CEAZA
EltonTraits 1.0: Species-level foraging attributes of the world’s birds and mammals.
Wilman, H., Belmaker, J., Simpson, J., de la Rosa, C., Rivadeneira, M., & Jetz, W.
Species are characterized by physiological, behavioral, and ecological attributes that are all subject to varying evolutionary and ecological constraints and jointly determine species' role and function in ecosystems. Attributes such as diet, foraging strata, foraging time, and body size, in particular, characterize a large portion of the “Eltonian” niches of species. Here we present a global species-level compilation of these key attributes for all 9993 and 5400 extant bird and mammal species derived from key literature sources. Global handbooks and monographs allowed the consistent sourcing of attributes for most species. For diet and foraging stratum we followed a defined protocol to translate the verbal descriptions into standardized, semiquantitative information about relative importance of different categories. Together with body size (continuous) and activity time (categorical) this enables a much finer distinction of species' foraging ecology than typical categorical guild assignments allow. Attributes lacking information for specific species are flagged, and interpolated values based on taxonomy are provided instead. The presented data set is limited by, among others, these select cases missing observed data, by errors and uncertainty in the expert assessment as presented in the literature, and by the lack of intraspecific information. However, the standardized and transparent nature and complete global coverage of the data set should support an array of potential studies in biogeography, community ecology, macroevolution, global change biology, and conservation. Potential uses include comparative work involving these traits as focal or secondary variables, ecological research on the trait or trophic structure of communities, or conservation science concerned with the loss of function among species or in ecosystems in a changing world. We hope that this publication will spur the sharing, collaborative curation, and extension of data to the benefit of a more integrative, rigorous, and global biodiversity science.
Año: 2014
Palabras claves: Bird; body size; diet; eco-informatics; foraging; function; mammal; mass; niche; stratum; traits; vertebrate.
Referencia APA: Wilman, H., Belmaker, J., Simpson, J., de la Rosa, C., Rivadeneira, M., & Jetz, W. (2014). EltonTraits 1.0: Species-level foraging attributes of the world's birds and mammals. Ecology, 95(7), 2027-2027.
Nutritional status affects the capacity of the snail Concholepas concholepas to synthesize Hsp70 when exposed to stressors associated with tidal regimes in the intertidal zone.
Jeno, K. & Brokordt, K.
Synthesis of the heat shock protein Hsp70 is one of the most important physiological mechanisms that intertidal organisms possess to counteract damage to macromolecules caused by stressors associated with the tidal cycle. However, the synthesis and activity of Hsp70 involves an elevated energetic cost. We evaluated the effect of the nutritional status (fed vs. starved for 2 weeks) of juvenile Concholepas concholepas mollusc on their capacity to synthesize Hsp70 during emersion (i.e. low tide) and immersion (i.e. high tide) at high temperatures (24 °C, e.g. summer conditions) and at low temperatures (7 °C, e.g. winter conditions). In addition, we evaluated whether Hsp70 is induced directly upon exposure to stress (emersion) or during recovery (re-immersion). Starvation decreased the content of stored energy substrates of juveniles as well as their ability to synthesize Hsp70 during emersion under thermal stress, especially at high temperatures. Additionally, analysis of environmental factors associated with laboratory simulation of tidal regimes indicated that juveniles in starvation, in contrast to fed juveniles, did not significantly increase their levels of Hsp70 during cold emersion (7 °C) or warm emersion (24 °C) or upon re-immersion. Induction of Hsp70 occurred during exposure to stress (low-tide conditions) and not when juveniles returned to “normal” conditions (high-tide conditions). Thus, the synthesis of Hsp70 for the juveniles of this intertidal snail species was coordinated and adapted to the tidal cycle, and the species responds in a similar way to hot and cold emersion conditions. The observed levels of Hsp70 reflect the ability of the individual to synthesize these proteins, which is dependent on the nutritional status of the individual.
Año: 2014
Palabras claves:
Referencia APA: Jeno, K. & Brokordt, K. (2014). Nutritional status affects the capacity of the snail Concholepas concholepas to synthesize Hsp70 when exposed to stressors associated with tidal regimes in the intertidal zone. Marine Biology, 161(5), 1039-1049.
Glacier meltwater flow paths and storage in a geomorphologically complex glacial foreland: The case of the Tapado glacier, dry Andes of Chile (30°S).
Pourrier, J., Jourde, H., Kinnard, C., Gascoin, S., & Monnier, S.
