The present paper reconstructs the biogeographic diversification for Nolana L.f. （Solanaceae）, a genus of 89 endemic species largely restricted to fog-dependent desert lomas formations of coastal Peru and Chile. Pre...The present paper reconstructs the biogeographic diversification for Nolana L.f. （Solanaceae）, a genus of 89 endemic species largely restricted to fog-dependent desert lomas formations of coastal Peru and Chile. Previous efforts have reconstructed a phylogenetic estimate for Nolana using a combination of molecular markers. Herein, we expand on those results to examine hypotheses of biogeographic origins and diversification patterns. Nolana occupies habitats within a continuous coastal desert and forms a terrestrial archipelago of discrete ＂islands＂ unique in size, topography, and species composition. Each locality contains at least one Nolana species and many contain multiple species in sympatry. The genus has a Chilean origin, with the basal clades confined to Chile with wide geographic and ecological distributions. Peru contains two strongly supported clades, suggesting two introductions with subsequent radiation. A Chilean clade of shrubby, small-flowered species appears to have had its origins from the same ancestors of the second line that radiated in Peru and northern Chile. Nolana galapagensis is endemic to the Islas Galapagos, with origins traced to Peruvian taxa with a divergence time of 0.35 mya. Rates of diversification over the past 4.02 mya in Nolana, in one of the driest habitats on Earth, suggest rapid adaptive radiation in several clades. Success in Nolana may be attributed to characters that confer a competitive advantage in unpredictable and water-dependent environments, such as succulent leaf anatomy and ecophysiology, and the reproductive mericarp unique to Nolana. The processes affecting or shaping the biota of western South America are discussed.展开更多
We report for the first time the presence of local populations of the starfish Odontaster penicillatus in the regions of Atacama and Antofagasta,Chile.This finding indicates an extension of the distribution limit of 5...We report for the first time the presence of local populations of the starfish Odontaster penicillatus in the regions of Atacama and Antofagasta,Chile.This finding indicates an extension of the distribution limit of 500 km with respect to the last observation made in 2007 in Isla Grande de Atacama.A total of 121 specimens of O.penicillatus were recorded at depths of between 8 m and 24 m.They were associated with rocky substrate and with different species of barnacles,sponges and bryozoans.The presence of O.penicillatus expands the knowledge of the benthic biodiversity of the region,and the development of studies on its ecological importance will be promoted.展开更多
A rust disease caused by <i>Uropyxis daleae</i> (Dietel & Holw.) Magnus was registered on the natural population of <i>Dalea pennelli</i> (Mac Bride) Mac Bride var. <i>chilensis</i...A rust disease caused by <i>Uropyxis daleae</i> (Dietel & Holw.) Magnus was registered on the natural population of <i>Dalea pennelli</i> (Mac Bride) Mac Bride var. <i>chilensis</i> Barneby in the highland near the Andes in the northernmost of Chile. This pathogen shows uredinia with the presence of paraphyses and features, larger urediniospores and teliospores than <i>U. daleae</i> (Dietel & Holway) Magn. var. <i>daleae</i>. Based on morphological combined with 28S sequence analysis, we propose this pathogen as a new fungal variety: <i>U. daleae</i> var. <i>socoromensis</i>. This is the first report of <i>Uropyxis daleae</i> var. <i>socoromensis</i> attacking <i>D. pennelli</i> var. <i>chilensis</i> in Northern Chile.展开更多
