9 resultados para wet season
em Consorci de Serveis Universitaris de Catalunya (CSUC), Spain
Resumo:
A seasonal period of water deficit characterizes tropical dry forests (TDFs). There, sympatric tree species exhibit a diversity of growth rates, functional traits, and responses to drought, suggesting that each species may possess different strategies to grow under different conditions of water availability. The evaluation of the long-term growth responses to changes in the soil water balance should provide an understanding of how and when coexisting tree species respond to water deficit in TDFs. Furthermore, such differential growth responses may be linked to functional traits related to water storage and conductance. We used dendrochronology and climate data to retrospectively assess how the radial growth of seven coexisting deciduous tree species responded to the seasonal soil water balance in a Bolivian TDF. Linear mixed-effects models were used to quantify the relationships between basal area increment and seasonal water balance. We related these relationships with wood density and sapwood production to assess if they affect the growth responses to climate. The growth of all species responded positively to water balance during the wet season, but such responses differed among species as a function of their wood density. For instance, species with a strong growth response to water availability averaged a low wood density which may facilitate the storage of water in the stem. By contrast, species with very dense wood were those whose growth was less sensitive to water availability. Coexisting tree species thus show differential growth responses to changes in soil water balance during the wet season. Our findings also provide a link between wood density, a trait related to the ability of trees to store water in the stem, and wood formation in response to water availability.
Resumo:
Monitoring thunderstorms activity is an essential part of operational weather surveillance given their potential hazards, including lightning, hail, heavy rainfall, strong winds or even tornadoes. This study has two main objectives: firstly, the description of a methodology, based on radar and total lightning data to characterise thunderstorms in real-time; secondly, the application of this methodology to 66 thunderstorms that affected Catalonia (NE Spain) in the summer of 2006. An object-oriented tracking procedure is employed, where different observation data types generate four different types of objects (radar 1-km CAPPI reflectivity composites, radar reflectivity volumetric data, cloud-to-ground lightning data and intra-cloud lightning data). In the framework proposed, these objects are the building blocks of a higher level object, the thunderstorm. The methodology is demonstrated with a dataset of thunderstorms whose main characteristics, along the complete life cycle of the convective structures (development, maturity and dissipation), are described statistically. The development and dissipation stages present similar durations in most cases examined. On the contrary, the duration of the maturity phase is much more variable and related to the thunderstorm intensity, defined here in terms of lightning flash rate. Most of the activity of IC and CG flashes is registered in the maturity stage. In the development stage little CG flashes are observed (2% to 5%), while for the dissipation phase is possible to observe a few more CG flashes (10% to 15%). Additionally, a selection of thunderstorms is used to examine general life cycle patterns, obtained from the analysis of normalized (with respect to thunderstorm total duration and maximum value of variables considered) thunderstorm parameters. Among other findings, the study indicates that the normalized duration of the three stages of thunderstorm life cycle is similar in most thunderstorms, with the longest duration corresponding to the maturity stage (approximately 80% of the total time).
Resumo:
A prior long-term and complex evaluation of the already available data on the geophysical prospecting during the first season work carried out at 2006, at the archaeological site of Tchinguiz Tepe of Termez, took place to decide the strategy to follow during the campaign of 2007. This previous evaluation of the information, on one hand, leaded to the decision to increase the geophysical prospecting at Tchinguiz Tepe, on the other hand, to decide the exact location of areas where the archaeological interventions.would carry out. The main objective at the beginning of this new season was to crosscheck the reliabilityof the measurements and, at the same time, to establish the unknown up to the present archaeologicaland chronological sequence of Tchinguiz Tepe. Meanwhile, the geophysical prospecting also wasextended to the outskirts of the city were the localisation of an unknown up to now Buddhist Monasterywas possible.
Resumo:
The International Pluridisciplinary Archaeological Expedition in Bactria (IPAEB) was created in 2006.The name underlines the international character of the team (which includes Uzbeks, Spanish, French, British and Greek members), the presence of specialists from various fields apart from archaeology and the fame of Bactria1.
Resumo:
This year the development of our project can be divided into two main clearly different parts, on one hand the laboratory work, where the sampled ceramic individuals has been prepared and analyzed and the elaboration of the data obtained during the excavation of 2007 has been finished and, on the other hand, the field work developed at the archaeological site during this specific year (2008).In the mark of the analytical work a significant number of ceramic individuals (144) from the different stratigraphical units from various areas of the excavation of Termez and Tchinguiz Tepe sampled duringthe new and previous field works has been archaeometrically characterized. This specific material includedindividuals dated into the Hellenistic and Sassanian period, which has been confirmed by C14dating upon organic samples.At the same time, in the mark of the field work of 2008 the archaeological record, already started tobe under study during the excavation of 2007, has been completed and two new archaeological recordshave been registered on of which is located in the area of Tchinguiz Tepe. For the archeological studythe information of the previous geophysical prospecting has been indisputably taken into considerationand the same methodology has been applied to crosscheck the latter archaeological results.
Resumo:
A prior long-term and complex evaluation of the already available data on the geophysical prospecting during the first season work carried out at 2006, at the archaeological site of Tchinguiz Tepe of Termez, took place to decide the strategy to follow during the campaign of 2007. This previous evaluation of the information, on one hand, leaded to the decision to increase the geophysical prospecting at Tchinguiz Tepe, on the other hand, to decide the exact location of areas where the archaeological interventions.would carry out. The main objective at the beginning of this new season was to crosscheck the reliabilityof the measurements and, at the same time, to establish the unknown up to the present archaeologicaland chronological sequence of Tchinguiz Tepe. Meanwhile, the geophysical prospecting also wasextended to the outskirts of the city were the localisation of an unknown up to now Buddhist Monasterywas possible.
Resumo:
The International Pluridisciplinary Archaeological Expedition in Bactria (IPAEB) was created in 2006.The name underlines the international character of the team (which includes Uzbeks, Spanish, French, British and Greek members), the presence of specialists from various fields apart from archaeology and the fame of Bactria1.
Resumo:
This year the development of our project can be divided into two main clearly different parts, on one hand the laboratory work, where the sampled ceramic individuals has been prepared and analyzed and the elaboration of the data obtained during the excavation of 2007 has been finished and, on the other hand, the field work developed at the archaeological site during this specific year (2008).In the mark of the analytical work a significant number of ceramic individuals (144) from the different stratigraphical units from various areas of the excavation of Termez and Tchinguiz Tepe sampled duringthe new and previous field works has been archaeometrically characterized. This specific material includedindividuals dated into the Hellenistic and Sassanian period, which has been confirmed by C14dating upon organic samples.At the same time, in the mark of the field work of 2008 the archaeological record, already started tobe under study during the excavation of 2007, has been completed and two new archaeological recordshave been registered on of which is located in the area of Tchinguiz Tepe. For the archeological studythe information of the previous geophysical prospecting has been indisputably taken into considerationand the same methodology has been applied to crosscheck the latter archaeological results.
Resumo:
El momento concreto del periodo reproductor puede incidir sobre la actividad diaria y los periodos de reposo de las aves paseriformes. Para investigar este aspecto, hemos analizado los movimientos diarios de 7 machos de curruca cabecinegra Sylvia melanocephala mediante radioseguimiento en un matorral mediterráneo. La actividad tiende en general a decrecer a lo largo del día aunque con algunas variaciones dependiendo del momento concreto del periodo reproductor de cada macho en particular. Se han registrado largos periodos de reposo que no dependen ni del estado reproductor ni del momento del día
