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Item type:Publicação, New frontiers in Amazonian Hypocreales (Ascomycota): from endophytism in Ophiocordyceps to novel spider-killing species(Instituto Nacional Pesquisas da Amazônia - INPA, 2025) Alves Júnior, Tales; Zartman, Charles Eugene; Araújo, João Paulo Machado de; Góes Neto, Aristóteles; Pereira, Thairine MendesThe Amazon Rainforest, renowned for its species megadiversity, exhibits vast potential for studying underexplored biological interactions, such as cross-kingdom association networks. Therefore, studies aiming to broaden the scope of our understanding of the taxonomy and ecology of hyperdiverse groups such as fungi, are fundamental to reconstructing (co)evolutionary histories and comprehending ecosystem functioning. Based on the assumption that certain Hypocrealean fungi, like the genus Ophiocordyceps, could also inhabit bryophytes via an endophytic lifestyle, and that fungal diversity is underestimated, this dissertation aimed to investigate the taxonomic and ecological diversity of fungi from the order Hypocreales (Ascomycota) within the Adolpho Ducke Forest Reserve (Manaus/AM), exploring the ecology of entomopathogenic and the taxonomy of araneopathogenic fungi. The first chapter investigated, through DNA metabarcoding, the presence of a dual lifestyle (endophytic-entomopathogenic) for fungi within the genus Ophiocordyceps, also known as the "zombie-ant fungi." The results revealed, for the first time, structured fungal communities within Amazonian bryophytes and the co-occurrence of identical or similar Ophiocordyceps lineages in both infected insects and the bryophytes, even those not associated with fungus-killed insects. This finding strongly supports the hypothesis that Ophiocordyceps possesses an endophytic lifestyle, challenging its historical classification as an obligate insect parasitoid. The second chapter focused on the taxonomic description of a new species of spider-parasitizing fungus, named Hevansia duckeana (Cordycipitaceae), based on morphological and ecological evidence. This discovery represents the first record of the genus Hevansia outside of Asia and Oceania, significantly expanding its known geographic distribution. Collectively, the findings challenge the view of Ophiocordyceps as an exclusive insect pathogen, suggesting that bryophytes might serve as an alternative niche within a complex coevolutionary framework, while also expanding our knowledge of Neotropical fungal diversity. Our study reinforces the Amazon as an inexhaustible frontier for mycology, underscoring the urgency of studies aimed at investigating its biological interactions to understand and justify the conservation of this tropical forest.Item type:Publicação, Mapeamento da severidade de incêndios florestais, perdas de carbono e análise das variáveis da paisagem que influenciam a sua ocorrência em uma área da Amazônia Central(2025) Ramos, Camila Julia Pacheco; Fearnside, Philip Martin; Graça, Paulo Maurício Lima de AlencastroThere are estimates that forest fires in the Amazon will become more intense and frequent, with the increase in severe droughts and the existence of different ignition sources, such as deforestation and agricultural fire management. The central Amazon is known for having relatively preserved forest areas, compared to those near the “deforestation arc”. However, in 2015, a year of intense ‘El Niño’, it was observed that large areas were burned in this region. The main objective of this study was to analyze the spatial and temporal dynamics of forest fires and their impacts on the forest in an area of the Negro-Solimões interfluve. To this end, the decision thresholds of the ∆NBR spectral index were adjusted to map the severities of these fires. The “Normalized Burn Ratio” (NBR) spectral index, which uses the near-infrared and short-wave infrared bands, was created for mapping burned areas and is one of the most widely used indices worldwide, including in the Amazon. The adjustment was made with data collected in the field from areas with different severities, hemispherical photographs of the forest canopy, and Landsat images. Radiometric normalization was performed before calculating the ∆NBR. PRODES data were used to help construct the deforestation masks. Forest fires were mapped from 1995 to 2021. To assess the influence of environmental variables, land and river access routes, land cover, and land tenure on the spread of fire across the landscape, the Weight of Evidence Coefficients statistical method was used in the Dinamica EGO software. The Maximum Cumulative Water Deficit (MCWD) was also calculated. To assess changes in forest structure, a forest inventory was carried out with 5 plots (0.25 ha each) in each of the four severity classes, ‘Unchanged’, ‘Low’ (LS), ‘Moderate’ (MS) and ‘High Severity’ (HS). Tree individuals were divided into forest compartments such as live trees, dead trees, trees without canopy, live palms, dead palms and woody residues. Canopy openness data were also collected. The agreement between the field severity classification and the classification based on the thresholds adjusted for the ∆NBR spectral index was satisfactory (overall accuracy = 74.2%; Kappa coefficient = 0.635). If the classic Key & Benson thresholds were used, the fire severity classification would be underestimated. For the temporal analysis, the years with the most fires