The Tapado catchment is located in the upper Elqui river basin (4000–5550 m) in northern Chile. It comprises the Tapado glacial complex, which is an assemblage of the Tapado glacier and the glacial foreland (debris-covered glacier, rock glacier, and moraines). Although the hydrological functioning of this catchment is poorly known, it is assumed to actively supply water to the lower semi-arid areas of the Elqui river basin. To improve our knowledge of the interactions and water transfers between the cryospheric compartment (glacier, debris-covered glacier, and rock glacier) and the hydrological compartment (aquifers, streams), the results of monitoring of meteorological conditions, as well as discharge, conductivity and temperature of streams and springs located in the Tapado catchment were analyzed. The hydrological results are compared to results inferred from a ground penetrating radar (GPR) survey of the underground structure of the glacial foreland. Water production from the Tapado glacier was shown to be highly correlated with daily and monthly weather conditions, particularly solar radiation and temperature. The resulting daily and monthly streamflow cycles were buffered by the glacial foreland, where underground transfers took place through complex flow paths. However, the development of a thermokarst drainage network in a portion of the glacial foreland enabled rapid concentrated water transfers that reduced the buffer effect. The glacial foreland was shown to act as a reservoir, storing water during high melt periods and supplying water to downstream compartments during low melt periods. GPR observations revealed the heterogeneity of the internal structure of the glacial foreland, which is composed of a mixture of ice and rock debris mixture, with variable spatial ice content, including massive ice lenses. This heterogeneity may explain the abovementioned hydrological behaviors. Finally, calculation of a partial hydrological budget confirmed the importance of the Tapado catchment in supplying water to lower areas of the Elqui river basin. Water production from, and transfer through, cryospheric compartments, and its subsequent interactions with hydrological compartments are key processes driving the summer water supply from the Tapado catchment.
Año: 2014
Palabras claves: Cryosphere hydrology; Debris-covered glacier; Rock glacier; Thermokarst; Water transfers; Semiarid Andes.
Referencia APA: Pourrier, J., Jourde, H., Kinnard, C., Gascoin, S., & Monnier, S. (2014). Glacier meltwater flow paths and storage in a geomorphologically complex glacial foreland: The case of the Tapado glacier, dry Andes of Chile (30°S). Journal Of Hydrology, 519, 1068-1083.
Rise and fall in diversity of Neogene marine vertebrates on the temperate Pacific coast of South America.
Villafaña, J. & Rivadeneira, M.
Año: 2014
Palabras claves:
Referencia APA: Villafaña, J. & Rivadeneira, M. (2014). Rise and fall in diversity of Neogene marine vertebrates on the temperate Pacific coast of South America. Paleobiology, 40(04), 659-674. http://dx.doi.org/10.1666/13069
Diversity of Quinoa in a Biogeographical Island: a Review of Constraints and Potential from Arid to Temperate Regions of Chile.
Bazile, D., Martínez, E., & Fuentes, F.
Chile, isolated by a hyper-arid desert in the north, the Andes Range to the east and the Pacific and Antarctic waters (west and south), has a highly endemic flora. This hotspot of biodiversity is in danger not only due to increasing desertification, but also because human activities can diminish agrobiodiversity. Quinoa (Chenopodium quinoa Willd.) is an Andean species producing highly nutritious grains, which almost disappeared from Chile during the Spanish colonization. Today less than 300 small-scale and highly isolated farmers still grow it as a rain-fed crop. This review describes the biogeographical-social context of quinoa in Chile, and its high genetic diversity as a product of a long domestication process, resulting in numerous local landraces whose conservation and use for breeding improved varieties is of paramount importance. We suggest the term “lighthouse crop” to emphasize its contribution to small scale ecological and bio diverse agriculture, particularly in stressful environments, to promote a healthier nutrition and more equitable markets in the world. Furthermore this crop and its exceptional nutritional properties were invoked by the United Nations Food and Agriculture Organization (FAO) to promote its use worldwide, and to declare 2013 the International Year of Quinoa.
Año: 2014
Palabras claves: Agrobiodiversity, agroecosystems, Chenopodium quinoa, conservation, cropping systems, lighthouse crop.
Referencia APA: Bazile, D., Martínez, E., & Fuentes, F. (2014). Diversity of Quinoa in a Biogeographical Island: a Review of Constraints and Potential from Arid to Temperate Regions of Chile. Not Bot Hort Agrobot Cluj, 42(2).
Positive interactions between the lichen Usnea antarctica (Parmeliaceae) and the native flora in Maritime Antarctica.
Molina-Montenegro, M., Ricote-Martínez, N., Muñoz-Ramírez, C., Gómez-González, S., Torres-Díaz, C., Salgado-Luarte, C., & Gianoli, E.
