Search

Este artigo, baseado em levantamento bibliográfico e documental, analisa a forma como a educação se insere no processo de luta de classes no contexto atual de degradação dos direitos sociais, resultante da efetivação de políticas neoliberais. Analisa as contradições entre distintos projetos de educação, ligadas ao processo de privatização dos serviços educacionais e descaracterização de seu sentido público e social. Contrariamente a essa tendência, discute-se uma concepção de educação capaz de articular-se a um projeto de superação do capitalismo, como condição para a emancipação humana. Aponta a atualidade do projeto ético-político do Serviço Social na construção de um projeto classista de educação que, ancorado na tradição marxista, valorize a formação profissional, a produção do conhecimento, o exercício profissional em articulação às lutas sociais em geral e em defesa da educação pública, laica, gratuita e de qualidade, referenciada em um projeto anticapitalista de sociedade

Este artigo apresenta uma discussão sobre os conceitos fundamentais e o contexto de emergência histórica da teoria social marxiana, no período de constituição da sociedade moderna. Como contraponto, discute-se a constituição e o caráter das “ciências sociais”, particularmente da sua vertente positivista, que, por um processo de segmentação da análise da sociedade, acaba por se afastar das possibilidades de apreensão, para além do nível fenomênico, da essência dos processos sociais, na perspectiva de uma totalidade articulada e historicamente constituída. O estudo, baseado em pesquisa bibliográfica, ratifica que o método marxiano articula-se profundamente a um projeto de transformação revolucionária da sociedade, que não prescinde do conhecimento cientificamente fundado da vida social

Spatial variation in species composition (β-diversity) is an important component of farmland biodiversity, which together with local richness (α-diversity) drives the number of species in a region (γ-diversity). However, β-diversity is seldom used to inform conservation, due to limited understanding of its responses to agricultural management, and lack of clear links between β-diversity changes and conservation outcomes. We explored the value of β-diversity to guide conservation on farmland, by quantifying the contribution of bird α- and β-diversity to γ-diversity variation in low- and high-intensity Mediterranean farmland, before (1995–1997) and after (2010–2012) the Common Agricultural Policy reform of 2003. We further related β-diversity to landscape heterogeneity, and assessed the conservation significance of β-diversity changes. In 1995–1997, bird diversity was highest in low-intensity farmland, where it further increased in 2010–2012 due to a strong positive contribution of α-diversity to γ-diversity. In high-intensity farmland, diversity converged over time to much the same values of low-intensity farmland, with strong positive contributions of both α- and β-diversity. These patterns were largely consistent for total, farmland and species of European conservation concern assemblages, and less so for steppe birds. Beta diversity increased with landscape heterogeneity, particularly related to spatial gradients from agricultural to natural habitats in low-intensity farmland, and from annual to permanent crops (olive groves) in high-intensity farmland. The first gradient was associated with the replacement of steppe birds of high conservation concern by more generalist species, while the second was associated with the replacement between species with lower or higher affinity for woodland and shrubland habitats. Synthesis and applications. In low-intensity farmland, spatial variation in species composition (β-diversity) was largely stable over time, reflecting a positive conservation outcome related to persistence of landscape heterogeneity patterns required by endangered steppe bird species. In contrast, β-diversity in high-intensity farmland was favoured by increases in landscape heterogeneity driven by olive grove expansion, contributing to enhancement of total bird diversity. Overall, our results stress the value of β-diversity to understand impacts of agricultural policies and conservation actions, but also highlight the need to evaluate β-diversity changes against specific conservation goals.

Copyright of O Social em Questão is the property of Faculdades Catolicas - Pontificia Universidade Catolica do Rio de Janeiro and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Conserving biodiversity on farmland is an essential element of worldwide efforts for reversing the global biodiversity decline. Common approaches involve improving the natural component of the landscape by increasing the amount of natural and seminatural habitats (e.g., hedgerows, woodlots, and ponds) or improving the production component of the landscape by increasing the amount of biodiversity-friendly crops. Because these approaches may negatively impact on economic output, it was suggested that an alternative might be to enhance the diversity (compositional heterogeneity) or the spatial complexity (configurational heterogeneity) of land cover types, without necessarily changing composition. Here, we develop a case study to evaluate these ideas, examining whether managing landscape composition or heterogeneity, or both, would be required to achieve conservation benefits on avian diversity in open Mediterranean farmland. We surveyed birds in farmland landscapes of southern Portugal, before (1995-1997) and after (2010-2012) the European Union's Common Agricultural Policy (CAP) reform of 2003, and related spatial and temporal variation in bird species richness to variables describing the composition, and the compositional and configurational heterogeneity, of the natural and production components of the landscape. We found that the composition of the production component had the strongest effects on avian diversity, with a particularly marked effect on the richness of farmland and steppe bird species. Composition of the natural component was also influential, mainly affecting the richness of woodland/shrubland species. Although there were some effects of compositional and configurational heterogeneity, these were much weaker and inconsistent than those of landscape composition. Overall, we suggest that conservation efforts in our area should focus primarily on the composition of the production component, by striving to maximize the prevalence of biodiversity-friendly crops. This recommendation probably applies to other areas such as ours, where a range of species of conservation concern is strongly associated with crop habitats.

