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Biogeographic patterns of Chilean littoral fishes RChHN
OJEDA,F. PATRICIO; LABRA,FABIO A; MUÑOZ,ALEJANDRO A.
In this study, we analyzed the biogeographic patterns of the Chilean littoral fish fauna, including latitudinal trends in teleost and chondrichthyan fish species richness, their distribution range patterns, and their level of endemism, both to the Chilean coast and the Southeastern Pacific. We determined the number and percentage of fish taxa within four different groups based on their biogeographic affinities. This was done, both for teleost and chondrichthyan fishes, at the species, genus and family level. In order to recognise the existence of biogeographic regions, we applied cluster and ordination analyses to the distribution data, using objective bootstrapping techniques at the three taxonomic levels used. We found that littoral fish diversity...
Tipo: Journal article Palavras-chave: Marine biogeography; Littoral fishes; Endemism; Southeastern Pacific Ocean; Latitudinal diversity patterns.
Ano: 2000 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2000000400007
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Biología de la raya Psammobatis extenta (Garman, 1913) (Batoidea: Rajidae) RChHN
BRACCINI,JUAN M.; CHIARAMONTE,GUSTAVO E..
Psammobatis extenta es un miembro común de la fauna de rayas de las costas de Sudamérica y su biología ha sido poco estudiada. Se investigaron aspectos de la biología de P. extenta a partir de datos obtenidos del descarte de arrastres comerciales de la flota pesquera de Puerto Quequén, Argentina, en febrero de 2000. La talla máxima alcanzada por las hembras fue 313 mm L T y 295 mm L T, por los machos. Las proporciones que presentaron menor variación y relación isométrica fueron: distancia narina-boca, distancia interorbital, longitud ojo+espiráculo, largo de disco y ancho de disco. La relación L T-Peso total presentó diferencias significativas (P < 0,05) entre hembras y machos, las primeras alcanzando un mayor peso para el mismo L T. Los machos alcanzan...
Tipo: Journal article Palavras-chave: Psammobatis; Rajidae; Puerto Quequén.
Ano: 2002 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2002000100017
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Biología poblacional de huirales submareales de Macrocystis integrifolia y Lessonia trabeculata (Laminariales, Phaeophyceae) en un ecosistema de surgencia del norte de Chile: variabilidad interanual y El Niño 1997-1998 RChHN
ALONSO VEGA,J.M.; VÁSQUEZ,JULIO A.; BUSCHMANN,ALEJANDRO H..
This paper describes the population biology of Lessonia trabeculata and Macrocystis integrifolia during and after the 1997-1998 El Niño in an area of permanent coastal upwelling in northern Chile. Spatial and temporal patterns of distribution were evaluated seasonally for adult and juvenile sporophytes of both species between 1996 and 2003. These two kelp form an assemblage distributed between 2 and 15 m depth, with disjunct patterns along a bathymetric gradient, including two morphs of L. trabeculata, the occurrence of which depends on the presence or absence of M. integrifolia. During the 1997-1998 El Niño the spatial-temporal patterns of abundance of the kelp assemblage were maintained by the continuity of coastal upwelling, which buffered and moderated...
Tipo: Journal article Palavras-chave: Subtidal habitats; Population and community ecology; Extinction and re-colonization processes; Kelp-herbivore interaction; El Niño; La Niña.
Ano: 2005 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2005000100004
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Biología reproductiva de Convolvulus chilensis (Convolvulaceae) en una población de Aucó (centro-norte de Chile) RChHN
Suárez,Lorena H.; González,Wilfredo L.; Gianoli,Ernesto.
Convolvulus chilensis es una hierba perenne, única representante endémica de la familia Convolvulaceae en Chile. Se estudió el sistema de reproducción, fenología, morfología y longevidad floral de C. chilensis en una población natural ubicada en la localidad de Aucó, dentro de la Reserva Nacional Las Chinchillas, IV Región, Chile. Se montó un experimento de polinización controlada considerando los tratamientos de polinización natural, polinización cruzada, autopolinización manual, autopolinización automática y apomixis, evaluándose su efecto sobre la formación de frutos y el número de semillas producidas por fruto. Adicionalmente, se compararon los siguientes atributos de la progenie según tipo de polinización (autopolinización o polinización cruzada):...
