DOAJ (DOAJ: Directory of Open Access Journals), Jun 1, 2006
Resumen. La estrecha relación existente entre la vegetación y el polen que ésta produce favorece ... more Resumen. La estrecha relación existente entre la vegetación y el polen que ésta produce favorece el estudio de las comunidades vegetales desde un punto de vista palinológico. De esta manera es posible obtener información sobre la distribución de la vegetación por medio de la dispersión y depositación de los granos de polen. La caracterización polínica de las comunidades vegetales permite investigar la historia de la vegetación desde la perspectiva actualista. El objetivo de este trabajo es caracterizar la dispersión-depositación del polen actual en relación con la distribución de la vegetación utilizando análisis estadísticos multivariados (clasifi cación y correspondencia) como un paso esencial para futuros estudios de la historia ambiental del Holoceno de la Isla Grande de Tierra del Fuego. El área de estudio está localizada en el sector argentino de la Isla Grande de Tierra del Fuego a 52°40'S-55°07'S; 65°05'O-68°40'O. El resultado de los métodos numéricos y su asociación con los parámetros ambientales ha permitido la diferenciación de un continuum de comunidades que pertenecen a diferentes unidades fi sonómicas: bosque y estepa graminosa. Palabras clave: palinología, lluvia de polen, comunidades, vegetación, análisis multivariados, Tierra del Fuego.
During the Holocene a vegetation shift occurred in Tierra del Fuego from a grass-dominated steppe... more During the Holocene a vegetation shift occurred in Tierra del Fuego from a grass-dominated steppe to a Nothofagus dominated forest. Here, the vegetation changes occurred in the second half of the Holocene in the centre of Isla Grande de Tierra del Fuego are analysed. We propose the hypothesis that from 4,420±110 years BP to now, the forest dominated the centre of the island. Pollen spectra from a core sample of a peat bog at Estancia Río Claro (54°22'S, 68°W) and a modern pollen dispersal model, previously published by the authors, were used for the identification of modern analogues. Changes in the composition of the pollen spectra along the peat bog profile show vegetation changes both at regional and local scales. Modern analogues showed the dominance of forest vegetation during the last 4,420 years in the central part of Isla Grande de Tierra del Fuego. However, an alternation of open and closed deciduous forests, and also water-filled and drier bog conditions were found throughout this period. The open forest was probably associated with lower precipitation and cold temperatures.
All the contents of this work, except where otherwise noted, is licensed under a Creative Commons... more All the contents of this work, except where otherwise noted, is licensed under a Creative Commons Attribution 4.0 International license. Todo o conteúdo deste trabalho, exceto quando houver ressalva, é publicado sob a licença Creative Commons Atribição 4.0. Todo el contenido de esta obra, excepto donde se indique lo contrario, está bajo licencia de la licencia Creative Commons Reconocimento 4.0.
La metodología que ha sido más utilizada para realizar la extracción de diferentes proxies biológ... more La metodología que ha sido más utilizada para realizar la extracción de diferentes proxies biológicos consiste en dividir los coprolitos en distintas submuestras para el análisis de cada uno. Estudios recientes han reconocido limitaciones en las interpretaciones alcanzadas en base a la utilización de este método. El objetivo de este trabajo fue diseñar un protocolo de análisis multiproxy para ser aplicado a una única muestra de heces de camélidos sudamericanos. El diseño se desarrolló con el propósito de minimizar la utilización de compuestos químicos y optimizar la recuperación de los diversos proxies a partir del análisis de diferentes consideraciones teóricas y metodológicas. Se realizaron modificaciones al protocolo estándar en función de los requerimientos para el análisis multiproxy. Con el fin de comenzar a optimizar este método, se aplicó el protocolo sobre un pool de cuatro heces actuales de guanacos (Lama guanicoe) recolectadas en la Patagonia Argentina. Se realizó el anál...
Abstract Learning about past biological interactions is possible thanks to the study of trace fos... more Abstract Learning about past biological interactions is possible thanks to the study of trace fossils, such as coprolites found in archaeological sites. The multiproxy analysis of coprolites may provide evidence of direct and indirect consumption of diet items and thus reconstructing the ecological dynamics of past ecosystems. In this study, we performed a comparative analysis of the content of plant fragments, pollen and silica phytoliths in coprolites found in the archaeological site Cerro Casa de Piedra 5 (47°57′S; 72°05′W), located in the Perito Moreno National Park, Santa Cruz, Argentina, in an archaeological layer dated to 6540 ± 110 years 14C BP (7402 cal years BP), with the aim to recognize dietary habits in those times. According to their morphological features and content, the coprolites were assigned to omnivores (humans/canids) and herbivores (camelids). The multiproxy analysis of these coprolites allowed us to reach a higher taxonomic resolution in the identification of some plant items in the diet, to make inferences on the indirect consumption of vegetation through the consumption of stomachs and other viscera of camelids by omnivores, and to observe similarities and complementarities in terms of the presence and abundance of taxa. The limitations and potentialities of multiproxy analysis to infer past dietary habits are discussed. The information obtained provides greater knowledge about the predator-prey interactions of the Middle Holocene in south-western Patagonia.
