CEAZA
Trends in Antarctic ecological research in Latin America shown by publications in international journals.
Stotz, G., Salgado-Luarte, C., Rios, R., Acuña-Rodriguez, I., Carrasco-Urra, F., Molina-Montenegro, M., & Gianoli, E.
Antarctica is a highly interesting region for ecologists because of its extreme climatic conditions and the uniqueness of its species. In this article, we describe the trends in Antarctic ecological research participation by Latin American countries. In a survey of articles indexed by the ISI Web of Science, we searched under the categories “Ecology,” “Biodiversity Conservation” and “Evolutionary Biology” and found a total of 254 research articles published by Latin American countries. We classified these articles according to the country of affiliation, kingdom of the study species, level of biological organization and environment. Our main finding is that there is a steady increase in the relative contribution of Latin American countries to Antarctic ecological research. Within each category, we found that marine studies are more common than terrestrial studies. Between the different kingdoms, most studies focus on animals and most studies use a community approach. The leading countries in terms of productivity were Argentina, Chile and Brazil, with Argentina showing the highest rate of increase.
Año: 2013
Palabras claves: Antarctica; Argentina; Brazil; Chile; research trends; scientific productivity.
Referencia APA: Stotz, G., Salgado-Luarte, C., Rios, R., Acuña-Rodriguez, I., Carrasco-Urra, F., Molina-Montenegro, M., & Gianoli, E. (2013). Trends in Antarctic ecological research in Latin America shown by publications in international journals. Polar Research, 32(0).
Influence of contrasting environments on seed composition of two quinoa genotypes: nutritional and functional properties.
Miranda, M., Vega-Gálvez, A., Martínez, E., López, J., Marín, R., Aranda, M., & Fuentes, F.
Quinoa (Chenopodium quinoa Willd.) in Chile represents a source of germplasm with high nutritional value. However, there is little information available related to quinoa seed quality grown under contrasting environments. In this study we evaluated the changes on seed composition of seeds of two lowland/coastal quinoa genotypes grown under arid (Vicuna) and cold-temperate (Temuco) conditions in Chile. Results showed that in the case of 'Regalona Baer' and 'Villarrica' genotypes the arid location (with irrigation) led to a significant increase (P < 0.05) in grain yield (4.2 and 5.1 t ha-1, respectively), soluble dietary fiber (16.8 ± 0.4 and 28.9 ± 2.1 g kg-1 DM, respectively), vitamin B3 (2.44 ± 0.005 and 2.26 ± 0.04 mg 100 g-1 DM, respectively), saponins (3.22 ± 0.38 mg 100 g-1 DM, 'Regalona Baer'), phenolic compounds (19.2 ± 5.48 and 31.92 ± 1.14 mg gallic acid 100 g-1 DM, respectively) and components of proximate analysis, except protein content. The cold-temperate climate (rainfed) affected positively seed size (2.22 ± 0.17 mm 'Villarrica') and 1000 seed weight (3.08 ± 0.08 and 3.29 ± 0.08 g, respectively), as well as insoluble dietary fiber content (112.3 ± 23.8 g kg-1 DM, 'Regalona Baer'). Furthermore, vitamin C was higher in 'Regalona Baer' genotype at arid locality (31.22 ± 4.2 mg 100 g-1 DM), but much higher content was registered in 'Villarrica' genotype at cold-temperate climate (49.3 ± 5.36 mg 100 g-1 DM). The environment-induced relationship among variables and genotypes was consistent with principal component analysis (PCA). The arid region of Vicuna in Chile represents a potential area for quinoa cultivation for lowland/coastal quinoa genotypes, whose nutritional and functional features were affected positively, due to the much more stressing climatic conditions.
Año: 2013
Palabras claves: Chenopodium quinoa, climate stress, antioxidant activity, phenolic compounds, protein, mineral content.