Tipo: Journal article Palavras-chave: Convolvulaceae; Convolvulus chilensis; Sistema de reproducción; Autocompatibilidad; Autogamia.
Ano: 2004 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2004000400001
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Biología reproductiva de la serpiente semiacuática Liophis semiaureus (Serpentes, Colubridae) en el nordeste de Argentina RChHN
LÓPEZ,SOLEDAD M; GIRAUDO,ALEJANDRO R; ARZAMENDIA,VANESA; CHIARAVIGLIO,MARGARITA.
Las serpientes tienen una notable flexibilidad y diversidad en sus tácticas reproductivas, a pesar de ello, los estudios acerca de la biología reproductiva de especies sudamericanas en zonas subtropicales-templadas son escasos. Se analizó la biología reproductiva de Liophis semiaureus en el nordeste de Argentina, incluyendo la madurez y dimorfismo sexual, fecundidad y ciclo reproductivo. Las hembras maduras fueron significativamente más largas, presentaron mayor peso corporal y alcanzaron la madurez sexual a una longitud mayor que los machos. Los machos tuvieron colas más largas que las hembras. El ciclo reproductivo fue estacional con mayor actividad en los períodos templados del año aunque previos a la época de inundaciones. Liophis semiaureus invirtió...
Tipo: Journal article Palavras-chave: Madurez; Dimorfismo sexual; Fecundidad; Ciclo reproductivo; Liophis semiaureus; Argentina.
Ano: 2009 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2009000200006
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Biología reproductiva del águila Geranoaetus melanoleucus (Aves: Accipitridae) en Chile central RChHN
PAVEZ,EDUARDO F..
Durante dos años (julio 1987­enero 1989) se estudió la biología reproductiva del águila (Geranoaetus melanoleucus) en San Carlos de Apoquindo, en Chile central. El inicio del período reproductivo se evidenció por un aumento del número de vuelos en pareja. Los cortejos incluyeron vuelos sincronizados de la pareja, capturas, transporte de material al nido y cópulas. Los traspasos de presas ocurrieron durante todo el año, aunque fuera del período reproductivo fueron escasos y forzados por la hembra. Se localizaron 4,7 nidos pareja-1, lo que está en el límite superior documentado para grandes águilas. Fuera del período reproductivo las águilas visitaron ocasionalmente los nidos. Antes de la postura el macho visitó el nido con mayor frecuencia y por menos...
Tipo: Journal article Palavras-chave: Águila; Geranoaetus melanoleucus; Conducta; Reproducción; Chile central.
Ano: 2001 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000300014
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Biología reproductiva y conservación: el caso de la regeneración de bosques templados y subtropicales de robles (Quercus spp.) RChHN
Pulido,Fernando J..
En este trabajo se revisan los resultados de 21 estudios experimentales sobre la regeneración de bosques de roble (Quercus spp.) en los que se analizan al menos tres de las fases del ciclo reproductivo: fertilización, desarrollo de frutos viables, dispersión, consumo postdispersivo, germinación-emergencia de plántulas, establecimiento de juveniles y reclutamiento de adultos. La mayoría de las poblaciones estudiadas se encontraban en bosques templados de Norteamérica y Europa, repartidos de forma equitativa entre bosques de ambientes xéricos (incluidos los mediterráneos) con especies perennes y habitualmente bajo explotación, y bosques de ambientes mésicos o montanos con especies generalmente caducifolias y escasamente alterados. Los estudios se...
Tipo: Journal article Palavras-chave: Dispersión; Facilitación; Herbivorismo; Producción de semillas; Quercus; Reclutamiento; Regeneración forestal; Robles; Sitios seguros.
Ano: 2002 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2002000100002
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Biomass partitioning and leaf area of Pinus radiata trees subjected to silvopastoral and conventional forestry in the VI region, Chile RChHN
RODRÍGUEZ,ROLANDO; HOFMANN,GLENN; ESPINOSA,MIGUEL; RÍOS,DARCY.
