64 resultados para Gressittacantha terranova


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We tested whether the distribution of three common springtail species (Gressittacantha terranova, Gomphiocephalus hodgsoni and Friesea grisea) in Victoria Land (Antarctica) could be modelled as a function of latitude, longitude, altitude and distance from the sea.

Victoria Land, Ross Dependency, Antarctica.

Generalized linear models were constructed using species presence/absence data relative to geographical features (latitude, longitude, altitude, distance from sea) across the species' entire ranges. Model results were then integrated with the known phylogeography of each species and hypotheses were generated on the role of climate as a major driver of Antarctic springtail distribution.

Based on model selection using Akaike's information criterion, the species' distributions were: hump-shaped relative to longitude and monotonic with altitude for Gressittacantha terranova; hump-shaped relative to latitude and monotonic with altitude for Gomphiocephalus hodgsoni; and hump-shaped relative to longitude and monotonic with latitude, altitude and distance from the sea for Friesea grisea.

No single distributional pattern was shared by the three species. While distributions were partially a response to climatic spatial clines, the patterns observed strongly suggest that past geological events have influenced the observed distributions. Accordingly, present-day spatial patterns are likely to have arisen from the interaction of historical and environmental drivers. Future studies will need to integrate a range of spatial and temporal scales to further quantify their respective roles.

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Soil fauna in the extreme conditions of Antarctica consists of a few microinvertebrate species patchily distributed at different spatial scales. Populations of the prostigmatic mite Stereotydeus belli and the collembolan Gressittacantha terranova from northern Victoria Land (Antarctica) were used as models to study the effect of soil properties on microarthropod distributions. In agreement with the general assumption that the development and distribution of life in these ecosystems is mainly controlled by abiotic factors, we found that the probability of occurrence of S. belli depends on soil moisture and texture and on the sampling period (which affects the general availability of water); surprisingly, none of the analysed variables were significantly related to the G. terranova distribution. Based on our results and literature data, we propose a theoretical model that introduces biotic interactions among the major factors driving the local distribution of collembolans in Antarctic terrestrial ecosystems. (c) 2007 Elsevier Ltd. All rights reserved.

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Soil fauna in the extreme conditions of Antarctica consists of a few microinvertebrate species patchily distributed at different spatial scales. Populations of the prostigmatic mite Stereotydeus belli and the collembolan Gressittacantha terranova from northern Victoria Land (Antarctica) were used as models to study the effect of soil properties on microarthropod distributions. In agreement with the general assumption that the development and distribution of life in these ecosystems is mainly controlled by abiotic factors, we found that the probability of occurrence of S. belli depends on soil moisture and texture and on the sampling period (which affects the general availability of water); surprisingly, none of the analysed variables were significantly related to the G. terranova distribution. Based on our results and literature data, we propose a theoretical model that introduces biotic interactions among the major factors driving the local distribution of collembolans in Antarctic terrestrial ecosystems.

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[ES]Rumbo al Gran Banco parte de los comienzos de la pesca industrial del bacalao española en el primer tercio del siglo XX, la situación que allí encontraron, los avatares humanos y los avances tecnológicos que se van incorporando, la Guerra Civil y la guerra mundial, la bonanza pesquera, la incorporación de las parejas, la concurrencia, así como la exploración de todo el Gran Banco. La gestión por parte de Canadá de las doscientas millas marinas y la moratoria del bacalao. También se presenta la historia de la pesca en Galicia y Terranova a lo largo de todo el siglo XX, dos territorios que comparten el mismo océano y una mirada puesta en la mar.

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3 volúmenes : ilustraciones fotografías a color

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Esta tesis nace como propuesta de traducción del español al italiano de un extracto de la novela "El bailarín de tango", del autor argentino Juan Terranova. El objetivo de este trabajo era producir un texto de carácter conversacional que fuera natural y comunicativo, con particular atención a la equivalencia de modismos, disfemismos y signos de puntuación, típicos del lenguaje oral. Se ha puesto el enfoque sobre los argentinismos y términos procedentes del lunfardo, presentes en número considerable en la obra, basada exclusivamente en conversaciones telefónicas entre dos mujeres, que hablan con el lenguaje coloquial del dialecto porteño. La tesis comienza con la presentación del texto original y de sus características formales, como el estilo, el tipo de lenguaje utilizado por el autor y su género textual, seguida por una breve presentación del autor y de la corriente literaria a la que pertenece esta novela, la Nueva Narrativa Argentina. Más adelante, en un análisis de la tarea realizada, se exponen los factores considerados más significativos desde el punto de vista traductológico, como la variedad argentina del español y sus elementos presentes en el texto, los culturemas y los ya nombrados disfemismos y signos de puntuación, acompañados por una explicación que justifica la elección tomada para su transmisión al italiano. Por último, se presenta la propuesta de traducción del capítulo en cuestión y, como anexo, el texto original.

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This chapter focuses on the more strategic activities that lead people in the regional community to decide how they want to respond to climate change. Such strategic activities include analysing, prioritising and deciding upon the best course of action. Planning for climate adaptation (usually seen to include the setting of visions and objectives, the determination of key strategies and the monitoring of broad outcomes) encompasses the strategic activities involved in the system of governance for climate adaptation. Planning occurs at all scales from global to the business, property, family and even individual scales. Applying a rapid appraisal technique, this chapter analyses the system of planning for climate adaptation as it relates to the achievement of adaptation outcomes within the Wet Tropics Cluster. It finds that some aspects of the system are healthier than others, and identifies several actions that regional NRM bodies may consider (either collectively or individually) to enhance adaptation outcomes by improving the planning system within the cluster.