Resumen Reconstruimos aquí parte de la historia de la vege-tación del Holoceno Tardío, utilizando... more Resumen Reconstruimos aquí parte de la historia de la vege-tación del Holoceno Tardío, utilizando un módulo del modelado ecosistémico, el Modelo de Retrodicción de Ecosistemas HEMO. Esta reconstrucción se re-laciona con la absorción de la radiación fotosintéti-camente activa (APAR) de las plantas, la cobertura vegetal y la humedad. Se presenta la reconstrucción del paleo-NDVI en el Valle de Ambato, Catamarca (Argentina) desde el año 442. Se discuten las ano-malías positivas y negativas ligadas a diferentes momentos de la ocupación Aguada, y la sensibilidad que presentó el modelo en relación con fenómenos globales. Palabras clave: Modelado ecosistémico; Valle de Ambato; Arqueología; Paleo-NDVI. Abstract In order to reconstruct the Late Holocene vegetation history we used a module from of HEMO (Hindcasting Ecosystems Model), an ecosystem-process model. This reconstruction of the environmental past in terms of the normalized difference vegetation index (NDVI) is related to plant's ...
Fil: Velazquez, Nadia Jimena. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas... more Fil: Velazquez, Nadia Jimena. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biologia. Laboratorio de Palinologia y Bioantropologia; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina
Abstract Coprolites are among the faunal traces of the archaeological and paleontological fossil ... more Abstract Coprolites are among the faunal traces of the archaeological and paleontological fossil record. This is the first study of multiple proxies in herbivore coprolites from the South-Central Andes. The study includes Late Holocene samples from Los Viscos Archaeological Site in Catamarca, Argentina, of the last 2000 years. The aim of this study was to determine the zoological origin of the coprolites as an additional line of evidence to identify the fauna that entered the site. Pellet morphology, parasite contents, ancient DNA (aDNA) and pollen were analysed. Consistently with other reports of local faunal remains, most samples were determined as from Camelidae and Cetartiodactyla. Capra hircus was also identified close to a c. 400-year-old occupation, suggesting an early presence of this European herbivore in the region. Most of the identified parasite remains were taxon-specific. The identification of Fasciola hepatica eggs in goat coprolites provides early evidence of this parasite in domestic ruminants of the region, possibly from the early Hispanic-Indigenous contact. Regarding the diet items of these herbivores, the pollen spectra in the coprolites provide some clues to their management. These results have also allowed us to pose some palaeoecological hypotheses that will be tested in future research as well as to discuss some methodological implications of this multiproxy approach.
Fil: Marconetto, Maria Bernarda. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Cent... more Fil: Marconetto, Maria Bernarda. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Antropologia de Cordoba. Universidad Nacional de Cordoba. Facultad de Filosofia y Humanidades. Instituto de Antropologia de Cordoba; Argentina
The aim of this study was to analyze pollen from the outer parts of camelid coprolites and contem... more The aim of this study was to analyze pollen from the outer parts of camelid coprolites and contemporaneous sediments to evaluate the potential of coprolites for the reconstruction of the vegetation history of Patagonia during the Holocene. The pollen composition of camelid coprolites coming from archeological layers between 10,920 yrs. cal BP and 2823 yrs. cal BP found in the sites Cerro Casa de Piedra 5 and 7 (Perito Moreno National Park, Santa Cruz, Argentina) were analyzed. Coprolites were divided into outer and inner subsamples. Outer subsample pollen extraction was performed through acetolysis and determination and counting under optical microscope. Morisita-Horn index and Wilcoxon test were performed to evaluate similarities between pollen spectra of outer subsamples of coprolites and contemporaneous sediments. The dominant pollen types were: Nothofagus (Nothofagaceae), Empetrum (Ericaceae), Asteraceae subf. Asteroideae, Nassauvia (Asteraceae subf. Mutisioideae), Poaceae and Caryophyllaceae. The similarities found between outer subsamples of coprolites and contemporaneous sediments reflected the dominant pollen types of the vegetation and forest development, whereas significant differences could be attributed to coprolite pollen spectra that may be biased by season of coprolite deposition, selectivity of the diet and/or higher temporal resolution. Also, the presence of pollen types in outer subsamples of coprolites absent in sediments could give information for paleoenvironmental reconstructions by enriching information of the past flora. This study demonstrates that coprolites can be a valuable tool for paleoenvironmental reconstructions in arid and semiarid areas where depositional environments that support pollen preservation are typically rare.
in the periods of 550-650 and 1550-1650 CE was carried out to test the efficacy of Artificial Neu... more in the periods of 550-650 and 1550-1650 CE was carried out to test the efficacy of Artificial Neural Network (ANN) to predict past environments for Archaeology. This work shows that both subtropical Yunga and xerophytic Chaqueña vegetations respond in contrasting fashion to changes in climate forcings. To predict the past an ANN perceptron multilayer model was used. Modern NDVI data and Tree-Ring data were obtained from NOAA-Paleoclimate, and other public sources. These data were used to train the model. Real data and predictions were close (Pearson correlation 0.83-0.90) and warranted the following step, hindcasting. Important paleo-NDVI fluctuations lasting 15 to 20 years were identified in both periods under study. The paleo-NDVI fluctuations in the earlier period were probably related to the unidentified eruption of 583. The fluctuations in the later period appear related to the eruption of 1600 of the Huaynaputina volcano (SW Peru). These findings suggest that the model accurately identified vegetation fluctuations in response to changes in the volcanic forcing. Hence, the ANNs may be considered as apt tools for modeling past environments in support of archaeology.
