806 resultados para Multifunctional landscape
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1. Analyses of species association have major implications for selecting indicators for freshwater biomonitoring and conservation, because they allow for the elimination of redundant information and focus on taxa that can be easily handled and identified. These analyses are particularly relevant in the debate about using speciose groups (such as the Chironomidae) as indicators in the tropics, because they require difficult and time-consuming analysis, and their responses to environmental gradients, including anthropogenic stressors, are poorly known. 2. Our objective was to show whether chironomid assemblages in Neotropical streams include clear associations of taxa and, if so, how well these associations could be explained by a set of models containing information from different spatial scales. For this, we formulated a priori models that allowed for the influence of local, landscape and spatial factors on chironomid taxon associations (CTA). These models represented biological hypotheses capable of explaining associations between chironomid taxa. For instance, CTA could be best explained by local variables (e.g. pH, conductivity and water temperature) or by processes acting at wider landscape scales (e.g. percentage of forest cover). 3. Biological data were taken from 61 streams in Southeastern Brazil, 47 of which were in well-preserved regions, and 14 of which drained areas severely affected by anthropogenic activities. We adopted a model selection procedure using Akaike`s information criterion to determine the most parsimonious models for explaining CTA. 4. Applying Kendall`s coefficient of concordance, seven genera (Tanytarsus/Caladomyia, Ablabesmyia, Parametriocnemus, Pentaneura, Nanocladius, Polypedilum and Rheotanytarsus) were identified as associated taxa. The best-supported model explained 42.6% of the total variance in the abundance of associated taxa. This model combined local and landscape environmental filters and spatial variables (which were derived from eigenfunction analysis). However, the model with local filters and spatial variables also had a good chance of being selected as the best model. 5. Standardised partial regression coefficients of local and landscape filters, including spatial variables, derived from model averaging allowed an estimation of which variables were best correlated with the abundance of associated taxa. In general, the abundance of the associated genera tended to be lower in streams characterised by a high percentage of forest cover (landscape scale), lower proportion of muddy substrata and high values of pH and conductivity (local scale). 6. Overall, our main result adds to the increasing number of studies that have indicated the importance of local and landscape variables, as well as the spatial relationships among sampling sites, for explaining aquatic insect community patterns in streams. Furthermore, our findings open new possibilities for the elimination of redundant data in the assessment of anthropogenic impacts on tropical streams.
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A recent debate has contrasted two conservation strategies in agricultural landscapes; either ""land sparing`` farm development combining intensive production practices with forest set-asides, or ""wildlife-friendly`` farming with greater on-farm habitat value but lower yields. We argue that in established mosaic landscapes including old cacao production regions where natural forest has already been reduced to relatively small fragments, a combination of both strategies is needed to conserve biodiversity. After reviewing the evidence for the insufficiency of either strategy alone if applied to such landscapes, the paper focuses on the cacao production landscape of southern Bahia, Brazil, once the world`s second largest cacao producer. Here, small remaining areas of Atlantic Forest are embedded in a matrix dominated by traditional cacao agroforests, resulting in a landscape mosaic that has proven favorable to the conservation of the region`s high biodiversity. We show that current land use dynamics and public policies pose threats but also offer opportunities to conservation and describe a three- pronged landscape conservation strategy, consisting of (i) expansion of the protected areas system, (ii) promotion of productive yet biodiversity-friendly cacao farming practices, and (iii) assistance to land users to implement legally mandated on-farm reserves and voluntary private reserves. We discuss recent experiences concerning the implementation of this strategy, discuss likely future scenarios, and reflect on the applicability of the Bahian experience to biodiversity rich cacao production regions elsewhere in the tropics.
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Brazil`s State of Sao Paulo Research Foundation
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This paper outlines the results obtained with biosensors designed for urea amperometric detection. The incorporation of urease into a bipolymeric substrate consisting of poly(pyrrole) and poly(5-amino-1-naphthol) was performed through four different approaches: direct adsorption, entrapment in cellulose acetate layer. cross-linking with glutaraldehyde, and also covalent attachment to the polymeric matrix. Poly(pyrrole) acts as amperometric transducer in these biosensors, while poly(5-amino-1-naphthol) drastically reduces the interference signal of agents such as ascorbic and uric acids. The biosensors containing urease covalently attached to the substrate provided interesting results in terms of sensitivity towards urea (0.50 mu A cm(-2) mmol(-1) L), lifetime (20 days) and short response times, due to the enzyme immobilization method used. All biosensors analyzed showed also a wide linear concentration range (up to 100 mmol L(-1)) and low detection limits (0.22-0.58 mmol L(-1)). (C) 2009 Elsevier B.V. All rights reserved.
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This field report presents fieldwork undertaken in Hjaltadalur, Skagafjördur, northern Iceland during summer 2010. The main aim was to initiate coring in selected mires in order to determine the composition of organic material and sediments in the mires, sub-sample for sedimentological and palaeoecological analyses, and initiate advanced landscape analysis of Hjaltadalur. Three mires were selected for sediments coring in Hjaltadalur: Ástunga close to Kolkóus, Hólakot at Viðvik, and Hólar. All three represented a landscape transect in NW to SE direction, from close to the coast to valley interior, i.e. close to the old settlement at Hólar.
