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Submissões Recentes
Rede de restauração agroecológica de paisagens e florestas: uma tecitura que se faz a muitas mãos
(Universidade Federal de Viçosa, 2025-03-31) Alvares, Bráulio Furtado; Cardoso, Irene Maria; http://lattes.cnpq.br/0987395900991283
Para reverter o cenário das emergências climáticas iniciativas como a Década de Restauração de Ecossistemas das Nações Unidas, ou no Brasil, o Pacto Pela Restauração da Mata Atlântica, têm metas ambiciosas de restauração. Entretanto, a restauração não ocorrerá de forma justa e duradoura sem a contribuição daqueles que vivem nos territórios. A pesquisa procurou responder às seguintes perguntas a partir da pesquisa participante: quais são e onde se localizam as experiências de restauração desenvolvidas a partir de inovações camponesas na Zona da Mata? Quais as características destas experiências? Quais são e como se dão os arranjos entre as instituições envolvidas na restauração ecológica e agroecologia na região? É possível identificar inovações camponesas e redes sociotécnicas capazes de desencadear novos processos de restauração agroecológica de paisagens e florestas no território? É possível ampliar a recuperação das paisagens e florestas a partir da restauração agroecológica? O primeiro capítulo, “Agroecossitemas restaurados a partir de inovações camponesas agroecológicas”, objetivou identificar, descrever e analisar experiências reconhecidas de restauração agroecológica de agroecossitemas e identificar como elas podem contribuir para o aumento da escala da restauração de paisagens e florestas. Estudou-se cinco agroecossitemas restaurados a partir de inovações camponesas agroecológicas na região Zona da Mata de Minas Gerais, considerada Polo Agroecológico e de Produção Orgânica. Entrevistas semiestruturadas e caminhadas transversais permitiram identificar o contexto socioambiental das pessoas envolvidas na restauração dos agroecossitemas visitados e suas motivações para a transição agroecológica e a importância de suas participações nas atividades do movimento agroecológico. O movimento levou a transformações pessoais, sociais e ambientais que resultaram na restauração agroecológica dos agroecossistemas. A restauração agroecológica de paisagens e florestas é capaz de contribuir com as metas Globais a partir dos territórios. São várias as trilhas para a restauração agroecológica identificadas, que passam pela eliminação do uso de agrotóxicos, o manejo da biodiversidade e a adoção de práticas de conservação do solo e da água. O segundo capítulo, “Tecendo uma rede de restauração agroecológica de paisagens e florestas”, objetivou modelar e estudar o potencial de redes de instituições organizações de restauração ecológica e agroecológica em contribuir para desencadear processos duradouros de restauração de paisagens e florestas. Utilizou-se do método bola de neve para identificar e entrevistar informantes chave de 30 organizações que forneceram informações para modelar em ambiente R a rede Completa, formada por essas organizações informantes e as parceiras informadas. A análise das métricas de centralidade da rede Completa definiu as organizações mais influentes, sendo elas, o Núcleo de Educação do Campo e Agroecologia da Universidade Federal de Viçosa, o Centro de Tecnologias Alternativas da Zona da Mata, o Instituto Socioambiental de Viçosa e The Nature Conservancy Brasil. A partir dessas organizações modelou-se uma nova rede denominada Coração e a análise de suas métricas de centralidade revelou equilíbrio na distribuição de influência entre as quatro organizações centrais. Técnicas de mineração de texto foram utilizadas para o estudo dos campos e modos de atuação das organizações. A agroecologia foi o termo mais citado entre as palavras geradoras e observou-se que há um alinhamento das organizações com a proposta da restauração agroecológica. A Rede de Restauração Agroecológica de Paisagens e Florestas do Polo tem potencial para desencadear ciclos de restauração agroecológica. O apoio às redes sociotécnicas dos territórios é importante para a construção de políticas públicas que incentivem, a partir deles, a transição agroecológica no contexto da restauração agroecológica de paisagens e florestas. Palavras-chave: inovação socioecológica; inovação camponesa; rede sociotécnica; trilhas para a restauração; Polo Agroecológico
Comparative cytogenomics of the repeatome landscape in Capsicum L.