Eight out of 13 species were positively associated with cushions of the widespread lichen U. antarctica, while only one species (U. aurantiaco-atra) showed a negative association with U. antarctica. Survival of Deschampsia was enhanced when growing associated with U. antarctica cushions. Our results indicate that cushions ameliorated the extreme conditions of Antarctic islands through increased temperature and soil moisture, decreased radiation and evaporative water loss and increased nutrient availability.
Año: 2013
Palabras claves: Antarctica; Deschampsia antarctica ; Facilitation; Global warming; Lichens; Mosses; Nurse effect.
Referencia APA: Molina-Montenegro, M., Ricote-Martínez, N., Muñoz-Ramírez, C., Gómez-González, S., Torres-Díaz, C., Salgado-Luarte, C., & Gianoli, E. (2013). Positive interactions between the lichen Usnea antarctica (Parmeliaceae) and the native flora in Maritime Antarctica. J Veg Sci, 24(3), 463-472. http://dx.doi.org/10.1111/j.1654-1103.2012.01480.x
Environmental Hypoxia Reduces the Escape Response Capacity of Juvenile and Adult Scallops Argopecten purpuratus.
Brokordt, K., Pérez, H., & Campos, F.
Natural beds and cultures of the scallop Argopecten purpuratus are exposed to hypoxia periodically because they are located near upwelling zones. We evaluated the effects of environmental hypoxia on juvenile and adult scallops' escape responses and recovery capacities using 3 different hypoxic cycle (i.e., a gradual decrease and increase of dissolved oxygen) trials. Trials 1 and 2 consisted of single (1-day) hypoxic cycles; trial 3 included exposure to several consecutive daily hypoxic cycles over 7 days, which occurs in the natural environment. Trial 1 evaluated the combined effects of energy demands from escape responses and metabolism on escape responses. during environmental hypoxia. Trial 2 evaluated only the effect of environmental hypoxia on the escape responses. Before and after the hypoxic cycles, the scallops were exposed to their main predator, the sea star Meyenaster gelatinosus. We evaluated 6 indicators of the scallops' escape response: reaction time, the total number of claps, duration of the clapping response until exhaustion, clapping speed, the proportion of claps, and recovery clapping rate after a recuperation of 5 min or 10 min (for juveniles and adults, respectively). The combined effect of functional and environmental hypoxia (trial 1) affected both juvenile and adult escape responses, with a reduction in their number of claps (15% and 25%, respectively), the clapping rate in juveniles (17%), and the clapping time in adults (19%). However, environmental hypoxia alone (trial 2) affected juvenile escape responses only, with a reduction in their number of claps (18%) and clapping rate (17%). After hypoxic exposure in trial 3, adults only showed a reduced escape capacity (clap number and clapping time of 16% and 17%, respectively), although both adult and juvenile scallops had a reduced capacity to recuperate their initial clap number (18% and 23%, respectively) and clapping rate (21% and 17%, respectively). Recovery capacity was associated with a strong reduction in phasic muscle carbohydrates during this period. Overall, hypoxia reduced the escape capacity of A. purpuratus, which may implicate a higher vulnerability to predation (for natural populations) and a decreased physiological status to support other stress factors (for cultured or natural populations).
Año: 2013
Palabras claves: Hypoxia, scallops, escape response, Argopecten purpuratus.
Referencia APA: Brokordt, K., Pérez, H., & Campos, F. (2013). Environmental Hypoxia Reduces the Escape Response Capacity of Juvenile and Adult Scallops Argopecten purpuratus. Journal Of Shellfish Research, 32(2), 369-376
Wind effects on snow cover in Pascua-Lama, Dry Andes of Chile.
Gascoin, S., Lhermitte, S., Kinnard, C., Bortels, K., & Liston, G.
We present the first application of a distributed snow model (SnowModel) in the instrumented site of Pascua-Lama in the Dry Andes (2600–5630 m above sea level, 29° S). A model experiment was performed to assess the effect of wind on the snow cover patterns. A particular objective was to evaluate the role of blowing snow on the glacier formation. The model was run using the data from 11 weather stations over a complete snow season. First, a cross-validation of the meteorological variables interpolation model (MicroMet submodel) was performed to evaluate the performance of the simulated meteorological forcing. Secondly, two SnowModel simulations were set up: one without and the other with the wind transport submodel (SnowTran-3D). Results from both simulations were compared with in situ snow depth measurements and remotely sensed snow cover data. The inclusion of SnowTran-3D does not change the fact that the model is unable to capture the small-scale snow depth spatial variability (as captured by in situ snow depth sensors). However, remote sensing data (MODIS daily snow product) indicate that at broader scales the wind module produced an improved representation of the snow distribution near the glaciers (2-D correlation coefficient increased from R = 0.04 to R = 0.27). The model outputs show that a key process is the sublimation of blowing snow, which amounts to 18% of the total ablation over the whole study area, with a high spatial variability. The effect of snow drift is more visible on the glaciers, where wind-transported snow accumulates preferentially. Net deposition occurred for 43% of the glacier grid points, whereas it is only 23% of non-glacier grid points located above the minimum glacier altitude (4475 m).
