Carolina Villagrán

Palynological evidence for increased aridity on the central Chilean coast during the Holocene

Abstract The late Quaternary vegetation of the semiarid coast of central Chile is inferred from the palynological analysis of profiles from Quereo (31°55′S) and Quintero (32°47′S). Prior to 11,400 yr B.P., wet conditions are suggested by the abundance of pollen indicators of swamp and aquatic taxa, such as Cyperaceae and Myriophyllum, and by the presence of traces of arboreal pollen. Since ca. 10,000 yr B.P., a trend toward increasingly drier conditions is implied by the almost complete absence of arboreal and aquatic taxa, and a general decrease in the diversity of the semiarid shrubland indicators. From 3000 yr B.P. onward, the pollen records show the reappearance of swamp and aquatic taxa, presumably associated with wetter conditions, which led to recolonization by forest taxa at 1720 yr B.P. in Quintero. The drier climate detected along the semiarid coast of central Chile during most of the Holocene extended inland to the Andean foot-hills, within the present mediterranean-type climate zone of Chile, and also affected the distribution of the winter-deciduous Nothofagus forests and the northern boundary of the temperate rain forests.

Expansion of Magellanic Moorland during the late Pleistocene: Palynological evidence from northern Isla de Chiloé, Chile

The late Quaternary vegetation of northern Isla de Chiloe is inferred from palynological analysis of a section in the Rio Negro drainage (42°03′S, 73°50′W). At ca. 30,500 yr B.P., maxima of Astelia and Donatia occurred, suggesting wetland development. From that time until ca. 27,000 yr B.P., steppe indicators such as Compositae/Gramineae dominated, suggesting drier conditions. After 27,000 yr B.P., the moorland shrub Dacrydium gradually increased, reaching a maximum by 18,000 yr B.P. At this time Astelia increased again, suggesting development of cushion bog during cold and wet conditions. The glacial-postglacial transition is characterized by a marked change from peaty sediments to clays, a decrease in the cushion bog flora, and the prevalence of Gramineae/ Compositae and swamp taxa. This vegetation prevailed until ca.7000 yr B.P. when forest taxa became dominant. The floristic pattern inferred from the pollen spectra of the Rio Negro section suggests that the late Pleistocene vegetation of Chiloe resembled modern Magellanic Moorland vegetation (52°–56°lat S). Based on climatic conditions presently associated with Magellanic Moorland, its occurrence in Chiloe at low elevations during the late Pleistocene implies a decrease in average temperature of at least 4°C and an increase in annual precipitation of at least 1500 mm.

Late quaternary vegetation of southern Isla Grande de Chiloé, Chile

Late-glacial-Holocene forest history of southern Isla Chiloe (latitude 43°10′ S) was reconstructed on the basis of pollen analysis in three profiles (Laguna Soledad, Laguna Chaiguata, Puerto Carmen). Prior to 12,500 yr B.P. pollen records are dominated by plant taxa characteristic of open habitats (Zone I). From 12,500 yr B.P. to the present, tree species predominate in the pollen records (Zones II–V). Between 12,500 and 9500 yr B.P. ombrophyllous taxa (Nothofagus, Podocarpus nubigena. Myrtaceae, Fitzroya/Pilgerodendron, and Drimys) are frequent in all pollen diagrams, suggesting a wetter and colder climate than the present. Between 9000 and 5500 yr B.P. Valdivian forest elements, such as Nothofagus dombeyi type, Weinmannia, and Eucryphia/Caldcluvia, dominate, indicating a period of drier and warmer climate. From 5500 yr B.P. onward, the expansion of mixed North Patagonian-Subantarctic forest elements and the increased frequence of Tepualia suggest increased rainfall and temperatures oscillating around the modern values. The change from open to forest vegetation (ca. 12,500 yr B.P.) probably represents the most pronounced climatic change in the record and can be interpreted as the glacial-postglacial transition in the study area.

Glacial climates and their effects on the history of the vegetation of Chile : a synthesis based on palynological evidence from Isla de Chiloé

Abstract Palynological evidence from Isla de Chiloe (42–43°S) suggests that hygrophyllous plant formations expanded northwards during the Late Pleistocene in Southern Chile. North Patagonian-Subantartic forest developed between 40,000 and 33,000 yr B.P.; followed between c. 27,000 and c. 13,500 and 12,500 yr B.P. by a Magellanic moorland mosaic. From this date onwards, forest taxa predominate in all the pollen records. Comparing these results with the present distribution of relict vegetation on the Coastal Range of Chile, and also with paleoenvironmental data for Central Chile, I suggest that, during the Pleistocene, rainfall increased along the west coast of southern America, between 30° and 43°S, probably due to the increased influence of the westerlies.