This work presents the preliminary results of the first field calibration campaign performed in the Atacama Desert,Chile,between the 18 and 22 August 2014,called the Atacama Field Campaign(ATAFIC 2014).In situ measure...This work presents the preliminary results of the first field calibration campaign performed in the Atacama Desert,Chile,between the 18 and 22 August 2014,called the Atacama Field Campaign(ATAFIC 2014).In situ measurements were performed in order to spectrally characterize the surface reflectance spectra between 0.3 and 2.5μm,radiometric temperature(8.0–14.0μm)and atmospheric measurements.A soil sample was collected and analyzed using Fourier Transform Infrared Spectroscopy and X-Ray Diffraction techniques to characterize the surface reflectance spectra and mineralogical composition,respectively.ASTER land surface emissivity in addition to GOES,MODIS and Landsat-8 land surface temperature(LST)were also used.Results showed that the spectral features of the Atacama soil and the characteristics of this geographical zone,which is featured as the most hyper-arid and cloudless place in the world,make this area a potential target for surface reflectance characterization.Day and night LST comparison between field and remote sensing data are lower than 2 K and the Root Mean Square Error for land surface emissivity is close to 2%.This work opens the possibilities to consider the Atacama Desert as a reference target for calibration and validation activities for earth observation missions’purposes.展开更多
Chile is a very important country that forms part of the Andean metallogenic belts. The Atacama and Domeyko fault systems in northern Chile control the tectonic- magmatic activities that migrate eastward and the types...Chile is a very important country that forms part of the Andean metallogenic belts. The Atacama and Domeyko fault systems in northern Chile control the tectonic- magmatic activities that migrate eastward and the types of mineral resources. In this paper, we processed and interpreted aeromagnetic data from northern Chile using reduction to pole, upward field continuation, the second derivative calculation in the vertical direction, inclination angle calculation, and analytical signal amplitude analysis. We revealed the locations and planar distribution characteristics of the regional deep faults along the NNE and NS directions. Furthermore, we observed that the major reasons for the formation of the tectonic-magmatic rocks belts were the nearly parallel deep faults distributed from west to east and multiple magmatic activities along these faults. We ascertained the locations of volcanic mechanisms and the relationships between them using these regional deep faults. We deduced the spatial distributions of the basic-intermediate, basic, and acidic igneous rocks, intrusive rocks, and sedimentary sequences. We showed the linear positive magnetic anomalies and magnetic anomaly gradient zones by slowly varying the background, negative magnetic anomaly field, which indicated the presence of strong magmatic activities in these regional deep faults; it also revealed the favorable areas of copper and polymetallic mineralization. This study provides some basic information for further research on the geology, structural characteristics, and mineral resource prospecting in northern Chile.展开更多
Andean high-altitude wetlands are important ecosystems that serve a range of socialecological functions. In the Andes, bofedales, a specific type of peat-producing wetland, are essential for the sustainability of moun...Andean high-altitude wetlands are important ecosystems that serve a range of socialecological functions. In the Andes, bofedales, a specific type of peat-producing wetland, are essential for the sustainability of mountain ecosystems and indigenous pastoralist communities. The Chucuyo bofedal in northern Chile is affected by climatic variability and water extraction for agricultural uses via the Lauca canal. Herders in the local community also actively manage this wetland according to their traditional ecological knowledge to ensure permanent fodder for their animals. In this article, we analyze the annual behavior of the Chucuyo bofedal after the wet season. Based on precipitation data, extracted water flows, vegetation vigor from satellite images, and an ethnographic approach, we determined that the bofedal’s productivity was negatively correlated with the amount of precipitation and positively correlated with the surface area of the wetland. However, water extraction via the Lauca channel had no significant relationship with either surface area or vegetation vigor. We identify community practices and traditional ecological knowledge as key elements in the maintenance of these ecosystems. This situation is critical in the context of an aging population and the current pattern of migration out of the region to urban areas. The results provide substantial empirical evidence for future decision-making regarding the conservation of these ecosystems.展开更多