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The scombrid Scomberomorus semifasciatus is an important component of inshore fisheries in tropical Australia. Data on the parasite fauna of 593 fish from areas off northern and eastern Australia were examined for evidence of discrete fish populations. The parasites used were juveniles of Pterobothrium pearsoni, Callitetrarhynchus gracilis, Anisakis simplex (sensu latu) and Terranova sp. Tukey Kramer pairwise comparisons gave significant differences in the abundances of two or more parasites between fish from the east coast, the eastern Gulf of Carpentaria and the remainder of northern Australia. Multivariate analysis gave further evidence of differences and the results suggest that at least 4 populations or stocks of grey mackerel occur along the northern and eastern coastline of Australia.

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[ES]El bacalao de los Grandes Bancos de Terranova sigue sin recuperar sus stoks biológicos en el año 2005. Se llegó a esta situación por una combinación de factores. Este trabajo muestra la respuesta de los pescadores ante la prohibición del pescar el Food Fishery, donde se analiza la reconstrucción de la memoria y el afianzamiento de espacios de poder en función de los datos.

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Two large hydrologic issues face the Kings Basin, severe and chronic overdraft of about 0.16M ac-ft annually, and flood risks along the Kings River and the downstream San Joaquin River. Since 1983, these floods have caused over $1B in damage in today’s dollars. Capturing flood flows of sufficient volume could help address these two pressing issues which are relevant to many regions of the Central Valley and will only be exacerbated with climate change. However, the Kings River has high variability associated with flow magnitudes which suggests that standard engineering approaches and acquisition of sufficient acreage through purchase and easements to capture and recharge flood waters would not be cost effective. An alternative approach investigated in this study, termed On-Farm Flood Flow Capture, involved leveraging large areas of private farmland to capture flood flows for both direct and in lieu recharge. This study investigated the technical and logistical feasibility of best management practices (BMPs) associated with On-Farm Flood Flow Capture. The investigation was conducted near Helm, CA, about 20 miles west of Fresno, CA. The experimental design identified a coordinated plan to determine infiltration rates for different soil series and different crops; develop a water budget for water applied throughout the program and estimate direct and in lieu recharge; provide a preliminary assessment of potential water quality impacts; assess logistical issues associated with implementation; and provide an economic summary of the program. At check locations, we measured average infiltration rates of 4.2 in/d for all fields and noted that infiltration rates decreased asymptotically over time to about 2 – 2.5 in/d. Rates did not differ significantly between the different crops and soils tested, but were found to be about an order of magnitude higher in one field. At a 2.5 in/d infiltration rate, 100 acres are required to infiltrate 10 CFS of captured flood flows. Water quality of applied flood flows from the Kings River had concentrations of COC (constituents of concern; i.e. nitrate, electrical conductivity or EC, phosphate, ammonium, total dissolved solids or TDS) one order of magnitude or more lower than for pumped groundwater at Terranova Ranch and similarly for a broader survey of regional groundwater. Applied flood flows flushed the root zone and upper vadose zone of nitrate and salts, leading to much lower EC and nitrate concentrations to a depth of 8 feet when compared to fields in which more limited flood flows were applied or for which drip irrigation with groundwater was the sole water source. In demonstrating this technology on the farm, approximately 3,100 ac-ft was diverted, primarily from April through mid-July, with about 70% towards in lieu and 30% towards direct recharge. Substantial flood flow volumes were applied to alfalfa, wine grapes and pistachio fields. A subset of those fields, primarily wine grapes and pistachios, were used primarily to demonstrate direct recharge. For those fields about 50 – 75% of water applied was calculated going to direct recharge. Data from the check studies suggests more flood flows could have been applied and infiltrated, effectively driving up the amount of water towards direct recharge. Costs to capture flood flows for in lieu and direct recharge for this project were low compared to recharge costs for other nearby systems and in comparison to irrigating with groundwater. Moreover, the potentially high flood capture capacity of this project suggests significant flood avoidance costs savings to downstream communities along the Kings and San Joaquin Rivers. Our analyses for Terranova Ranch suggest that allocating 25% or more flood flow water towards in lieu recharge and the rest toward direct recharge will result in an economically sustainable recharge approach paid through savings from reduced groundwater pumping. Two important issues need further consideration. First, these practices are likely to leach legacy salts and nitrates from the unsaturated zone into groundwater. We develop a conceptual model of EC movement through the unsaturated zone and estimated through mass balance calculations that approximately 10 kilograms per square meter of salts will be flushed into the groundwater through displacing 12 cubic meters per square meter of unsaturated zone pore water. This flux would increase groundwater salinity but an equivalent amount of water added subsequently is predicted as needed to return to current groundwater salinity levels. All subsequent flood flow capture and recharge is expected to further decrease groundwater salinity levels. Second, the project identified important farm-scale logistical issues including irrigator training; developing cropping plans to integrate farming and recharge activities; upgrading conveyance; and quantifying results. Regional logistical issues also exist related to conveyance, integration with agricultural management, economics, required acreage and Operation and Maintenance (O&M).