Fire has shaped the environment and has been important for human cultural development. In this pa... more Fire has shaped the environment and has been important for human cultural development. In this paper, we propose to study past fire events using ecological modelling. For instance, the ecology of fire can help us to understand and interpret archaeological problems related to past settlement patterns or environmental scenarios. Variation in fire regimens are related to both, vegetation and precipitation fluctuations. Recently, we have model past ecosystem dynamics using remote sensing in the Ambato Valley (Catamarca NW Argentina) ranging from 442 to 1998 CE. Our aim here is to use remotely sensed vegetation data to enhance our understanding of environmental disturbance in the period 2000-2011. We characterised the spatial-time dynamics of the annual NDVI as an indicator of vegetation functioning. Then we related the NDVI dynamics to precipitation and fire events in an arid highland environment in the area. Further, we analysed the vegetation data (monthly NDVI, MODIS/TERRA satellite, 1km 2 pixels), and the climate data: annual precipitation. Then we calculated the NDVI annual average of every pixel and the NDVI anomalies of every year over the studied period. Lastly, we related NDVI data with annual precipitation and compared the NDVIs prior to and after known fire events in this period. On a spatial scale, the results show that the NDVI values were (a) low in shrublands and in cultivated areas, (b) medium in grasslands and piedmont forest with anthropic impact, and (c) high in highland forests. Within the studied time-period, extreme positive and negative anomalies were detected. The precipitation interannual variations were greater than the NDVI inter-annual variations, thus demonstrating that in some areas of the valley the horizontal precipitation can make important contributions to the ecosystem humidity. Extreme negative anomalies were observed the year of fire and fire scars at least for the next two years. These results demonstrate the relation between structure and function of vegetation, precipitation and fire. Understanding these relations can enable us to explain results when hindcasting ("predicting" what happened during past episodes of climate change) palaeoenvironmental conditions and fire events, thus helping us to interpret different archaeological contexts related to fire events.
The objective of this work is to carry out an integral study of macro and microbotanical remains ... more The objective of this work is to carry out an integral study of macro and microbotanical remains with the aim of providing information to the palaeoenvironmental reconstruction and understanding the different practices employed in the acquisition of woody material used by hunter-gatherer societies from the northwestern region of the Santa Cruz Province, Argentine Patagonia, during the early and middle Holocene. For this purpose, we study macrobotanical remains (carbonized and non-carbonized wood) recovered from different combustion structures and from the sediment of the three stratigraphic levels dated by 14 C and resulting in ages of 9640 ± 190 years BP; 8380 ± 120 years BP and 6150 ± 105 years BP, of the Cerro Casa de Piedra 7 site. Also, pollen and small plant fragments of human and camelid coprolites were studied. The analysis conducted show differences in the taxonomic resolution obtained by each one of the proxies. The marked representation of Nothofagus pumilio among charcoal and wood makes clear that the forest was an environment recurrently used by hunter-gatherers occupying CCP7. The study of pollen and plant fragments coming from coprolites, allowed the identification of grass species typical of the steppe environments and forest-steppe ecotonal areas. In this way, plant fragments provide higher level of taxonomic resolution and a greater diversity for paleoenvironmental reconstruction. The results obtained by means of the multi-proxy analysis allowed us not only to enlarge the reconstruction of the hunter-gatherers livable environment, but also to recognize the availability and use of the plant resources in the Early-Mid-Holocene in the region.
A soil profile from the southern margin of Colhue Huapi Lake, at La Campanita site (45º38' S, 68º... more A soil profile from the southern margin of Colhue Huapi Lake, at La Campanita site (45º38' S, 68º37' W), was analysed for pollen and algae content to know the past vegetation communities and to infer changes in lake water level occurred during the Late Holocene. Samples were dated by AMS 14 C methods. Radiocarbon ages were of 1711 ± 35 14 C yr BP at the base, 95cm depth, and another of 979 ± 42 14 C yr BP at 40cm depth. The record was dominated by no arboreal taxa, Chenopodiaceae being the principal shrub taxon and Cyperaceae the herbaceous one. Changes in the pollen record occurred mainly at a local scale and few differences were observed in the input of regional and extra regional pollen. From 1711 ± 35 14 C yr BP until ca. 1212 yr BP, a high lake water level was indicated by the low representation of Cyperaceae associated with few shallow areas available to be colonized and high percentages of Pediastrum and Botryococcus algae. Between ca. 1212 and 414 yr BP a period of changes with several fluctuations in water depth developed. This trend would modify at 979 ± 42 14 C yr BP with a decrease in the waters reflected by the expansion of Cyperaceae and algal reduction. From ca. 414 yr BP until 195 yr BP lake water level continued falling with a less fluctuating and net trend as indicated by the highest percentage of Cyperaceae in the sequence and a low algal representation. The subsequent reduction in Cyperaceae percentage and the moderate increase in the algae would indicate a recovery of the lake water level for the last ca. 195 yr BP. Additionally La Campanita sequence was statistically compared with a sequence obtained from the northwestern margin of the lake. Both sites registered a similar trend before 979 ± 42 14 C yr BP.