Referencia APA: Miranda, M., Vega-Gálvez, A., Martínez, E., López, J., Marín, R., Aranda, M., & Fuentes, F. (2013). Influence of contrasting environments on seed composition of two quinoa genotypes: nutritional and functional properties. Chilean J. Agric. Res., 73(2), 06-07.
Mesoscale Variation of Mechanisms Contributing to Stability in Rocky Shore Communities.
Valdivia N, González AE, Manzur T, Broitman BR.
Environmental fluctuations can generate asynchronous species’ fluctuations and community stability, due to compensatory dynamics of species with different environmental tolerances. We tested this hypothesis in intertidal hard-bottom communities of north-central Chile, where a persistent upwelling centre maintains a mosaic in sea surface temperatures (SST) over 10s of kilometres along the shore. Coastal upwelling implies colder and temporally more stable SST relative to downstream sites. Uni- and multivariate analyses of multiyear timeseries of SST and species abundances showed more asynchronous fluctuations and higher stability in sites characterised by warmer and more variable SST. Nevertheless, these effects were weakened after including data obtained in sites affected by less persistent upwelling centres. Further, dominant species were more stable in sites exposed to high SST variability. The strength of other processes that can influence community stability, chiefly statistical averaging and overyielding, did not vary significantly between SST regimes. Our results provide observational evidence supporting the idea that exogenously driven compensatory dynamics and the stabilising effects of dominant species can determine the stability of ecosystems facing environmental fluctuations.
Año: 2013
Palabras claves: Community ecology, Algae, Barnacles, Ecosystems, Oceanography, Surface temperature, Taxonomy, Species interactions.
Referencia APA: Valdivia N, González AE, Manzur T, Broitman B. (2013). Mesoscale Variation of Mechanisms Contributing to Stability in Rocky Shore Communities. PLoS ONE 8(1): e54159.
Seabirds modify El Niño effects on tree growth in a southern Pacific island.
Molina-Montenegro, M., Torres-Díaz, C., Gallardo-Cerda, J., Leppe, M., & Gianoli, E.
Oceanic island ecosystems are particularly sensitive to El Niño effects due to their dependence on energy and nutrient inputs from marine systems. Seabirds play a key role in transporting resources of marine origin to insular ecosystems. We report tree-growth patterns showing how the effects of El Niño rainy events on tree species in a southern Pacific island depend on the presence of local seabird colonies. We performed manipulative experiments in order to assess the mechanisms underlying these patterns. Tree ring data showed that, in normal years, the growth of all tree species (Aextoxicon punctatum, Cryptocarya alba, and Pinus radiata) was significantly lower in seabird sites compared to adjacent patches without seabirds (control sites). In contrast, in El Niño years, trees formerly hosting seabird colonies grew more than those in control sites. Experiments showed that (1) pine plants on soil from seabird sites grew more than those on soil from control sites, (2) pine individuals with seabird feces on their leaves grew less than those sprayed with an aqueous solution, and (3) soil moisture had little effect on plant growth. The stress produced by massive cormorant nesting on trees, which impairs tree growth and physiological performance, is relieved during El Niño events because of seabird migration due to decreased prey availability and pouring rains that flood nests. Soils enriched by the seabird guano, together with the increased water availability associated with El Niño, foster the growth of trees from seabird sites. We suggest that El Niño may be a key determinant of tree performance in forest communities from island and coastal ecosystems of the Pacific Ocean.
Año: 2013
Palabras claves: Aextoxicon punctatum; colonial seabirds; Cryptocarya alba; ecophysiology; El Niño Southern Oscillation, ENSO; global change; island system interactions; Neotropic Cormorant, Phalacrocorax brasilianus; Pinus radiata; Quiriquina Island, Chilean coast; tree rings.
Referencia APA: Molina-Montenegro, M., Torres-Díaz, C., Gallardo-Cerda, J., Leppe, M., & Gianoli, E. (2013). Seabirds modify El Niño effects on tree growth in a southern Pacific island. Ecology, 94(11), 2415-2425.
Variabilidad ambiental y recursos pesqueros en el Pacifico suroriental: estado de la investigacion y desafios para el manejo pesquero.