(Universidade Federal de Viçosa, 2025-03-21) Almeida, Breno Machado de; Clarindo, Wellington Ronildo; http://lattes.cnpq.br/1573949472165597
Capsicum L. (Solanaceae) comprises ~43 species, which are represented by sweet and hot peppers. Capsicum repeatome impacts its genome structure and diversity, as the nuclear 1C value and chromosome composition and organization that varies among the species. In this context, we aim to characterize and map the repeatome in Capsicum species. The first chapter presents an updated and in-depth review of the structural genome and the epigenome of Capsicum. We revisited data about 1C value, karyotype, sequencing, and cytogenomics mapping of 35S and 5S rDNA, satellite DNA (satDNA), transposable elements (TEs) and histone post-translational modification marks. These data were integrated into an ideogram for each chromosome, allowing a better understanding of the composition, structure, organization and evolution of the Capsicum karyotypes. Furthermore, we highlighted the main gaps and challenges related to 1C value measurement, genome sequencing of domesticated and wild species, comparative cytogenomics (rDNA, satDNA and TEs), and the epigenomic landscape. The second chapter was dedicated to the 1C value measurement, in silico analysis and comparative genomics of 35S and 5S rDNA, and LINEs RTE, LINEs L1, SINEs, ERVs, MULEs in Capsicum. The mean 1C value of C. annuum, C. chinense, C. frutescens, C. baccatum, C. pubescens, C. rabenii and C. flexuosum was measured, confirming the intraspecific variation from C. chinense with 1C = 3.96 ± 0.124 pg to C. flexuosum with 1C = 8.40 ± 0.251 pg. Capsicum 35S rDNA sites by 2n complement ranged from 2 (C. annuum and C. chinense) to 15 (C. baccatum), also varying the fluorescence signal intensity. In contrast, only one pair with 5S rDNA was mapped in the distal portions of the short arms of the C. annuum, C. chinense, C. frutescens, and C. baccatum chromosomes. The investigated TEs (LINEs RTE, LINEs L1, SINEs, ERVs, MULEs) proportions also oscillated among the Capsicum genomes: 1.26% in C. annuum, 1.0% in C. chinense and 0.99% in C. baccatum. SINEs, ERVs and MULEs were grouped into three distinct clusters, while LINEs RTE and LINEs L1 formed a single cluster, as revealed by MDS projection. In general, TEs exhibited scattered signals along the chromosomes. Moreover, hybridization signals were observed in the centromere and pericentromere, as well as in interstitial and distal chromosome regions. This study reinforces the value of Capsicum as a model for exploring repetitive DNA in cytogenomic and evolutionary contexts. Our data not only illuminates genome organization through integrated molecular, cytogenetic, and bioinformatic approaches but also serves as a key resource for in silico cytogenomics and comparative repeatome research in plants, particularly in the genus Capsicum. Keywords: Peppers; Molecular Cytogenetics ; FISH; Genomics; Repeatome ; Mobile Elements.
