CEAZA
Late Quaternary climate change, relict populations and present-day refugia in the northern Atacama Desert: a case study from Quebrada La Higuera (18° S).
Mujica, M., Latorre, C., Maldonado, A., González-Silvestre, L., Pinto, R., de Pol-Holz, R., & Santoro, C.
In deserts, past climate change (and particularly past rainfall variability) plays a large role in explaining current plant species distributions. We ask which species were most and which were least affected by changes in rainfall during the late Quaternary in northernmost Chile.
Año: 2015
Palabras claves: Altiplano; Atacama Desert; central Andes; late Quaternary; pluvial events; refugia; relict populations; rodent middens.
Referencia APA: Mujica, M., Latorre, C., Maldonado, A., González-Silvestre, L., Pinto, R., de Pol-Holz, R., & Santoro, C. (2015). Late Quaternary climate change, relict populations and present-day refugia in the northern Atacama Desert: a case study from Quebrada La Higuera (18° S). Journal Of Biogeography, 42(1), 76-88.
Ancient and modern introduction of Broussonetia papyrifera ([L.] Vent.; Moraceae) into the Pacific: genetic, geographical and historical evidence.
González-Lorca, J., Rivera-Hutinel, A., Moncada, X., Lobos, S., Seelenfreund, D., & Seelenfreund, A.
Broussonetia papyrifera (L.) Vent. (Moraceae), or paper mulberry, is a species of cultural importance in South East Asia, East Asia and the Pacific. Originally from mainland South East Asia or East Asia, this plant was introduced into the Pacific range by prehistoric Austronesian voyagers. We used non-coding internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA and inter-simple sequence repeat (ISSR) on 79 samples of B. papyrifera from different islands of Remote Oceania, and South East Asia and East Asia. Our results show an absence of genetic diversity in the introduced range of Remote Oceania, with the sole exception of Hawaii. By contrast, Asian samples show genetic diversity. The data obtained suggest a prehistoric human-mediated introduction of this species from East Asia to Remote Oceania and a second, possibly historic, human-mediated introduction to Hawaii.
Año: 2015
Palabras claves: Asia, human-mediated dispersal, ISSR, ITS, paper mulberry, Polynesia.
Referencia APA: González-Lorca, J., Rivera-Hutinel, A., Moncada, X., Lobos, S., Seelenfreund, D., & Seelenfreund, A. (2015). Ancient and modern introduction of Broussonetia papyrifera ([L.] Vent.; Moraceae) into the Pacific: genetic, geographical and historical evidence. New Zealand Journal Of Botany, 53(2), 75-89
Sampling of riverine litter with citizen scientists — findings and recommendations.
Rech, S., Macaya-Caquilpán, V., Pantoja, J., Rivadeneira, M., Campodónico, C., & Thiel, M.
The quantity and composition of litter at riversides and in the surface waters, as well as the occurrence of illegal dumping sites, were studied along four rivers in Chile. Data generated by volunteers were compared to the results from a professional survey, using an identical protocol. Litter was found in considerable quantities at the riversides and in the surface waters at all the sites investigated. A generalized linear mixed model analysis showed that the recorded litter densities did not differ between volunteers and professionals, even after controlling for river, site, or distance between sampling locations, demonstrating that the volunteers successfully applied the sampling protocol. Differences occurred with respect to litter composition, which is most likely due to difficulties in the classification of litter items and particles and to the underestimation of litter present in surface water samples. Even though this study was only conducted at a small number of rivers and sites, a comparatively consistent pattern of direct and intentional litter deposition at riversides was recorded, highlighting that river basins require more protection. The results also show that the citizen science approach can be a suitable means for more extensive litter surveys at riversides and in other natural environments.
Año: 2015
Palabras claves: Citizen science, Data validation, Litter abundance, Litter sources, Riverine litter, Floating microplastics.
Referencia APA: Rech, S., Macaya-Caquilpán, V., Pantoja, J., Rivadeneira, M., Campodónico, C., & Thiel, M. (2015). Sampling of riverine litter with citizen scientists — findings and recommendations. Environmental Monitoring And Assessment, 187(6).