Parada, C., Yannicelli, B., Hormazabal, S., Vasquez, S., Porobic, J., & Ernst, B. et al.
Las fluctuaciones en abundancia, biomasa, estructura de edad y patrones de distribución de los recursos pesqueros responden, entre otros, a la variabilidad ambiental. Estas respuestas son consecuencia tanto de efectos climáticos directos sobre los recursos como indirectos actuando sobre niveles tróficos relacionados. En este estudio se revisa: i) el estado del conocimiento de los mecanismos físicos asociados a la variabilidad océano-atmósfera y las escalas de variabilidad espaciales y temporales del ambiente y la relación con recursos marinos, basados en datos observacionales y modelos hidrodinámicos, ii) la relación ambiente-recurso para pesquerías pelágicas, demersales y bentónicas, y el uso de modelos biofísicos para entender estas relaciones, iii) manejo actual de recursos pelágicos, demersales y bentónicos y los alcances en relación al uso de variables ambientales, y iv) se discuten los desafíos hacia la asesoría en relación a las estrategias para mejorar la comprensión de la relación ambiente-recurso, así como, las estrategias para incorporar la modelación biofísica y variables ambientales en modelos operacionales para la asesoría hacia el manejo.
Año: 2013
Palabras claves: Variabilidad ambiental, sistemas de surgencia, recursos pesqueros, modelación biofísica, dinámica poblacional, modelos operacionales para el manejo pesquero, Pacífico suroriental, Chile.
Referencia APA: Parada, C., Yannicelli, B., Hormazabal, S., Vasquez, S., Porobic, J., & Ernst, B. et al. (2013). Variabilidad ambiental y recursos pesqueros en el Pacifico suroriental: estado de la investigacion y desafios para el manejo pesquero. Latin American Journal Of Aquatic Research, 41(1), 1-28.
Differential effects of grazer species on periphyton of a temperate rocky shore.
Aguilera, M., Navarrete, S., & Broitman, B.
Species-specific traits are relevant to understand variation in the effect of grazers on primary producers and are critical in determining their functional roles as controllers of productivity in marine ecosystems. In intertidal habitats, periphyton, composed of bacteria, cyanophytes, microalgae and early stages of macroalgae, constitutes the main food for many benthic grazers. Using field experiments, we examined the overall effect of grazers and the importance of direct and indirect effects of different grazer species on periphyton composition, richness, diversity and productivity. We manipulated the main grazer species present along Chilean rocky shores, enclosing adult individuals of the keyhole limpet Fissurella crassa, the chiton Chiton granosus, the scurrinid limpet Scurria araucana and the pulmonate limpet Siphonaria lessoni. These organisms overlap broadly in diet but exhibit differences in foraging behavior. Differences in the individual effects of grazer species on periphyton productivity, as well as on richness and diversity characterized the assemblage. C. granosus grazing led to lower periphyton productivity, richness and diversity compared with all other grazers, who had positive effects for all variables. Richness and diversity of the major periphyton groups were maximal at intermediate levels of total grazing pressure, highlighting the importance of ecological interactions within the periphyton assemblage. Our results demonstrate the complexity of functional roles and relationships of grazers involved in the control of composition and production of the periphyton assemblage. Given the importance of direct and indirect effects of grazers, understanding species interactions within the microbenthic community can shed light on the mechanisms through which herbivores modify community structure and productivity.
Año: 2013
Palabras claves: Grazer assemblage, Periphyton, Productivity, Diversity, Foraging behavior.
Referencia APA: Aguilera, M., Navarrete, S., & Broitman, B. (2013). Differential effects of grazer species on periphyton of a temperate rocky shore. Marine Ecology Progress Series, 484, 63-78.
Environmental and climatic changes in Central Chilean Patagonia since the Late Glacial (Mallín El Embudo, 44° S).
de Porras, M., Maldonado, A., Quintana, F., Martel-Cea, A., Reyes, O., & Méndez, C.
