ULS-CEAZA
Effects of high hydrostatic pressure on microstructure, texture, colour and biochemical changes of red abalone (Haliotis rufecens) during cold storage time.
Briones-Labarca, V., Perez-Won, M., Zamarca, M., Aguilera-Radic, J., & Tabilo-Munizaga, G.
This study was carried out to evaluate the effect of high hydrostatic pressure on quality changes (microstructure, colour, texture and biochemical) of red abalone (Haliotis rufecens) during storage time at 4 °C. High hydrostatic pressure (HHP) treatments were applied at 500 MPa for 8 min and 550 MPa for 3 and 5 min. Biochemical indices covering pH, total volatile basic nitrogen (TVB-N) and trimethylamine (TMA), as well as instrumental texture, microstructure and colour of abalone samples were determined immediately after treatment and throughout subsequent storage at 4 °C. Results have shown that HHP-treated abalones have significantly (p ≤ 0.05) higher pH, moisture and ash content than untreated abalones. Protein and fat contents of treated abalones were significantly (p ≤ 0.05) lower compared to untreated sample (control). TVB-N and TMA levels for HHP-treated abalones rose over the storage period but did not exceed 28 mg TVB-N/100 g and 3 mg TMA/100 g, respectively at the end of 60 days. Instead, the untreated sample exceeded the allowed limit in a 30 day period for the TVB-N and TMA. However, all HHP treatments had less negative effects on tissue colour of abalone than untreated samples in the cold storage time; moreover, whiteness index was reduced to 8% at the end of day 60. A more compact structure was identified as high hydrostatic pressure was higher. Thus, it was concluded that holes in muscle fibres were often due to protein gelation, whenever pressure and protein concentration are high enough, confirming that the structure of abalone muscle treated with high hydrostatic pressure differed significantly from that of raw abalone meat.
Año: 2012
Palabras claves: High hydrostatic pressure; Abalone; Colour; pH; TVB-N; TMA; Microstructure
Referencia APA: Briones-Labarca, V., Perez-Won, M., Zamarca, M., Aguilera-Radic, J., & Tabilo-Munizaga, G. (2012). Effects of high hydrostatic pressure on microstructure, texture, colour and biochemical changes of red abalone (Haliotis rufecens) during cold storage time. Innovative Food Science & Emerging Technologies, 13, 42-50.
Hydro-meteorological trends in semi-arid north-central Chile (29–32°S): water resources implications for a fragile Andean region
Souvignet, M., Oyarzún, R., Verbist, K., Gaese, H., & Heinrich, J.
Changes in hydro-meteorological historical records are of considerable importance for future planning. This study analyses trends of hydro-climatological indices of annual and seasonal precipitation, temperature and discharge in the “Norte Chico” region of Chile (29–32°S), located in the Central Andes. It addresses how these trends possibly impacted on the water resources in a nival regime, typical for arid mountainous regions. Homogenous records were tested against monotonic trends using the non-parametric rank-based Mann-Kendall test. The results suggested, at a very high confidence level, a strong warming signal trend over recent decades, consistent at the annual and seasonal levels. Furthermore, warmer days are observed in summer, especially at higher elevations. The region also experienced a shift in the rainy season over the last 42 years. However, an increase in precipitation was observed over recent decades, whereas an annual decrease was the general tendency when the whole century was considered. Changes in discharge were not unequivocal and glacier retreat has been compensated for possibly by an increase in snowmelt in recent years. Hence, in an under-studied area, from the hydrological perspective, this work provides some insights for a better understanding of changing hydrological processes in the mid-latitude Andes Cordillera.
Año: 2012
Palabras claves: trend detection, variability, climate change, hydro-climatological indices, arid region, Chile.
Referencia APA: Souvignet, M., Oyarzún, R., Verbist, K., Gaese, H., & Heinrich, J. (2012). Hydro-meteorological trends in semi-arid north-central Chile (29–32°S): water resources implications for a fragile Andean region. Hydrological Sciences Journal, 57(3), 479-495.
Shrub facilitation increases plant diversity along an arid scrubland-temperate rain forest boundary in South America
van Zonneveld, M., Gutiérrez, J., & Holmgren, M.
Theoretical models predict nurse plant facilitation enhances species richness by ameliorating stressful environmental conditions and expanding distributional ranges of stress-intolerant species into harsh environments. We studied the role of nurse facilitation on the recruitment of perennial plants along an arid scrubland–temperate rain forest boundary to test the following predictions: (1) nurse shrub canopy increases seedling abundance and species richness along the rain forest–scrubland boundary; (2) scrubland species are less dependent on facilitative interactions than temperate rain forest species, especially at the moister, upper end of the gradient.
