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Functional traits determine plant co-occurrence more than environment or evolutionary relatedness in global drylands.

Autores:

Soliveres, S., Maestre, F., Bowker, M., Torices, R., Quero, J., & García-Gómez, M., Cabrera, O., Ceag, A.P., Coaguila, D., Eldridge D.J., Espinosa, C.I., Hemmings, F., Monerris, J.J., Tighe, M., Delgado-Baquerizo, M., Escolar, C., García-Palacios, P., Gozalo, B., Ochoa, V., Blones, J., Derak, M., Ghiloufi, W., Gutiérrez, J.R., Hernández, R.M., Noumi, Z.

Resumen:

Plant–plant interactions are driven by environmental conditions, evolutionary relationships (ER) and the functional traits of the plants involved. However, studies addressing the relative importance of these drivers are rare, but crucial to improve our predictions of the effects of plant–plant interactions on plant communities and of how they respond to differing environmental conditions. To analyze the relative importance of – and interrelationships among – these factors as drivers of plant–plant interactions, we analyzed perennial plant co-occurrence at 106 dryland plant communities established across rainfall gradients in nine countries. We used structural equation modelling to disentangle the relationships between environmental conditions (aridity and soil fertility), functional traits extracted from the literature, and ER, and to assess their relative importance as drivers of the 929 pairwise plant–plant co-occurrence levels measured. Functional traits, specifically facilitated plants’ height and nurse growth form, were of primary importance, and modulated the effect of the environment and ER on plant–plant interactions. Environmental conditions and ER were important mainly for those interactions involving woody and graminoid nurses, respectively. The relative importance of different plant–plant interaction drivers (ER, functional traits, and the environment) varied depending on the region considered, illustrating the difficulty of predicting the outcome of plant–plant interactions at broader spatial scales. In our global-scale study on drylands, plant–plant interactions were more strongly related to functional traits of the species involved than to the environmental variables considered. Thus, moving to a trait-based facilitation/competition approach help to predict that: (1) positive plant–plant interactions are more likely to occur for taller facilitated species in drylands, and (2) plant–plant interactions within woody-dominated ecosystems might be more sensitive to changing environmental conditions than those within grasslands. By providing insights on which species are likely to better perform beneath a given neighbour, our results will also help to succeed in restoration practices involving the use of nurse plants.

Año: 2014

Palabras claves: Aridity; Competition; Facilitation; Phylogenetic distance; Semi-arid; Soil fertility.

Referencia APA: Soliveres, S., Maestre, F., Bowker, M., Torices, R., Quero, J., & García-Gómez, M., Cabrera, O., Ceag, A.P., Coaguila, D., Eldridge D.J., Espinosa, C.I., Hemmings, F., Monerris, J.J., Tighe, M., Delgado-Baquerizo, M., Escolar, C., García-Palacios, P., Gozalo, B., Ochoa, V., Blones, J., Derak, M., Ghiloufi, W., Gutiérrez, J.R., Hernández, R.M., Noumi, Z. (2014). Functional traits determine plant co-occurrence more than environment or evolutionary relatedness in global drylands. Perspectives In Plant Ecology, Evolution And Systematics, 16(4), 164-173.

Seed predation by rodents results in directed dispersal of viable seed fragments of an endangered desert shrub.

Autores:

Loayza, A., Carvajal, D., García-Guzmán, P., Gutierrez, J., & Squeo, F.

Resumen:

Seed predation and seed dispersal are important ecological processes with antagonistic effects on plant recruitment. In the southern edge of the Atacama Desert in Chile, Myrcianthes coquimbensis is an endangered, large-seeded, vertebrate-dispersed shrub that in the present-day has no known dispersers. Native rodents hoard and eat the seeds of M. coquimbensis but leave viable seed fragments at the hoarding sites; soil interspaces within rock outcrops where seedlings recruit. Here we examined whether rodents act as effective dispersers of M. coquimbensis by discarding viable seed fragments in sites suitable for recruitment. We simulated different levels of endosperm loss to determine if seedlings could develop from seed fragments. We assessed how frequently rodents discarded fragments, and the probability that these fragments produced seedlings. Finally, we compared emergence and seedling survival at the hoarding sites and in two other habitats where seeds arrive to evaluate the suitability of the hoarding sites. Seeds of M. coquimbensis developed seedlings even after 87% of their storage tissue was removed. Rodents left seed fragments in more than 50% of the trials; almost 60% of the discarded fragments produced seedlings. Seedlings did not emerge from open ground habitats, and emergence was higher under M. coquimbensis shrubs than in rock habitats. Survival of two-year-old seedlings was higher in rock habitats than under conspecific adult shrubs. Our results suggest that rodents may play a dual role in the recruitment dynamics of M. coquimbensis, acting simultaneously as seed predators and effective dispersers. Therefore, though seed predators impose costs, their net effect on plant fitness in this system—where dispersers of large-seeded species have been lost—is likely positive.