The existence of the thorium element in the ores from the Atacama region, Chile, and its importance in the activities of the nuclear industry, have generated the interest of the Chilean Nuclear Energy Commission (CChE...The existence of the thorium element in the ores from the Atacama region, Chile, and its importance in the activities of the nuclear industry, have generated the interest of the Chilean Nuclear Energy Commission (CChEN) to study the technical feasibility of its recovery, like ThO2 through the implementation of hydrometallurgical techniques, such as leaching, solvent extraction, among others. The present work has become a report about the research carried out in the Extractive Metallurgy Area of the Department of Advanced Materials of CChEN, whose objective is to know the behavior of the thorium element when the mineral carrier is leached. The leaching tests were carried out in a glass reactor in batch mode, by mechanical agitation, varying different operational parameters, such as: type of leaching solution, concentration of acid in the solution, system temperature and granulometry of the mineral. The results indicate that there is technical feasibility for the recovery of thorium by leaching the mineral carrier with hydrochloric and/or sulfuric solution. The highest recovery of thorium for a sulfuric solution was 70.0% and for a hydrochloric solution of 83.8%, so the process presents a good efficiency in both cases. For a hydrochloric solution, the mathematical model of the thorium recovery efficiency obtained is: Y=31.14+26.25*X1+8.69*X2−0.82*X3+9.5*X12−0.83*X13−3.71*X23−1.83*X123+6.45 The concentration of HCl and temperature, as well as their interaction, significantly affect the recovery of thorium for Sierra Indiana mineral, as well as temperature and granulometry. The previous model gives a good representativeness of 99.98%. For a sulfuric solution, the mathematical model of the thorium recovery efficiency obtained is: Y=29.78+25.92*X1+0.99*X2−1.05*X3−2.05*X12−9.84*X13−5.26*X23−3.87*X123+15.18 The model indicates that the recovery of thorium for the mineral is significantly affected by the concentration of sulfuric acid, and to a lesser degree by the temperature and granulometry. The model provides a representativeness of 98.3%.展开更多
海沟是全球大洋体系的重要组成部分。研究这一极端环境的生物地球化学循环过程有助于我们进一步理解海洋的物质循环。前期研究发现,海沟表层水体的初级生产力(NPP)对海沟沉积物埋藏的有机碳性质具有重要影响,但是,颗粒有机碳(POC)在沉...海沟是全球大洋体系的重要组成部分。研究这一极端环境的生物地球化学循环过程有助于我们进一步理解海洋的物质循环。前期研究发现,海沟表层水体的初级生产力(NPP)对海沟沉积物埋藏的有机碳性质具有重要影响,但是,颗粒有机碳(POC)在沉降过程中被微生物呼吸和降解的过程尚不清楚。因此,本研究利用2018年春“太阳号”阿塔卡马海沟(Atacama Trench)国际联合航次SO261所采集的表层水样品,测试其中POC浓度、C/N、δ^(13)C、δ^(15)N等参数,并结合0.2—0.8、0.8—3.0、>3.0μm三种粒径微生物群落呼吸(microbial community respiration,MCR)速率测试,探究其日变化模式及不同站位的空间变化模式,进而衡量微生物对POC的呼吸降解作用。结果表明,该海域表层水中对POC降解占主导作用的微生物类群粒径为0.8—3.0μm;24 h时间序列实验表明MCR随时间呈现“M”型曲线的双峰变化模式,且和C/N、δ^(13)C、δ^(15)N等参数变化趋势吻合,表明同一站位的呼吸速率主要与光强有关,并对代谢有机碳的元素性质产生影响;在空间上,海沟站位表层的MCR显著大于非海沟站位,并受初级生产力的影响。最后,本文计算得到表层水微生物对NPP的呼吸降解比例在0.5%—4.6%之间。展开更多
Urban coastal wetlands are fragile ecosystems that provide important ecosystemic services.However,these ecosys-tems are subject to considerable external pressures from urban development,which leads to serious disturba...Urban coastal wetlands are fragile ecosystems that provide important ecosystemic services.However,these ecosys-tems are subject to considerable external pressures from urban development,which leads to serious disturbances in their structure,functioning,and diversity as a result of the advancement of urban,agricultural,foraging,and drainage activities,as well as displacement of endemic species by invasive ones.Within the biological communities of these ecosystems,arthropods play an important trophic and ecological role as food resource,pollinating agents,biological controllers,organic matter decomposers,and nutrient cyclers.In this paper we characterize the taxonomic richness and abundance of the