Año: 2012
Palabras claves:
Referencia APA: van Zonneveld, M., Gutiérrez, J., & Holmgren, M. (2012). Shrub facilitation increases plant diversity along an arid scrubland-temperate rain forest boundary in South America. J Veg Sci, 23(3), 541-551.
Seasonal and Multiannual Patterns in Avian Assemblage Structure and Composition in Northern Chilean Thorn-Scrub
Douglas A. Kelt, Andrew Engilis Jr., Juan Monárdez, Robert Walsh, Peter L. Meserve, And Julio R. Gutiérrez.
The species composition of the Chilean avifauna is well-defined taxonomically but is not well known ecologically. We sampled avian communities at a biosphere reserve in coastal north-central Chile in three seasons over six years (18 surveys total) and characterized them in terms of community structure and composition. The avifauna (S = 56 species) was dominated by insectivores (S = 20), carnivores (S = 14), and granivores (S = 13), with lesser contributions by omnivores (S = 5), nectarivores (S = 2), folivores (S = 1), and one vagrant piscivore. The fauna varied greatly between summer and winter, and in most years the breeding season also was distinct. Eighteen species constituted a core group of residents observed in nearly all surveys, but at least 15 species were nomadic or migratory. Our site supported more insectivorous species in winter but more granivores and omnivores in the breeding season, although this observation may be confounded by species' detectability. The structure of the set of species was nested temporally, but this was not clearly caused by seasonal influx supplementing a core fauna of residents. Ordination clearly segregated all three seasons, except for one survey that was explained by very dry conditions in that year. Further research will quantify productivity and demographic responses to long-term climatic variation to compare avian and mammalian patterns with respect to extrinsically generated pulses in resources (e.g., El Niño/Southern Oscillation).
Año: 2012
Palabras claves: avian community structure, avian diversity, biosphere reserve, Chile, migration, seasonality, semiarid thorn scrub
Referencia APA: Douglas A. Kelt, Andrew Engilis Jr., Juan Monárdez, Robert Walsh, Peter L. Meserve, And Julio R. Gutiérrez. (2012). Seasonal and Multiannual Patterns in Avian Assemblage Structure and Composition in Northern Chilean Thorn-Scrub. The Condor, 114(1), 30-43.
Integrating Ecology and Environmental Ethics: Earth Stewardship in the Southern End of the Americas
Rozzi, R., Armesto, J.J., Gutiérrez, J.R., Massardo, F., Likens, G.E., Anderson, C.B., Poole, A., Moses, K.P., Hargrove, E., Mansilla, A.O., Kennedy, J.H., Willson, M., Jax, K., Jones, C.G., Callicott,J.B., and Arroyo, M.T.K.
The South American temperate and sub-Antarctic forests cover the longest latitudinal range in the Southern Hemisphere and include the world's southernmost forests. However, until now, this unique biome has been absent from global ecosystem research and monitoring networks. Moreover, the latitudinal range of between 40 degrees (°) south (S) and 60° S constitutes a conspicuous gap in the International Long-Term Ecological Research (ILTER) and other international networks. We first identify 10 globally salient attributes of biological and cultural diversity in southwestern South America. We then present the nascent Chilean Long-Term Socio-Ecological Research (LTSER) network, which will incorporate a new biome into ILTER. Finally, we introduce the field environmental philosophy methodology, developed by the Chilean LTSER network to integrate ecological sciences and environmental ethics into graduate education and biocultural conservation. This approach broadens the prevailing economic spectrum of social dimensions considered by LTSER programs and helps foster bioculturally diverse forms of Earth stewardship.
Año: 2012
Palabras claves: conservation, temperate forests, sub-Antarctic ecoregion, long-term ecological research, field stations
Referencia APA: Rozzi, R., Armesto, J.J., Gutiérrez, J.R., Massardo, F., Likens, G.E., Anderson, C.B., Poole, A., Moses, K.P., Hargrove, E., Mansilla, A.O., Kennedy, J.H., Willson, M., Jax, K., Jones, C.G., Callicott,J.B., and Arroyo, M.T.K. (2012). Integrating Ecology and Environmental Ethics: Earth Stewardship in the Southern End of the Americas. Bioscience, 62(3), 226-236.
The ecology, distribution and conservation status of Myrcianthes coquimbensis : a globally endangered endemic shrub of the Chilean Coastal Desert
García-Guzman, P., Loayza, A., Carvajal, D., Letelier, L., & Squeo, F.
The current distribution of M. coquimbensis extends along 82.8 km of the Chilean coast, where the species is mainly threatened by habitat loss. Only 13% of the individuals flowered during 2010, and 66% of these plants lost their entire flower crop due to desiccation. Few seeds (7.5%) were lost to post-dispersal seed predation. The populations are composed mainly of adult plants (70% of the individuals), and little to no recruitment was observed.