Año: 2013
Palabras claves: Snow; Glacier; Wind; Sublimation; Andes; MODIS.
Referencia APA: Gascoin, S., Lhermitte, S., Kinnard, C., Bortels, K., & Liston, G. (2013). Wind effects on snow cover in Pascua-Lama, Dry Andes of Chile. Advances In Water Resources, 55, 25-39.
Barotropic and baroclinic semidiurnal tidal currents in two contrasting coastal upwelling zones of Chile.
Bravo, L., Ramos, M., Sobarzo, M., Pizarro, O., & Valle-Levinson, A.
Current velocity observations from the continental shelves of Coquimbo (~30°S) and Concepcion (~36°30'S), central Chile, were analyzed to evaluate the role of water column stratification and shelf width on baroclinic semidiurnal tidal currents. Semidiurnal barotropic currents off both zones were typically < 5 cm/s, but depth-dependent semidiurnal flows could exceed 10 cm s-1 during stratified conditions. Both zones are recognized as pronounced upwelling centers, with maximum upwelling-favorable winds in spring and summer, respectively. At the northern zone, stratification was mainly controlled by temperature differences between surface and bottom waters with maximum stratification during summer. The southern zone showed more stratification during winter because of freshwater input from local rivers. Consequently, greater variability in the baroclinic semidiurnal currents was observed during summer at the northern continental shelf and in winter at the south. In both regions, much of the semidiurnal variability was consistent with an internal wave's first baroclinic mode of wavelengths of ~10–13 km. Nevertheless, during the period of maximum energy fluxes off the north, the second baroclinic mode (wavelength ~7 km) was also important and matched periods of low upwelling index (relaxation of upwelling favorable winds). Typical energy fluxes during summer integrated in the water column, related to the semidiurnal internal tides were 0.12 W/m of the northern site and 0.1 W/m off the southern site. Possible sites of internal wave generation off the south were the Biobío submarine canyon and the slope/shelf break, while off the north, the generation site was the slope/shelf break.
Año: 2013
Palabras claves: Baroclinic waves; semidiurnal; energy flux.
Referencia APA: Bravo, L., Ramos, M., Sobarzo, M., Pizarro, O., & Valle-Levinson, A. (2013). Barotropic and baroclinic semidiurnal tidal currents in two contrasting coastal upwelling zones of Chile. J. Geophys. Res. Oceans, 118(3), 1226-1238
Within-population genetic diversity of climbing plants and trees in a temperate forest in central Chile.
Torres-Díaz, C., Ruiz, E., Salgado-Luarte, C., Molina-Montenegro, M., & Gianoli, E.
The climbing habit is a key innovation in angiosperm evolution: climbing plant taxa have greater species richness than their non-climbing sister groups. It is considered that highly diversified clades should show increased among-population genetic differentiation. Less clear is the expected pattern regarding within-population genetic diversity in speciose lineages. We tested the hypothesis of greater within-population genetic diversity in climbing plants compared to trees in a temperate forest in central Chile. The assumption underlying this hypothesis is that higher among-population differentiation in climbers compared to trees should reflect higher genetic diversity as well. AFLP markers from 167 individual plants from 14 species (seven climbers and seven trees) were used to estimate the following indices of within-population genetic diversity: mean unbiased expected heterozygosity (He), percentage of polymorphic loci (PPL), Shannon information index (I), and the effective number of alleles (Ne). Overall, within-population genetic diversity did not differ between climbing plants and trees. The He for climbing plants was slightly higher than that of trees (0.247 vs. 0.231), and PPL was higher in trees (93.6) than in climbers (81.8), but these differences were not statistically significant. Both I and Ne were very similar for both groups. The expected greater genetic diversity in climbers might have been counterbalanced by tree-related ecological factors that turned to be relevant in the species assemblages studied. Results of this preliminary study should be further confirmed with a broader approach including several forest sites and larger sample sizes.