terrestrial arthropod fauna of the Aguada de La Chimba urban coastal wetland(Antofagasta Region,Chile)using various methods.From a total of 1,874 specimens,we identified 109 terrestrial arthropod species,where Insecta was the most represented taxon,with 85 species,47 families,and 15 orders.The estimated species rich-ness values were higher than the observed values for the different groups under study,and insects showed the high-est species values in all estimators.Based on their origin,the communities identified included native(24%),natural-ized(22%),and to a lesser extent,endemic species.We also characterize the major threats to this urban wetland and discuss the importance of building public-private partnerships with the local community for the success of biodiver-sity conservation programs in coastal ecosystems.展开更多
基金supported,in part,by grants to MOD from the National Science Foundation (DEB 0415573,DEB 9801297,DEB 8513205)
文摘The present paper reconstructs the biogeographic diversification for Nolana L.f. （Solanaceae）, a genus of 89 endemic species largely restricted to fog-dependent desert lomas formations of coastal Peru and Chile. Previous efforts have reconstructed a phylogenetic estimate for Nolana using a combination of molecular markers. Herein, we expand on those results to examine hypotheses of biogeographic origins and diversification patterns. Nolana occupies habitats within a continuous coastal desert and forms a terrestrial archipelago of discrete ＂islands＂ unique in size, topography, and species composition. Each locality contains at least one Nolana species and many contain multiple species in sympatry. The genus has a Chilean origin, with the basal clades confined to Chile with wide geographic and ecological distributions. Peru contains two strongly supported clades, suggesting two introductions with subsequent radiation. A Chilean clade of shrubby, small-flowered species appears to have had its origins from the same ancestors of the second line that radiated in Peru and northern Chile. Nolana galapagensis is endemic to the Islas Galapagos, with origins traced to Peruvian taxa with a divergence time of 0.35 mya. Rates of diversification over the past 4.02 mya in Nolana, in one of the driest habitats on Earth, suggest rapid adaptive radiation in several clades. Success in Nolana may be attributed to characters that confer a competitive advantage in unpredictable and water-dependent environments, such as succulent leaf anatomy and ecophysiology, and the reproductive mericarp unique to Nolana. The processes affecting or shaping the biota of western South America are discussed.
文摘We report for the first time the presence of local populations of the starfish Odontaster penicillatus in the regions of Atacama and Antofagasta,Chile.This finding indicates an extension of the distribution limit of 500 km with respect to the last observation made in 2007 in Isla Grande de Atacama.A total of 121 specimens of O.penicillatus were recorded at depths of between 8 m and 24 m.They were associated with rocky substrate and with different species of barnacles,sponges and bryozoans.The presence of O.penicillatus expands the knowledge of the benthic biodiversity of the region,and the development of studies on its ecological importance will be promoted.
文摘A rust disease caused by <i>Uropyxis daleae</i> (Dietel & Holw.) Magnus was registered on the natural population of <i>Dalea pennelli</i> (Mac Bride) Mac Bride var. <i>chilensis</i> Barneby in the highland near the Andes in the northernmost of Chile. This pathogen shows uredinia with the presence of paraphyses and features, larger urediniospores and teliospores than <i>U. daleae</i> (Dietel & Holway) Magn. var. <i>daleae</i>. Based on morphological combined with 28S sequence analysis, we propose this pathogen as a new fungal variety: <i>U. daleae</i> var. <i>socoromensis</i>. This is the first report of <i>Uropyxis daleae</i> var. <i>socoromensis</i> attacking <i>D. pennelli</i> var. <i>chilensis</i> in Northern Chile.
基金partially funded by Fondecyt Initial[CONICYT/ref-11130359]The authors would also like to thank CNPq and CAPES for the scholarship given to Ms.Cibele T.Pinto and its research financial support.