Año: 2012
Palabras claves: Atacama Desert, Chile, conservation biology, habitat loss, Myrtaceae, restricted-range species,
Referencia APA: García-Guzman, P., Loayza, A., Carvajal, D., Letelier, L., & Squeo, F. (2012). The ecology, distribution and conservation status of Myrcianthes coquimbensis: a globally endangered endemic shrub of the Chilean Coastal Desert. Plant Ecology & Diversity, 5(2), 197-204.
Progress in creating a joint research agenda that allows networked long-term socio-ecological research in southern South America: Addressing crucial technological and human capacity gaps limiting its application in Chile and Argentina.
Anderson, C., Celis-Diez, J., Bond, B., Martínez Pastur, G., Little, C., & Armesto, J., Ghersa, C., Austin, A., Schlichter, T., Lara, A., Carmona, M., Chaneton, E.J., Gutierrez, J.R.,et al.
Since 1980, more than 40 countries have implemented long-term ecological research (LTER) programs, which have shown their power to affect advances in basic science to understand the natural world at meaningful temporal and spatial scales and also help link research with socially relevant outcomes. Recently, a disciplinary paradigmatic shift has integrated the human dimensions of ecosystems, leading to a long-term socio-ecological research (LTSER) framework to address the world's current environmental challenges. A global gap in LTER/LTSER only exists in the latitudinal range of 40–60°S, corresponding to Argentina and Chile's temperate/sub-Antarctic biome. A team of Chilean, Argentine and US researchers has participated in an ongoing dialogue to define not only conceptual, but also practical barriers limiting LTER/LTSER in southern South America. We have found a number of existing long-term research sites and platforms throughout the region, but at the same time it has been concluded an agenda is needed to create and implement further training courses for students, postdoctoral fellows and young scientists, particularly in the areas of data and information management systems. Since LTER/LTSER efforts in Chile and Argentina are incipient, instituting such courses now will enhance human and technical capacity of the natural science and resource community to improve the collection, storage, analysis and dissemination of information in emerging LTER/LTSER platforms. In turn, having this capacity, as well as the ongoing formalization of LTER/LTSER programs at national levels, will allow the enhancement of crucial collaborations and comparisons between long-term research programs within the region and between hemispheres and continents. For Spanish version of the entire article, see Online Supporting Information (Appendix S1).
Año: 2012
Palabras claves: environmental monitoring; information management; long-term ecological research; LTER; LTSER; science policy; socio-ecology
Referencia APA: Anderson, C., Celis-Diez, J., Bond, B., Martínez Pastur, G., Little, C., & Armesto, J., Ghersa, C., Austin, A., Schlichter, T., Lara, A., Carmona, M., Chaneton, E.J., Gutierrez, J.R., et al. (2012). Progress in creating a joint research agenda that allows networked long-term socio-ecological research in southern South America: Addressing crucial technological and human capacity gaps limiting its application in Chile and Argentina. Austral Ecology, 37(5), 529-536.
Leaf morphological and genetic divergence in populations of Drimys (Winteraceae) in Chile.
Jara-Arancio, P., Carmona, M., Correa, C., Squeo, F., & Arancio, G.
The genus Drimys is distributed in Chile from semiarid zones to sub-Antarctic forests; there are three species of this tree, D. andina, D. confertifolia and D. winteri, the latter with varieties chilensis and winteri. Northern populations are found in small disjunct natural refuges, specifically mountain cloud forests and the bottom of ravines. The size and continuity of populations are greater in the south, where wetter conditions prevail. Morphological differences between populations have been observed, particularly between the northern populations of Fray Jorge and Talinay. This observation, led to the following questions: a) what is the level of morphological and genetic divergence among the populations of Drimys in Chile? and b) do the populations from Fray Jorge/Talinay, currently classified as D. winteri var. chilensis, differ genetically from the other populations of this variety? To answer these questions, we collected leaf samples from 37 populations of all Chilean Drimys, performed leaf morphology analysis and estimated genetic divergence using RAPD markers. We found a high degree of leaf morphological and genetic divergence between the populations of Fray Jorge/Talinay and the other Chilean species of Drimys. The morphological and genetic divergence among varieties of D. winteri was greater than that among the species of Drimys, which may indicate problems with their taxonomic classification.
Año: 2012
Palabras claves: Drimys; RAPD; Fray Jorge/Talinay; Divergence
Referencia APA: Jara-Arancio, P., Carmona, M., Correa, C., Squeo, F., & Arancio, G. (2012). Leaf morphological and genetic divergence in populations of Drimys (Winteraceae) in Chile. Genetics And Molecular Research, 11(1), 229-243.