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OALib Journal期刊

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Diversidad de árboles y arbustos en fragmentos de bosque nativo en el sur de Chile
Pincheira-Ulbrich,J; Rau,JR; Hauenstein,E;
Phyton (Buenos Aires) , 2008,
Abstract: we sampled the diversity of trees and shrubs, and built the rarefaction and accumulation species curve in 10 native forest fragments in southern chile. results indicated that: (1) there were 23 species in all sampled fragments, (2) species richness increased significantly with fragment size, (3) all fragments require a minimal sampling from 40 to 170 individuals to reach the maximum theoretical species richness, and (4) sampling richness was greater than that theoretically expected (20 species).
Estado de conservación de las aves rapaces de Chile
Pincheira-Ulbrich,Jimmy; Rodas-Trejo,Jenner; Almanza,Viviana P.; Rau,Jaime R.;
El hornero , 2008,
Abstract: we classified 30 species of raptors in chile using the technique proposed by reca et al. (1994) and the conservation categories proposed by grigera and úbeda (2000). the results were obtained by means of an index that considers 12 variables that represent factors of importance for the survival or the conservation of the species. eight species (27%) were classified in the category of maximum priority, nine (30%) in the special attention category, and 13 (43%) in the no priority category. strix rufipes and buteo exsul were considered with the highest priority of conservation, and together with accipiter chilensis, buteo albigula, buteo ventralis, phalcoboenus australis, vultur gryphus, and phalcoboenus albogularis conform the category of maximum priority conservation. diurnal raptors (falconiformes) need a greater conservation priority than nocturnal raptors (strigiformes). at the family level, accipitridae had the highest species richness and also showed major conservation problems. we concluded that the technique is a useful tool with simple application that allows orienting the public conservation decisions on this taxonomic group.
Cambio de uso del suelo en los geosistemas de la cuenca costera del río Boroa (Chile) entre 1994 y 2004
Pe?a-Cortés,Fernando; Escalona-Ulloa,Miguel; Pincheira-Ulbrich,Jimmy; Rebolledo,Gonzalo;
Revista de la Facultad de Ciencias Agrarias. Universidad Nacional de Cuyo , 2011,
Abstract: we analyzed the major changes in land use in the landscape units (geosystems) of boroa river basin between 1994 and 2004. to do this, we hypothesized that changes in landscape structure have been driven primarily by human action, generating significant changes in the ecological landscape. categorical maps of use/land cover made from aerial photographs, cartographic material and its subsequent correction in the field were used. this information was complemented by an analysis of the geomorphology and environmental units of the basin. significant variation was found in the area of forest plantations (mainly eucalyptus spp.) which varied between 3.2 and 28%, associated principally with the conversion of the use and occupation of metamorphic mountain chains. at the same time, the expansion in wetlands areas on waterlogged soils was found, all of which have reduced the total agricultural area in 61%, transforming the landscape into a period of only ten years. these changes are discussed on the basis of a combination of economic, legal and environmental, concluding that the human factor has been primarily responsible for driving changes in land use in the boroa river basin.
Tama?o y forma de fragmentos de bosque y su relación con la riqueza de especies de árboles y arbustos
Pincheira-Ulbrich,J; Rau,JR; Pe?a-Cortés,F;
Phyton (Buenos Aires) , 2009,
Abstract: the size and shape of 10 native forest patches were related to tree and shrub species richness in the pre coastal mountain range in osorno province, southern chile. four regression models were adjusted (lineal, logarithm, exponential, and power regression) between patch size (area = x) and tree and shrub species richness (y). patch shape was quantified through three indexes (patton diversity index, compactness index and fractal dimension) which were correlated with the tree and shrub richness. results allowed to conclude that (1) species richness tends to increase significantly with patch size; this relationship was explained by the four study models. nevertheless, the best adjustment was achieved through simple lineal regression, (r2 = 65.1%; y = 5.9 + 0.15x); (2) patch shapes were complex in general being alike to fractal objects, and (3) area was the most consistent factor explaining tree and shrub richness (rxy.z = 0.699); shape did not have a significant effect on variation of tree and shrub species richness.
