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Qualea grandiflora é uma espécie típica da fisionomia cerradão, de importância ecológica, florística e medicinal. No entanto, são pouco os estudos no que se refere a sua fenologia. Diante do exposto, objetivou-se verificar a sazonalidade e influência das variáveis climáticas nos eventos reprodutivos de Qualea grandiflora em cerradão. Marcaram-se 15 indivíduos que foram visitados mensalmente entre julho de 2016 e junho de 2018 para registrar os eventos: botões florais, antese, frutos imaturos e maduros. A intensidade de Fournier e sincronia foram correlacionadas com a precipitação, temperatura máxima, média e mínima através da correlação de Spearman, e a sazonalidade por meio da estatística circular. A espécie produziu botões e flores durante a estação chuvosa, o que resultou em correlação positiva com a precipitação. A formação de frutos ocorreu tanto na época chuvosa quanto na seca, já a maturação dos frutos ocorreu na estação seca. O evento de frutos imaturos foi o único não sazonal devido a sua duração. Os eventos reprodutivos de Qualea grandiflora se correlacionaram com a temperatura e a precipitação, de modo que a espécie utiliza essa influência para potencializar suas chances de reprodução.

O conhecimento advindo da fenologia vegetal em ecossistemas naturais promove o entendimento da biodiversidade, produtividade, organizacao das comunidades vegetais e sobre as interacoes das plantas com a fauna, sendo de grande importância em programas de conservacao. Entretanto, informacoes fenologicas de algumas especies sao insuficientes, este e o caso de Qualea multiflora Mart. Diante do exposto, este estudo teve o objetivo de descrever a sua fenologia reprodutiva e vegetativa em fitofisionomia de Cerradao, Estado de Goias, Brasil. Para tal, foram marcados 15 individuos que foram visitados mensalmente entre julho de 2016 e junho de 2018 e os eventos reprodutivos (botao floral, antese, fruto imaturo e fruto maduro) e vegetativos (broto foliar, folha jovem, folha adulta e senescencia) foram registrados. A intensidade e sincronia foram avaliadas e testada a sazonalidade e correlacao de Spearman da fenologia com variaveis climaticas locais. A floracao ocorreu na transicao do periodo seco para o chuvoso e durante as chuvas. A frutificacao foi registrada durante todos os meses de estudo e a maturacao dos frutos na epoca mais seca. A brotacao foliar, producao de folhas e senescencia ocorreram na maioria dos meses de observacao, com maior intensidade em meses secos e quentes. A folhagem adulta esteve presente durante todo o estudo. Este estudo evidencia que mesmo que Q. multiflora apresente comportamento fenologico semelhante ao ja encontrado na literatura para especies arboreas do cerradao, ha algumas particularidades, principalmente no corpo vegetativo. REPRODUCTIVE AND VEGETATIVE PHENOLOGY OF Qualea multiflora MART. IN CERRADAO. Knowledge of plant phenology in natural ecosystems promotes the understanding of biodiversity, productivity, organization of plant communities, and interactions between plants and fauna, being of great importance in conservation programs. However, phenological information of some species is insufficient, which is the case of Qualea multiflora Mart. In this context, this study describes reproductive and vegetative phenology of Qualea multiflora Mart. in a phytophysiognomy of Cerrado biome (Cerradao), Goias State, Brazil. For that, 15 individuals were accompanied monthly between July 2016 and June 2018 and reproductive events (flower budding, anthesis, unripe fruit and ripe fruit) and vegetative events (leaf budding, young leaf, adult leaf and senescent leaf) were registered. The intensity and synchrony were evaluated and we also tested the seasonality and Spearman correlation of phenology and local climatic variables. Flowering occurred in the transition from the dry period to the rainy season and during the rainy season. Fruiting was recorded during all studied months and fruit ripening occurred in the dry season. Leaf budding, leaf production and senescence occurred during most of observation period, with higher intensity in dry and hot months. Adult leaves were present throughout the study. This study shows that even though Q. multiflora presents phenological behavior similar to that already found in the literature for Cerradao tree species, there are some particularities, especially in the vegetative body.

The remarkable phytogeographic characteristics of the Brazilian savanna (Cerrado) resulted in a vegetation domain composed of plants with high structural and functional diversity to tolerate climate extremes. Here we used a key Cerrado species (Dipteryx alata) to evaluate if species of this domain present a mechanism of stress memory, responding more quickly and efficiently when exposed to recurrent drought episodes. The exposure of D. alata seedlings to drought resulted in several changes, mainly in physiological and biochemical traits, and these changes differed substantially when the water deficit was imposed as an isolated event or when the plants were subjected to drought cycles, suggesting the existence of a drought memory mechanism. Plants submitted to recurrent drought events were able to maintain essential processes for plant survival when compared to those submitted to drought for the first time. This differential acclimation to drought was the result of orchestrated changes in several metabolic pathways, involving differential carbon allocation for defense responses and the reprogramming and coordination of primary, secondary and antioxidant metabolism. The stress memory in D. alata is probably linked the evolutionary history of the species and reflects the environment in which it evolved.

Bark is a structure involved in multiple physiological functions, but which has been traditionally associated with protection against fire. Thus, little is known about how the morpho-anatomical variations of this structure are related to different ecological pressures, especially in tropical savanna species, which are commonly subjected to frequent fire and drought events. Here we evaluated how the structural and functional variations of bark are related to the processes of resilience and resistance to fire, as well as transport and storage of water in 31 native species from the Brazilian Cerrado. Because of their thick bark, none of the trees analyzed were top-killed after a severe fire event. The structural and functional variations of the bark were also associated with water storage and transport, functions related to properties of the inner bark. In fact, species with a thicker and less dense inner bark were the ones that had the highest water contents in the wood, bark, and leaves. Lower bark density was also related to higher stem hydraulic conductivity, carbon assimilation, and growth. Overall, we provide strong evidence that in addition to protection from fire, the relative investment in bark also reflects different strategies of water use and conservation among many Cerrado tree species.

The reproduction of cerrado species varies according to climatic conditions. This study describes the reproductive phenology of Qualea parviflora in cerradao, located at Fazenda Fontes do Saber (17°47’12 “S and 50° 57’48” W), Rio Verde, Goias, where 11 individuals were followed between July 2016 and June 2018 to register the intensity of flower bud, anthesis, immature and mature fruits. The evaluations consisted of intensity, seasonality and correlation of the phenophases with the climatic variables. Flower buds and flowers occurred during the rainny season, immature fruits in the rainy and dry period, and maturation in the dry season. All events were seasonal, except for immature fruits. In terms of correlations, only the events of flower buds had strong and significant correlations with rainfall and thermal variations of the study area.