Año: 2014

Palabras claves: Anachronism; Atacama; captive feeding trials; hoarding; Myrcianthes coquimbensis; rodent; seedling establishment.

Referencia APA: Loayza, A., Carvajal, D., García-Guzmán, P., Gutierrez, J., & Squeo, F. (2014). Seed predation by rodents results in directed dispersal of viable seed fragments of an endangered desert shrub. Ecosphere, 5(4), art43.

Using stakeholders’ perspective of ecosystem services and biodiversity features to plan a marine protected area.

Autores:

Cárcamo, P., Garay-Flühmann, R., Squeo, F., & Gaymer, C.

Resumen:

The definition of a common vision that includes social and environmental goals, ecosystem services and/or biodiversity features that people are interested in maintaining or restoring is a great challenge for marine protected areas (MPAs). Recent initiatives have promoted broadening the focus from biodiversity conservation alone to the conservation of both ecosystem services and biodiversity, indicating that this integration should improve support and compliance from stakeholders. Using a Multiple-Use Coastal Marine Protected Area recently proposed in northern Chile, we investigated (i) stakeholders’ perceptions of the valuation of ecosystem services, threats to their provision, and the prioritization of ecosystem services, biodiversity features, and uses in a planning scenario, and (ii) stakeholders’ expectations for the establishment of a new MPA. The perceptions of different groups of stakeholders were compared and statistically analyzed, and the relationships among prioritizations were studied using a network approach. Stakeholders identified and valued 13 ecosystem services, 28 biodiversity features, 20 uses and activities, and 22 threats. Significant differences among the valuations and prioritizations of different stakeholder groups were attributable principally to artisanal fishermen's perceptions of some components that are directly related to their activities and livelihoods. High expectations of benefits from a new MPA implementation were observed for all categories of stakeholders. To relate the different valuated components, we proposed a network-based conceptual model that reduces complexity, and also as a strategy to communicate relationships and trade-offs occurring in this particular social–ecological system to the several stakeholders. We strongly recommend early stakeholder engagement so as to understand the variability in environmental perceptions and then reflect that variation in the planning and management actions of MPAs, thus improving support for their implementation and achieving conservation and societal goals. Our findings indicate that stakeholders’ perceptions and prioritizations of ecosystem services, biodiversity features and uses should be used as the basis for starting the MPA implementation and planning process.

Año: 2014

Palabras claves: Biodiversity; Chile; Ecosystem services; Fishermen; Multiple-Use Coastal Marine Protected Area; Stakeholders’ perceptions.

Referencia APA: Cárcamo, P., Garay-Flühmann, R., Squeo, F., & Gaymer, C. (2014). Using stakeholders’ perspective of ecosystem services and biodiversity features to plan a marine protected area. Environmental Science & Policy, 40, 116-131

Estudios socio-ecológicos de largo plazo en los sitios fundadores de la red LTSER-Chile: desafíos y oportunidades para el futuro.

Autores:

Gaxiola, A., Celis-Diez, J., Rozzi, R., & Gutiérrez, J.

Resumen:

The research carried out in the three foundational sites of the Chilean Long-Term Socio-Ecological Research Network (LTSER-Chile) aims to answer questions that reflect the regional context in which each site is immersed. The formation of the network in 2008 provided an opportunity to establish comparative studies and analyse the effects of the different components of global change could exert on different ecosystems in Chile. This study presents an analysis of the research programs of each of the three sites and presents the context in which these lines have been established. Each founder site has identified key aspects associated with local needs and the interests of the research groups that initiated and have directed the ecological or socio-ecological long-term studies. At the national scale these different approaches are complementary. First, we present an analysis and evaluation of the research conducted by each of these groups. Then, we develop a diagnosis of the research developed at each of the sites during the last two decades with the goal of identifying gaps and future research opportunities. Furthermore, this characterization will contribute to addressing the challenges and opportunities in basic and applied long-term socio-ecological research.