The effects of silvicultural regimes on leaf area and biomass distribution were analyzed in 16-year old Pinus radiata trees growing in the semiarid zone of Chile. Three stands with different silvopastoral management were compared with a conventionally managed stand. Data were obtained through destructive sampling of 36 trees and analyzed by MANOVA and regression models of ANCOVA. Results show that the management regime affects the leaf area. Specific leaf area was affected by both silvicultural regime and crown position. Total biomass per tree under the silvopastoral regime was 2.1 to 2.5 times larger than in the conventional forestry regime. However, aboveground biomass partitioning was neither affected by the silvicultural regime nor by the schemes of...
Tipo: Journal article Palavras-chave: Leaf area; Biomass; Silvopastoral management.
Ano: 2003 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2003000300008
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Biomechanical and ecological relationships of wing morphology of eight Chilean bats RChHN
CANALS,MAURICIO; GROSSI,BRUNO; IRIARTE-DÍAZ,JOSE; VELOSO,CLAUDIO.
In this study we compared the wing morphology of eight species of bats inhabiting Chile, including two previous studied species. We correlated the results with ecological information. Aspect ratio, wing span, wing area, wing loading and the second moment of area of humerus midshaft were estimated for the molossid Mormopterus kalinowskii, the phyllostomidae Desmodus rotundus and the vespertilionids Histiotus montanus, Histiotus macrotus, Lasiurus borealis, and Lasiurus cinereus. The free-tailed bats T. brasiliensis and M.kalinowskii and D. rotundus, without uropatagyum, showed a low wing area, but whilst the molossids showed large aspect ratios, that of D. rotundus was only moderate. Desmodus rotundus showed the lowest wing span (relative to the expected...
Tipo: Journal article Palavras-chave: Bats; Biomechanics; Flight.
Ano: 2005 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2005000200005
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Bio-optical characteristics of phytoplankton populations in the upwelling system off the coast of Chile RChHN
STUART,VENETIA; ULLLOA,OSVALDO; ALARCÓN,GADIEL; SATHYENDRANATH,SHUBHA; MAJOR,HEATHER; HEAD,ERICA J.H.; PLATT,TREVOR.
Phytoplankton samples collected from two cruises off the coast of Chile were analysed for pigment composition and absorption characteristics. High pigment concentrations (up to 20 mg chl-a m-3) were found in the upwelled waters over the shelf break off the coast of Concepción during spring (October 1998), but relatively oligotrophic conditions were found further offshore. Similarly, stations further north (between Coquimbo and Iquique), sampled during the austral summer (February 1999), also showed low pigment concentrations, characterised by the presence of prymnesiophytes, and cyanobacteria including Prochlorococcus sp. The specific absorption coefficient of phytoplankton at 443 nm (a*ph(443)) was much higher for the offshore population than the inshore...
Tipo: Journal article Palavras-chave: Phytoplankton absorption; HPLC pigments; SeaWiFS ocean-colour; Chile.
Ano: 2004 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2004000100008
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Body mass and body weight: a dual reference system in biology RChHN
GÜNTHER,BRUNO; MORGADO,ENRIQUE.
ABSTRACT The aim of the present study was to compare two different biological similarity criteria, one was based on body mass (M) as a theoretical reference system in accordance with the MLT-system of physics, while the other utilized the body weight (W) for the same purpose. The mass-dependent allometry should be applied during space flights as well as during fetal and newborn conditions of life, whereas the weight-dependence should prevail in earth-bound physiology. The above mentioned distinctions are relevant not only for the specific metabolic rates but also for numerous biological time functions, as for instance for the heart and respiratory rates of all mammals, whose allometric exponent is b = - 0.09 during fetal life, and b = - 0.25 in all adult...
Tipo: Journal article Palavras-chave: Dimensional analysis; Biological similarity; Allometry; Biological time; Fetal life; Space physiology.
Ano: 2003 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2003000100006
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Body mass variation in the Geoffroy's cat (Oncifelis geoffroyi) RChHN
LUCHERINI,MAURO; MANFREDI,CLAUDIA; LUENGOS,ESTELA; DIAS MAZIM,FÁBIO; SOLER,LUCÍA; CASANAVE,EMMA B..
