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The vegetation history and climate in southeastern Brazil, as well as the oceanic dynamics of the tropical Atlantic Ocean offshore, were reconstructed for the last 7.4 cal ka BP. This reconstruction was based on pollen, fern spores and dinoflagellate cysts identified in a marine core (CF10–04B). It was possible to verify the presence of an ombrophilous forest from 7.4 cal ka BP. Near the base of the PI zone low concentrations of pollen and fern spores are recorded, along with low frequencies of forest taxa and fern spores and an increase in pollen types of open vegetation, suggesting less humid climatic conditions than currently observed in the coastal regions of Southeastern Brazil. The assemblages of dinoflagellate cysts suggest a neritic zone with warm upper column temperature, high salinity and oligotrophic environment (evidenced by the presence of O. centrocarpum , Spiniferites spp. and L. machaerophorum). An increase in Tropical Waters (TW) and the approximation of the Brazilian Current (BC) in the middle shelf of southeastern Brazil in the mid-Holocene probably influenced the low accumulation of cysts, pollen grains, fern spores, and their associations. It is still possible to verify that at approximately 4.6 cal ka BP, an increase in the rainfall in the southeastern Brazilian region was probably the fundamental factor for the expansion of vegetation, mainly based on the considerable increases in hygrophytic and aquatic plants. The marked increase in the accumulation of dinoflagellate cysts, with the dominance of autotroph taxa (mainly O. centrocarpum , followed by Spiniferites spp), evidences the warmer waters of the BC and more intense surface upwelling of the South Atlantic Central Water (SACW). [ABSTRACT FROM AUTHOR]

Integration of late Quaternary continental and marine proxies allows improved reconstruction of palaeoenvironment and palaeoclimates models for the south-eastern coast of Brazil. In this paper, we analyse pollen, fern spores, and dinoflagellate cysts in a marine sediment core (GL74) over the last ∼109 kyr. Results showed that, between 109 and 89.5 kyr, low sea levels promoted the expansion of herbaceous taxa across open areas while climatic conditions were relatively warm and humid, as indicated by the high frequency of Atlantic rainforest Ombrophilous forest pollen types and abundant of fern spores. Between ∼79–49 kyr, higher concentrations of palynomorphs were recorded, which were likely related to the low relative sea level during the last glacial period. During this interval, there was a decrease in tree pollen grains and an increase in shrub and herbaceous pollen grains, indicating cold and relatively dry weather conditions. In the Holocene period, the low deposition of palynomorphs may have been influenced by the gradual submergence of the central part of the Brazilian coast. This process was associated with warm and humid climatic conditions, as suggested by the expansion of rainforests and the presence of hygrophyte/aquatic taxa and fern spores, as well as the retraction of grassland pollen types. Dinocyst assemblages suggest that nutrient-rich waters and/or the presence of upwelling cells were dominant between ∼109–88 kyr, but gradually reduced between 88 and 65 kyr (and/or ∼ 88–20 kyr) under the influence of subtropical fronts. The study culminated in the dominance of unproductive warm water in the upper column between 65 and 0.5 kyr. • Correlation of continental and marine proxies in south-eastern Brazil during the late Quaternary Late • Quaternary dynamics of the South Atlantic Ocean based on dinocysts • Reconstruction of palaeovegetation and palaeoclimate for the last ∼109 kyr along the southeast coast of Brazil [ABSTRACT FROM AUTHOR]

Here palynological assemblages are presented from channel surface sediment samples from the Caceribu, Guaraí and Guapimirim-Macacú rivers located in an important area of the Brazilian coast (Guanabara Bay, State of Rio de Janeiro), in order to provide information relevant for the interpretation of palaeoecological records. The data indicate the predominance of pollen types from the Atlantic Forest in all samples and a relatively low representation of mangrove pollen, suggesting distant (regional) fluvial transport. Avicennia and Rhizophora were represented in those samples closer to the intertidal zone, Rhizophora being the most important. It was possible to verify a marked difference in pollen concentration/deposition among the three rivers, probably related to the different hydrodynamic pattern of each river. A low concentration of palynomorphs occurred in the Macacú-Guapimirim River, resulting from its higher flow, and there was a high deposition of palynomorphs in the sediments of Guaraí River, in response to its isolation from the hydrographic Guanabara Bay basin. It was possible to verify other interesting data, such as low palynomorph concentration in samples from near the mouth and an increase of palynomorphs in the upstream samples, mainly due to the more active action of the tidal currents. Meanwhile, the increase in the total concentration of the palynomorphs in the upstream samples coincides with the maximum reach of the saline waters and their meeting with the internal flow of the rivers. [ABSTRACT FROM AUTHOR]

Sixty-one samples of dried bee pollen collected from various apiaries in the southern Brazilian macro-region were examined to detect the botanical origin of the pollen and to enable more accurate product certification. The palynological analysis of the samples followed the standard methodology and was conducted without the use of acetolysis. The samples were washed once or twice with ethanol and then with water. The sediment obtained was homogenised in a water/glycerine solution for microscopic observation. The target number of pollen grains to be counted was 500 pollen grains or more per sample. The results demonstrated that 35 samples consisted of a unique pollen type representing more than 90% of the pollen sum (or more than 60% if no accessory pollen was present). These samples were considered monofloral. Several pollen types grouped in a sample were related to heterofloral pollen batches. The most frequent pollen types were ofMimosa scabrella, Eucalyptus, Andira, Machaerium, MyrciaandPiptocarpha. The results of the current study were related to the surrounding vegetation of the apiaries and reflected the resources available to the bees. Furthermore, these results are relevant to apicultural activities and are commercially significant. [ABSTRACT FROM PUBLISHER]

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