ABSTRACT Background: The Amazon rainforest plays an essential role in sheltering global biodiversity and providing essential ecosystem services. However, the region has been threatened by increased rates of deforestation and degradation, which is often reported as the failure of the Brazilian conservation policy that could affect the image of agriculture Brazilian products abroad. In this sense, here we aimed to evaluate the foreign environmental perception of the region using data from social medias, to assess which are the main terms related to the region, how their importance varies over time and whether this perception tends to be more negative or positive. For this, we used data from posts made on Twitter® involving the term “Amazon rainforest” over 18 weeks using a data mining process. From these posts, we extracted the text, which went through steps of cleaning and organization, as well as crossing with additional databases (such as the sentiment dictionary). From the final data set, we first evaluated which are the main terms present in these posts and how their importance varied in the evaluated period. Next, we assess whether the terms cited are mainly negative or positive and how this sentiment varied over the monitoring period. Results: We found that the main terms are related to the environmental context such as “carbon”, “deforestation” and “fire” and that there is a relationship between their importance and the occurrence of fires in the region, which is positive with a temporal lag. In addition, we also found that the posts are, on average, composed of 68.47% of negative terms and that this sentiment predominates throughout the entire time series, being higher during the fire peaks in the region. Conclusion: Our results indicate that the environmental perception of the region presented in the posts in Twitter® is mainly negative, due to the degradation and fires observed over the last few years. We also discuss limitations of the approach and establish perspectives for future work.

ABSTRACT Background: Brazil Nuts (BN) tree is a species of high importance in Amazon region. Their continuous use by traditional communities is often related to disturbances that lead to larger degraded areas where this species is commonly found (“BN groves”). Here we aimed to explore the ecological patterns of BN groves vegetation and its relationship with BN trees and evaluate their potential as a source of carbon credits. We sampled 15 circular plots, with Brazilian Nut trees as the center (focal trees) and collected morphometric data from the focal trees. Additionally, we evaluated fruit production for a period of 5 years to obtain annual measurements, which were used as a proxy of the anthropic impact associated with the collection process. Through analysis of the data, we: i) examined the effects of BN trees on the adjacent vegetation; ii) quantified the potential amount of carbon credits in the adjacent vegetation and in the focal trees by converting carbon stock to equivalent CO2. Results: The adjacent vegetation structure was influenced by the size of BN trees (focal trees). No important effects of BN trees on the adjacent vegetation floristic composition and functional attributes were found. Additionally, we found that Brazilian Nut groves possess a significant potential for carbon credits that could be leveraged in the future carbon credit market, Conclusion: The study highlights the potential for carbon credit generation in Brazil nut groves in the Southeast Amazon as a means of supporting conservation and restoration efforts in these environments.

ABSTRACT Our research focused on the reproductive phenology of Mauritiella armata, a key veredas species in southeastern Brazil, and aspects of its floral and fruit morphology and sexual system. We observed the reproductive phenological patterns of M. armata for 36 months, and examined the relationships between phenophases and environmental variables to describe its phenological patterns in relation to environmental filters, as well as its floral and fruit morphologies, sexual system (to evaluate dioecy), and the biometry of its reproductive parts. Flowering was observed in the dry season and at the beginning of the rainy season, with fruiting occurring during the rainy season. The reproductive phenophases responded to environmental seasonality, principally temperature in the period immediately preceding the expression of the phenophase, as well as to environmental variations that had occurred up to six months earlier. The dioecious sexual system of M. armata was confirmed, with flowering synchronization between the sexes. The population studied did not exhibit apomixis, having xenogamy as its reproductive system. The staminate inflorescences were larger than the pistillate inflorescences and had greater numbers of flowers, although the pistillate flowers were larger. Wind pollen dispersal was not observed, thereby indicating that this species requires biotic pollination for fruit production.

Abstract Currently, protected areas around the world have a demand for volunteer work. At the same time, people in several countries that house protected areas seek out these spaces to serve as volunteers. This process occurs in a scenario strongly influenced by the neoliberal economy, which is marked by cuts in environmental management budgets and increased protected areas visitation. Based on this context, the objective was to analyze the role of volunteer work in protected areas in the context of neoliberal paradigm predominance. For this purpose, it was established a current overview of volunteer activity through a case study in Brazil by collecting information from volunteers and managers, heads or managers of protected areas receptive to volunteer work in interviews using structured questionnaires. It was found that Parques Nacionais are the categories with the greatest demand for volunteer work. It was also found the most part of volunteers is between 20 and 30 years old, and their education level is higher education in undergraduate courses related to biological sciences. It was identified significant differences between the perceptions of managers and volunteers about volunteer work objectives. However, both groups indicated that “Environmental education/environmental interaction and interpretation” and “Support for visitation” are the most frequently performed activities, and the main form of support and trade-off for volunteer work is the offering of certificates. Thus, volunteer work seeks to contribute to the protected areas objectives by supporting the management of these areas during public use activities. However, in the current scenario, this work is palliative in the face of the impacts of the dismantling of environmental policy that affects most countries that have Protected areas and have surrendered to neoliberal conservation.

