability (m2) and genetic correlations (rG) of growth traits (shell length and width, total mass, flesh mass and foot protein as an indicator of meat quality) measured during 2 years (every 4 months) from the juvenile stage (27 months) to the adult harvesting age (51 months), in 60 full-sib red abalone families. Heritabilities for growth traits measured in juveniles and young adults (27–35 months of age), were low (0.07–0.17) and not significant. Initial low h2 were associated with significant amounts of maternal/common environmental effects (m2 = 0.4). In young adults and abalone near the harvest age (39–51 months of age) h2 were much higher (0.32–0.75). These results emphasize the importance of multiple estimations of h2 over time. Among meat quality traits, only the h2 for the flesh mass for adults at harvesting age was significant (0.15). We observed strong positive rG (>0.9) between shell sizes (easy to measure) and total and flesh masses (trait more related to market value than shell sizes but harder to measure) for adults at harvesting age. Thus, if the 5% largest 51 month old abalone were selected from the population as broodstock we expect a positively correlated response on flesh mass of 23.4%.
Año: 2015
Palabras claves: Abalone aquaculture; heritability; maternal effects; growth; genetic improvement; Haliotis rufescens.
Referencia APA: Brokordt, K., Winkler, F., Farías, W., González, R., Castaño, F., Fullsack, P., & Herbinger, C. (2015). Changes of heritability and genetic correlations in production traits over time in red abalone (Haliotis rufescens) under culture. Aquaculture Research, 46(9), 2248-2259.
Mitochondrial DNA diversity of feral pigs from Karukinka Natural Park, Tierra del Fuego Island, Chile.
Aravena, P., Skewes, O., & Gouin, N.
: Control or eradication of exotic species is one of the greatest challenges facing biodiversity and ecosystem conservation. Domestic pigs (Sus scrofa domestica) were released and became feral in the southern region of Chilean Tierra del Fuego Island in the 1900s.
Currently, they inhabit part of Karukinka Natural Park, an area of global conservation concern. To gain insight into the control of this invasive species, we analyzed genetic variation in the mitochondrial DNA control region to determine the origin and population subdivision of feral pigs in Tierra del Fuego. Sequences from a sample of 42 feral pigs, 10 domestic pigs from local farms, and references from other countries and commercial breeds revealed 2 highly differentiated populations,
1 in the western and the other in the eastern area of the park, each harboring a different haplotype, suggesting no connectivity between populations. Comparison of these haplotypes with reference sequences from other countries and commercial breeds indicated that feral pigs from Chilean Tierra del Fuego are of European origin, very likely from
2 separate introduction events. The haplotype found in the western feral population was also identified in domestic pigs from a farm. This raises concerns regarding the possible connectivity between stocks from local farms and the wild population. Based on these results, we recommend the development of strategies for controlling the population of this invasive species in Karukinka Natural Park.
Año: 2015
Palabras claves: Feral pigs; Invasive species; mtDNA control region;Sus scrofa; Tierra del Fuego Island.
Referencia APA: Aravena, P., Skewes, O., & Gouin, N. (2015). Mitochondrial DNA diversity of feral pigs from Karukinka Natural Park, Tierra del Fuego Island, Chile. Genetics And Molecular Research, 14(2), 4245-4257.
Tefrocronología en curso superior del valle del río Cisne (44°S), Chile Austral.
Stern, C., De Porras, M., & Maldonado, A.
Based on their petrography and chemistry, 18 tephra analyzed from two lake and bog cores and one outcrop in the upper Río Cisnes valley are believed to have been derived from nine different eruptions of the Mentolat volcano, four of the Melimoyu volcano, and one from the Hudson volcano. Some of these tephra correlate chronologically and petrochemically with previously documented large eruptions of these volcanoes, including the Late-Glacial Ho eruption of Hudson (17,340 cal yrs BP), the mid-Holocene MEN1 eruption of Mentolat (7,710 cal yrs BP), and the Late-Holocene MEL2 eruption of Melimoyu (1,680 cal yrs BP). A Melimoyu-derived tephra from the outcrop occurs in glacial-lacustrine sediments and is considered to pre-date the Last Glacial Maximum (>19,670 cal yrs BP). The data suggest that none of the tephra were produced by explosive eruptions of the Maca, Cay and Yanteles volcanoes.
Año: 2015
Palabras claves: Tephra, Tephrochronology, Tephrostratigraphy, Volcanism, Andes, Chile.
Referencia APA: Stern, C., De Porras, M., & Maldonado, A. (2015). Tefrocronología en curso superior del valle del río Cisne (44°S), Chile Austral. Andean Geology, 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.