Año: 2014

Palabras claves: Global change, climatic change, Cape Horn, Chiloé, Fray Jorge National Park.

Referencia APA: Gaxiola, A., Celis-Diez, J., Rozzi, R., & Gutiérrez, J. (2014). Estudios socio-ecológicos de largo plazo en los sitios fundadores de la red LTSER-Chile: desafíos y oportunidades para el futuro. Bosque (Valdivia), 35(3), 421-428.

Influence of process temperature on drying kinetics, physicochemical properties and antioxidant capacity of the olive-waste cake.

Autores:

Uribe, E., Lemus-Mondaca, R., Vega-Gálvez, A., Zamorano, M., Quispe-Fuentes, I., Pasten, A., & Di Scala, K.

Resumen:

The objective of this study was to determine the effect of drying temperature on the drying kinetics, proximal analysis, energy consumption and the antioxidant capacity of the olive-waste cake “Picual” variety from 40 to 90 °C. Evaluation of proximal analysis evidenced the influence of temperature on the waste parameters. Values of effective moisture coefficients were in the range of 1.97–6.05 × 10−9 m2 s−1 under the studied conditions. Activation energy was found to be 28.24 kJ mol−1. The Weibull model was successfully applied (r2 > 0.973). Specific energy consumption decreased as temperature increased, showing the effect of drying times over temperature. Although dehydrated samples decreased the initial total phenolic content, significant differences were not detected. Effects of drying temperatures did not present significant differences on antioxidant capacity (ORAC and DPPH) when compared to fresh samples. The oleic acid (main fatty acid in fresh samples) presented a maximum increased at 90 °C.

Año: 2014

Palabras claves: Olive-waste cake; Phenolic compounds; Antioxidant activity; Fatty acid profile; Convective dehydration.

Referencia APA: Uribe, E., Lemus-Mondaca, R., Vega-Gálvez, A., Zamorano, M., Quispe-Fuentes, I., Pasten, A., & Di Scala, K. (2014). Influence of process temperature on drying kinetics, physicochemical properties and antioxidant capacity of the olive-waste cake. Food Chemistry, 147, 170-176.

Effect of Osmotic Dehydration Under High Hydrostatic Pressure on Microstructure, Functional Properties and Bioactive Compounds of Strawberry (Fragaria Vesca).

Autores:

Núñez-Mancilla, Y., Vega-Gálvez, A., Pérez-Won, M., Zura, L., García-Segovia, P., & Di Scala, K.

Resumen:

Sliced strawberries were subjected to combined osmotic dehydration (40 °Brix) and high hydrostatic pressure (HHP) at 100, 200, 300, 400 and 500 MPa for 10 min. This research was carried out to study the effects of pressure on firmness, polysaccharides, total dietary fibre and microstructure, functional properties (rehydration ratio and water holding capacity) and bioactive compounds (anthocyanins, flavonoid and total phenolic). HHP affected the texture of the fruits leading to soft fruits due to increasing pressure. Fruit microstructure evidenced influence of pressure presenting the pressurised samples irregular matrices compared to samples treated at 0.1 MPa (control samples). Polysaccharides increased with pressure. Total dietary fibre, anthocyanins, flavonoids and total phenolic content showed a decrease with pressure when compared to control samples. Based on results, minor alterations of the mentioned quality parameters were evidenced when working in the range of 300–500 MPa.

Año: 2014

Palabras claves: Strawberry, High hydrostatic pressure, Osmotic dehydration, Microstructure, Anthocyanins, Firmness.

Referencia APA: Núñez-Mancilla, Y., Vega-Gálvez, A., Pérez-Won, M., Zura, L., García-Segovia, P., & Di Scala, K. (2014). Effect of Osmotic Dehydration Under High Hydrostatic Pressure on Microstructure, Functional Properties and Bioactive Compounds of Strawberry (Fragaria Vesca). Food Bioprocess Technol, 7(2), 516-524.