Diversidad de plantas trepadoras y epífitas vasculares en un paisaje agroforestal del sur de chile: una comparación entre fragmentos de bosque nativo
Jimmy Pincheira-Ulbrich,Jaime R Rau,Cecilia Smith-Ramírez
Boletín de la Sociedad Argentina de Botánica , 2012,
Abstract: Se comparó la diversidad de plantas trepadoras y epífitas vasculares entre un fragmento de bosque siempreverde (Laureliopsis philippiana y Eucryphia cordifolia) y cuatro fragmentos de bosque secundario dominados por Nothofagus obliqua en una matriz agroforestal en la precordillera costera de la provincia de Osorno (Chile). Sobre la base de un muestreo por transectos con observaciones desde la base del suelo, se obtuvo la riqueza de especies, la composición florística, la frecuencia de ocurrencia (fo) y parámetros estructurales del bosque. Los resultados mostraron que: (1) la riqueza fue mayor en el fragmento siempreverde (19 especies) y decreció en los fragmentos de N. obliqua (16 a 10 especies), (3) la familia Hymenophyllaceae (epíftas) fue el grupo más diverso (10 especies), y con mayor fo en el fragmento siempreverde, (4) las trepadoras incrementaron su fo en los fragmentos de N. obliqua, (5) cuatro y cinco especies sólo se encontraron en el bosque siempreverde y N. obliqua, respectivamente, (6) la similitud florística varió entre 38 % y 75 % entre fragmentos, (7) el estado de desarrollo del bosque fue desigual entre las comunidades forestales. Se concluye que los cambios de diversidad de las especies ocurren por efecto de los cambios en la estructura del bosque. Vascular epiphytes and climbing plants diversity in an agroforestal landscape in southern Chile: a comparison among native forest fragments. We compared the diversity of vines and vascular epiphytes among an evergreen forest fragment (Laureliopsis philippiana y Eucryphia cordifolia) and four fragments of secondary forest dominated for Nothofagus obliqua in an agro-forestry matrix landscape localized in the coastal range of Osorno, in Chile. Based on a sampling transects with ground-based observations, we obtained the species richness, floristic composition, frequency of occurrence (fo) and forest structure. The results showed that: (1) the richness was higher in the evergreen forest (19 species) and decreased in the fragments of N. obliqua (16 to 10 species), (2) the Hymenophyllaceae family (epiphytes) was the most diverse group (10 species), and presented more fo in the evergreen fragment, (3) vines increased their fo in the fragments of N. obliqua, (4) four and five species were found only in evergreen forest and N. obliqua, respectively, (5) floristic similarity ranged between 38% and 75%, (6) the state of forest development varied among forest communities. We conclude that changes in species diversity occur as a result of changes in forest structure.
Territorial Planning for Coastal Zones in Chile: The Need for Geographical-Environmental and Natural Risk Indicators for Spatial Decision Support Systems  [PDF]
Fernando Pe?a-Cortés, Daniel Rozas-Vásquez, Gonzalo Rebolledo, Jimmy Pincheira-Ulbrich, Miguel Escalona, Enrique Hauenstein, Luis Vargas-Chacoff, Carlos Bertrán, Jaime Tapia, Marco Cisternas
International Journal of Geosciences (IJG) , 2013, DOI: 10.4236/ijg.2013.46A2003
Abstract:

Coastal zones are very dynamic and fragile environments, constituting a landscape ever more heterogeneous, fragmented and with increasing levels of complexity due to the changing relationship between man and nature. Integrated coastal zone management therefore requires detailed knowledge of the system and its components, based—to a large extent—on technical and scientific information. However, the information generated must be in line with the political requirements necessary for decision-making and planning. Thus the use of indicators to give a simplified view of the many components of the territory, and at the same time to provide important information about patterns or trends, becomes a tool of the utmost importance. These indicators can be understood as measurable characteristics of the environment, which facilitate comprehension of the processes occurring at different scales and serve as a reference to inform the population and support decision-making. The aim of the present note is to demonstrate briefly the need to develop geographical-environmental and natural risk indicators to facilitate comprehension of the dynamic of spatial and temporal landscape patterns, particularly in coastal environments. This approach offers an historical summary of the natural, socio-economic and political processes which currently make up the territory, and which without doubt will continue to influence it in the future. At the same time, it is proposed that information should be integrated on the basis of this framework with a view to generating spatial decision support systems in a context of planning and integrated management of the coastal zones of Chile.