Multi-millennial environmental and climatic changes in central Chilean Patagonia (44–49° S) during the Last Glacial–Interglacial cycle have been of particular interest as changes in the position and strength of the southern westerlies are the major forcing factor conditioning the environmental dynamics. Recent attempts to reconstruct regional environmental and climatic signals from central Chilean Patagonia reveal some discrepancies and unclear issues among the records. This paper presents the 13 ka pollen and charcoal records from Mallín El Embudo (44° 40' S, 71° 42' W) located in the deciduous Nothofagus forest in the middle Río Cisnes valley. The paper aims to (1) establish the timing and magnitude of local vegetation changes and fire activity since the Late Glacial and (2) integrate these results at the regional scale in order to discuss the discrepancies and depict the environmental and climatic dynamics in central Chilean Patagonia since the Late Glacial. Open landscapes dominated by grasses associated with scattered Nothofagus forest patches dominated the middle Río Cisnes valley between 13 and 11.2 ka suggesting low effective moisture but also indicating that landscape configuration after glacial retreat was still ongoing. At 11.2 ka, the sudden development of an open and quite dynamic Nothofagus forest probably associated with the synchronous high fire activity occurred, suggesting a rise in effective moisture associated with dry summers. Since 9.5 ka, the record reflects the presence of a closed Nothofagus forest related to higher effective moisture conditions than before combined with moderate dry summers that may have triggered a high frequency of low-magnitude crown fires that did not severely affect the forest. The forest experienced a slight canopy opening after 5.7 ka, probably due to slightly drier conditions than before followed by a sudden change to open forest conditions around 4.2 ka associated with fire and volcanic disturbances. Around 2 ka, the recovery of a closed Nothofagus forest related to slightly wetter conditions (similar to present) occurred and persisted under highly variable climatic conditions up to 0.1 ka when massive forest burning and logging due to European settlements occurred. Central Chilean Patagonian climatic and environmental changes at millennial–centennial timescales since the Late Glacial were driven by changes in the southern westerlies latitudinal position and/or intensity, but during the late Holocene fire, volcanism and humans arose as forces contributing to environmental dynamics.
Año: 2013
Palabras claves:
Referencia APA: de Porras, M., Maldonado, A., Quintana, F., Martel-Cea, A., Reyes, O., & Méndez, C. (2013). Environmental and climatic changes in Central Chilean Patagonia since the Late Glacial (Mallín El Embudo, 44° S). Clim. Past Discuss., 9(5), 5747-5784.
Can a breakdown in competition-colonization tradeoffs help explain the success of exotic species in the California flora?
Molina-Montenegro, M., Cleland, E., Watts, S., & Broitman, B.
Determining combinations of functional traits that allow a species to colonize new habitats has been central in the development of invasion ecology. Species able to establish in new communities harbor abilities or traits that allow them to use resources or tolerate stress in ways that native species cannot. Tradeoffs among species functional traits along the competition–colonization (CC) continuum, where competitive ability is a decreasing function of dispersal capacity, may allow invasive species to establish themselves in new habitats. The California flora offers a well-characterized model system to examine whether native and exotic species differ in the distribution of functional traits and to examine whether a breakdown of the CC tradeoff is present. We used a random subset of 1000 plants and examined seed traits and life form characteristics along with their seed size and adult height using the Jepson Manual of the plants of California. To test the hypothesis that active dispersal strategies aid in the success of exotic species, we classified species into four seed types according to the presence/absence of mechanisms associated with efficient dispersal. In addition, for each species we compiled data on seed size and adult plant height. We conducted all comparisons between native and exotic species within the four most speciose families to control for potential taxonomic non-independence. Exotic species had smaller seed size but greater plant height than natives of the same families. On the other hand, exotic species also displayed significantly greater proportions of functional traits that enhanced dispersal ability. Additionally, certain sets of functional traits were significantly associated with exotic species, such as annual life histories with small seeds and high dispersal capacity. In the random subset of the California flora examined, exotics of the most speciose plant families show functional trait combinations that appear to violate the tradeoff structures observed in their California counterparts. Our results suggest that taxonomically controlled comparisons of the CC tradeoff structure between natives and exotic species may shed light of the capacity of those exotic species invasive ability to colonize new habitats.