Geographic patterns of diversification and the latitudinal gradient of richness of rocky intertidal gastropods: the ‘into the tropical museum’ hypothesis.
Rivadeneira, M., Alballay, A., Villafaña, J., Raimondi, P., Blanchette, C., & Fenberg, P.
The existence of a canonical LGR in rocky intertidal gastropods can be explained by the combined effect of reduced extinction rates in the tropics and the range expansion of taxa from the extra-tropics toward the tropics, in what we have called the ‘into the tropical museum’ hypothesis.
Año: 2015
Palabras claves: Biodiversity; dispersal; diversification dynamics; extinction; fossil record; origination.
Referencia APA: Rivadeneira, M., Alballay, A., Villafaña, J., Raimondi, P., Blanchette, C., & Fenberg, P. (2015). Geographic patterns of diversification and the latitudinal gradient of richness of rocky intertidal gastropods: the ‘into the tropical museum’ hypothesis. Global Ecology And Biogeography, 24(10), 1149-1158.
Mid Holocene radiocarbon ages in the Subtropical Andes (∼29°–35° S), climatic change and implications for human space organization.
Méndez, C., Gil, A., Neme, G., Nuevo Delaunay, A., Cortegoso, V., & Huidobro, C., Durán, V., Maldonado, A.
This article discusses the distribution of radiocarbon age signatures obtained from archeological sites between 29° and 35° S in Central Chile and Midwest Argentina. The goal of this analysis is to establish bases from which to interpret regional trends in the distribution of the archaeological record that connect these areas, which have been traditionally considered to be geographically decoupled. We propose a standardized methodology for selecting ages that provide a reliable human signature. Variations in date frequencies in a regional scale are discussed with the use of summed probability distributions. Radiocarbon voids at the regional level previously identified in Midwest Argentina are explored. Regional chronological information is compared to the available paleoenvironmental records, thereby emphasizing the possible role of climate pulses in the spatial organization of human populations. Significant arid conditions between 7800 and 5700 cal BP are coincidental with a focused occupation of the Andes Mountains, an area which may have offered stable resources and thus was more effectively occupied than other environmental bands.
Año: 2015
Palabras claves: Radiocarbon dates; Climate change; Human paleoecology; Hunter–gatherers; Mid-Holocene; Subtropical Andes.
Referencia APA: Méndez, C., Gil, A., Neme, G., Nuevo Delaunay, A., Cortegoso, V., Huidobro, C., Durán, V. & Maldonado, A. (2015). Mid Holocene radiocarbon ages in the Subtropical Andes (∼29°–35° S), climatic change and implications for human space organization. Quaternary International, 356, 15-26.
Positive interactions by cushion plants in high mountains: fact or artifact?.
Molina-Montenegro, M., Oses, R., Acuña-Rodríguez, I., Fardella, C., Badano, E., & Torres-Morales, P. et al.
Positive interactions are defined as non-trophic interactions where at least one of the interacting species is benefited in terms of fitness and the other remains unaffected. Nevertheless, the bidirectional feedbacks between species may be positive, neutral or negative. Thus, if facilitated species induce negative effects on their ‘nurses’, the assumed definition of positive interactions could be reconsidered.
Año: 2015
Palabras claves: Cushion plants, facilitation, nurse effect, positive interactions, stress gradient hypothesis.
Referencia APA: Molina-Montenegro, M., Oses, R., Acuña-Rodríguez, I., Fardella, C., Badano, E., & Torres-Morales, P. et al. (2015). Positive interactions by cushion plants in high mountains: fact or artifact?. Journal Of Plant Ecology, 9(2), 117-123
Reproduction reduces HSP70 expression capacity in Argopecten purpuratus scallops subject to hypoxia and heat stress.
Brokordt, K., Pérez, H., Herrera, C., & Gallardo, A.