Resistor Geometry Comparison With Respect to Current Noise and Trim Sensitivity
W. Ulbrich
Active and Passive Electronic Components , 1977, DOI: 10.1155/apec.4.63
Abstract:
Predictable Variation of Range-Sizes across an Extreme Environmental Gradient in a Lizard Adaptive Radiation: Evolutionary and Ecological Inferences
Daniel Pincheira-Donoso
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0028942
Abstract: Large-scale patterns of current species geographic range-size variation reflect historical dynamics of dispersal and provide insights into future consequences under changing environments. Evidence suggests that climate warming exerts major damage on high latitude and elevation organisms, where changes are more severe and available space to disperse tracking historical niches is more limited. Species with longer generations (slower adaptive responses), such as vertebrates, and with restricted distributions (lower genetic diversity, higher inbreeding) in these environments are expected to be particularly threatened by warming crises. However, a well-known macroecological generalization (Rapoport's rule) predicts that species range-sizes increase with increasing latitude-elevation, thus counterbalancing the impact of climate change. Here, I investigate geographic range-size variation across an extreme environmental gradient and as a function of body size, in the prominent Liolaemus lizard adaptive radiation. Conventional and phylogenetic analyses revealed that latitudinal (but not elevational) ranges significantly decrease with increasing latitude-elevation, while body size was unrelated to range-size. Evolutionarily, these results are insightful as they suggest a link between spatial environmental gradients and range-size evolution. However, ecologically, these results suggest that Liolaemus might be increasingly threatened if, as predicted by theory, ranges retract and contract continuously under persisting climate warming, potentially increasing extinction risks at high latitudes and elevations.
NOTA SOBRE LA ALIMENTACION DE PLEURODEMA BUFONINA BELL, 1843 (ANURA -- LEPTODACTYLIDAE)
Pincheira-Donoso,Daniel;
Gayana (Concepción) , 2002, DOI: 10.4067/S0717-65382002000100011
Abstract: abstract is studied for the first time the diet of pleurodema bufonina using digestive contents of preserved specimens. ants (36.4%), nymphs (21.3%) and seeds (13.3%) were the most numerous prey item found
Los geckos de Chile (Scleroglossa, Gekkonidae, Gekkoninae). Parte II: Biogeografía y cambios ontogenéticos en el patrón de coloración de Phyllodactylus gerrhopygus. Puede la evidencia sostener la presencia de Phyllodactylus inaequalis en Chile?
Pincheira-Donoso,Daniel;
Multequina , 2006,
Abstract: research on chilean gekkonid lizards remains largely ignored. only a few studies have focused in the specific analysis of the known populations. as a consequence, several fundamental aspects of the biological structure of this group are still a mystery. indeed, in spite of the scarce number of taxa reported in chile, it is hard to draw on more detailed conclusions about the species diversity in this territory. the genus phyllodactylus, restricted to the northern deserts, has commonly been recognized on the basis of three species: p. gerrhopygus, p. heterurus and p. inaequalis. nonetheless, different studies often claim divergent opinions about the status of these taxa. in the present contribution, i analyze those populations identified as p. gerrhopygus and p. inaequalis, which would be characterized by different colour patterns and distributions. however, my results suggest that both taxa represent only one widespread species. the contrasting observed colour patterns can be explained as a consequence of ontogenetic shifts. therefore, i conclude that the presence of p. inaequalis in chile has been based on juvenile individuals of p. gerrhopygus. key words: biogeography, ontogeny, phyllodactylus gerrhopygus, phyllodactylus inaequalis, gekkonidae, chile, peru.
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