Ecological niche models (ENMs) are a powerful tool to predict the spread of invasive alien species (IAS) and support the implementation of actions aiming to reduce the impact of biological invasions. While calibrating ENMs with distribution data from species' native ranges can underestimate the invasion potential due to possible niche shifts, using distribution data combining species' native and invasive ranges may overestimate the invasion potential due to a reduced fitness and environmental tolerance of species in invaded ranges. An alternative may be using the increasingly available distribution data of IAS as they spread their invaded ranges, to iteratively forecast invasions as they unfold. However, while this approach accounts for possible niche shifts, it may also underestimate the species' potential range, particularly at the early stages of the invasion when the most suitable conditions may not yet be represented in the distribution range data set. Here, we evaluate the capacity of ENMs to forecast the distribution of IAS based on distribution data on invaded ranges as these data become available. We further use dispersion models to assess the expansion process using the predicted potential distributions. Specifically, we used the common waxbill (Estrilda astrild) in the Iberian Peninsula as a model system. We built ENMs with 10×10 km grid cells distribution records cumulatively for each decade from 1960 to 2019, and yearly bioclimatic variables, to forecast the species potential range in the coming decades. Then, we assessed the performance of the models for each decade in forecasting the species' observed range expansion in the following decades and evaluated how the number of distribution records determined the quality of the forecasts. Finally, we performed dispersal estimates (based on species traits, topography, climate and land cover) to analyse the prediction capacity of models as their uncertainty may be reduced when projecting them to the next decades. Our results show that invasion-only ENMs successfully forecasted the species' range expansion over three decades after invasion, while dispersion models were not important in forecasting common waxbill expansion. Our study highlights the importance of constantly monitoring alien species, suggesting that iterative updating of ENMs with observed distribution data may accurately forecast the range expansion of alien species. [ABSTRACT FROM AUTHOR]

Aim: Recent studies highlight the importance of linking landscape ecology and macroecology for a better understanding of broad‐scale biodiversity patterns. The "landscape context effect" denotes that species responses and biodiversity in a focal area are shaped by neighbouring landscape composition and structure outside the focal area. Here, we test whether the landscape context effect could be pronounced at macroecological scales. Location: Sub‐Saharan Africa and continental China. Time period: Late 20th to early 21st centuries. Taxa studied: Terrestrial mammals (≥2 kg). Methods: We calculated species richness on the basis of grid cells of 50 km × 50 km and 100 km × 100 km. We used ordinary least square and random forest models to examine the relationships between species richness within grid cells and landscape context (defined as composition and structure of the neighbouring landscape outside the grid cells, with distances of 10–400 km to the boundary of a given grid cell). We used variation partitioning to quantify the independent and shared explanatory power of the landscape context variables, grouping species by body size and diet. Results: Landscape context alone explained ≤20% of the variation in species richness, even when controlling for correlations with macroenvironmental variables (climate, productivity and topography) and correlations with landscape attributes within the grid cells. Importantly, the explanatory power of landscape context at the scales of 100–400 km ofen outweighed grid‐cell landscape attributes or macro‐environmental variables. The independent explanatory power of landscape context was lowest for small‐sized omnivores. Furthermore, we found higher independent explanatory power for large herbivores in sub‐Saharan Africa than in continental China. Main conclusions: Landscape context plays a substantial role in shaping local biodiversity patterns at regional and continental scales, with its strength varying with organism diet and movement needs and possibilities. These findings support that conservation efforts should include effective management of landscape structure, with attention to differing space requirements among organism groups. Our work also illustrates the scope for testing landscape ecological hypotheses at macroecological scales. [ABSTRACT FROM AUTHOR]