ABSTRACT Background: Seasonally Dry Tropical Forests (SDTF) are recognized by their great biological diversity, but little is known about their temporal patterns, which may be crucial in a changing world. Here we aimed to characterize the SDTF dynamic patterns in floristic and structural changes, and also to evaluate shifts in dynamic rates and structural attributes such as richness, number of trees and biomass. Our hypothesis is that SDTF tree communities have their dynamic characterized by temporal fluctuations related to an instability pattern, in according to the already found for others tropical forests. For this we used a data of 42 400 m² plots in three fragments in the Brazilian Arboreal Caatinga, measured in 2005, 2010 and 2015. We evaluated temporal changes in richness, species composition, trees density, biomass and rates of tree mortality and recruitment; and also rates of biomass gain and loss. Results: We found a pattern of floristic composition stability, but with changes in structure and dynamics. There was a tree density decrease driven by constant mortality and by recruitment decrease, and biomass increase due to decrease in biomass loss and to increase in biomass gain. The biomass increase was main related to a small set of dominant species that are the most representative in the community dynamics. Conclusion: SDTF dynamics are related to stability in species composition, but with structural changes towards higher biomass stocks. The results are main related to community dynamics and to SDTF attributes such as climatic seasonality that drives the local ecological processes.

Resumo As novas condições ambientais impostas por eventos de distúrbios criam um mosaico de manchas em diferentes estágios sucessionais. Nosso objetivo foi descrever a variação temporal de uma floresta estacional semidecidual em função do histórico de perturbação antrópica, verificando possíveis mudanças na dinâmica e estrutura da floresta. Nós amostramos a vegetação arbórea com diâmetro a 1,3 m do solo (DAP) ≥ 5 cm em 15 parcelas permanentes de 20 × 20 m onde realizamos quatro inventários (2003, 2005, 2007 e 2015). Nós verificamos uma diminuição da densidade e aumento da área basal, o que indica que a comunidade arbórea analisada se encontra em estágio tardio de sucessão. A estrutura fitossociológica, a riqueza e a diversidade de espécies da comunidade arbórea não apresentaram mudanças ao longo dos monitoramentos. Entretanto, o predomínio da espécie Protium spruceanum pode ser uma resposta às mudanças ambientais provocadas pela mineração que ocorreu na área há 250 anos. As influências duradouras dos distúrbios antrópicos tornam este tipo de trabalho imprescindível por permitir a compreensão dos processos ecológicos, possibilitando um gerenciamento factual das florestas pelo manejo e conservação efetivos.

Abstract The new environmental conditions imposed by disturbance events often create a mosaic of spots in different successional stages. Our objective was to describe the temporal variation of a semideciduous seasonal forest based on its anthropic disturbance history, verifying possible changes in forest dynamics and structure. We sampled the arboreal vegetation with a diameter at breast height (1.3 m above the ground; DBH) ≥ 5 cm in 15 permanent plots of 20 × 20 m where we performed four inventories (2003, 2005, 2007 and 2015). We observed a density decrease and a basal area increase, which indicates the late successional stage of the analyzed tree community. The phytosociological structure, richness and species diversity of the tree community did not show changes throughout the monitoring. However, the Protium spruceanum predominance may be a response to the environmental changes caused by the mining occurred in the area 250 years ago. The anthropic disturbances enduring influences make this type of work indispensable because it allows the ecological processes understanding, allowing a factual management of the forests by the its effective management and conservation.

ABSTRACT The objective of this work was to evaluate if the soil heterogeneity expressed by the different soil classes would condition tree communities with different dynamic behaviors. The data were collected from 25 plots sized 20 × 20 (400 m²), 10 of them with Inceptisols, 9 with Ultisols, 5 with Entisols B and 1 with Entisols A. All individuals with DBH ≥ 5.0 cm in the plots were sampled in 2000, 2005, 2009 and 2015. Rates of mortality, recruitment, gain, loss and turnover dynamics in number of individuals and basal area were estimated for each soil class. The tree communities present in the soil classes showed no differences in the dynamic behavior to the point of expressing edaphic fragment heterogeneity. The differences are associated with stochastic fluctuations in rates caused by small disturbances, suggesting little influence of the soils on the dynamics of small-scale communities.