文摘This work presents the preliminary results of the first field calibration campaign performed in the Atacama Desert,Chile,between the 18 and 22 August 2014,called the Atacama Field Campaign(ATAFIC 2014).In situ measurements were performed in order to spectrally characterize the surface reflectance spectra between 0.3 and 2.5μm,radiometric temperature(8.0–14.0μm)and atmospheric measurements.A soil sample was collected and analyzed using Fourier Transform Infrared Spectroscopy and X-Ray Diffraction techniques to characterize the surface reflectance spectra and mineralogical composition,respectively.ASTER land surface emissivity in addition to GOES,MODIS and Landsat-8 land surface temperature(LST)were also used.Results showed that the spectral features of the Atacama soil and the characteristics of this geographical zone,which is featured as the most hyper-arid and cloudless place in the world,make this area a potential target for surface reflectance characterization.Day and night LST comparison between field and remote sensing data are lower than 2 K and the Root Mean Square Error for land surface emissivity is close to 2%.This work opens the possibilities to consider the Atacama Desert as a reference target for calibration and validation activities for earth observation missions’purposes.
基金supported by the National Science Foundation of China(No.41404070)China Geological Survey(No.DD20160102-02)
文摘Chile is a very important country that forms part of the Andean metallogenic belts. The Atacama and Domeyko fault systems in northern Chile control the tectonic- magmatic activities that migrate eastward and the types of mineral resources. In this paper, we processed and interpreted aeromagnetic data from northern Chile using reduction to pole, upward field continuation, the second derivative calculation in the vertical direction, inclination angle calculation, and analytical signal amplitude analysis. We revealed the locations and planar distribution characteristics of the regional deep faults along the NNE and NS directions. Furthermore, we observed that the major reasons for the formation of the tectonic-magmatic rocks belts were the nearly parallel deep faults distributed from west to east and multiple magmatic activities along these faults. We ascertained the locations of volcanic mechanisms and the relationships between them using these regional deep faults. We deduced the spatial distributions of the basic-intermediate, basic, and acidic igneous rocks, intrusive rocks, and sedimentary sequences. We showed the linear positive magnetic anomalies and magnetic anomaly gradient zones by slowly varying the background, negative magnetic anomaly field, which indicated the presence of strong magmatic activities in these regional deep faults; it also revealed the favorable areas of copper and polymetallic mineralization. This study provides some basic information for further research on the geology, structural characteristics, and mineral resource prospecting in northern Chile.
文摘Andean high-altitude wetlands are important ecosystems that serve a range of socialecological functions. In the Andes, bofedales, a specific type of peat-producing wetland, are essential for the sustainability of mountain ecosystems and indigenous pastoralist communities. The Chucuyo bofedal in northern Chile is affected by climatic variability and water extraction for agricultural uses via the Lauca canal. Herders in the local community also actively manage this wetland according to their traditional ecological knowledge to ensure permanent fodder for their animals. In this article, we analyze the annual behavior of the Chucuyo bofedal after the wet season. Based on precipitation data, extracted water flows, vegetation vigor from satellite images, and an ethnographic approach, we determined that the bofedal’s productivity was negatively correlated with the amount of precipitation and positively correlated with the surface area of the wetland. However, water extraction via the Lauca channel had no significant relationship with either surface area or vegetation vigor. We identify community practices and traditional ecological knowledge as key elements in the maintenance of these ecosystems. This situation is critical in the context of an aging population and the current pattern of migration out of the region to urban areas. The results provide substantial empirical evidence for future decision-making regarding the conservation of these ecosystems.
