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Cyclones are an increasing disturbance in the subtropical region of South America, but their impacts over the forests are still poorly documented. Here, we evaluate the effects of an extratropical cyclone over tree mortality in Araucaria Forest remnants in southern Brazil. We surveyed 116 sites (10 × 20 m each) and collected data on all tree individuals presenting DBH ≥ 4.8 cm before (2009) and after (2014) the occurrence of an extratropical cyclone. Using GLM models, we checked how the cyclone occurrence, different plant traits (DBH, trunk branching, wood density, successional group and evolutionary distinctiveness) and site characteristics (basal area, exposure, landscape protection, nearest border distance, cyclone border distance and the presence of native bamboo species) could impact tree mortality. The GLM model selection shows that the lowest AIC model considers all predictors separately and their interaction with the cyclone. The results showed that the cyclone occurrence and some site characteristics (bamboo presence, site exposure, landscape protection, nearest border distance and cyclone border distance) and plant traits (successional group and evolutionary distinctiveness) are related to tree mortality. The intense deforestation and fragmentation of the Araucaria Forest coupled with the increase in cyclone frequency expected for the region due to climate change may increase mortality rates of these forests, affecting their resilience and phylogenetic structure. Further biodiversity conservation efforts in the Araucaria Forest need to consider the characteristics of sites for enabling the protection of forest remnants in areas under different exposures to cyclone impacts. [ABSTRACT FROM AUTHOR]

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To study the carbon storage increase of major forest ecosystems in tropical South America, such as Amazon rain forest, Atlantic rain forest, semideciduous forest, and Araucaria forest, the Last Glacial Maximum (LGM) and the early Holocene vegetation cover were reconstructed by pollen records. Marked forest expansion points to a significant total carbon storage increase by tropical forests in South America since the LGM and the early Holocene. The Amazon rain forest expansion, about 39% in area, had 28.3×109 tC (+20%), the highest carbon storage increase since the LGM. The expansion of the other much smaller forest areas also had a significant carbon storage increase since the LGM, the Atlantic rain forest with 4.9×109 tC (+55%), the semideciduous forest of eastern Brazil with 6.3×109 tC (+46%), the Araucaria forest with 3.4×109 tC (+108%). The estimated carbon storage increase of the four forest biomes since the early Holocene is also remarkable. The extensive deforestation in the last century strongly affected the carbon storage by tropical forests. [Copyright &y& Elsevier]