RESUMO Este trabalho teve como objetivo analisar a ocorrência de processo sucessional em uma floresta madura, utilizando para isto a distribuição das árvores em fases de desenvolvimento. O fragmento estudado consiste em uma floresta estacional semidecidual em estágio avançado de recuperação com cerca de 11 ha, localizado as margens do Rio Capivari no município de Lavras, estado de Minas Gerais, Brasil. A coleta de dados ocorreu nos anos de 1998, 2003, 2009 e 2014, nos quais foram mensurados e identificados em nível de espécie todos os indivíduos arbóreos que atingiram o critério de inclusão preestabelecido (circunferência a 1,3 m do solo - CAP≥15,7 cm). A partir destes dados foram obtidos os valores de riqueza para cada uma das quatro fases estabelecidas com base em critérios de circunferência (Juvenis, Preestabelecidos, Estabelecidos e Emergentes), bem como informações sobre rotatividade de espécies, estrutura, composição florística e compartilhamento entre essas fases. Os resultados indicaram a inexistência de diferenças temporais quanto à estrutura e distribuição da riqueza em fases de desenvolvimento. Foram observadas movimentações temporais de espécies principalmente entre as fases menores. Com relação à similaridade entre fases, ocorreu a divisão em um grupo contendo as duas menores e outro composto pelas duas maiores, nos quais a composição florística e espécies mais representativas foram mais semelhantes. Ademais, observou-se uma substituição não direcional das espécies mais representativas de cada fase, provavelmente relacionado a não correspondência entre ciclos de vida das populações. Assim, a ocorrência de modificações temporais nos padrões de riqueza na floresta indica a existência de processos sucessionais dinâmicos em uma comunidade em estágio clímax.

ABSTRACT This study aimed to test the occurrence of the successional process in a mature forest using the distribution of the trees in phases of development. The study forest remnant, a 11-ha old-growth seasonal forest, is located in the margins of Rio Capivari in Lavras, Minas Gerais state, Brazil. The data collection was carried out in 1998, 2003, 2009 and 2014, when we measured and identified to species level all trees that have reached the pre-established inclusion criteria (circumference at 1.3 above the ground level - CBH ≥15,7 cm). From these data, we obtained the species richness for each of the four development phases established on the basis of circumference criteria (Juvenile, Pre-established, Established and Emerging), as well as information on the species turnover, structure, floristic composition and the sharing between these phases The results indicated that there are no significant temporal differences in the structure and the distribution of species richness in development phases. Besides, we found a subtle movement of species mainly among the small phases. Concerning to the similarity among phases, we observed a clustering of the two smallest development phases and the clustering of the two largest ones, in which the floristic composition and most representative species were more similar. In addition, there was a non-directional turnover of the most representative species of each phase, probably related to a mismatch among the population life cycles. Thus, the occurrence of temporal changes in richness’ patterns can indicate the existence of dynamic succession processes in a climax stage community.

RESUMO A caatinga corresponde a um dos dois maiores núcleos das Florestas Tropicais Sazonalmente Secas (FTSS) e se encontra totalmente inserida no território brasileiro. Objetivou-se com este estudo avaliar a estrutura de dois micro-habitats relacionando-a com as variáveis ambientais. Foram alocadas 24 parcelas, nas quais mensuramos o CAP e fizemos a identificação botânica de todos os indivíduos arbóreos com CAP ≥ 10 cm. Com a presença de lajedos de calcário na área, foi possível distinguir dois micro-habitats. A CCA e a análise de espécies indicadoras mostraram uma nítida distribuição das espécies de acordo com os micro-habitats. Concluímos que a presença dos lajedos de calcário proporcionou a formação dos micro-habitats, influenciando na distribuição e composição das espécies arbustiva-arbóreas, caracterizando a unidade fitoecológica aqui denominada como “furados”.

ABSTRACT Caatinga represents one of the two major centers of Seasonally Dry Tropical Forests (SDTF) and is completely inserted in the Brazilian territory. The present work aimed to evaluate the structure of two micro-environments and relate them to environmental variables. Twenty 20 × 20 m plots were placed in which we measured the height and CBH and made the botanical identification of all trees with CBH ≥10 cm. The CCA and indicator species analysis presented a clear distribution of species according to the micro-environments. We concluded that the presence of limestone slabs provided the formation of microhabitats, thus influencing the distribution and composition of tree species, what characterized the phytoecological unit here referred as “furados”.