RECONSTRUCCION MULTIDISCIPLINAR1A DE LA OCUPACION PREHISTORICA DE QUEREO, CENTRO DE CHILE

A late Pleistocene-Holocene natural and cultural sequence was identified about 5 km south of Los Vilos, in the southern coast of the semiarid region of Chile, associated with human activities and fossil fauna. Vertical and horizontal excavations were done to map paleontological and archaeological evidence in situ. Approximately 217 m3 of lacustrine sediments were wet sieved and organic materials recovered from the supernatant portion. Three stratigraphic columns were sampledfor sedimentological, microfaunistic, palynological, and paleontological analysis. The Quebrada Quereo Formation (Quaternary) was defined and consists of six members forming the infill of a tectonic trough emplaced in the semiarid coast of central Chile. Multidisciplinary analyses focused on four levels of occupation and their interrelations with environmental, faunal, andfloral changes during the Upper PleistoceneHolocene transition. Correlations are proposed among the sequence of lithochronostratigraphic units, paleogeographic and biotic conditions, geomorphologic events, and the levels of the cultural sequence. The Quereo I level (> 11,400 years B.P.) contains evidencefor materials of likely human origin associated with the hunting of Equus sp. The conditions of aridity at the end of the Pleistocene would have accelerated the overexploitation of megafauna (Quereo II level) by about 11,100 + 150 to 9,370 + 180 years B.P. Later, favorable social and environmental conditions reactivated the Quereo habitat, which is represented by a Late Archaic occupation (Quereo III level) dated to 2,475 + 90 years B.P. and by another agro-ceramic period (Quereo IVlevel) dated to 1,280 + 75 years B.P.

ETHNOBOTANY OF THE SOUTHERN ANDES WITHIN THE FIRST REGION OF CHILE: A CONNECTION BETWEEN ALTIPLANO CULTURES AND THE HIGH CANYONS OF THE SUPERIOR LOA

Se presenta un estudio etnobotanico en el territorio andino limitrofe entre la I Region y II Region de Chile, area que, historicamente, ha funcionado como un enlace entre diversas culturas andinas. Para la flora consultada (146 taxa), se registraron 384 vernaculos, correspondiendo el mayor porcentaje a las lenguas aymara-quechua (70% de los nombres). El 90% tenia utilizacion, registrandose un total de 228 usos, distribuidos en forrajes (36%), medicinas (31%) y comestibles (10%). Se registra: (a) Predominio de vernaculos aymara-quechua y etnocategorias, preferentemente, de acuerdo a la nomenclatura de la I Region; (b) Etnoclasificaciones con hasta tres niveles jerarquicos; (c) Frecuente uso del principio de opuestos complementarios, tanto en los criterios de distincion de especies como en los procedimientos terapeuticos de la flora; (d) Especies ceremoniales similares a las usadas en el extremo norte de Chile, Bolivia y Loa Superior; (e) Heterogeneidad dentro del territorio estudiado, entre las comunidades del area de Ollague y las residentes en el Oasis de Pica, tanto en las especies ceremoniales como en los nombres vernaculares. Estos rasgos destacan al area de estudio como transicional, entre las culturas del altiplano de la Region de Tarapaca y las de quebradas altas, de la Region de Antofagasta

Vegetation and pollen dispersal in the subtropical-temperate climatic transition of Chile and Argentina

Abstract The interpretation of the late Quaternary pollen records in terms of palaeoclimate requires an accurate study on the relationship between modern pollen rain, the composition of the source vegetation and climatic factors. We present the results of present pollen rain and its relation to modern vegetation and climate on a trans-Andean transect through the steppe formations that occur between Zapala, Argentina (38°53′S, 70°02′W) and Lonquimay, Chile (38°26′S, 71°15′W). This area constitutes a climatic transition between the westerlies of mid-latitudes and the subtropical eastern circulation. It also represents the easternmost limit of the temperate rain forest and sclerophyllous subtropical forest in Chile and of the westernmost limit of the Monte Desert and Patagonian Steppe formations in Argentina. Systematic sampling of vegetation and superficial soil samples were taken every 100 m along an altitudinal gradient at both slopes of the Andes and isolated samples were taken at the summits of the Cordillera de las Raices and at the foothills of Lonquimay volcano. Multivariate analysis (cluster analysis and principal components analysis) were applied for 32 pollen samples. Five pollen units were recognized: (1) subdesert shrublands; (2) Mulinun -dwarf-shrubland steppe; (3) mid-grass steppe; (4) High Andean and Volcanic scoria steppes; and (5) Acaena -shrubland and rhamnaceous thickets. These units were correlated with the vegetation communities, precipitation and temperature. The most important discontinuity in the composition of the pollen rain corresponds to that between the subdesert shrubland and the Mulinum steppe, on the eastern end of the transect and the spectra corresponding to the High Andean formations, of the western slopes. This sharp transition in modern vegetation and recent pollen rain lies upon the 71°W longitude, and is possibly determined by the strong differences in distribution and amount of precipitation and temperature.

