Cas d'ús HTCondor & Amazon EC2

En aquest Treball Final de Grau s'ha implementat un clúster d'alta eficiència (HTC) amb nodes físics d'una aula d'informàtica i nodes virtuals a partir d'instàncies d'Amazon EC2 (Elastic Compute Cloud). Mitjançant la creació de dos bash scripts es gestionarà la posada en marxa dels nodes del clúster, tant físics com virtuals, per tal d'optimitzar l'ús dels recursos físics, reduir el cost energètic i disposar de la flexibilitat que ofereix el sistema de màquines virtuals d'Amazon EC2.

Physiologie du chasseur / par Deyeux ; vignettes d'Eugène Forest

Référence bibliographique : Lhéritier, 60

Hyperbolic reaction-diffusion equations for a forest fire model

Forest fire models have been widely studied from the context of self-organized criticality and from the ecological properties of the forest and combustion. On the other hand, reaction-diffusion equations have interesting applications in biology and physics. We propose here a model for fire propagation in a forest by using hyperbolic reaction-diffusion equations. The dynamical and thermodynamical aspects of the model are analyzed in detail

Improving the organisation and commercialisation of small coffee and cocoa producers in the Northern Amazon Region of Ecuador

Coffee and cocoa represent the main sources of income for small farmers in the Northern Amazon Region of Ecuador. The provinces of Orellana and Sucumbios, as border areas, have benefited from investments made by many public and private institutions. Many of the projects carried out in the area have been aimed at energising the production of coffee and cocoa, strengthening the producers’ associations and providing commercialisation infrastructure. Improving the quality of life of this population threatened by poverty and high migration flows mainly from Colombia is a significant challenge. This paper presents research highlighting the importance of associative commercialisation to raising income from coffee and cocoa. The research draws on primary information obtained during field work, and from official information from the Ministry of Agriculture. The study presents an overview of current organisational structures, initiatives of associative commercialisation, stockpiling of infrastructure and ownership regimes, as well as estimates for both ‘robusta’ coffee and national cocoa production and income. The analysis of the main constraints presents different alternatives for the implementation of public land policies. These policies are aimed at mitigating the problems associated with the organisational structure of the producers, with processes of commercialisation and with environmental aspects, among others.

Shifts in species and phylogenetic diversity between sapling and tree communities indicate negative density dependence in a lowland rain forest

1. As trees in a given cohort progress through ontogeny, many individuals die. This risk of mortality is unevenly distributed across species because of many processes such as habitat filtering, interspecific competition and negative density dependence. Here, we predict and test the patterns that such ecological processes should inscribe on both species and phylogenetic diversity as plants recruit from saplings to the canopy. 2. We compared species and phylogenetic diversity of sapling and tree communities at two sites in French Guiana. We surveyed 2084 adult trees in four 1-ha tree plots and 943 saplings in sixteen 16-m2 subplots nested within the tree plots. Species diversity was measured using Fisher's alpha (species richness) and Simpson's index (species evenness). Phylogenetic diversity was measured using Faith's phylogenetic diversity (phylogenetic richness) and Rao's quadratic entropy index (phylogenetic evenness). The phylogenetic diversity indices were inferred using four phylogenetic hypotheses: two based on rbcLa plastid DNA sequences obtained from the inventoried individuals with different branch lengths, a global phylogeny available from the Angiosperm Phylogeny Group, and a combination of both. 3. Taxonomic identification of the saplings was performed by combining morphological and DNA barcoding techniques using three plant DNA barcodes (psbA-trnH, rpoC1 and rbcLa). DNA barcoding enabled us to increase species assignment and to assign unidentified saplings to molecular operational taxonomic units. 4. Species richness was similar between saplings and trees, but in about half of our comparisons, species evenness was higher in trees than in saplings. This suggests that negative density dependence plays an important role during the sapling-to-tree transition. 5. Phylogenetic richness increased between saplings and trees in about half of the comparisons. Phylogenetic evenness increased significantly between saplings and trees in a few cases (4 out of 16) and only with the most resolved phylogeny. These results suggest that negative density dependence operates largely independently of the phylogenetic structure of communities. 6. Synthesis. By contrasting species richness and evenness across size classes, we suggest that negative density dependence drives shifts in composition during the sapling-to-tree transition. In addition, we found little evidence for a change in phylogenetic diversity across age classes, suggesting that the observed patterns are not phylogenetically constrained.

Thermal energetics of the New-Guinean moss-forest rat (Rattus niobe) in comparison with other tropical murid rodents.