Toxicity assessment of pesticides and biopesticides on wild and managed bees (Hymenoptera, Apoidea), and richness evaluation in mediterranean and tropical agroecosystems
(Universidade Federal de Viçosa, 2025-02-21) Catania, Roberto; Siqueira, Maria Augusta Lima; http://lattes.cnpq.br/8921922664198131
Bees (Hymenoptera, Apoidea) are the main pollinator insects for wild and cultivated plants, being of crucial environmental and economic importance. Their global decline, driven by anthropogenic factors, including the use of synthetic pesticides, is an alarming concern. Biopesticides can be a viable alternative for the protection of cultivated plants due to their high selectivity and short environmental persistence. Despite their natural origin, biopesticides can cause lethal and sublethal effects on non-target organisms. During this PhD project, we studied the toxicity of synthetic pesticides and biopesticides on wild and managed bees, using different products marketed in Mediterranean and tropical areas, and some nanoformulations of essential oils (EOs) tested on pests but not yet commercialized. Lethal and sublethal effects caused by pesticides commonly used in Italian and Brazilian agroecosystems, including greenhouses, were evaluated, with particular attention to some biopesticides of botanical origin, such as EOs. Synthetic and botanical pesticides caused lethal and sublethal effects on social (honeybees, bumblebees, Neotropical stingless bees), and solitary bees. Specifically, EOs caused lethal effects after topical and oral exposure to Apis mellifera, Bombus terrestris, Osmia bicornis, and Melipona mondury. Changes in feeding behavior and locomotor alterations caused by exposure to EOs were observed on the stingless bee M. mondury. Commonly used pesticides and biopesticides caused reduced survival of ground-nesting wild bees of Andrena and Eucera species, and altered the locomotor behavior of managed bees. Synthetic insecticides used to protect greenhouse tomato plants reduced the survival and caused changes in feeding behavior, and midgut alterations in B. terrestris. These results may be important for the appropriate use of pesticides and biopesticides in integrated pest and pollinator management, providing crucial data for the conservation of pollinating insects. In addition, populations of wild bees were studied in two tree crops in Southern Italy, one Mediterranean (almond) and one tropical (mango), comparing species richness and abundance between integrated and organic management. Keywords: ecotoxicology; social bees; solitary bees; lethal effects; sublethal effects; essential oils; management; almond; mango exposure; integrated pest and pollinator.
Developing novel natural and synthetic tools for a more sustainable management of Euschistus heros (Hemiptera: Pentatomidae)
(Universidade Federal de Viçosa, 2025-02-20) Francesco, Leonardo Semençato; Oliveira, Eugênio Eduardo de; http://lattes.cnpq.br/4889276299285924
Chemical control is the primary strategy for managing Euschistus heros in soybean production. However, excessive use of synthetic insecticides raises concerns about resistance development and impacts on non-target organisms, such as natural enemies and pollinators. This study evaluated essential oils and biorational molecules as sustainable alternatives. The essential oils of Minthostachys verticillata (peperina) and Pelargonium graveolens (rose geranium) were tested alongside the synthetic butenolide K16 for their toxicity against third instar nymphs of E. heros and selectivity toward Telenomus podisi and Apis mellifera. In order to determine their insecticidal potential, lethal concentrations (LC) were estimated for each treatment. For P. graveolens essential oil, the LC50 was 1,784 µL/L (?2= 4.1627, P = 0.2444), and the LC80 reached 5,368 µL/L. For M. verticillata essential oil, the LC50 was 2,483 µL/L (?2= 1.9762, P = 0.3723), and the LC80 was 5,365 µL/L. In addition, to parasitoid T. podisi, P. graveolens EO caused 0.83% mortality at LC10, 32.36% at LC50, and 83.86% at LC80. M. verticillata EO, resulted in 0.83%, 21.4%, and 75.18% mortality at the same concentrations, respectively selectivity only up to LC50. For the pollinator A. mellifera, LC80 mortality in the first five hours was 60.24% for P. graveolens and 31.39% for M. verticillata, with no mortality in the control group. The synthetic butenolide K16 showed strong insecticidal activity in a dose-dependent manner. The LC20 was 181.47 µg/L, LC50 was 423.48 µg/L, and LC20 reached 988.23 µg/L. K16 demonstrated selective toxicity, with Telenomus podisi showing no significant mortality at LC20 (P = 0.0014) but reaching 100% mortality at LC80 (P = 1), indicating loss of selectivity at higher concentrations. In Apis mellifera, mortality increased from 6.67% at LC20 to 28.33% at LC80, highlighting potential risks to pollinators. These results suggest that essential oils and butenolide-based molecules are potential alternatives to conventional insecticides. However, optimizing their application is crucial to minimize risks to beneficial organisms. Future research should focus on improving formulations, reducing environmental persistence, and evaluating field-scale efficacy to enhance sustainable pest management. Keywords: sustainable pest control; non-target organisms; selective toxicity; soybean insect management.