Morphogenesis by mass movements in western Andes (Chile).

Autores:

Novoa Jerez, J.

Resumen:

Numerous examples of mass movements on slopes of western Andes and related landforms are analyzed. Regionalization of the country is fulfilled, taking into account climatic and hydrologic factors. 9 regions were distinguished with more or less similar physical-geographical conditions for mass movements’ development. Recommendations are suggested concerning future investigations in the field of mass movements risk under the rising anthropogenic impact.

Año: 2013

Palabras claves: ground mass movements, slope, morphogenesis, the Andes, zoning, risk, danger, anthropogenic impact.

Referencia APA: Novoa Jerez, J. (2013). Morphogenesis by mass movements in western Andes (Chile). Geomorfologiâ (Mosk.), (2), 81

Use of 222 radon as a simple tool for surface water-groundwater connectivity assessment: a case study in the arid Limarí basin, north-central Chile.

Autores:

Oyarzún, R., Jofré, E., Maturana, H., Oyarzún, J., & Aguirre, E.

Resumen:

We report the results from a pilot study on the use of 222Rn (222radon) for river–aquifer interaction assessment in the Limarí watershed, north-central Chile. Previous studies on this tool for such applications are not abundant at international level, and no records exist for Chile. The lowest 222Rn levels (less than 1000 Bq/m3) were found in water reservoirs, thus indicating that this isotope is easily lost (and therefore usually absent) in surface waters. Conversely, the highest levels of 222Rn were found in groundwater, with maxima activities around 20 000 Bq/m3. This remarkable contrast allowed clear identification of zones of surface water–groundwater connectivity in the searched watershed domain.

Año: 2013

Palabras claves: Environmental tracer; radioactive isotope; watershed hydrology.

Referencia APA: Oyarzún, R., Jofré, E., Maturana, H., Oyarzún, J., & Aguirre, E. (2013). Use of 222 radon as a simple tool for surface water-groundwater connectivity assessment: a case study in the arid Limarí basin, north-central Chile. Water And Environment Journal, n/a-n/a.

Influence of Pacific Ocean multidecadal variability on the distributional properties of hydrological variables in north-central Chile.

Autores:

Núñez, J., Rivera, D., Oyarzún, R., & Arumí, J.

Resumen:

This paper addresses the relationship between multitemporal variability and regime shifts in the Pacific Decadal Oscillation and El Niño Southern Oscillation, with precipitation and streamflows in Andean watersheds of the north-central region of Chile. In addition, an analysis of the effect of a regime shift displayed by annual streamflow records on their distributional properties is performed. By applying empirical fluctuation processes to monthly standardized PDO, Niño 3.4, precipitation and streamflow time series, the occurrence of a regime shift in the streamflow series, consistent with that for PDO, but highly dependent on the latitude of particular watersheds, is shown. No regime shift is detected for the precipitation time series. Using the ensemble Empirical Mode Decomposition procedure on all series, a relationship between climatic indices and hydrological variables in two main modes is determined: the former associated with a mean period of quasi 1.5–3 years related to interannual variability, and the latter with a mean period of quasi 30–35 years, related to decadal low frequency variability. Using the regional frequency analysis based on the L-moments procedure, it is found that the distributional properties of streamflow records are influenced by the phases of the PDO, with changes that affect the mean, L-CV, L-skewness and L-kurtosis in three identified homogeneous regions. The importance of incorporating low-frequency climate variability for distributional analysis and the implications of these results for water resources management and planning in north-central Chile and similar areas is discussed.

Año: 2013

Palabras claves: Climate variability; Distributional analysis; L-moments; Pacific Decadal Oscillation; Empirical Mode Decomposition.

Referencia APA: Núñez, J., Rivera, D., Oyarzún, R., & Arumí, J. (2013). Influence of Pacific Ocean multidecadal variability on the distributional properties of hydrological variables in north-central Chile. Journal Of Hydrology, 501, 227-240.

Long-term monitoring of mammals in the face of biotic and abiotic influences at a semiarid site in north-central Chile.

Autores:

Kelt, D., Meserve, P., Gutiérrez, J., Milstead, W., & Previtali, M.