The analysis of coprolite inclusions is instrumental in exploring certain features of paleodiets ... more The analysis of coprolite inclusions is instrumental in exploring certain features of paleodiets and paleoenvironments, and in determining the time when the sites were occupied by those who deposited the feces. Plant remains found in palaeofeces can be recognized by means of optical microscopes and through microhistological techniques. The aim of this study is to perform a microhistological analysis of plant remains in probable human coprolites from the Cerro Casa de Piedra, Cueva 7 site, province of Santa Cruz, Argentina, with the purpose of identifying the plants included in the diet of the hunter-gatherers who lived in Patagonia during the Pleistocene-Holocene transition and the Holocene, of recognizing some of their cultural practices and of determining the seasonality of the shelters they used. Our microscope study of the samples revealed epidermal fragments of Ephedra sp. stem, leaf and fruit remains of Empetrum rubrum and Gaultheria mucronata, remains of vascular bundles of Azorella monantha leaves and of Armeria maritima epidermis. Only representatives of the Poaceae family were found among the monocots. Our microhistological study of coprolite provided evidence to endorse the consumption of fruits, namely of E. rubrum and G. mucronata. In addition, by determining the time of the year in which the mentioned species bear fruit, we were able to infer that humans used this cave in summer. Likewise, the identification of Ephedra sp., Armeria maritima and Azorella monantha also allowed us to infer that plants of these species were used as medicine and fuel.
Pollen studies on Patagonian camelid coprolites (Argentina) focus on palaeodiet analyses and pala... more Pollen studies on Patagonian camelid coprolites (Argentina) focus on palaeodiet analyses and palaeoenvironmental reconstructions. The elucidation of the source of pollen in coprolites is a main issue to interpret what and how past facts happened. The aim of this work is to evaluate the source of the pollen contained in both modern Lama guanicoe feces and camelid coprolites to evaluating the post-depositing contamination. Pellets were separated into outer and inner parts, and pollen extraction was made of each for analysis. As to pollen concentration, differences probably linked to the pollination season were found between both parts of the feces. The presence of certain taxa only in the outer part could be due to postdepositional contamination. Coprolites evidenced more Nothofagus anemophilous pollen concentration in the outer surface of feces and certain taxa were only registered in a single part. A separate pollen analysis of the outer and inner parts of modern feces and coprolites yields information referred to contamination by environmental pollen; thus, the items conforming part of the diet of the vegetation area not consumed by the organisms can be discriminated.
DOAJ (DOAJ: Directory of Open Access Journals), Jun 1, 2006
Resumen. La estrecha relación existente entre la vegetación y el polen que ésta produce favorece ... more Resumen. La estrecha relación existente entre la vegetación y el polen que ésta produce favorece el estudio de las comunidades vegetales desde un punto de vista palinológico. De esta manera es posible obtener información sobre la distribución de la vegetación por medio de la dispersión y depositación de los granos de polen. La caracterización polínica de las comunidades vegetales permite investigar la historia de la vegetación desde la perspectiva actualista. El objetivo de este trabajo es caracterizar la dispersión-depositación del polen actual en relación con la distribución de la vegetación utilizando análisis estadísticos multivariados (clasifi cación y correspondencia) como un paso esencial para futuros estudios de la historia ambiental del Holoceno de la Isla Grande de Tierra del Fuego. El área de estudio está localizada en el sector argentino de la Isla Grande de Tierra del Fuego a 52°40'S-55°07'S; 65°05'O-68°40'O. El resultado de los métodos numéricos y su asociación con los parámetros ambientales ha permitido la diferenciación de un continuum de comunidades que pertenecen a diferentes unidades fi sonómicas: bosque y estepa graminosa. Palabras clave: palinología, lluvia de polen, comunidades, vegetación, análisis multivariados, Tierra del Fuego.