Año: 2013
Palabras claves: AFLP, climbers, evolution, genetic variability, key innovation.
Referencia APA: Torres-Díaz, C., Ruiz, E., Salgado-Luarte, C., Molina-Montenegro, M., & Gianoli, E. (2013). Within-population genetic diversity of climbing plants and trees in a temperate forest in central Chile. Gayana Bot., 70(1), 36-43
Different photoprotective responses under drought conditions of two predominant Chilean swamp forest species.
Bascuñán-Godoy, L., Alcaíno, C., Carvajal, D., Sanhueza, C., Montecinos, S., & Maldonado, A.
Myrceugenia exsucca (DC.) O.Berg (Myrtaceae) and Luma chequen (Molina) A. Gray (Myrtaceae) are two predominants species from swamp forests of Chile. These species present differential microhabitat distribution across soil moisture and north-south precipitation gradients, with only L. chequen being commonly found in lower moisture sites. It is hypothesized that L. chequen has greater plasticity than M. exsucca in the attributes involved in photoprotection under drought conditions. To test this hypothesis: both species were exposed to short term drought treatment. A group of individuals was maintained irrigated (with of -0.58 and -0.73 MPa for M. exsucca and L. chequen, respectively), while another group was exposed to drought treatment with around -1.4 MPa ( D). High relationship was founded between relative water content (RWC) and water potential () forM. exsucca (r2= 0.74) more than for L. chequen (r2= 0.46), indicating thatM. exsucca experienced larger dehydration during the drought treatment. As functional attributes of photosynthetic apparatus, amount of total chlorophyll and chlorophyll a fluorescence parameter levels were studied in both species. The results show that L. chequen reduced total content of chlorophylls and maximum efficiency of PSII (Fv / Fm) related to decrease of energy capture increasing significantly the thermal dissipation (qN). On the other hand, M. exsucca does not change these parameters, but significantly reduced the level of photochemical processes (qL), indicating an energy imbalance. The results indicate M. exsucca has less plasticity than L. chequen under drought conditions. It is believed that these differences may be crucial in the establishment period and may be influencing the limited distribution ofM. exsucca in sites with lower water availability.
Año: 2013
Palabras claves: Thermal dissipation, water potential, native plants, Myrtaceae family, wetland plants.
Referencia APA: Bascuñán-Godoy, L., Alcaíno, C., Carvajal, D., Sanhueza, C., Montecinos, S., & Maldonado, A. (2013). Different photoprotective responses under drought conditions of two predominant Chilean swamp forest species. Gayana Bot., 70(2), 267-274.
Meteorological drivers of ablation processes on a cold glacier in the semi-arid Andes of Chile.
MacDonell, S., Kinnard, C., Mölg, T., Nicholson, L., & Abermann, J.
Meteorological and surface change measurements collected during a 2.5 yr period are used to calculate surface mass and energy balances at 5324 m a.s.l. on Guanaco Glacier, a cold-based glacier in the semi-arid Andes of Chile. Meteorological conditions are marked by extremely low vapour pressures (annual mean of 1.1 hPa), strong winds (annual mean of 10 m s−1), shortwave radiation receipt persistently close to the theoretical site maximum during cloud-free days (mean annual 295 W m−2; summer hourly maximum 1354 W m−2) and low precipitation rates (mean annual 45 mm w.e.). Snowfall occurs sporadically throughout the year and is related to frontal events in the winter and convective storms during the summer months. Net shortwave radiation provides the greatest source of energy to the glacier surface, and net longwave radiation dominates energy losses. The turbulent latent heat flux is always negative, which means that the surface is always losing mass via sublimation, which is the main form of ablation at the site. Sublimation rates are most strongly correlated with net shortwave radiation, incoming shortwave radiation, albedo and vapour pressure. Low glacier surface temperatures restrict melting for much of the period, however episodic melting occurs during the austral summer, when warm, humid, calm and high pressure conditions restrict sublimation and make more energy available for melting. Low accumulation (131 mm w.e. over the period) and relatively high ablation (1435 mm w.e.) means that mass change over the period was negative (−1304 mm w.e.), which continued the negative trend recorded in the region over the last few decades.
Año: 2013
Palabras claves:
Referencia APA: MacDonell, S., Kinnard, C., Mölg, T., Nicholson, L., & Abermann, J. (2013). Meteorological drivers of ablation processes on a cold glacier in the semi-arid Andes of Chile. The Cryosphere, 7(5), 1513-1526. http://dx.doi.org/10.5194/tc-7-1513-2013