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The purpose of my Senior Scholar project was to create a series of sculptures that are based on the interaction of natural forms within a selected landscape setting. I hope to convey a sense of how I view and interpret the landscape and to create works that stimulate a sense of wonder in the mind of the viewer. This fascination, perhaps even obsession, with the power of the landscape has kept me going throughout the year. As a source of ideas and imagery, the landscape can never be depleted. There will always be new combinations of landscape elements, different light conditions, and changing seasons to provide me with fresh ideas. Research for the project took me to many different places, be it my trip to Monhegan Island or driving to New York City to study the cityscape. I began the year working in steel and plaster, combining the two in works that explore the interaction between living tree roots and inanimate rocks. This led to a series entitled Landscape Recollections, comprised of welded steel forms housed in protective wooden boxes and lit from inside. After visiting New York City, architecture began to playa role in my work, as seen in the two Roadcut pieces and the Cathedral Woods series. Roadcut #1 and Roadcut #2 explore the relationship between a man-made road and the landscape that lies beneath and around it. The Cathedral Woods pieces incorporate architecture in a more abstract manner, using imagery derived from Gothic cathedrals to convey a sense of quiet peacefulness. The soaring verticality of Gothic architecture integrates with the tall tree forms in each piece, enabling me to intertwine these two elements into one another and create a harmonious relationship between architecture and nature. Throughout the year I have kept a sketchbook in which I draw from life, jot down ideas, and take notes on how the project is progressing. I have also completed several large charcoal drawings of my sculptures in which I explore different ways of viewing the steel forms. I am grateful to have had the opportunity to undertake this project, as it has been a very difficult but rewarding process of observing, interpreting, and manifesting the landscape according to my personal vision and experiences.
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The aim of this thesis was to evaluate historical change of the landscape of Madeira Island and to assess spatial and temporal vegetation dynamics. In current research diverse “retrospective techniques”, such as landscape repeat photography, dendrochronology, and research of historical records were used. These, combined with vegetation relevés, aimed to gather information about landscape change, disturbance history, and vegetation successional patterns. It was found that landscape change, throughout 125 years, was higher in the last five decades manly driven by farming abandonment, building growth and exotic vegetation coverage increase. Pristine vegetation was greatly destroyed since early settlement and by the end of the nineteenth century native vegetation was highly devastated due to recurrent antropogenic disturbances. These actions also helped to block plant succession and to modify floristical assemblages, affecting as well as species richness. In places with less hemeroby, although significant growth of vegetation of lower seral stages was detected, the vegetation of most mature stages headed towards unbalance between recovery and loss, being also very vulnerable to exotic species encroachment. Recovery by native vegetation also occurred in areas formerly occupied by exotic plants and agriculture but it was almost negligible. Vegetation recovery followed the successional model currently proposed, attesting the model itself. Yet, succession was slower than espected, due to lack of favourable conditions and to recurrent disturbances. Probable tempus of each seral stage was obtained by growth rates of woody taxa estimated through dendrochronology. The exotic trees which were the dominant trees in the past (Castanea sativa and Pinus pinaster) almost vanished. Eucalyptus globulus, the current main tree of the exotic forest is being replaced by other cover types as Acacia mearnsii. The latter, along with Arundo donax, Cytisus scoparius and Pittosporum undulatum are currently the exotic species with higher invasive behaviour. However, many other exotic species have also proved to be highly pervasive and came together with the ones referred above to prevent native vegetation regeneration, to diminish biological diversity, and to block early successional phases delaying native forest recovery.
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On this qualitative study, it has been discussed the school inclusion paths done by a student with cerebral palsy, who we call Liz, and who was also the reference and indirect subject for this study. For the representation of landscapes found, it follows throughout historical, political and pedagogical paths, getting through the case study method references on the current Brazilian educational context, analyzing, which concepts are attributed to the inclusion and which practices are developed by educational managers and teachers in a regular school of the City of Natal/RN. The theory which based this research is supported on Vygotsky's central ideas (1991, 1997, 2004) and his followers. Furthermore, it was essential to bring to this investigative journey a literature which could dialogue with the most relevant aspects of the cultural-historical approach, emphasizing the assumptions of a progressive education tendency, which promotes the subject involvement of his/her work in the world and for the world. This way, it was necessary to seek for theoretical support on assistive technology and on alternative communication, in order to show the importance of establishing other communications, which is, to break away from the conventional pattern established by the school. On this journey it was used procedures for the data construction, such as: observation, conducting semistructured interviews and questionnaires; and document analysis that supported and legitimized the inclusion, besides the permanent field diaries record. On the access paths to this landscape it entered in the Youth and Adults Education (Educação de Jovens e Adultos - EJA), seeking to establish a dialogue among Youth and Adult Education and Special Education. It was verified that, still, there are large gaps in these policies articulation. Among the results obtained it was raised discussions on new scenery, in which Youth and Adults Education (EJA) emerges as prominent mode of the established relationships throughout the school inclusion process. There were target reflections on: the planning and evaluation systematic, the pedagogical articulation among the Youth and Adults Education (EJA) teachers and the multifunctional resource room teacher's actions and the continuous training importance of the educators involved. It was considered, therefore, that the necessary mediations for school inclusion may be sustained if the walkers are involved in a permanent contact with the nature of a proposal from the Special Education inclusive perspective
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The general statement that birds are recorded more often on morning than on afternoon counts is quite common and widespread among ornithologists. Although many investigators have reported temporal variations in bird detections using Point Counts in temperate regions, few researches regarding the same objectives have been conducted in Neotropical habitats or used transect counts as field method. We used transect counts to test the hypothesis that birds are evenly recorded between times of day in a predominantly open Cerrado landscape in southeastern Brazil. Although not always significantly, the number of species and individuals were consistently greater during the morning counts, which corroborates the fact that birds can be more detectable during this time of day. However, a few families as well as a small percentage of species were more likely to be recorded during either one of the two periods we analyzed. Our results suggest that morning counts should detect higher number of both species and individuals in our study area, but specific taxa show distinct patterns of detection which should be acknowledged prior to sampling.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)