Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Unidad de excelencia María de Maeztu CEX2019-000940-MAim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

Long-term thermal sensitivity of Earth’s tropical forests

The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate

A política externa de Lula da Silva: a estratégia da autonomia pela diversificação Lula da Silva's foreign policy: the autonomy through diversification strategy

O objetivo deste artigo é analisar as mudanças trazidas pela política externa do primeiro governo Lula da Silva (2003-2006). Para discutir o tema, utilizaremos o trabalho de Hermann (1990) sobre as motivações das mudanças na política externa dos Estados, integrando-o com insights construtivistas, que são úteis para examinar o papel das idéias na formulação da política externa brasileira depois de 2003. Para complementar nossa análise, utilizaremos três noções - "autonomia pela distância", "autonomia pela participação" e "autonomia pela diversificação" - que explicam as principais transformações pelas quais passou a política externa brasileira da década de 1980 até meados da primeira década deste século. Concluiremos demonstrando como a idéia de "autonomia pela diversificação" se aplica melhor ao período analisado, considerando que os dois primeiros níveis de Hermann, ajustes e mudanças de programa aconteceram de fato. Sugerimos que o terceiro nível, mudanças de problemas/metas, poderá efetivar-se com a consolidação e ampliação dos dois primeiros níveis.<br>The objective of this article is to analyze the changes brought about by the foreign policy of Lula da Silva's first government (2003-2006). To discuss the topic, we will make use of Hermann's (1990) article on foreign policy change and the motivation behind it, integrating it with constructivist insights useful to examine the roles of the ideas in the formulation of the Brazilian foreign policy after 2003. To compliment our analysis, we will make use of three notions: autonomy through distance, autonomy through participation, and autonomy through diversification. These notions explain the main changes occurring in Brazilian foreign policy from 1980 through to the mid-2000s. We will conclude by demonstrating how the autonomy through diversification best applies to the aforementioned period, acknowledging that the first two levels of Hermann's theory, adjustment change and program change, did in fact happen. We suggest that the third level, problem/goal changes, can come into effect with the consolidation and amplification of the first two levels

Data from Sullivan et al. (2020) Long-term thermal sensitivity of Earth’s tropical forests. Science. DOI: 10.1126/science.aaw7578.

ABSTRACT: The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater rate of decline in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate

Comenta&#769;rios a uma sentenc&#807;a anunciada : o processo Lula

“Comentários a uma sentença: o Caso Lula” é talvez o mais importante documento jurídico publicado no Brasil em décadas. A presente coletânea de artigos nasceu de um movimento espontâneo e bastante significativo de juristas brasileiros e estrangeiros que examinaram cuidadosamente a sentença proferida no âmbito do processo que tramitou na 13ª Vara Federal de Curitiba, no caso que ficou conhecido na mídia como o do “tríplex do Guarujá”. <br>De la presentación de Geraldo Prad