Año: 2012
Palabras claves:
Referencia APA: Molina-Montenegro, M., Cleland, E., Watts, S., & Broitman, B. (2012). Can a breakdown in competition-colonization tradeoffs help explain the success of exotic species in the California flora?. Oikos, 121(3), 389-395.
Characterization of the interactions between subterranean and superficial fluxes within an Andean catchment as a function of the spatio- temporal variability of climate.
Jourde, H., Blanc, M., Rochette, R., Ruelland, D., Hicks, E., & Oyarzun, R
In the semi-arid region of Norte Chico (Chile), climate variability, mainly controlled by ENSO and LNSO events, generates a high variability of both surface water and groundwater fluxes. Taking the upper Elqui catchment as an example, this study found that, during LNSO events, the abnormally high values of the runoff coefficient may be the consequence of a groundwater contribution to surface water flow. During ENSO events, however, the lower values of the runoff coefficient and the dynamics of the water table level highlight the recharge of the subsurface compartment. For the hydrological years characterized by a high pluviometric index during the 1977–2008 period, three dynamics of interaction between groundwater and surface water are identified : (i) the water table increases before the river discharge, and its logarithmic increase highlights a rapid recharge related to the concomitance of snowmelt and rainfall events ; (ii) the water table increases after the river discharge and its exponential increase shows a progressive intensification of the recharge over time ; and (iii) the water table and the river discharge increase are concomitant. Dynamics (i) and (ii) are observed during the ENSO events, when precipitation occurs over a long time period ; dynamic (iii) is observed during the neutral years, when high intensity precipitations occur over short periods. The analysis of these dynamics and runoff coefficients shows that when the mean annual precipitation is less than 70 mm, the relative equilibrium between runoff and recharge processes is broken, which may generate a high hydrological deficit; this threshold could thus be used as a warning for drought. Finally, the spatial variability of runoff coefficients shows a larger contribution of the subsurface compartment in catchment with a larger proportion of granites, suggesting a mountain front recharge from the alterites in the granitic watershed.
Año: 2012
Palabras claves: hydro-climatic variability, water resource, surface, subsurface interactions, snowmelt, Río Elqui, North-Central Chile.
Referencia APA: Jourde, H., Blanc, M., Rochette, R., Ruelland, D., Hicks, E., & Oyarzun, R. (2012). Caractérisation des interactions entre flux souterrains et superficiels dans un bassin andin en fonction de la variabilité spatio-temporelle du climat. La Houille Blanche, (2), 18-25
Activity patterns and predatory behavior of an intertidal nemertean from rocky shores: Prosorhochmus nelsoni (Hoplonemertea) from the Southeast Pacific.
Caplins, S., Penna-Diaz, M., Godoy, E., Valdivia, N., Turbeville, J., & Thiel, M.
Understanding the impact of environmental stressors on predator activity is a prerequisite to understanding the underlying mechanisms shaping community structure. The nemertean Prosorhochmus nelsoni is a common predator in the mid-intertidal zone on rocky shores along the Chilean coast, where it can reach very high abundances (up to 260 ind m−2) in algal turfs, algal crusts, barnacle crusts, and mixed substrata. Tidal and diurnal scans revealed that the activity of P. nelsoni is primarily restricted to night and early-morning low tides and is relatively low when air temperatures are high. On average, larger worms crawled faster than smaller worms, with their maximum velocity being influenced by substratum type. Their estimated rate of predation is 0.092 prey items nemertean−1 day−1, just below the laboratory rate of ~0.2 amphipods nemertean−1 day−1 previously estimated for this species. P. nelsoni consumes a diverse spectrum of prey items (i.e., amphipods, isopods, decapods, barnacles, and dipterans) and is possibly exerting a significant influence on its prey populations. We suggest that the opportunistic predatory behavior of this intertidal predator is caused by the trade-off between immediate persistence (e.g., avoidance of desiccation) and long-term survival through successful foraging.