文摘The existence of the thorium element in the ores from the Atacama region, Chile, and its importance in the activities of the nuclear industry, have generated the interest of the Chilean Nuclear Energy Commission (CChEN) to study the technical feasibility of its recovery, like ThO2 through the implementation of hydrometallurgical techniques, such as leaching, solvent extraction, among others. The present work has become a report about the research carried out in the Extractive Metallurgy Area of the Department of Advanced Materials of CChEN, whose objective is to know the behavior of the thorium element when the mineral carrier is leached. The leaching tests were carried out in a glass reactor in batch mode, by mechanical agitation, varying different operational parameters, such as: type of leaching solution, concentration of acid in the solution, system temperature and granulometry of the mineral. The results indicate that there is technical feasibility for the recovery of thorium by leaching the mineral carrier with hydrochloric and/or sulfuric solution. The highest recovery of thorium for a sulfuric solution was 70.0% and for a hydrochloric solution of 83.8%, so the process presents a good efficiency in both cases. For a hydrochloric solution, the mathematical model of the thorium recovery efficiency obtained is: Y=31.14+26.25*X1+8.69*X2−0.82*X3+9.5*X12−0.83*X13−3.71*X23−1.83*X123+6.45 The concentration of HCl and temperature, as well as their interaction, significantly affect the recovery of thorium for Sierra Indiana mineral, as well as temperature and granulometry. The previous model gives a good representativeness of 99.98%. For a sulfuric solution, the mathematical model of the thorium recovery efficiency obtained is: Y=29.78+25.92*X1+0.99*X2−1.05*X3−2.05*X12−9.84*X13−5.26*X23−3.87*X123+15.18 The model indicates that the recovery of thorium for the mineral is significantly affected by the concentration of sulfuric acid, and to a lesser degree by the temperature and granulometry. The model provides a representativeness of 98.3%.
文摘海沟是全球大洋体系的重要组成部分。研究这一极端环境的生物地球化学循环过程有助于我们进一步理解海洋的物质循环。前期研究发现,海沟表层水体的初级生产力(NPP)对海沟沉积物埋藏的有机碳性质具有重要影响,但是,颗粒有机碳(POC)在沉降过程中被微生物呼吸和降解的过程尚不清楚。因此,本研究利用2018年春“太阳号”阿塔卡马海沟(Atacama Trench)国际联合航次SO261所采集的表层水样品,测试其中POC浓度、C/N、δ^(13)C、δ^(15)N等参数,并结合0.2—0.8、0.8—3.0、>3.0μm三种粒径微生物群落呼吸(microbial community respiration,MCR)速率测试,探究其日变化模式及不同站位的空间变化模式,进而衡量微生物对POC的呼吸降解作用。结果表明,该海域表层水中对POC降解占主导作用的微生物类群粒径为0.8—3.0μm;24 h时间序列实验表明MCR随时间呈现“M”型曲线的双峰变化模式,且和C/N、δ^(13)C、δ^(15)N等参数变化趋势吻合,表明同一站位的呼吸速率主要与光强有关,并对代谢有机碳的元素性质产生影响;在空间上,海沟站位表层的MCR显著大于非海沟站位,并受初级生产力的影响。最后,本文计算得到表层水微生物对NPP的呼吸降解比例在0.5%—4.6%之间。
文摘Urban coastal wetlands are fragile ecosystems that provide important ecosystemic services.However,these ecosys-tems are subject to considerable external pressures from urban development,which leads to serious disturbances in their structure,functioning,and diversity as a result of the advancement of urban,agricultural,foraging,and drainage activities,as well as displacement of endemic species by invasive ones.Within the biological communities of these ecosystems,arthropods play an important trophic and ecological role as food resource,pollinating agents,biological controllers,organic matter decomposers,and nutrient cyclers.In this paper we characterize the taxonomic richness and abundance of the terrestrial arthropod fauna of the Aguada de La Chimba urban coastal wetland(Antofagasta Region,Chile)using various methods.From a total of 1,874 specimens,we identified 109 terrestrial arthropod species,where Insecta was the most represented taxon,with 85 species,47 families,and 15 orders.The estimated species rich-ness values were higher than the observed values for the different groups under study,and insects showed the high-est species values in all estimators.Based on their origin,the communities identified included native(24%),natural-ized(22%),and to a lesser extent,endemic species.We also characterize the major threats to this urban wetland and discuss the importance of building public-private partnerships with the local community for the success of biodiver-sity conservation programs in coastal ecosystems.
