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This study examined the spatial and temporal patterns of the canopy layer urban heat islands (UHIUCL) in a small city in southeastern Brazil using the local climate zone (LCZ) system. We analysed the influence of weather conditions, LCZs characteristics, and local surface relief on the UHIUCL magnitudes. Mobile traverses were used to measure air temperatures during representative nights of wet and dry seasons. Daily maximum magnitudes were observed in compact classes (LCZs 3 and 7) under ideal weather conditions (dry, clear skies, and calm) and higher anthropogenic heat release (weekdays). Seasonal effects on LCZ thermal differences were negligible. The peripheral landscapes were warmer than the city centre in both seasons. Among the warmer areas in the city, magnitudes in compact LCZs 3 and 7 were consistently higher than in LCZ 6. In general, representative sites of the main 'built' LCZs in the study area exhibit similar inter‐zone temperature patterns to those reported for cities of different sizes from tropical and midlatitude regions. Thermal contrasts of ΔTLCZ 3 − D in the study area reveal significant evidence that small cities can have as strong heat islands as bigger cities. These findings highlight the importance of the LCZ system to identify the main controlling factors driving such thermal differences and the need to extend the application of this approach in other South American cities to yield systematic data of UHIUCL for urban planning given the coming challenges of climate change over the region. [ABSTRACT FROM AUTHOR]

The classic models of cuesta evolution in south‐eastern Brazil have temporal gaps in their denudation chronology. Here, we analyzed the colluvial deposits located on the rim of the Serra Geral escarpments in the Paraná Basin to propose a model with an absolute age range of minor landform evolution within this cuesta morphology. Correlation of the optically stimulated luminescence ages with the regional paleoclimatic conditions demonstrates that the successive phases of colluviation reflect either short‐term intervals of variability in moisture availability or dry periods in the Holocene. The potential effects of other contributing factors (vegetation changes, local geomorphic settings and human activity) add complexity to the denudation responsible for the development of the investigated geomorphic chronosequences. The proposed model consists of five stages of hillslope sediment remobilization that were responsible for further remodeling of the minor vertical steps during the following chronological distribution: (i) 9.13 ± 1.2–7.09 ± 0.96 ka; (ii) 5.66 ± 0.86–4.5 ± 0.75 ka; (iii) 3.94 ± 0.605–3.45 ± 0.6 ka; (iv) 2.66 ± 0.315–2.3 ± 0.4 ka; and (v) after 1960 to the present day. [ABSTRACT FROM AUTHOR]

This paper offers a historical perspective on the interactions between legal standards and agricultural practices relating to guaraná, an energy-inducing Amazonian plant that is in increasing demand. Guaraná is managed in a number of socio-technical contexts, ranging from the fizzy drink industry to alternative agro-ecological farming systems, and is subject to a great many legal rules that determine the conditions for its use and appropriation. The paper shows how, in guaraná's native region of Maués, Brazilian Amazonia, various stakeholders including the indigenous population, associations of smallholdings and multinationals use legal standards in order to gain prerogatives over the plant and/or win a share of a growing market. In spite of the fact that the plant has been domesticated by the Sateré- Mawé and that traditional knowledge has been recognized in Brazil, to a certain extent history has dispossessed them of their rights to guaraná. New political and economic circumstances have favoured those actors committed to strategies of agricultural modernization and industrial processing. On the other hand, the ecologization of agriculture and the increasing numbers of instruments for differentiating production (such as fair trade, organic farming and geographical indications) seem to be favouring diversification in the methods of managing guaraná, as well as a certain re-appropriation of the plant by local communities. [ABSTRACT FROM AUTHOR]

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The loss of biodiversity, one of the environmental problems with an acknowledged planet-wide impact, has been addressed by a convention which highlights the need to take into account the “knowledge, innovations and practices of indigenous and local communities” in a context of sustainable development. This rehabilitation of the traditional practices and knowledge of communities undermined by several decades of development raises a number of problems as to its relevance, forms, and procedures. The multidisciplinary research we have carried out in Brazilian Amazonia on the management of the varietal diversity of cassava by various local groups provides a good illustration of this. After presenting the Amazonian context in which cassava is cultivated, we look at the institutional and organizational environments in which the communities concerned live before taking up the question of emerging political configurations involved in preserving local knowledge. Non-governmental organisations play a significant role politically, as intermediaries between the local level and the state's political and administrative institutions. The dynamics observed testify to a far-reaching change in the way “indigenous communities” relate to the society around them. [ABSTRACT FROM AUTHOR]

Acacia mearnsii De Wild. is one of the most widely cultivated forest species in Brazil. Despite its importance, studies on breeding strategies for this species are scarce. Therefore, the aim of this study was to evaluate the progeny and develop early selection strategies for A. mearnsii. Individuals of half-sib progenies were classified according to their genotypic value and selected based on their relative performance. The additive effect was only significant for plant height. The best progenies and plants should be selected based on plant height after approximately 60 days of being in nursery and 2 years of field cultivation. This strategy eliminates the worse progenies, discards inferior genotypes in the nursery, eliminates unselected genotypes based on plant height before flowering, and intercrosses only the best plants in field cultivation. This resulted in an annual genetic gain of 3% for plant height and 2% for diameter at breast height. [ABSTRACT FROM AUTHOR]