Año: 2012
Palabras claves:
Referencia APA: Caplins, S., Penna-Diaz, M., Godoy, E., Valdivia, N., Turbeville, J., & Thiel, M. (2012). Activity patterns and predatory behavior of an intertidal nemertean from rocky shores: Prosorhochmus nelsoni (Hoplonemertea) from the Southeast Pacific. Marine Biology, 159(6), 1363-1374.
Species replacement along a linear coastal habitat: phylogeography and speciation in the red alga Mazzaella laminarioides along the south east pacific.
Montecinos, A., Broitman, B., Faugeron, S., Haye, P., Tellier, F., & Guillemin, M.
The Chilean shoreline, a nearly strait line of coast expanding across 35 latitudinal degrees, represents an interesting region to assess historical processes using phylogeographic analyses. Stretching along the temperate section of the East Pacific margin, the region is characterized by intense geologic activity and has experienced drastic geomorphological transformations linked to eustatic and isostatic changes during the Quaternary. In this study, we used two molecular markers to evaluate the existence of phylogeographic discontinuities and detect the genetic footprints of Pleistocene glaciations among Patagonian populations of Mazzaella laminarioides, a low-dispersal benthic intertidal red seaweed that inhabits along ~3,700 km of the Chilean coastal rocky shore.
Año: 2012
Palabras claves: Phylogeography, South East Pacific coast, COI, rbcL, Red seaweed, Parapatric distribution, Sister-species, complex, Pleistocene glaciations
Referencia APA: Montecinos, A., Broitman, B., Faugeron, S., Haye, P., Tellier, F., & Guillemin, M. (2012). Species replacement along a linear coastal habitat: phylogeography and speciation in the red alga Mazzaella laminarioides along the south east pacific. BMC Evol Biol, 12(1), 97.
Application of the Watershed Sustainability Index to the Elqui river basin, North-Central Chile
Cortés, A., Oyarzún, R., Kretschmer, N., Chaves, H., Soto, G., & Soto, M. et al.
El índice WSI, desarrollado para estimar la sustentabilidad de una cuenca en forma integrada con énfasis en la gestión de recursos hídricos, fue determinado en la Cuenca del Río Elqui considerando un período de 5 años (2001-2005). La cuenca del Río Elqui se ubica en una región semiárida de Chile, y ha sido incorporada a la red de cuencas hidrográficas del programa HELP de la UNESCO. El resultado fue un valor global de 0.61 para el indicador WSI (en el rango de 0 a 1), calificando el nivel de sustentabilidad como "intermedio". Las mayores fortalezas de la cuenca se relacionaron con los indicadores de Ambiente y de Políticas. Por otro lado, las mayores debilidades observadas en la cuenca se relacionaron con el indicador de Hidrología, debido principalmente a la situación de escasez hídrica. La identificación de estas limitantes representan una oportunidad para mejorar la actual situación en la cuenca, lo que obliga a una coordinación más eficiente entre las diferentes instituciones involucradas en la gestión de los recursos naturales. La aplicación del WSI a la Cuenca de Elqui demostró su utilidad como instrumento analítico asi como herramienta de gestión para autoridades relacionadas con el agua, usuarios y grupos de interés. Sin embargo, la actualización de la información local es necesaria para la planificación a mediano y largo plazo y la formulación de estrategias de desarrollo para esta cuenca y otras.
Año: 2012
Palabras claves: gestión integrada de cuencas, hidrología, ambiente, calidad de vida, políticas
Referencia APA: Cortés, A., Oyarzún, R., Kretschmer, N., Chaves, H., Soto, G., & Soto, M. et al. (2012). Application of the Watershed Sustainability Index to the Elqui river basin, North-Central Chile. Obras Y Proyectos, (12), 57-69.