Ethnobotany of pre-altiplanic community in the Andes of northern Chile

The perception of the surrounding environment and use of the flora by the inhabitants of Toconce, a Pre-Altiplanic community in the Andes of northern Chile, were investigated. Six ecological units, which are given the local names of Pampa, Tolar, Medano, Pajonal, Hoyada, and Paniso, are recognized by the people of Toconce on the basis of their different dominant plants, geomorphology and microclimate. These units are in turn integrated into 3 units of landscape utilization: Cerro, Campo and Chacra. The latter is an artificial unit, corresponding to the man-made terraces located on the steep slopes of the Andean canyons. The Campo is a pastoral area, mainly for llamas. The Cerro, situated at higher elevation, has ritual as well as economic importance. This altitudinal sector is the place for the gathering of llareta, the most valuable vegetal fuel in Toconce. Seven categories of plant use are defined: forage, medicinal, food, fuel, crafts, ritual and construction. The inhabitants of Toconce have maximized the use of the plant resources in each altitudinal level. This long-lasting cultural pattern is being gradually modified due to the influence of industrial development and growth of the neighboring urban centers.

Principios de la investigación en ciencias naturales históricas: ¿Por qué en biología es necesaria la Historia Natural de los organismos?

Se discute en este trabajo el desarrollo historico, significado y valor heuristico de la Historia Natural en la reflexion teorica y generacion de hipotesis en biologia. Sobre esta base se fundamenta la validez de una metodologia propia en el dominio de las ciencias naturales historicas, en general. Primero se examinan de manera critica los principios generales y metodologias que rigen la investigacion en ciencias naturales historicas, en contraste con las ciencias biologicas experimentales. Se comenta el actualismo, un principio fundamental que valida el uso de analogos actuales y la formulacion de retrodicciones en la investigacion del pasado. Tambien se comentan brevemente los metodos mas comunes de la investigacion historica, como la iteracion de patrones procedentes de distintas fuentes de datos paleoambientales (proxy data), las evidencias correlativas que permiten reconstruir condiciones paleoecologicas a traves de series de tiempo. Se discute la validez del principio de causa comun en el juicio e interpretacion historica de acontecimientos pasados sobre la base de una causalidad temporal asimetrica (asimetria de sobredeterminacion). Esta causalidad justifica la inferencia historica (postdiccion), en contraste con la prediccion. En la segunda parte de este trabajo se consideran preguntas especificas sobre Historia Natural de los organismos. Con este proposito se introducen brevemente los principios de autoorganizacion y acoplamiento estructural organismo-espacio de vida, ideas heuristicas que fundamentan conceptos y metodologias propias en los estudios de los seres vivos (como adaptacion, homologia, analogia, anomalia estructural, disyuncion, etc.), tanto en las investigaciones sobre desarrollo y morfologia como en sistematica, filogenia, paleontologia, ecologia, evolucion, y biogeografia. Finalmente, se destaca la importancia de la consideracion de esta diversidad metodologica en ciencias naturales historicas como una contribucion al debate actual acerca de la validez del campo de la Historia Natural.

Una reflexión en torno a la flora, vegetación y etnobotánica en Homero

RESUMEN Este estudio constituye una contribucion al conocimiento de la concepcion descriptivo-mitica de la naturaleza vegetal en la epoca homerica, realizado sobre la base de las referencias botanicas y etnobotanicas consignadas en la Iliada y la Odisea. El objetivo es formalizar un examen de la biodiversidad, ecologia y usos de las plantas nativas y cultivadas; dimension estetica y sentido de los similes botanicos; y claves que ofrece el poema para profundizar en el pensamiento de la geografia mitica que vertebra la vision de la naturaleza que impera en el periodo. El examen se realizo sobre la base de la elaboracion de un Catalogo con los nombres griegos de plantas registrados en Homero, sus transliteraciones latinas, los lugares donde aparecen, los nombres espanoles y cientificos de los taxa, y las clases de referencias mencionadas. La evaluacion de la importancia relativa y clases de relaciones de los 59 nombres griegos de plantas registrados en el Catalogo muestra que: (i) En la descripcion de la flora nativa y cultivada revisten mayor importancia (19%) las comunidades caracteristicas de los ecosistemas forestales y sus especies arboreas dominantes, como la encina, el olivo, el fresno y distintas especies de coniferas. En el paisaje cultural, los cereales y la vid; (ii) Entre las clases de referencias botanicas homericas, el uso del recurso poetico del simil -que destaca las comparaciones con elementos vegetales- corresponde al segundo lugar en importancia (17%); (iii) Los elementos miticos corresponden a un 13% del total de las relaciones consideradas, sea en la atribucion de poderes magico-terapeuticos y caracteristicas sobrenaturales adjudicadas a ciertas plantas o comunidades vegetales; sea en la funcion de plantas sagradas en rituales y ceremonias; (iv) Las restantes clases de relaciones botanicas se refieren a usos de la flora, sea en construccion, artesanias, alimentacion, forraje, u otras practicas varias. Se destacan dos conclusiones principales: (i) rol fundante del poema homerico en Historia Natural, tanto en la inauguracion de la nomenclatura como en terminologia botanica; (ii) trascendencia del simil poetico y del mito homerico que incluyen plantas -como simbolismo del sentido de la condicion humana-.