Oreopanax fulvus is a species endemic to the Brazilian Atlantic Forest, assessed as rare and vulnerable in the states of Paraná and Rio Grande do Sul, respectively. This adverse situation requires conservation actions that must be supported by the understanding of its autecology. We aimed to identify the phenological patterns of O. fulvus populations from two Araucaria Rainforest remnants in Paraná. Monthly phenology monitoring of 19 trees in each site was performed over 24 months. We quantified the vegetative (i.e., leaf flushing, mature leaves, and leaf-senescence) and reproductive phenophases (i.e., buds production, blooming, immature, and mature fruits). Circular statistics based on activity index were applied to identify the phenophases seasonality. Spearman correlations were performed among phenophases and meteorological parameters. Leaf flushing and mature leaves were recorded in all months, with a decrease of mature leaves during November and December. Leaf-senescence was seasonal, occurring from May to December. The reproductive phenophases were seasonal: blooming from January to May; and fruiting from March to November, with fruits starting to mature in September. Vegetative and reproductive phenophases were highly influenced by average temperature and photoperiod. Although there were dissimilarities in reproductive phenological patterns, the different populations studied had similar phenological performances.
RESUMOEste estudo teve como objetivos caracterizar a morfologia dos frutos, sementes e plântulas, e avaliar o comportamento germinativo de Oreopanax fulvus Marchal. Após coleta, as infrutescências foram caracterizadas quanto a sua biometria e morfologia, assim como os frutos, sementes e plântulas. Dois experimentos de germinação foram instalados: o primeiro para avaliar o desempenho da germinação sobre diferentes substratos e o segundo para testar o efeito do grau de maturação dos frutos na germinação. As infrutescências possuem frutos globosos, indeiscentes com coloração roxa quando maduros. Não houve diferença significativa do tamanho de frutos em diferentes graus de maturação. As sementes são pequenas, elípticas com endosperma ruminado e embrião espatulado. A germinação é fanerocotiledonar e a plântula epígea. Os cotilédones permaneceram na plântula por cerca de 150 dias após o início da germinação. Não houve diferença significativa na germinação de sementes sobre diferentes substratos, com média geral de 42,2%. No teste de influência da maturação apenas sementes de frutos maduros germinaram (68,3%), demonstrando ser este um requisito essencial para a adequada germinação de O. fulvus. Palavras-chave:Araliaceae, biometria, morfologia, maturação, substrato Morphological characterization of fruits, seeds, seedlings and germination of Oreopanax fulvus Marchal ABSTRACTThis study aimed to characterize the morphology of fruits, seeds and seedlings and evaluate the germination of Oreopanax fulvus Marchal. After collection, it was carried out the biometrical and morphological characterization of infructescences, fruits and seeds. Seedlings were also characterized, after germination procedures. Two germination experiments were realised: the first one to evaluate the performance of germination on different substrates and the second to test the effects of the fruit maturation on the germination parameters. The fruits are globose, indehiscent and purple when mature. There is no significant difference in fruit size regarding to maturation. The seeds are small and elliptical, with ruminated endosperm and spatulated embryo. Germination is phanero-epigeal. The cotyledons remain in the seedlings for 150 days after germination. There was no significant difference on seed germination rates over different substrates, the overall average was 42.2%. In the maturation experiment only seeds from mature fruits germinated (68.3%), demonstrating that this is an essential requirement for adequate germination of O. fulvus.
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Logging and agricultural exploitation have led to the degradation of Araucaria Forest remnants and the alteration of its last preserved patches. This forest typology contains many endangered plant species, as is the case of the tree Oreopanax fulvus Marchal. To support conservation of this species and understand how different landscape matrices can influence its populations, we evaluated the demographic structure and spatial distribution of O. fulvus in two Araucaria Forest remnants in Paraná state. We delimited two plots (urban and rural population), each with 1 ha, subdivided them into 100 subplots (10 x 10 m), and recorded diameter at ground level (DGL), height, and coordinates of two post-germinative developmental stage of individuals. In each subplot, we measured slope, luminosity, and canopy height. We used Ripley’s K function analysis to describe distribution patterns of the species and the spatial relationship between mature and juvenile trees. We performed correlations between abundance and environmental and structural variables of the O. fulvus populations. Abundance varied between remnants, from 183 individuals/ha (12 mature and 171 juvenile) to 1306 individuals/ha (10 and 1296). The remnants varied in abundance and plant frequency. The species showed an investment in seedling banks. Most juvenile had DGL up to 3.0 cm and height up to 1.0 m and presented aggregated spatial distribution, while adults had random distribution. In the rural population juvenile abundance were correlated with canopy height (positively) and distance to mature trees (negatively). The slope was correlated for both sites, but oppositely, indicating that other factors might have interfered in the regeneration abundance. The urban remnant showed a high abundance of this endangered species, calling attention for potential studies in urban arborization, management and conservation of these remnants.
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