were those with El Niño events, 1997 (4,179 ha), 2009 (1,843 ha) and 2015 (17,475 ha). There was little repetition of burned areas, with 95%, 4% and 0.08% burning once, twice and three times, respectively. For 2015, the year with the largest burned area, 60.7%, 19% and 20% were classified as MS, HS and LS, respectively. The MS class has approximately 33% of canopy openness. Although 2015 had the largest burned area, its MCWD (-181 mm) was smallerr than that of 1997 (-235 mm) and 2009 (-224 mm), indicating that, among the variables analyzed in addition to drought, factors such as slope, proximity to roads and watercourses, indigenous lands and conservation units also influence the occurrence of fires. The severity classes respond similarly to the influence of the variables. The total dry biomass stock for Unchanged was 242 (± 60) Mg ha-1. The mortality rate was 29.4, 49 and 88.6% for LS, MS and HS. The largest committed CO2 emission occurred in 2015, 3,966 Gg CO2. Most of this emission occurred in MS (2,241 Gg CO2), the class that had the largest burned area. The results of the threshold adjustment corroborate the importance of this adjustment for each study area to classify fire severity using ∆NBR. Areas of the central Amazon that are considered relatively well preserved are subject to large losses due to forest fires during a severe drought event, even with relatively constant deforestation rates. The classification of fire severity contributes to improving estimates of carbon emissions and the impacts of fire on the structure of the Amazon forest.Item type:Publicação, Estudo fitoquímico das plântulas e avaliação da sazonalidade sobre o teor de metabólitos secundários em Duroia macrophylla Huber (Rubiaceae)(Instituto Nacional Pesquisas da Amazônia - INPA, 2023) Carvalho, Amanda Bezerra; Nunez, Cecilia VeronicaThe Rubiaceae family is renowned as one of the most species-rich families within the Amazon rainforest. With a predominantly tropical distribution, it harbors a plethora of secondary metabolites, encompassing iridoids, anthraquinones, triterpenes, and indole alkaloids among others. Notably, the species Duroia macrophylla Huber stands out due to its substantial abundance of secondary metabolites, particularly notable for their antituberculosis and antitumor activities. Previous research conducted by our group has unveiled discrepancies in the levels of these secondary metabolites, varying in accordance with environmental conditions and seasonal variations, albeit requiring further substantiation. The current study endeavors to scrutinize the secondary metabolite content of Duroia macrophylla Huber collected across diverse locales and timeframes, alongside an assessment of the phytochemical profile of extracts derived from in vitro-cultivated seedlings. Extracts obtained from leaves, stems, and roots of in vitro plant material were extracted using methanol and subjected to analysis utilizing ¹H Nuclear Magnetic Resonance (NMR) spectroscopy. These extracts were subsequently fractionated via open column chromatography, facilitating the isolation of the methyl ester of monotropein iridoid and another potentially nitrogenous compound, albeit characterization was impeded due to its diminished mass. To scrutinize the secondary metabolite content, leaves and branches were harvested from four distinct individuals at three-month intervals over a span of one year: situated within the Adolfo Ducke Reserve (Individuals 1 and 2), ZF-2 (Individual 3), and INPA (Individual 4). Three of these individuals were mature (1, 2, and 3), while one was juvenile (Individual 4), from which root samples were additionally procured, yielding a total of 36 extracts. The ¹H NMR spectra of these extracts were processed to accommodate FID processing, phase adjustments, and baseline alignment, with delineations of regions of interest performed utilizing the iSTATS software and subsequently analyzed via the Metaboanalyst software to glean chemometric insights encompassing PCA, k-means, and PLS-DA analyses. Two distinct analyses were conducted: one entailing spectral "whole" spectrum cuts, excluding regions encompassing sugars and "grease", alongside the solvent signal; and another scrutinizing solely the most shielded hydrogen atoms. In assessing the complete spectrum, the most pronounced differentiation amidst the samples was observed within leaf extracts, particularly evident within PLS-DA analyses where substantial sample segregation was noted, hinting at disparate metabolite content contingent on the sampling months. Conversely, branch extracts demonstrated greater internal coherence, while root extracts from individual 4 exhibited minimal correspondence with other samples, barring intragroup resemblances. Albeit no overt pattern of sample similarity was discerned within chemometric analyses of unprotected hydrogen regions, the PCA model, facilitated through k-means clustering, emerged as the most apt, elucidating distinct groupings predicated upon the plant parts procured: leaves and branches. Notwithstanding these analyses, it remains apparent that the extracts indeed manifest varying secondary metabolite levels, albeit a definitive pattern elucidating secondary metabolite seasonality remains somewhat elusive.Item type:Item, Emergência climática e a sociobiodiversidade amazônica(2025-11-06) fernanda p. werneck; Felipe Zanusso; Jordana Guimarães FerreiraItem type:Pessoa,