During the Holocene a vegetation shift occurred in Tierra del Fuego from a grass-dominated steppe... more During the Holocene a vegetation shift occurred in Tierra del Fuego from a grass-dominated steppe to a Nothofagus dominated forest. Here, the vegetation changes occurred in the second half of the Holocene in the centre of Isla Grande de Tierra del Fuego are analysed. We propose the hypothesis that from 4,420±110 years BP to now, the forest dominated the centre of the island. Pollen spectra from a core sample of a peat bog at Estancia Río Claro (54°22'S, 68°W) and a modern pollen dispersal model, previously published by the authors, were used for the identification of modern analogues. Changes in the composition of the pollen spectra along the peat bog profile show vegetation changes both at regional and local scales. Modern analogues showed the dominance of forest vegetation during the last 4,420 years in the central part of Isla Grande de Tierra del Fuego. However, an alternation of open and closed deciduous forests, and also water-filled and drier bog conditions were found throughout this period. The open forest was probably associated with lower precipitation and cold temperatures.
All the contents of this work, except where otherwise noted, is licensed under a Creative Commons... more All the contents of this work, except where otherwise noted, is licensed under a Creative Commons Attribution 4.0 International license. Todo o conteúdo deste trabalho, exceto quando houver ressalva, é publicado sob a licença Creative Commons Atribição 4.0. Todo el contenido de esta obra, excepto donde se indique lo contrario, está bajo licencia de la licencia Creative Commons Reconocimento 4.0.
La metodología que ha sido más utilizada para realizar la extracción de diferentes proxies biológ... more La metodología que ha sido más utilizada para realizar la extracción de diferentes proxies biológicos consiste en dividir los coprolitos en distintas submuestras para el análisis de cada uno. Estudios recientes han reconocido limitaciones en las interpretaciones alcanzadas en base a la utilización de este método. El objetivo de este trabajo fue diseñar un protocolo de análisis multiproxy para ser aplicado a una única muestra de heces de camélidos sudamericanos. El diseño se desarrolló con el propósito de minimizar la utilización de compuestos químicos y optimizar la recuperación de los diversos proxies a partir del análisis de diferentes consideraciones teóricas y metodológicas. Se realizaron modificaciones al protocolo estándar en función de los requerimientos para el análisis multiproxy. Con el fin de comenzar a optimizar este método, se aplicó el protocolo sobre un pool de cuatro heces actuales de guanacos (Lama guanicoe) recolectadas en la Patagonia Argentina. Se realizó el anál...
Abstract Learning about past biological interactions is possible thanks to the study of trace fos... more Abstract Learning about past biological interactions is possible thanks to the study of trace fossils, such as coprolites found in archaeological sites. The multiproxy analysis of coprolites may provide evidence of direct and indirect consumption of diet items and thus reconstructing the ecological dynamics of past ecosystems. In this study, we performed a comparative analysis of the content of plant fragments, pollen and silica phytoliths in coprolites found in the archaeological site Cerro Casa de Piedra 5 (47°57′S; 72°05′W), located in the Perito Moreno National Park, Santa Cruz, Argentina, in an archaeological layer dated to 6540 ± 110 years 14C BP (7402 cal years BP), with the aim to recognize dietary habits in those times. According to their morphological features and content, the coprolites were assigned to omnivores (humans/canids) and herbivores (camelids). The multiproxy analysis of these coprolites allowed us to reach a higher taxonomic resolution in the identification of some plant items in the diet, to make inferences on the indirect consumption of vegetation through the consumption of stomachs and other viscera of camelids by omnivores, and to observe similarities and complementarities in terms of the presence and abundance of taxa. The limitations and potentialities of multiproxy analysis to infer past dietary habits are discussed. The information obtained provides greater knowledge about the predator-prey interactions of the Middle Holocene in south-western Patagonia.
Resumen Reconstruimos aquí parte de la historia de la vege-tación del Holoceno Tardío, utilizando... more Resumen Reconstruimos aquí parte de la historia de la vege-tación del Holoceno Tardío, utilizando un módulo del modelado ecosistémico, el Modelo de Retrodicción de Ecosistemas HEMO. Esta reconstrucción se re-laciona con la absorción de la radiación fotosintéti-camente activa (APAR) de las plantas, la cobertura vegetal y la humedad. Se presenta la reconstrucción del paleo-NDVI en el Valle de Ambato, Catamarca (Argentina) desde el año 442. Se discuten las ano-malías positivas y negativas ligadas a diferentes momentos de la ocupación Aguada, y la sensibilidad que presentó el modelo en relación con fenómenos globales. Palabras clave: Modelado ecosistémico; Valle de Ambato; Arqueología; Paleo-NDVI. Abstract In order to reconstruct the Late Holocene vegetation history we used a module from of HEMO (Hindcasting Ecosystems Model), an ecosystem-process model. This reconstruction of the environmental past in terms of the normalized difference vegetation index (NDVI) is related to plant's ...