The thermal energetics of rodents from cool, wet tropical highlands are poorly known. Metabolic rate, body temperature and thermal conductance were measured in the moss-forest rat, Rattus niobe (Rodentia), a small murid endemic to the highlands of New Guinea. These data were evaluated in the context of the variation observed in the genus Rattus and among tropical murids. In 7 adult R. niobe, basal metabolic rate (BMR) averaged 53.6±6.6mLO2h(-1), or 103% of the value predicted for a body mass of 42.3±5.8g. Compared to other species of Rattus, R. niobe combines a low body temperature (35.5±0.6°C) and a moderately low minimal wet thermal conductance cmin (5.88±0.7mLO2h(-1)°C(-1), 95% of predicted) with a small size, all of which lead to reduced energy expenditure in a constantly cool environment. The correlations of mean annual rainfall and temperature, altitude and body mass with BMR, body temperature and cmin were analyzed comparatively among tropical Muridae. Neither BMR, nor cmin or body temperature correlated with ambient temperature or altitude. Some of the factors which promote high BMR in higher latitude habitats, such as seasonal exposure to very low temperature and short reproductive season, are lacking in wet montane tropical forests. BMR increased with rainfall, confirming a pattern observed among other assemblages of mammals. This correlation was due to the low BMR of several desert adapted murids, while R. niobe and other species from wet habitats had a moderate BMR.

Comunidade de formigas que nidificam em pequenos galhos da serrapilheira em floresta da Amazônia Central, Brasil

Community of ants that nest in dead twigs on the ground of Central Amazonian forest, Brazil. A total area of 2,880 m² in four forest sites, near Manaus, Brazil, was searched for ant colonies nesting in dead twigs on the ground. An amount of 3,706 twigs (0.5-5 cm in diameter) were gathered, of which only 623 (16.8%) had ants, which is equivalent to a density of 0.22 nests per m². Seventy species have been found. The predominant genera were Pheidole (Westwood), Crematogaster (Lund), and Solenopsis (Westwood). For most species, many of the nests found had only workers and brood, suggesting that colonies either use multiple twigs to nest or do not live exclusively in the twigs, using other types of substrate (e.g., leaf-litter, soil, fruit pods) to nest. Most colonized twigs were hollow or partially hollow inside and relatively easy to break apart. There were significant differences among species with respect to the size (diameter) of twig used as nest. No correlation was found between the number of twigs available and the number colonized by ants, suggesting that ant populations were not limited by the amount of nesting sites (twigs). The three most common Pheidole species had small colonies with less than 200 workers. Colony size was not related to twig size (volume), for any of these three species.

Análise de parcimônia de endemismo de cercopídeos neotropicais (Hemiptera, Cercopidae)

The spittlebugs have an extent distribution in the American continent. Their diversity may determinate endemism areas based on their occurence in different localities. We have used Parsimony Analysis of Endemicity method, which is an important historic biogeography tool for detecting and establishing the relationship among endemics areas. A data matrix was built up based on the occurence registration for the species by 66 genus in whole localities divided in five degrees quadrats in the Neotropical Region, using 49 OGUs (Operative Geografic Units). The presence of the taxa in the areas was coded 1 and the absence 0. The data matrix was analysed based on parsimony analysis through the computer program Hennig 86. Nine endemic areas were stipulated (Mexico + Central America, Venezuelan Savana, Guiana + Suriname, Chaco, Trans-andean, Cerrado, Amazon, Pampa and Atlantic Forest) in the first analysis corroborated with ecological and physiographic patterns in each region. The second analysis was made using 48 genera to obtain the relationship among the nine areas stipulated before. In this analysis just one cladogram (3((1,2)((8,9)(6(7(4,5)))))) was obtained with 192 steps, consistence index 0.80 and retention index 0.85.

A new spot-thoraxed species of Drosophila from the Atlantic Forest of southeastern Brazil (Diptera, Drosophilidae)

Drosophila boraceia sp. nov. is described from a single male specimen collected at the Estação Biológica de Boracéia, Salesópolis, state of São Paulo, Brazil. At first inspection it looks like a species of Drosophila belonging to the fasciola subgroup of the repleta group, mainly because of the fasciola-like pattern of fused spots on the thorax. However, mostly due to the quite distinct structures of the male terminalia, it seems to be more similar to one ungrouped and also spot-thoraxed South American species, Drosophila atalaia Vilela & Sene, 1982. Illustrations of the terminalia are also provided.

The housing boom and forest fires

This paper provides evidence that the combination of land-use restrictions and anincreasing demand for housing can create incentives to induce forest fires as a means tocircumvent regulation and increase the supply of land available for residential construction.I estimate the effect of the price of housing on the incidence of forest fires using Spanishdata by region for 1991-2005. The results suggest that higher house prices led to asignificant increase in the incidence of forest fires in a region. I also find that the increasedincidence of forest fires led to a subsequent reduction in forest area and an increase in urbanland area. This evidence supports the claims often found in the media that propertyspeculators trying to build in forest land may be behind the recent increases in the incidenceof forest fires in Mediterranean countries.

