Volatile compounds in off-odor honey.

EN-US: Climatic conditions in the mid-northern region of Mato Grosso State in Brazil are favorable for beekeeping. However, since 2011, the honey production chain has suffered losses because the production of off-odor honey has made it impossible to market the honey. Reports from beekeepers indicated a relationship between the off-odor in the honey and the nectar of Borreria verticillata (L.) G. Mey (Rubiaceae). In this study, the botanical origins and volatile profiles of ten off-odor honeys (H1-H10) and flowers of B. verticillata were evaluated. Palynological and sensorial analyses of the honeys were performed; a scale from 1 to 4 was applied for the sensorial analysis, in which 1 indicates no off-odor and 4 indicates extreme off-odor. Analysis of volatile was performed by using headspace solid-phase microextraction and gas chromatography-mass spectroscopy methods. The honeys investigated were classified with very high to intense off-odors, except H4 and H5, which did not differ from the control honey (no off-odor). Palynological analyses showed that honeys H1-H4, H7, and H9 were monofloral from B. verticillata, whereas in H5, H6, H8, and H10 this pollen were accessory. However, there was no quantitative correlation between the B. verticillata pollen content and the off-odor attributes of the honeys. Skatole was identified in all of the honeys except H4, H5, and the control honeys, suggesting that skatole contributed to the off-odor attributes of the products. However, further studies are required to investigate the origin of the skatole because it is not transferred directly from B. verticillata flowers to the honey. | PT-BR: As condições climáticas da região Centro-Norte do Estado de Mato Grosso são favoráveis a apicultura, contudo ocorrem prejuízos nesta cadeia produtiva desde 2011 devido a produção de mel com odor indesejável, o que impossibilitou sua comercialização. Relatos dos apicultores apontaram relação da ocorrência do odor indesejável no mel com o néctar Borreria verticillata (L.) G. Mey (Rubiaceae). Neste estudo foi avaliado a origem botânica e o perfil de voláteis de méis (M1 até M10) com odor indesejável e das flores de B. verticillata. Foi realizada a análise polínica do mel e também sensorial, empregando-se uma escala de um a quatro pontos, em que um refere-se a nenhum odor desagradável e quatro, extremo odor desagradável. A análise de compostos voláteis no mel e nas flores de B. verticillata foi realizada utilizando microextração em fase sólida por headspace e cromatografia gasosa acoplada a detector por espectrometria de massas. Os méis investigados foram classificados desde muito a extremo odor desagradável, exceto os méis M4 e M5, que não diferiram do mel controle (sem odor indesejável). Os méis M1 até M4, M7 e M9 eram monoflorais de B. verticillata, enquanto M5, M6, M8 e M10 o pólen B. verticillata era acessório. Todavia, não foi observada correlação quantitativa entre o teor deste pólen e o atributo odor indesejável. O escatol foi identificado nos méis investigados, exceto em M4, M5 e mel controle. Estes resultados sugerem que o escatol contribuiu para o atributo odor desagradável do produto. Contudo, mais estudos devem ser conduzidos para investigar a origem do odor indesejável, porque o escatol não foi transferido diretamente das flores para o mel

Brazilian montane rainforest expansion induced by Heinrich Stadial 1 event

The origin of modern disjunct plant distributions in the Brazilian Highlands with strong floristic affinities to distant montane rainforests of isolated mountaintops in the northeast and northern Amazonia and the Guyana Shield remains unknown. We tested the hypothesis that these unexplained biogeographical patterns reflect former ecosystem rearrangements sustained by widespread plant migrations possibly due to climatic patterns that are very dissimilar from present-day conditions. To address this issue, we mapped the presence of the montane arboreal taxa Araucaria, Podocarpus, Drimys, Hedyosmum, Ilex, Myrsine, Symplocos, and Weinmannia, and cool-adapted plants in the families Myrtaceae, Ericaceae, and Arecaceae (palms) in 29 palynological records during Heinrich Stadial 1 Event, encompassing a latitudinal range of 30°S to 0°S. In addition, Principal Component Analysis and Species Distribution Modelling were used to represent past and modern habitat suitability for Podocarpus and Araucaria. The data reveals two long-distance patterns of plant migration connecting south/southeast to northeastern Brazil and Amazonia with a third short route extending from one of them. Their paleofloristic compositions suggest a climatic scenario of abundant rainfall and relative lower continental surface temperatures, possibly intensified by the effects of polar air incursions forming cold fronts into the Brazilian Highlands. Although these taxa are sensitive to changes in temperature, the combined pollen and speleothems proxy data indicate that this montane rainforest expansion during Heinrich Stadial 1 Event was triggered mainly by a less seasonal rainfall regime from the subtropics to the equatorial region.This work was funded by FAPESP research grant 2015/50683-2 to P.E. De Oliveira, VULPES Project, Belmount Forum

Beyond Refugia: New insights on Quaternary climate variation and the evolution of biotic diversity in tropical South America

Haffer’s (Science 165: 131–137, 1969) Pleistocene refuge theory has provided motivation for 50 years of investigation into the connections between climate, biome dynamics, and neotropical speciation, although aspects of the orig- inal theory are not supported by subsequent studies. Recent advances in paleocli- matology suggest the need for reevaluating the role of Quaternary climate on evolutionary history in tropical South America. In addition to the many repeated large-amplitude climate changes associated with Pleistocene glacial-interglacial stages (~40 kyr and 100 kyr cyclicity), we highlight two aspects of Quaternary climate change in tropical South America: (1) an east-west precipitation dipole, induced by solar radiation changes associated with Earth’s precessional variations (~20 kyr cyclicity); and (2) periods of anomalously high precipitation that persisted for centuries-to-millennia (return frequencies ~1500 years) congruent with cold “Heinrich events” and cold Dansgaard-Oeschger “stadials” of the North Atlantic region. The spatial footprint of precipitation increase due to this North Atlantic forcing extended across almost all of tropical South America south of the equator. Combined, these three climate modes present a picture of climate change with different spatial and temporal patterns than envisioned in the original Pleistocene refuge theory. Responding to these climate changes, biomes expanded and contracted and became respectively connected and disjunct. Biome change undoubtedly influenced biotic diversification, but the nature of diversification likely was more complex than envisioned by the original Pleistocene refuge theory. In the lowlands, intermittent forest expansion and contraction led to species dispersal and subsequent isolation, promoting lineage diversification. These pulses of climate-driven biotic interchange profoundly altered the composition of regional species pools and triggered new evolutionary radiations. In the special case of the tropical Andean forests adjacent to the Amazon lowlands, new phylogenetic data provide abundant evidence for rapid biotic diversification during the Pleistocene. During warm interglacials and intersta- dials, lowland taxa dispersed upslope. Isolation in these disjunct climate refugia led to extinction for some taxa and speciation for others.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155561/1/Baker2020.pdfDescription of Baker2020.pdf : Main articl