Fil: Velazquez, Nadia Jimena. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas... more Fil: Velazquez, Nadia Jimena. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biologia. Laboratorio de Palinologia y Bioantropologia; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas; Argentina
Abstract Coprolites are among the faunal traces of the archaeological and paleontological fossil ... more Abstract Coprolites are among the faunal traces of the archaeological and paleontological fossil record. This is the first study of multiple proxies in herbivore coprolites from the South-Central Andes. The study includes Late Holocene samples from Los Viscos Archaeological Site in Catamarca, Argentina, of the last 2000 years. The aim of this study was to determine the zoological origin of the coprolites as an additional line of evidence to identify the fauna that entered the site. Pellet morphology, parasite contents, ancient DNA (aDNA) and pollen were analysed. Consistently with other reports of local faunal remains, most samples were determined as from Camelidae and Cetartiodactyla. Capra hircus was also identified close to a c. 400-year-old occupation, suggesting an early presence of this European herbivore in the region. Most of the identified parasite remains were taxon-specific. The identification of Fasciola hepatica eggs in goat coprolites provides early evidence of this parasite in domestic ruminants of the region, possibly from the early Hispanic-Indigenous contact. Regarding the diet items of these herbivores, the pollen spectra in the coprolites provide some clues to their management. These results have also allowed us to pose some palaeoecological hypotheses that will be tested in future research as well as to discuss some methodological implications of this multiproxy approach.
Fil: Marconetto, Maria Bernarda. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Cent... more Fil: Marconetto, Maria Bernarda. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Antropologia de Cordoba. Universidad Nacional de Cordoba. Facultad de Filosofia y Humanidades. Instituto de Antropologia de Cordoba; Argentina
The aim of this study was to analyze pollen from the outer parts of camelid coprolites and contem... more The aim of this study was to analyze pollen from the outer parts of camelid coprolites and contemporaneous sediments to evaluate the potential of coprolites for the reconstruction of the vegetation history of Patagonia during the Holocene. The pollen composition of camelid coprolites coming from archeological layers between 10,920 yrs. cal BP and 2823 yrs. cal BP found in the sites Cerro Casa de Piedra 5 and 7 (Perito Moreno National Park, Santa Cruz, Argentina) were analyzed. Coprolites were divided into outer and inner subsamples. Outer subsample pollen extraction was performed through acetolysis and determination and counting under optical microscope. Morisita-Horn index and Wilcoxon test were performed to evaluate similarities between pollen spectra of outer subsamples of coprolites and contemporaneous sediments. The dominant pollen types were: Nothofagus (Nothofagaceae), Empetrum (Ericaceae), Asteraceae subf. Asteroideae, Nassauvia (Asteraceae subf. Mutisioideae), Poaceae and Caryophyllaceae. The similarities found between outer subsamples of coprolites and contemporaneous sediments reflected the dominant pollen types of the vegetation and forest development, whereas significant differences could be attributed to coprolite pollen spectra that may be biased by season of coprolite deposition, selectivity of the diet and/or higher temporal resolution. Also, the presence of pollen types in outer subsamples of coprolites absent in sediments could give information for paleoenvironmental reconstructions by enriching information of the past flora. This study demonstrates that coprolites can be a valuable tool for paleoenvironmental reconstructions in arid and semiarid areas where depositional environments that support pollen preservation are typically rare.
in the periods of 550-650 and 1550-1650 CE was carried out to test the efficacy of Artificial Neu... more in the periods of 550-650 and 1550-1650 CE was carried out to test the efficacy of Artificial Neural Network (ANN) to predict past environments for Archaeology. This work shows that both subtropical Yunga and xerophytic Chaqueña vegetations respond in contrasting fashion to changes in climate forcings. To predict the past an ANN perceptron multilayer model was used. Modern NDVI data and Tree-Ring data were obtained from NOAA-Paleoclimate, and other public sources. These data were used to train the model. Real data and predictions were close (Pearson correlation 0.83-0.90) and warranted the following step, hindcasting. Important paleo-NDVI fluctuations lasting 15 to 20 years were identified in both periods under study. The paleo-NDVI fluctuations in the earlier period were probably related to the unidentified eruption of 583. The fluctuations in the later period appear related to the eruption of 1600 of the Huaynaputina volcano (SW Peru). These findings suggest that the model accurately identified vegetation fluctuations in response to changes in the volcanic forcing. Hence, the ANNs may be considered as apt tools for modeling past environments in support of archaeology.
Fire has shaped the environment and has been important for human cultural development. In this pa... more Fire has shaped the environment and has been important for human cultural development. In this paper, we propose to study past fire events using ecological modelling. For instance, the ecology of fire can help us to understand and interpret archaeological problems related to past settlement patterns or environmental scenarios. Variation in fire regimens are related to both, vegetation and precipitation fluctuations. Recently, we have model past ecosystem dynamics using remote sensing in the Ambato Valley (Catamarca NW Argentina) ranging from 442 to 1998 CE. Our aim here is to use remotely sensed vegetation data to enhance our understanding of environmental disturbance in the period 2000-2011. We characterised the spatial-time dynamics of the annual NDVI as an indicator of vegetation functioning. Then we related the NDVI dynamics to precipitation and fire events in an arid highland environment in the area. Further, we analysed the vegetation data (monthly NDVI, MODIS/TERRA satellite, 1km 2 pixels), and the climate data: annual precipitation. Then we calculated the NDVI annual average of every pixel and the NDVI anomalies of every year over the studied period. Lastly, we related NDVI data with annual precipitation and compared the NDVIs prior to and after known fire events in this period. On a spatial scale, the results show that the NDVI values were (a) low in shrublands and in cultivated areas, (b) medium in grasslands and piedmont forest with anthropic impact, and (c) high in highland forests. Within the studied time-period, extreme positive and negative anomalies were detected. The precipitation interannual variations were greater than the NDVI inter-annual variations, thus demonstrating that in some areas of the valley the horizontal precipitation can make important contributions to the ecosystem humidity. Extreme negative anomalies were observed the year of fire and fire scars at least for the next two years. These results demonstrate the relation between structure and function of vegetation, precipitation and fire. Understanding these relations can enable us to explain results when hindcasting ("predicting" what happened during past episodes of climate change) palaeoenvironmental conditions and fire events, thus helping us to interpret different archaeological contexts related to fire events.