We report new data on the intersexual and geographical variation in body mass of the Geoffroy's cat (Oncifelis geoffroyi d'Orbigny and Gervais 1844), a little known small cat from South America, and combine them with the existing information to compare alternative hypotheses for variation in body mass. Most data on the body mass of O. geoffroyi have been obtained from previous research on this felid in four study areas of southern Brazil and central and southern Argentina. These data were added to those reported for other three additional locations. Our results set the body mass of O. geoffroyi to 4.26 ± 1.03 kg (mean ± SD, n = 56). We also show that males generally are heavier than females throughout most of this species' distributional range. Body mass...
Tipo: Journal article Palavras-chave: Carnivores; Felids; Oncifelis geoffroyi; South America; Body mass.
Ano: 2006 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2006000200003
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Bofedales: high altitude peatlands of the central Andes RChHN
SQUEO,FRANCISCO A; WARNER,BARRY G; ARAVENA,RAMÓN; ESPINOZA,DIANA.
There is an exceptional group of alpine peatlands in the world situated in the arid grasslands of the central Andes. The peatlands in northern Chile occur in the most arid part of their range. Members of the Juncaceae are the primary peat-forming plant species. Fresh and mildly saline groundwaters originate from glaciers, snowmelt and rain are the water sources for the northern Chile peatlands. Paleoecological investigations suggest that some peatlands are recent features of the landscape having developed within the last three thousand years or less. These peatlands are unique, extremely fragile water features sensitive to climate changes and human disturbances such as regional mining activity. Much more work is required to develop scientifically based...
Tipo: Journal article Palavras-chave: Peatlands; Arid grasslands; South America.
Ano: 2006 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2006000200010
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Branch whorls of juvenile Araucaria araucana (Molina) Koch: are they formed annually? RChHN
LUSK,CHRISTOPHER H.; LE-QUESNE,CARLOS.
The growth of Araucaria araucana, like that of many other conifers, is characterised by the production of a monopodial stem with branch whorls. However, the periodicity of whorl formation in this species has not been subjected to systematic study. We used growth ring counts to determine the frequency of whorl formation in sun- and shade-grown juvenile A. araucana in a montane forest in the Chilean coast range. Whorls were not annual in any of the 35 individuals studied, growth rings outnumbering whorls by a factor of 1.8 to 3.9. The mean interval between successive whorls was significantly shorter in sun-grown (2.1 yrs whorl -1) than in shade-grown trees (2.6 yrs whorl-1), suggesting a relationship with plant carbon balance. Mean distance between whorls...
Tipo: Journal article Palavras-chave: Araucariaceae; Conifers; Dendroecology; Tree growth; Tree rings.
Ano: 2000 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2000000300013
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Breeding distribution and abundance of seabirds on islands off north-central Chile RChHN
SIMEONE,ALEJANDRO; LARA-JORQUERA,GUILLERMO; BERNAL,MARIANO; GARTHE,STEFAN; SEPÚLVEDA,FELIPE; VILLABLANCA,ROBERTO; ELLENBERG,URSULA; CONTRERAS,MACARENA; MUÑOZ,JULIETA; PINCE,TAMARA.
Between 1999 and 2003 we collected information on the breeding distribution and abundance of 12 seabird species occurring on nine islands off the coasts of north and central Chile (27°-33°S). The Peruvian booby Sula variegata was the most abundant seabird with a breeding population of ca. 18,000 pairs concentrated in two islands, followed by the Humboldt penguin Spheniscus humboldti with ca. 9,000 pairs, the largest colony being at Chañaral Island with ca. 7,000 pairs. Kelp gulls Larus dominicanus bred at all the surveyed sites in colonies of variable size, ranging from 40 to 2,000 pairs. Peruvian diving-petrels Pelecanoides garnotii and Peruvian pelicans Pelecanus occidentalis bred at restricted sites, but generally in large colonies. Magellanic penguins...
Tipo: Journal article Palavras-chave: Aves marinas; Colonia reproductiva; Abundancia; Conservación; Corriente de Humboldt; Chile.
Ano: 2003 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2003000200016
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Breeding of Markham's Storm-Petrel (Oceanodroma markhami, Aves: Hydrobatidae) in the desert of northern Chile RChHN
TORRES-MURA,JUAN C; LEMUS,MARINA L.