Species of Euglossa (Glossura) in the Brazilian Atlantic forest, with taxonomic notes on Euglossa stellfeldi Moure (Hymenoptera, Apidae, Euglossina)

The species of Euglossa (Glossura) occuring in the Brazilian Atlantic forest were revised and an identification key to males and females is provided. The status of Euglossa annectans Dressler and E. stellfeldi Moure is reevaluated and the latter species is transferred from E. (Glossura) to E. (Glossurella). Here we also synonymize E. carinilabris Dressler under E. stellfeldi. Taxonomic notes are provided and relevant morphological features are illustred. Latitudinal color variation along the Brazilian Atlantic forest, found in two of the species studied here, is also presented and discussed.

Improving generalized regression analysis for the spatial prediction of forest communities

Aim This study used data from temperate forest communities to assess: (1) five different stepwise selection methods with generalized additive models, (2) the effect of weighting absences to ensure a prevalence of 0.5, (3) the effect of limiting absences beyond the environmental envelope defined by presences, (4) four different methods for incorporating spatial autocorrelation, and (5) the effect of integrating an interaction factor defined by a regression tree on the residuals of an initial environmental model. Location State of Vaud, western Switzerland. Methods Generalized additive models (GAMs) were fitted using the grasp package (generalized regression analysis and spatial predictions, http://www.cscf.ch/grasp). Results Model selection based on cross-validation appeared to be the best compromise between model stability and performance (parsimony) among the five methods tested. Weighting absences returned models that perform better than models fitted with the original sample prevalence. This appeared to be mainly due to the impact of very low prevalence values on evaluation statistics. Removing zeroes beyond the range of presences on main environmental gradients changed the set of selected predictors, and potentially their response curve shape. Moreover, removing zeroes slightly improved model performance and stability when compared with the baseline model on the same data set. Incorporating a spatial trend predictor improved model performance and stability significantly. Even better models were obtained when including local spatial autocorrelation. A novel approach to include interactions proved to be an efficient way to account for interactions between all predictors at once. Main conclusions Models and spatial predictions of 18 forest communities were significantly improved by using either: (1) cross-validation as a model selection method, (2) weighted absences, (3) limited absences, (4) predictors accounting for spatial autocorrelation, or (5) a factor variable accounting for interactions between all predictors. The final choice of model strategy should depend on the nature of the available data and the specific study aims. Statistical evaluation is useful in searching for the best modelling practice. However, one should not neglect to consider the shapes and interpretability of response curves, as well as the resulting spatial predictions in the final assessment.

Seasonality and temporal structuration of Alticini community (Coleoptera, Chrysomelidae, Galerucinae) in the Araucaria Forest of Parana, Brazil

Seasonality was studied for Alticini trapped with malaise over a period of two years in the Vila Velha State Park, Parana, Brazil. Coleoptera, Chrysomelidae and Alticini showed seasonal distribution, with the highest abundance during spring and summer months. The abundance peaks of these groups were not synchronized. Of all environmental variables tested, photoperiod had the larger effect on the distributional patterns of Coleoptera, Chrysomelidae and Alticini. Also, Chrysomelidae and Alticini probably are related to the quality and availability of host-plants. When richness was high there was a greater similarity among seasons of different years. However, when richness was not pronounced, seasons showed more similarity within the same year than between years. The Alticini community was seasonally structured and a possible mechanism underlying this pattern is asymmetric competition. Nevertheless, it is necessary to account for indirect interactions (plant-enemy mediated) to better understand how Alticini community is structured.

A new species of the genus Pimelerodius Vanin from the Amazon Region, with notes on the geografic distribution of Pimelerodius motacilla (Boheman) (Coleoptera, Curculionidae, Otidocephalini)

Pimelerodius punctiventris sp. nov. (type locality Brazil, Amazonas, Itacoatiara) is described and illustrated. The new taxon is compared with similar species, being distinguished from the other 12 known species of the genus by the presence of punctures in ventrite I. The available published key for identification of species of Pimelerodius is adapted to include the new species. A modification of the generic description of the aedeagus of Pimelerodius is provided, a necessity due to the differences observed in the aedeagus of the new species. The occurrence of P. motacilla (Boheman, 1843) in the Amazon Region, recorded in sympatry with P. punctiventris in Itacoatiara, AM, is discussed and confirmed, based on the study of 41 available specimens.