The objective of this work is to carry out an integral study of macro and microbotanical remains ... more The objective of this work is to carry out an integral study of macro and microbotanical remains with the aim of providing information to the palaeoenvironmental reconstruction and understanding the different practices employed in the acquisition of woody material used by hunter-gatherer societies from the northwestern region of the Santa Cruz Province, Argentine Patagonia, during the early and middle Holocene. For this purpose, we study macrobotanical remains (carbonized and non-carbonized wood) recovered from different combustion structures and from the sediment of the three stratigraphic levels dated by 14 C and resulting in ages of 9640 ± 190 years BP; 8380 ± 120 years BP and 6150 ± 105 years BP, of the Cerro Casa de Piedra 7 site. Also, pollen and small plant fragments of human and camelid coprolites were studied. The analysis conducted show differences in the taxonomic resolution obtained by each one of the proxies. The marked representation of Nothofagus pumilio among charcoal and wood makes clear that the forest was an environment recurrently used by hunter-gatherers occupying CCP7. The study of pollen and plant fragments coming from coprolites, allowed the identification of grass species typical of the steppe environments and forest-steppe ecotonal areas. In this way, plant fragments provide higher level of taxonomic resolution and a greater diversity for paleoenvironmental reconstruction. The results obtained by means of the multi-proxy analysis allowed us not only to enlarge the reconstruction of the hunter-gatherers livable environment, but also to recognize the availability and use of the plant resources in the Early-Mid-Holocene in the region.
A soil profile from the southern margin of Colhue Huapi Lake, at La Campanita site (45º38' S, 68º... more A soil profile from the southern margin of Colhue Huapi Lake, at La Campanita site (45º38' S, 68º37' W), was analysed for pollen and algae content to know the past vegetation communities and to infer changes in lake water level occurred during the Late Holocene. Samples were dated by AMS 14 C methods. Radiocarbon ages were of 1711 ± 35 14 C yr BP at the base, 95cm depth, and another of 979 ± 42 14 C yr BP at 40cm depth. The record was dominated by no arboreal taxa, Chenopodiaceae being the principal shrub taxon and Cyperaceae the herbaceous one. Changes in the pollen record occurred mainly at a local scale and few differences were observed in the input of regional and extra regional pollen. From 1711 ± 35 14 C yr BP until ca. 1212 yr BP, a high lake water level was indicated by the low representation of Cyperaceae associated with few shallow areas available to be colonized and high percentages of Pediastrum and Botryococcus algae. Between ca. 1212 and 414 yr BP a period of changes with several fluctuations in water depth developed. This trend would modify at 979 ± 42 14 C yr BP with a decrease in the waters reflected by the expansion of Cyperaceae and algal reduction. From ca. 414 yr BP until 195 yr BP lake water level continued falling with a less fluctuating and net trend as indicated by the highest percentage of Cyperaceae in the sequence and a low algal representation. The subsequent reduction in Cyperaceae percentage and the moderate increase in the algae would indicate a recovery of the lake water level for the last ca. 195 yr BP. Additionally La Campanita sequence was statistically compared with a sequence obtained from the northwestern margin of the lake. Both sites registered a similar trend before 979 ± 42 14 C yr BP.
The analysis of coprolite inclusions is instrumental in exploring certain features of paleodiets ... more The analysis of coprolite inclusions is instrumental in exploring certain features of paleodiets and paleoenvironments, and in determining the time when the sites were occupied by those who deposited the feces. Plant remains found in palaeofeces can be recognized by means of optical microscopes and through microhistological techniques. The aim of this study is to perform a microhistological analysis of plant remains in probable human coprolites from the Cerro Casa de Piedra, Cueva 7 site, province of Santa Cruz, Argentina, with the purpose of identifying the plants included in the diet of the hunter-gatherers who lived in Patagonia during the Pleistocene-Holocene transition and the Holocene, of recognizing some of their cultural practices and of determining the seasonality of the shelters they used. Our microscope study of the samples revealed epidermal fragments of Ephedra sp. stem, leaf and fruit remains of Empetrum rubrum and Gaultheria mucronata, remains of vascular bundles of Azorella monantha leaves and of Armeria maritima epidermis. Only representatives of the Poaceae family were found among the monocots. Our microhistological study of coprolite provided evidence to endorse the consumption of fruits, namely of E. rubrum and G. mucronata. In addition, by determining the time of the year in which the mentioned species bear fruit, we were able to infer that humans used this cave in summer. Likewise, the identification of Ephedra sp., Armeria maritima and Azorella monantha also allowed us to infer that plants of these species were used as medicine and fuel.