Tipo: Journal article
Ano: 2013 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2013000400013
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Breeding system of Embothrium coccineum (Proteaceae) in two populations on different slopes of the Andes RChHN
ROVERE,ADRIANA E; SMITH-RAMÍREZ,CECILIA; ARMESTO,JUAN J; PREMOLI,ANDREA C.
Plant breeding systems are considered to reflect species' life history characteristics, selection due to biotic or abiotic factors, pollination conditions, or a combination of these. Reproductive systems may vary over ecological gradients. The breeding system of the ornithophilous Embothrium coccineum (Proteaceae) from temperate South America was studied by pollination treatments: manual self-pollination, manual cross-pollination, automatic self-pollination, and natural pollination. These treatments were conducted in a coastal western and an Andean eastern population. Embothrium coccineum was found to be self-incompatible and highly dependent on the pollinating agent at both sites. However, pollen limitations were greater in the coastal population, as...
Tipo: Journal article Palavras-chave: Self-incompatibility; Endemic species; Temperate forest.
Ano: 2006 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2006000200008
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Brennand: resonancia y universalidad de las formas RChHN
TORO,G. CECILIA.
Este trabajo propone la búsqueda y exposición de patrones de formas, tanto de algunas obras producidas por la naturaleza como de algunas de las obras producidas por la mano del hombre, quien como un microcosmos, que forma parte de la naturaleza recrea el macrocosmos. En una cultura en que el hombre ha perdido contacto con la naturaleza, con sus semejantes y con sus orígenes, otro objetivo de este trabajo es re emparentar al hombre con la naturaleza de la que forma parte. Se pretende mostrar al hombre, como un fractal del Universo, que es capaz de recrear, independientemente del tiempo, del espacio y de la escala de magnitudes, las mismas formas que crea el Universo, con la fuerza de la belleza en toda su pureza y en todo lo terrible con que a veces se nos...
Tipo: Journal article Palavras-chave: Brennand; Resonancia mórfica; Evolución; Arte; Sincronía; Arquetipo.
Ano: 2001 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000000022
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Brood care in Brachyuran crabs: the effect of oxygen provision on reproductive costs RChHN
FERNÁNDEZ,MIRIAM; BRANTE,ANTONIO.
The quantification of the costs associated with parental care of marine invertebrates requires a first and necessary step, which is the identification of the different forms of care exhibited by this group. Among marine invertebrates, provision of oxygen to the aggregation of embryos may be critical, although most evidence on the link between oxygen limitation and parental care is indirect. Species which show active behavior directed at providing oxygen to the brood offer a good model to establish the direct link between behavioural patterns and oxygen provision to the embryos, and to estimate the costs associated with this form of care. In this manuscript, we conducted a review of the current knowledge about oxygen limitation in embryos aggregations of...
Tipo: Journal article Palavras-chave: Reproduction; Brood care; Crabs; Oxygen; Marine invertebrates.
Ano: 2003 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2003000200003
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Cambio del uso del suelo en el centro sur de Chile a fines del siglo XX: Entendiendo la dinámica espacial y temporal del paisaje RChHN
AGUAYO,MAURICIO; PAUCHARD,ANÍBAL; AZÓCAR,GERARDO; PARRA,OSCAR.
Los humanos han transformado gran parte de la superficie del planeta en los últimos 300 años. La tala de bosques, las prácticas agrícolas de subsistencia, la intensificación de la producción agrícola y la expansión de los centros urbanos han cambiado drásticamente el paisaje. En el centro y sur de Chile las transformaciones han estado asociadas, en un inicio, a la expansión de la frontera agropecuaria que permitió satisfacer tanto las necesidades internas como la creciente demanda externa por productos agrícolas. Posteriormente, un fuerte incentivo a la forestación, comandado por el Estado, generó un acelerado proceso de desarrollo forestal que explica, en gran medida, la actual configuración del paisaje en esta región. En este trabajo hemos analizados la...
Tipo: Journal article Palavras-chave: Cambio de uso del suelo; Chile; Desforestación; Dinámica del paisaje.
Ano: 2009 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2009000300004
Registros recuperados: 845
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