In scallops, gonad production is highly demanding energetically, and reproduction usually occurs during spring-summer, a period of strong environmental changes. The synthesis of heat-shock proteins (HSPs) is a major mechanism of stress tolerance in animals, including scallops, and HSP expression contributes considerably to cellular energy demand. Therefore, reproductive investment may limit the availability of energy (in terms of ATP) for the expression of HSP in organisms exposed to environmental stress. We evaluated the stress response capacity of adult Argopecten purpuratus scallops to high temperature and hypoxia. Stress response capacity was assessed through gene expression (for temperature stress) and protein induction of 70 kD HSP at 3 reproductive stages: immature, mature and spawned. We also evaluated the effect of reproductive status on the cellular ATP provisioning capacity through citrate synthase activity. Immature scallops exposed to thermal stress showed 1.3- and 1.5-fold increases in hsp70 mRNA and HSP70 protein levels, respectively, and those exposed to hypoxia doubled their level of HSP70 compared to non-stressed immature scallops. However, following gonad maturation and spawning, hsp70 mRNA increased by only 0.49- and 0.65-fold, respectively, after thermal stress and HSP70 protein levels of scallops exposed to thermal and hypoxia stressors did not differ from those of non-stressed animals. In parallel, citrate synthase showed its highest level in immature scallops, declined with gonad maturation, and was lowest in spawned scallops. These results suggest that reproductive investment reduces the stress response capacity of A. purpuratus and that mature and spawned scallops could be more vulnerable to environmental stressors than immature individuals.
Año: 2015
Palabras claves: Reproductive cost, HSP70, hsp70 mRNA, Stress response, Thermal stress, Hypoxia stress, Scallops, Argopecten purpuratus.
Referencia APA: Brokordt, K., Pérez, H., Herrera, C., & Gallardo, A. (2015). Reproduction reduces HSP70 expression capacity in Argopecten purpuratus scallops subject to hypoxia and heat stress. Aquat. Biol., 23(3), 265-274.
Estudio de la relación polen-vegetación actual en el Norte de Chile, en el transecto Pozo Almonte-Salar de Huasco (20º15’S/69º06’O).
Collao-alvarado, K., Maldonado, A., González, L., Sandoval, A., De Porras, M., Zamora, A., & Arancio, G.
La diversidad vegetal de la zona andina del Norte Grande de Chile ha sido estudiada desde diversos puntos de vista (florísticos, fisonómicos, etnobotánicos, conservacionistas, etc.); sin embargo, hasta ahora no se ha estudiado desde un punto de vista palinológico. Así, este trabajo tiene como objetivo aportar al conocimiento de la vegetación y su señal polínica en los distintos pisos altitudinales del Norte Grande de Chile, aportando además a la identificación de los principales tipos polínicos presentes. Este estudio presenta la relación entre lluvia de polen y vegetación actual en un transecto altitudinal entre Pozo Almonte y el Salar de Huasco, en el norte de Chile, junto con fotografías y descripciones de 12 morfotipos polínicos representativos de la zona. Los resultados de los muestreos de vegetación corroboran las tendencias descritas en trabajos previos identificándose los principales pisos de vegetación descritos anteriormente (piso prepuneño, puneño, altoandino y subnival). De igual manera los resultados de la lluvia de polen muestran una clara relación con los ensambles de vegetación que la produce, siendo posible diferenciar cada uno de los pisos de vegetación a partir de su señal polínica. Así, los resultados pueden ser de gran interés para la interpretación de registros polínicos fósiles o para estudios de carácter ecológico.
Año: 2015
Palabras claves: Palinología, lluvia de polen, pisos altitudinales, diversidad vegetal.
Referencia APA: Collao-alvarado, K., Maldonado, A., González, L., Sandoval, A., De Porras, M., Zamora, A., & Arancio, G. (2015). Estudio de la relación polen-vegetación actual en el Norte de Chile, en el transecto Pozo Almonte-Salar de Huasco (20º15’S/69º06’O). Gayana Bot., 72(1), 125-136.
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.