Resumen:

The data set covers a 16-year period (1989–2005) of monthly small-mammal surveys and associated habitat and environmental data. Small mammals are trapped every month on all experimental plots, and both ephemeral and perennial plant cover and soil seed bank composition are measured at regular intervals. Rainfall is recorded and compiled annually (through 1998) or monthly; information on captured small mammals and on all vegetative and rainfall data is contained in associated files. These data have been applied to diverse population- and community-level analyses and remain useful for investigations of population dynamics, species interactions, and the relative influence of biotic and abiotic factors. Sampling is ongoing, and data will be added over time.

Año: 2013

Palabras claves: Biotic vs. abiotic interactions; climate; competition; ENSO; ephemeral plant cover; LTREB data; predation; semiarid ecosystem; shrub cover; small mammals.

Referencia APA: Kelt, D., Meserve, P., Gutiérrez, J., Milstead, W., & Previtali, M. (2013). Long-term monitoring of mammals in the face of biotic and abiotic influences at a semiarid site in north-central Chile. Ecology, 94(4), 977-977.

Osmotic dehydration under high hydrostatic pressure: Effects on antioxidant activity, total phenolics compounds, vitamin C and colour of strawberry (Fragaria vesca).

Autores:

Nuñez-Mancilla, Y., Pérez-Won, M., Uribe, E., Vega-Gálvez, A., & Di Scala, K.

Resumen:

Simultaneous application of osmotic dehydration under high hydrostatic pressure conditions of strawberries was studied with the purpose of analyzing the effect of the combined process on the antioxidant capacity, phenolic compounds, colour and vitamin C of strawberries during refrigerated storage. The osmotic solution was prepared using commercial sugar at 40 °Brix. Samples were pressurized between 100 and 500 MPa for 10 min. The radical scavenging activity showed higher antioxidant activity at 400 MPa rather than at low pressure (100, 200 and 300 MPa). The total phenolic content increased with pressure presenting a maximum at 400 MPa. Pressurized samples retained vitamin C content. Based on these results, working at 400 MPa for 10 min ensures physicochemical and high levels of nutritional parameters in osmo-dried strawberries.

Año: 2013

Palabras claves: Osmotic dehydration; High hydrostatic pressure; Antioxidant capacity; Total phenolic content; Colour; Vitamin C; Strawberry

Referencia APA: Nuñez-Mancilla, Y., Pérez-Won, M., Uribe, E., Vega-Gálvez, A., & Di Scala, K. (2013). Osmotic dehydration under high hydrostatic pressure: Effects on antioxidant activity, total phenolics compounds, vitamin C and colour of strawberry (Fragaria vesca). LWT - Food Science And Technology, 52(2), 151-156.

Rehydration Capacity of Chilean Papaya (Vasconcellea pubescens): Effect of Process Temperature on Kinetic Parameters and Functional Properties.

Autores:

Zura, L., Uribe, E., Lemus-Mondaca, R., Saavedra-Torrico, J., Vega-Gálvez, A., & Di Scala, K.

Resumen:

Slabs of Chilean papaya hot air-dried at 60 °C were rehydrated at 20, 40, 60, and 80 °C to study the influence of process temperature on mass transfer kinetics during rehydration. Diffusive and empirical models were selected to simulate the experimental rehydration curves. All models parameters showed dependence with temperature, thus activation energy could be estimated according to an Arrhenius-type equation. Among the applied models, Weibull provided the best fit for each rehydration curve based on the statistical tests RMSE, SSE, and chi-square. According to these results, this model could be used to estimate the rehydration time of Chilean papaya. In addition, rehydration ratio and water-holding capacity were analyzed. Both indices showed a decrease with increasing rehydration temperature indicating modification of the papaya cell structure due to thermal treatment which resulted in a reduction of the rehydration ability, in particular at high rehydration temperatures.

Año: 2013

Palabras claves: Chilean papaya, Rehydration kinetics, Mathematical modeling, Water-holding capacity, Rehydration ratio.

Referencia APA: Zura, L., Uribe, E., Lemus-Mondaca, R., Saavedra-Torrico, J., Vega-Gálvez, A., & Di Scala, K. (2013). Rehydration Capacity of Chilean Papaya (Vasconcellea pubescens): Effect of Process Temperature on Kinetic Parameters and Functional Properties. Food Bioprocess Technol, 6(3), 844-850.