Pollen studies on Patagonian camelid coprolites (Argentina) focus on palaeodiet analyses and pala... more Pollen studies on Patagonian camelid coprolites (Argentina) focus on palaeodiet analyses and palaeoenvironmental reconstructions. The elucidation of the source of pollen in coprolites is a main issue to interpret what and how past facts happened. The aim of this work is to evaluate the source of the pollen contained in both modern Lama guanicoe feces and camelid coprolites to evaluating the post-depositing contamination. Pellets were separated into outer and inner parts, and pollen extraction was made of each for analysis. As to pollen concentration, differences probably linked to the pollination season were found between both parts of the feces. The presence of certain taxa only in the outer part could be due to postdepositional contamination. Coprolites evidenced more Nothofagus anemophilous pollen concentration in the outer surface of feces and certain taxa were only registered in a single part. A separate pollen analysis of the outer and inner parts of modern feces and coprolites yields information referred to contamination by environmental pollen; thus, the items conforming part of the diet of the vegetation area not consumed by the organisms can be discriminated.
Con el objetivo de conocer las comunidades vegetales del lago Colhue Huapi e inferir los cambios ... more Con el objetivo de conocer las comunidades vegetales del lago Colhue Huapi e inferir los cambios en el nivel del lago ocurridos durante el Holoceno Tardío, se analizó el contenido polínico y algal de un perfil de la margen sur, sitio La Campanita (45º38’ S, 68º37’ O). El segmento analizado posee dos dataciones 14C (AMS), una de 1711 ± 35 14C años AP a 95 cm de profundidad, correspondiente a la base del perfil, y otra de 979 ± 42 14C años AP a 40 cm. Se observó un predominio de taxa no arbóreos, de los cuales Chenopodiaceae fue el taxón arbustivo más importante y Cyperaceae el taxón herbáceo principal. El perfil mostró cambios a nivel local y pocas diferencias respecto del ingreso de polen regional y extra regional. Desde 1711 ± 35 14C años AP hasta ca. 1212 años AP, la baja representación de Cyperaceae - relacionada con una menor disponibilidad de sitios someros para colonizar - y los mayores porcentajes de las algas planctónicas estudiadas, sugieren un nivel alto del lago. Entre ca. 1212 y 414 años AP se observa un período de cambio en el nivel del lago, con reiteradas fluctuaciones. La tendencia se modificaría hacia 979 ± 42 14C años AP con una disminución del nivel del agua indicado por una expansión de las Cyperaceae y una reducción de las algas. Desde ca. 414 años AP hasta ca. 195 años AP continuó el descenso del nivel del lago aunque con una tendencia más neta y menos fluctuante, indicado por los mayores porcentajes de Cyperaceae del perfil y más bajos para las algas. Para los últimos ca. 195 años AP se registró una recuperación del nivel del lago dada por una reducción de los porcentajes de Cyperaceae, y un leve aumento de las algas. Asimismo, el perfil La Campanita se comparó estadísticamente con un perfl extraído de la margen noroeste del mismo lago. Ambas secuencias reflejaron tendencias similares de variaciones de nivel del lago para los intervalos anteriores a 979 ± 42 14C años AP.
The study of micro and macrobotanical remains allow to infer about vegetation type and to know th... more The study of micro and macrobotanical remains allow to infer about vegetation type and to know the role of vegetable resources in the economy of a society. However, despite presence of plant remains from archaeological contexts represents a great potential for paleoenvironmental reconstructions and assessing past human behavior, its study as a whole is still rare in Patagonian hunter-gatherer archaeological research. The objectives of this work are the integral study of micro and macrobotanical remains, the assessing of taxonomic resolution levels and the contribution offered by each type of proxies. For this purpose, micro and macrobotanical remains (pollen and small plant remains) of human and camelids coprolites, and macrobotanical remains of sediments (wood and charcoal) coming from three stratigraphic levels dated by 14 C and resulting in ages of 9,640 ± 190 years BP, 8,380± 120 years BP and 6,150 ± 105 years BP, of the site Cerro Casa de Piedra 7 were analysed. The results of this study show different taxonomic resolutions. Coprolite pollen analysis allowed the identification of Nothofagus sp., whereas macroremains analysis evidenced the presence of N. pumilio and N. antarctica species. Furthermore, Poaceae pollen was determined whereas microhistological analysis allowed the identification of several species of Poaceae. Also Apiaceae pollen was identified and Azorella monantha were determined by microhistological analysis. The analyses performed in this study enriched the floristic list for each stratigraphic level. These results show the value of multiproxy studies for the integral study of archaeological sites.
Uploads
Papers by Lidia Burry