Drivers of ecosystem functioning in secondary tropical forests: the roles of carbon stocks, endemic species, and anthropogenic disturbance
(Universidade Federal de Viçosa, 2025-12-05) Silva, Nathália; Meira Neto, João Augusto Alves; http://lattes.cnpq.br/1814298753509846
Understanding the mechanisms that structure biodiversity and determine carbon stocks in tropical forests is central in the face of global change, fragmentation, and intensified anthropogenic disturbances. In this thesis, we investigate the functional, phylogenetic, environmental, and anthropogenic determinants of carbon stocks and the functional diversity of endemic and threatened species in secondary forest fragments of the Atlantic Forest, one of the most endangered biomes on the planet. We used data from 23 fragments, where tree communities were sampled with information on functional traits, phylogenetic structure, and biomass, integrated with environmental variables and disturbance history. In Chapter 1, we evaluate how the mechanisms of niche complementarity and mass ratio regulate aboveground carbon stocks (AGC) and how abiotic factors and anthropogenic disturbances modulate these processes. We hypothesize that (1) the mass ratio mechanism will exert a greater influence on AGC; (2) aboveground carbon stocks will be positively related to environmental factors widely associated with increased productivity and biomass accumulation in tropical forests, such as higher temperature, water availability, and soil fertility; and (3) the influence of ecological mechanisms on carbon stocks will depend on levels of anthropogenic disturbance. In areas with low disturbance, we expect that niche complementarity will play a predominant role, since reduced anthropogenic pressure and greater ecological niche availability can support the coexistence of diverse functional strategies that promote biomass accumulation. Conversely, in highly disturbed areas, the mass ratio mechanism may exert a stronger influence on carbon stocks, as disturbance can select for more resilient or tolerant functional strategies. In Chapter 2, we expand the analysis to explore multiple carbon compartments (AGC, root biomass carbon – RC, and soil organic carbon – SOC), aiming to understand how functional diversity, trait dominance, phylogenetic diversity, and environmental and anthropogenic gradients interact to shape these stocks. We hypothesize that aboveground carbon stocks will be primarily influenced by water availability, soil fertility and functional structure of plants, with communities dominated by species with conservative traits storing more biomass and carbon aboveground. In addition, we expect phylogenetic diversity to have a positive effect on AGC through complementarity and niche partitioning. For root carbon, in addition to sharing similarities with environmental conditions favorable for AGC, since it also represents live biomass, we expect stronger associations with acquisitive functional strategies of plants, since fine roots need to cope with resource fluctuations in the soil. For soil organic carbon, we predict stronger associations with climatic seasonality and edaphic factors, since litter decomposition is constrained during dry periods and organic matter stabilization is favored, and it also appears to be reinforced by resource-conserving strategies that promote stabilization and generate more recalcitrant litter inputs. Finally, in Chapter 3, we explore the role of endemic and threatened species in the functional diversity of secondary tropical forests, evaluating their distribution in functional space and the potential consequences of their loss. We hypothesize that these groups occupy restricted subsets of functional space with more conservative strategies, and that their exclusion would reduce functional richness and dispersion, increasing the regularity of trait distribution. Together, the three chapters provide evidence that maintaining diversity and functional structure is fundamental to sustaining carbon stocks and ecosystem functions in Atlantic Forest remnants, highlighting the importance of conservation strategies that integrate biodiversity, key groups, the influence of anthropogenic degradation, and multiple carbon compartments. Keywords: ecosystem functioning; biodiversity conservation; trait-based ecology